diff --git a/README.md b/README.md
index 1d3c1f9..9591632 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,8 @@ composer require utopia-php/usage
 use Utopia\Usage\Usage;
 use Utopia\Usage\Adapter\ClickHouse;
 
-// Configuration is fixed at construction; only the tenant changes per request.
+// Configuration is fixed at construction. The adapter is fully stateless —
+// the tenant is passed explicitly on every call (see below).
 $adapter = new ClickHouse(
     host: 'clickhouse-server',
     username: 'default',
@@ -46,7 +47,6 @@ $adapter = new ClickHouse(
     namespace: 'my_app',
     sharedTables: true,
 );
-$adapter->setTenant('project_123');
 
 $usage = new Usage($adapter);
 $usage->setup(); // Creates events, gauges, and daily MV tables
@@ -65,6 +65,35 @@ $usage = new Usage($adapter);
 $usage->setup();
 ```
 
+## Multi-tenancy
+
+`Usage` is stateless: every query/mutation takes the tenant as its first
+argument, and `addBatch` carries a `tenant` on each metric row (so one batch can
+span tenants). This makes a single `Usage` instance safe to share across
+tenants and coroutines.
+
+```php
+$usage->getTotal('project_123', 'bandwidth');           // read for one tenant
+$usage->addBatch([
+    ['tenant' => 'project_123', 'metric' => 'bandwidth', 'value' => 5000, 'tags' => []],
+    ['tenant' => 'project_456', 'metric' => 'bandwidth', 'value' => 2000, 'tags' => []],
+], Usage::TYPE_EVENT);
+```
+
+Callers that only ever touch one tenant can bind it once with the `Tenant`
+decorator, which forwards to `Usage` with the tenant pre-filled (and stamps it
+onto every `addBatch` row):
+
+```php
+use Utopia\Usage\Tenant;
+
+$tenant = new Tenant($usage, 'project_123');
+$tenant->getTotal('bandwidth');                          // no tenant argument
+$tenant->addBatch([
+    ['metric' => 'bandwidth', 'value' => 5000, 'tags' => []], // tenant stamped automatically
+], Usage::TYPE_EVENT);
+```
+
 ## Metric Types
 
 ### Events (Additive)
@@ -79,8 +108,13 @@ Event-specific columns (see `Metric::EVENT_COLUMNS`): `path`, `method`, `status`
 `deviceModel`.
 
 ```php
-// Collect events — values accumulate in-memory buffer (summed per metric)
-$usage->collect('bandwidth', 5000, Usage::TYPE_EVENT, [
+use Utopia\Usage\Accumulator;
+
+// Buffer metrics in memory and flush them in batch
+$accumulator = new Accumulator($usage);
+
+// Collect events — tenant first; values accumulate in-memory (summed per tenant+metric)
+$accumulator->collect('project_123', 'bandwidth', 5000, Usage::TYPE_EVENT, [
     'path' => '/v1/storage/files',
     'method' => 'POST',
     'status' => '201',
@@ -114,9 +148,9 @@ Gauge-specific columns (see `Metric::GAUGE_COLUMNS`): `teamId`,
 `teamInternalId`, `resourceId`, `resourceInternalId`.
 
 ```php
-// Collect gauges — last value wins per metric in buffer
-$usage->collect('users', 1500, Usage::TYPE_GAUGE);
-$usage->collect('storage.size', 1048576, Usage::TYPE_GAUGE, [
+// Collect gauges — last value wins per tenant+metric in buffer
+$accumulator->collect('project_123', 'users', 1500, Usage::TYPE_GAUGE);
+$accumulator->collect('project_123', 'storage.size', 1048576, Usage::TYPE_GAUGE, [
     'teamId' => 'team_x',
     'teamInternalId' => '7',
     'resourceId' => 'abc123',
@@ -126,28 +160,28 @@ $usage->collect('storage.size', 1048576, Usage::TYPE_GAUGE, [
 
 ### Flushing
 
+The accumulator exposes raw signals — `count()` (buffered entries) and
+`elapsedSeconds()` (seconds since last flush) — and leaves the flush policy to
+the caller.
+
 ```php
-// Check if flush is recommended (threshold or interval reached)
-if ($usage->shouldFlush()) {
-    $usage->flush(); // Writes events to events table, gauges to gauges table
+// Flush when the buffer grows large or enough time has passed
+if ($accumulator->count() >= 5000 || $accumulator->elapsedSeconds() >= 10) {
+    $accumulator->flush(); // Writes events to events table, gauges to gauges table
 }
-
-// Configure thresholds
-$usage->setFlushThreshold(5000);  // Flush after 5000 collect() calls (default: 10,000)
-$usage->setFlushInterval(10);     // Flush after 10 seconds (default: 20)
 ```
 
 ### Batch Writes
 
 ```php
-// Write directly without buffering
+// Write directly without buffering — each row carries its tenant
 $usage->addBatch([
-    ['metric' => 'requests', 'value' => 100, 'tags' => ['path' => '/v1/users', 'method' => 'GET']],
-    ['metric' => 'bandwidth', 'value' => 50000, 'tags' => ['country' => 'DE', 'region' => 'fra']],
+    ['tenant' => 'project_123', 'metric' => 'requests', 'value' => 100, 'tags' => ['path' => '/v1/users', 'method' => 'GET']],
+    ['tenant' => 'project_123', 'metric' => 'bandwidth', 'value' => 50000, 'tags' => ['country' => 'DE', 'region' => 'fra']],
 ], Usage::TYPE_EVENT);
 
 $usage->addBatch([
-    ['metric' => 'users', 'value' => 42, 'tags' => ['teamId' => 'team_x']],
+    ['tenant' => 'project_123', 'metric' => 'users', 'value' => 42, 'tags' => ['teamId' => 'team_x']],
 ], Usage::TYPE_GAUGE);
 ```
 
@@ -158,8 +192,8 @@ $usage->addBatch([
 ```php
 use Utopia\Query\Query;
 
-// Find events filtered by metric and time range
-$metrics = $usage->find([
+// Find events filtered by metric and time range (tenant first)
+$metrics = $usage->find('project_123', [
     Query::equal('metric', ['bandwidth']),
     Query::equal('country', ['US']),
     Query::greaterThanEqual('time', '2026-01-01'),
@@ -168,12 +202,12 @@ $metrics = $usage->find([
 ], Usage::TYPE_EVENT);
 
 // Find gauges
-$gauges = $usage->find([
+$gauges = $usage->find('project_123', [
     Query::equal('metric', ['users', 'storage.size']),
 ], Usage::TYPE_GAUGE);
 
 // Query both tables (type = null)
-$all = $usage->find([
+$all = $usage->find('project_123', [
     Query::equal('metric', ['bandwidth']),
 ]);
 ```
@@ -182,12 +216,13 @@ $all = $usage->find([
 
 ```php
 // Get total for a single metric (SUM for events, latest for gauges)
-$total = $usage->getTotal('bandwidth', [
+$total = $usage->getTotal('project_123', 'bandwidth', [
     Query::greaterThanEqual('time', '2026-03-01'),
 ], Usage::TYPE_EVENT);
 
 // Batch totals — single query with GROUP BY
 $totals = $usage->getTotalBatch(
+    'project_123',
     ['bandwidth', 'executions', 'requests'],
     [Query::greaterThanEqual('time', '2026-03-01')],
     Usage::TYPE_EVENT
@@ -200,6 +235,7 @@ $totals = $usage->getTotalBatch(
 // Get time series with query-time aggregation
 // Events: SUM per bucket, Gauges: argMax per bucket
 $series = $usage->getTimeSeries(
+    tenant: 'project_123',
     metrics: ['bandwidth', 'requests'],
     interval: '1d',        // '1h' or '1d'
     startDate: '2026-03-01',
@@ -217,20 +253,21 @@ The daily materialized view pre-aggregates events by `metric + tenant + day` for
 
 ```php
 // Sum a single metric from the daily table
-$total = $usage->sumDaily([
+$total = $usage->sumDaily('project_123', [
     Query::equal('metric', ['bandwidth']),
     Query::between('time', '2026-03-01', '2026-04-01'),
 ]);
 
 // Sum multiple metrics in one query
 $totals = $usage->sumDailyBatch(
+    'project_123',
     ['bandwidth', 'executions', 'storage.size'],
     [Query::between('time', '2026-03-01', '2026-04-01')]
 );
 // Returns: ['bandwidth' => 5000000, 'executions' => 12345, 'storage.size' => 0]
 
 // Find daily aggregated rows
-$rows = $usage->findDaily([
+$rows = $usage->findDaily('project_123', [
     Query::equal('metric', ['bandwidth']),
     Query::orderDesc('time'),
     Query::limit(30),
@@ -241,12 +278,12 @@ $rows = $usage->findDaily([
 
 ```php
 // Purge all event metrics older than 90 days
-$usage->purge([
+$usage->purge('project_123', [
     Query::lessThan('time', '2026-01-01'),
 ], Usage::TYPE_EVENT);
 
 // Purge all gauge metrics
-$usage->purge([], Usage::TYPE_GAUGE);
+$usage->purge('project_123', [], Usage::TYPE_GAUGE);
 ```
 
 ## Architecture
@@ -321,22 +358,23 @@ $usage->purge([], Usage::TYPE_GAUGE);
 Extend `Utopia\Usage\Adapter` and implement:
 
 - `getName()`, `setup()`, `healthCheck()`
-- `addBatch(array $metrics, string $type, int $batchSize): bool`
-- `find(array $queries, ?string $type): array`
-- `count(array $queries, ?string $type): int`
-- `sum(array $queries, string $attribute, ?string $type): int`
-- `getTimeSeries(array $metrics, string $interval, string $startDate, string $endDate, array $queries, bool $zeroFill, ?string $type): array`
-- `getTotal(string $metric, array $queries, ?string $type): int`
-- `getTotalBatch(array $metrics, array $queries, ?string $type): array`
-- `findDaily(array $queries): array`
-- `sumDaily(array $queries, string $attribute): int`
-- `sumDailyBatch(array $metrics, array $queries): array`
-- `purge(array $queries, ?string $type): bool`
-- `setTenant(?string $tenant): self`
-
-Namespace, database, shared-tables mode, async inserts, query logging and the
-dual-read sample rate are set once via the adapter constructor (see "Using
-ClickHouse Adapter" above). Only the tenant changes over an instance's lifetime.
+- `addBatch(array $metrics, string $type, int $batchSize): bool` (each metric carries its own `tenant`)
+- `find(string $tenant, array $queries, ?string $type): array`
+- `count(string $tenant, array $queries, ?string $type, ?int $max): int`
+- `sum(string $tenant, array $queries, string $attribute, string $type): int`
+- `getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries, bool $zeroFill, ?string $type): array`
+- `getTotal(string $tenant, string $metric, array $queries, ?string $type): int`
+- `getTotalBatch(string $tenant, array $metrics, array $queries, ?string $type): array`
+- `findDaily(string $tenant, array $queries): array`
+- `sumDaily(string $tenant, array $queries, string $attribute): int`
+- `sumDailyBatch(string $tenant, array $metrics, array $queries): array`
+- `purge(string $tenant, array $queries, ?string $type): bool`
+
+All configuration — namespace, database, shared-tables mode, async inserts,
+query logging — is set once via the adapter constructor (see "Using ClickHouse
+Adapter" above). Adapters hold no per-request state; the tenant is passed
+explicitly on every call, so one instance is safe to share across tenants and
+coroutines.
 
 ## System Requirements
 
diff --git a/src/Usage/Accumulator.php b/src/Usage/Accumulator.php
new file mode 100644
index 0000000..965c229
--- /dev/null
+++ b/src/Usage/Accumulator.php
@@ -0,0 +1,188 @@
+<?php
+
+namespace Utopia\Usage;
+
+/**
+ * In-memory metric accumulator.
+ *
+ * Buffers collect() calls and flushes them to a Usage instance in batches.
+ * Events are summed per metric+tags; gauges use last-write-wins.
+ *
+ * The accumulator exposes raw signals — count() and elapsedSeconds() — so
+ * callers can decide when to flush rather than baking a policy in here.
+ */
+class Accumulator
+{
+    private Usage $usage;
+
+    /**
+     * In-memory buffer for metrics.
+     * Keyed by "{tenant}:{metric}:{type}:{tagsHash}" — events are summed, gauges
+     * use last-write-wins. Tenant is part of the key so metrics for different
+     * tenants never collapse into one entry.
+     *
+     * @var array<string, array{tenant: string, metric: string, value: int, type: string, tags: array<string, mixed>}>
+     */
+    private array $buffer = [];
+
+    /** @var float Timestamp of the last flush */
+    private float $flushedAt;
+
+    /**
+     * @param  Usage  $usage  The Usage instance to flush buffered metrics to
+     */
+    public function __construct(Usage $usage)
+    {
+        $this->usage = $usage;
+        $this->flushedAt = microtime(true);
+    }
+
+    /**
+     * Collect a metric into the in-memory buffer for deferred flushing.
+     *
+     * For event type: multiple collect() calls for the same metric are summed.
+     * For gauge type: last-write-wins semantics.
+     * No period fan-out — raw timestamps are used.
+     *
+     * @param string $tenant Tenant scope (shared-tables mode)
+     * @param string $metric Metric name
+     * @param int $value Value
+     * @param string $type Metric type: 'event' or 'gauge'
+     * @param array<string,mixed> $tags Optional tags
+     * @return self
+     */
+    public function collect(string $tenant, string $metric, int $value, string $type, array $tags = []): self
+    {
+        // Compare against '' rather than empty(): the string "0" is a valid
+        // tenant/metric id but empty("0") is true in PHP.
+        if ($tenant === '') {
+            throw new \InvalidArgumentException('Tenant cannot be empty');
+        }
+        if ($metric === '') {
+            throw new \InvalidArgumentException('Metric name cannot be empty');
+        }
+        if ($value < 0) {
+            throw new \InvalidArgumentException('Value cannot be negative');
+        }
+        if ($type !== Usage::TYPE_EVENT && $type !== Usage::TYPE_GAUGE) {
+            throw new \InvalidArgumentException("Invalid metric type '{$type}'. Allowed: " . Usage::TYPE_EVENT . ', ' . Usage::TYPE_GAUGE);
+        }
+
+        // Hash the full identity so distinct (tenant, metric, type, tags)
+        // tuples never collide on the key — a raw `:`-join would let
+        // e.g. tenant "a"/metric "b:c" and tenant "a:b"/metric "c" share one
+        // entry. Tags are sorted first so key order doesn't matter.
+        $canonicalTags = $tags;
+        ksort($canonicalTags);
+        $key = md5(json_encode([$tenant, $metric, $type, $canonicalTags], JSON_THROW_ON_ERROR));
+
+        if ($type === Usage::TYPE_EVENT && isset($this->buffer[$key])) {
+            // Additive: sum values for the same tenant + metric + tags combination
+            $this->buffer[$key]['value'] += $value;
+        } else {
+            // New event entry, or gauge (last-write-wins)
+            $this->buffer[$key] = [
+                'tenant' => $tenant,
+                'metric' => $metric,
+                'value' => $value,
+                'type' => $type,
+                'tags' => $tags,
+            ];
+        }
+
+        return $this;
+    }
+
+    /**
+     * Flush the in-memory buffer to storage.
+     *
+     * Separates buffered metrics into events and gauges, then writes each batch
+     * to the appropriate table via addBatch(). Only entries whose batch write
+     * succeeds are removed from the buffer, so a partial failure preserves
+     * the unwritten metrics for retry on the next flush.
+     *
+     * If addBatch() throws mid-flush, any earlier successful batches have
+     * already been cleared from the buffer — the exception is allowed to
+     * propagate so the caller can observe the failure.
+     *
+     * @return bool True if all batches succeeded (or buffer was empty)
+     * @throws \Exception
+     */
+    public function flush(): bool
+    {
+        if (empty($this->buffer)) {
+            $this->flushedAt = microtime(true);
+            return true;
+        }
+
+        // Separate events and gauges; keep track of buffer keys so we can
+        // selectively unset only the entries whose write succeeded.
+        $eventKeys = [];
+        $gaugeKeys = [];
+        $events = [];
+        $gauges = [];
+
+        foreach ($this->buffer as $key => $entry) {
+            if ($entry['type'] === Usage::TYPE_EVENT) {
+                $events[] = $entry;
+                $eventKeys[] = $key;
+            } else {
+                $gauges[] = $entry;
+                $gaugeKeys[] = $key;
+            }
+        }
+
+        $overallResult = true;
+
+        // Flush events — clear buffer entries only on success.
+        if (!empty($events)) {
+            if ($this->usage->addBatch($events, Usage::TYPE_EVENT)) {
+                foreach ($eventKeys as $key) {
+                    unset($this->buffer[$key]);
+                }
+            } else {
+                $overallResult = false;
+            }
+        }
+
+        // Flush gauges — clear buffer entries only on success.
+        if (!empty($gauges)) {
+            if ($this->usage->addBatch($gauges, Usage::TYPE_GAUGE)) {
+                foreach ($gaugeKeys as $key) {
+                    unset($this->buffer[$key]);
+                }
+            } else {
+                $overallResult = false;
+            }
+        }
+
+        // Only restart the timer when nothing is left pending. On a partial
+        // failure the retained entries keep aging so elapsedSeconds() reflects
+        // how overdue they are instead of resetting to a fresh interval.
+        if (empty($this->buffer)) {
+            $this->flushedAt = microtime(true);
+        }
+
+        return $overallResult;
+    }
+
+    /**
+     * Number of unique metric entries currently buffered.
+     *
+     * @return int
+     */
+    public function count(): int
+    {
+        return count($this->buffer);
+    }
+
+    /**
+     * Seconds elapsed since the last flush.
+     *
+     * @return float
+     */
+    public function elapsedSeconds(): float
+    {
+        return microtime(true) - $this->flushedAt;
+    }
+}
diff --git a/src/Usage/Adapter.php b/src/Usage/Adapter.php
index 20c53ed..ddbf659 100644
--- a/src/Usage/Adapter.php
+++ b/src/Usage/Adapter.php
@@ -28,7 +28,10 @@ abstract public function setup(): void;
      * For events, path/method/status/resource/resourceId are extracted from tags
      * into dedicated columns; remaining tags stay in the tags JSON.
      *
-     * @param  array<array{metric: string, value: int, tags?: array<string,mixed>}>  $metrics
+     * Each metric carries its own `tenant` (shared-tables mode), so a single
+     * batch may span multiple tenants.
+     *
+     * @param  array<array{tenant: string, metric: string, value: int, tags?: array<string,mixed>}>  $metrics
      * @param  string  $type  Metric type: 'event' or 'gauge' — determines which table to write to
      * @param  int  $batchSize  Maximum number of metrics per INSERT statement
      */
@@ -40,6 +43,7 @@ abstract public function addBatch(array $metrics, string $type, int $batchSize =
      * Groups data by the specified interval (1h or 1d) and applies
      * SUM for event metrics and argMax for gauge metrics.
      *
+     * @param  string  $tenant  Tenant scope (shared-tables mode)
      * @param  array<string>  $metrics  List of metric names
      * @param  string  $interval  Aggregation interval: '1h' or '1d'
      * @param  string  $startDate  Start datetime string
@@ -49,7 +53,7 @@ abstract public function addBatch(array $metrics, string $type, int $batchSize =
      * @param  string|null  $type  Metric type: 'event', 'gauge', or null (query both)
      * @return array<string, array{total: float, data: array<array{value: float, date: string}>}>
      */
-    abstract public function getTimeSeries(array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array;
+    abstract public function getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array;
 
     /**
      * Get total value for a single metric.
@@ -57,42 +61,46 @@ abstract public function getTimeSeries(array $metrics, string $interval, string
      * Returns sum for event metrics, latest value for gauge metrics.
      * When $type is null, queries both tables.
      *
+     * @param  string  $tenant  Tenant scope (shared-tables mode)
      * @param  string  $metric  Metric name
      * @param  array<\Utopia\Query\Query>  $queries  Additional query filters
      * @param  string|null  $type  Metric type: 'event', 'gauge', or null (query both)
      * @return int
      */
-    abstract public function getTotal(string $metric, array $queries = [], ?string $type = null): int;
+    abstract public function getTotal(string $tenant, string $metric, array $queries = [], ?string $type = null): int;
 
     /**
      * Get totals for multiple metrics in a single query.
      *
      * Returns sum for event metrics, latest value for gauge metrics.
      *
+     * @param  string  $tenant  Tenant scope (shared-tables mode)
      * @param  array<string>  $metrics  List of metric names
      * @param  array<\Utopia\Query\Query>  $queries  Additional query filters
      * @param  string|null  $type  Metric type: 'event', 'gauge', or null (query both)
      * @return array<string, int>
      */
-    abstract public function getTotalBatch(array $metrics, array $queries = [], ?string $type = null): array;
+    abstract public function getTotalBatch(string $tenant, array $metrics, array $queries = [], ?string $type = null): array;
 
     /**
      * Purge usage metrics matching the given queries.
      * When no queries are provided, all metrics are deleted.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string|null $type Metric type: 'event', 'gauge', or null (purge both)
      */
-    abstract public function purge(array $queries = [], ?string $type = null): bool;
+    abstract public function purge(string $tenant, array $queries = [], ?string $type = null): bool;
 
     /**
      * Find metrics using Query objects.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string|null $type Metric type: 'event', 'gauge', or null (query both)
      * @return array<Metric>
      */
-    abstract public function find(array $queries = [], ?string $type = null): array;
+    abstract public function find(string $tenant, array $queries = [], ?string $type = null): array;
 
     /**
      * Count metrics using Query objects.
@@ -102,12 +110,13 @@ abstract public function find(array $queries = [], ?string $type = null): array;
      * This keeps large counts cheap for endpoints that only need a capped
      * total. When $max is null the count is unbounded.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string|null $type Metric type: 'event', 'gauge', or null (count both)
      * @param int|null $max Optional upper bound for the count (inclusive)
      * @return int
      */
-    abstract public function count(array $queries = [], ?string $type = null, ?int $max = null): int;
+    abstract public function count(string $tenant, array $queries = [], ?string $type = null, ?int $max = null): int;
 
     /**
      * Sum metric values using Query objects.
@@ -115,12 +124,13 @@ abstract public function count(array $queries = [], ?string $type = null, ?int $
      * Events-only by default because summing gauges is semantically meaningless
      * (adding point-in-time snapshots doesn't produce a useful total).
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string $attribute Attribute to sum (default: 'value')
      * @param string $type Metric type: 'event' or 'gauge'
      * @return int
      */
-    abstract public function sum(array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int;
+    abstract public function sum(string $tenant, array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int;
 
     /**
      * Find event metrics from the pre-aggregated daily table.
@@ -130,10 +140,11 @@ abstract public function sum(array $queries = [], string $attribute = 'value', s
      * Note: Daily MV only stores event metrics. This method always queries
      * the daily events table — gauges are never pre-aggregated.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries  Filters (metric, time range, resource, etc.)
      * @return array<Metric>
      */
-    abstract public function findDaily(array $queries = []): array;
+    abstract public function findDaily(string $tenant, array $queries = []): array;
 
     /**
      * Sum event metric values from the pre-aggregated daily table.
@@ -141,11 +152,12 @@ abstract public function findDaily(array $queries = []): array;
      * Note: Daily MV only stores event metrics. This method always queries
      * the daily events table — gauges are never pre-aggregated.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string $attribute Attribute to sum (default: 'value')
      * @return int
      */
-    abstract public function sumDaily(array $queries = [], string $attribute = 'value'): int;
+    abstract public function sumDaily(string $tenant, array $queries = [], string $attribute = 'value'): int;
 
     /**
      * Sum multiple event metrics from the pre-aggregated daily table in one query.
@@ -153,9 +165,10 @@ abstract public function sumDaily(array $queries = [], string $attribute = 'valu
      * Note: Daily MV only stores event metrics. This method always queries
      * the daily events table — gauges are never pre-aggregated.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<string> $metrics List of metric names
      * @param array<\Utopia\Query\Query> $queries Additional filters (e.g. date range)
      * @return array<string, int> Metric name => sum value
      */
-    abstract public function sumDailyBatch(array $metrics, array $queries = []): array;
+    abstract public function sumDailyBatch(string $tenant, array $metrics, array $queries = []): array;
 }
diff --git a/src/Usage/Adapter/ClickHouse.php b/src/Usage/Adapter/ClickHouse.php
index 6b87e7b..9cf0cd5 100644
--- a/src/Usage/Adapter/ClickHouse.php
+++ b/src/Usage/Adapter/ClickHouse.php
@@ -98,8 +98,6 @@ class ClickHouse extends SQL
 
     private readonly RequestFactory $requestFactory;
 
-    protected ?string $tenant = null;
-
     protected readonly bool $sharedTables;
 
     protected readonly string $namespace;
@@ -371,23 +369,6 @@ private function escapeIdentifier(string $identifier): string
         return '`' . str_replace('`', '``', $identifier) . '`';
     }
 
-    /**
-     * Set the tenant ID for multi-tenant support.
-     *
-     * Tenant is the one piece of adapter configuration that legitimately
-     * changes over an instance's lifetime — a single adapter serves many
-     * tenants across requests — so it stays a mutable setter while the rest
-     * of the configuration is fixed at construction.
-     *
-     * @param string|null $tenant
-     * @return self
-     */
-    public function setTenant(?string $tenant): self
-    {
-        $this->tenant = $tenant;
-        return $this;
-    }
-
     /**
      * Get the base table name with namespace prefix.
      *
@@ -1258,12 +1239,17 @@ private function validateMetricsBatch(array $metrics, string $type): void
             $tags = $metricData['tags'] ?? [];
             $this->validateMetricData($metric, $value, $type, $tags, $index);
 
-            if (array_key_exists('$tenant', $metricData)) {
-                $tenantValue = $metricData['$tenant'];
+            $hasTenant = array_key_exists('tenant', $metricData);
 
-                if ($tenantValue !== null && !is_string($tenantValue)) {
-                    throw new Exception("Metric #{$index}: '\$tenant' must be a string or null, got " . gettype($tenantValue));
-                }
+            // Shared tables filter every read by tenant, so a row written
+            // without one would be invisible to normal tenant-scoped reads.
+            // Reject it at write time rather than silently storing dead data.
+            if ($this->sharedTables && (!$hasTenant || !is_string($metricData['tenant']) || $metricData['tenant'] === '')) {
+                throw new Exception("Metric #{$index}: 'tenant' is required (non-empty string) when shared tables are enabled");
+            }
+
+            if ($hasTenant && $metricData['tenant'] !== null && !is_string($metricData['tenant'])) {
+                throw new Exception("Metric #{$index}: 'tenant' must be a string or null, got " . gettype($metricData['tenant']));
             }
         }
     }
@@ -1341,11 +1327,7 @@ public function addBatch(array $metrics, string $type, int $batchSize = self::IN
      */
     private function resolveTenantFromMetric(array $metricData): ?string
     {
-        $tenant = array_key_exists('$tenant', $metricData) ? $metricData['$tenant'] : $this->tenant;
-
-        if ($tenant === null) {
-            return null;
-        }
+        $tenant = $metricData['tenant'] ?? null;
 
         if (is_string($tenant)) {
             return $tenant;
@@ -1367,12 +1349,12 @@ private function resolveTenantFromMetric(array $metricData): ?string
      * @return array<Metric>
      * @throws Exception
      */
-    public function find(array $queries = [], ?string $type = null): array
+    public function find(string $tenant, array $queries = [], ?string $type = null): array
     {
         $this->setOperationContext('find()');
 
         if ($type !== null) {
-            return $this->findFromTable($queries, $type);
+            return $this->findFromTable($tenant, $queries, $type);
         }
 
         // Cursor pagination is per-table — paginating across both events and
@@ -1397,10 +1379,10 @@ public function find(array $queries = [], ?string $type = null): array
         // requested limit. Tables whose schema doesn't support every filter
         // attribute (e.g. `path` on a gauge query) are skipped.
         $events = $this->queriesMatchType($queries, Usage::TYPE_EVENT)
-            ? $this->findFromTable($queries, Usage::TYPE_EVENT)
+            ? $this->findFromTable($tenant, $queries, Usage::TYPE_EVENT)
             : [];
         $gauges = $this->queriesMatchType($queries, Usage::TYPE_GAUGE)
-            ? $this->findFromTable($queries, Usage::TYPE_GAUGE)
+            ? $this->findFromTable($tenant, $queries, Usage::TYPE_GAUGE)
             : [];
 
         $merged = array_merge($events, $gauges);
@@ -1457,12 +1439,12 @@ private function queriesMatchType(array $queries, string $type): bool
      * @return array<Metric>
      * @throws Exception
      */
-    private function findFromTable(array $queries, string $type): array
+    private function findFromTable(string $tenant, array $queries, string $type): array
     {
         $tableName = $this->getTableForType($type);
         $fromTable = $this->buildTableReference($tableName);
 
-        $parsed = $this->parseQueries($queries, $type);
+        $parsed = $this->parseQueries($tenant, $queries, $type);
 
         // Cursor pagination is incompatible with time-bucketed aggregation —
         // aggregated rows have no stable identity to anchor a keyset cursor on.
@@ -1695,12 +1677,12 @@ private function parseAggregatedResults(string $result, string $type = 'event'):
      * @return int
      * @throws Exception
      */
-    public function count(array $queries = [], ?string $type = null, ?int $max = null): int
+    public function count(string $tenant, array $queries = [], ?string $type = null, ?int $max = null): int
     {
         $this->setOperationContext('count()');
 
         if ($type !== null) {
-            return $this->countFromTable($queries, $type, $max);
+            return $this->countFromTable($tenant, $queries, $type, $max);
         }
 
         // Count from both tables. Each per-table count is independently
@@ -1708,10 +1690,10 @@ public function count(array $queries = [], ?string $type = null, ?int $max = nul
         // Cap the combined total at $max in PHP to honour the contract.
         // Skip a table when its schema can't satisfy every filter attribute.
         $events = $this->queriesMatchType($queries, Usage::TYPE_EVENT)
-            ? $this->countFromTable($queries, Usage::TYPE_EVENT, $max)
+            ? $this->countFromTable($tenant, $queries, Usage::TYPE_EVENT, $max)
             : 0;
         $gauges = $this->queriesMatchType($queries, Usage::TYPE_GAUGE)
-            ? $this->countFromTable($queries, Usage::TYPE_GAUGE, $max)
+            ? $this->countFromTable($tenant, $queries, Usage::TYPE_GAUGE, $max)
             : 0;
 
         $total = $events + $gauges;
@@ -1732,12 +1714,12 @@ public function count(array $queries = [], ?string $type = null, ?int $max = nul
      * @return int
      * @throws Exception
      */
-    private function countFromTable(array $queries, string $type, ?int $max = null): int
+    private function countFromTable(string $tenant, array $queries, string $type, ?int $max = null): int
     {
         $tableName = $this->getTableForType($type);
         $fromTable = $this->buildTableReference($tableName);
 
-        $parsed = $this->parseQueries($queries, $type);
+        $parsed = $this->parseQueries($tenant, $queries, $type);
 
         $params = $parsed['params'];
         unset($params['limit'], $params['offset']);
@@ -1782,15 +1764,15 @@ private function countFromTable(array $queries, string $type, ?int $max = null):
      * @return int
      * @throws Exception
      */
-    public function sum(array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
+    public function sum(string $tenant, array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
     {
         $this->setOperationContext('sum()');
 
         if ($type === Usage::TYPE_EVENT && $attribute === 'value') {
-            return $this->routedSum($queries, 'sum');
+            return $this->routedSum($tenant, $queries, 'sum');
         }
 
-        return $this->sumFromTable($queries, $attribute, $type);
+        return $this->sumFromTable($tenant, $queries, $attribute, $type);
     }
 
     /**
@@ -1800,24 +1782,24 @@ public function sum(array $queries = [], string $attribute = 'value', string $ty
      *
      * @param array<Query> $queries
      */
-    private function routedSum(array $queries, string $operation): int
+    private function routedSum(string $tenant, array $queries, string $operation): int
     {
         $plan = $this->extractRoutingPlan($queries);
         $route = $this->selectAggregateSource($plan);
         $this->recordRoute($operation, $plan, $route);
 
         if ($route === 'daily') {
-            $total = $this->sumDaily($this->translateInclusiveMidnightForDaily($queries), 'value');
-            $this->maybeDualRead($queries, $route, $plan, $total);
+            $total = $this->sumDailyTotal($tenant, $this->translateInclusiveMidnightForDaily($queries), 'value');
+            $this->maybeDualRead($tenant, $queries, $route, $plan, $total);
             return $total;
         }
         if ($route === 'hybrid') {
-            $total = $this->sumHybridDailyAndRaw($queries, $plan);
-            $this->maybeDualRead($queries, $route, $plan, $total);
+            $total = $this->sumHybridDailyAndRaw($tenant, $queries, $plan);
+            $this->maybeDualRead($tenant, $queries, $route, $plan, $total);
             return $total;
         }
 
-        return $this->sumFromTable($queries, 'value', Usage::TYPE_EVENT);
+        return $this->sumFromTable($tenant, $queries, 'value', Usage::TYPE_EVENT);
     }
 
     /**
@@ -2364,7 +2346,7 @@ private function appendRouteLogEntry(array $entry): void
      * @param string $route
      * @param array{metric: ?string, start: ?string, end: ?string, filterColumns: array<int, string>, dimensions: array<int, string>, interval: ?string, orderColumns?: array<int, string>, hasCursor?: bool} $plan
      */
-    private function maybeDualRead(array $queries, string $route, array $plan, int $rolledTotal): void
+    private function maybeDualRead(string $tenant, array $queries, string $route, array $plan, int $rolledTotal): void
     {
         if ($this->dualReadSampleRate <= 0.0) {
             return;
@@ -2374,7 +2356,7 @@ private function maybeDualRead(array $queries, string $route, array $plan, int $
         }
 
         try {
-            $rawTotal = $this->sumFromTable($queries, 'value', Usage::TYPE_EVENT);
+            $rawTotal = $this->sumFromTable($tenant, $queries, 'value', Usage::TYPE_EVENT);
         } catch (Throwable $e) {
             return;
         }
@@ -2406,7 +2388,7 @@ private function maybeDualRead(array $queries, string $route, array $plan, int $
      * @param array<Query> $queries
      * @param array{metric: ?string, start: ?string, end: ?string, filterColumns: array<int, string>, dimensions: array<int, string>, interval: ?string} $plan
      */
-    private function sumHybridDailyAndRaw(array $queries, array $plan): int
+    private function sumHybridDailyAndRaw(string $tenant, array $queries, array $plan): int
     {
         $startOfToday = (new DateTime('today', new DateTimeZone('UTC')))->format('Y-m-d H:i:s.v');
 
@@ -2414,9 +2396,9 @@ private function sumHybridDailyAndRaw(array $queries, array $plan): int
         $eventsTable = $this->buildTableReference($this->getEventsTableName());
 
         $split = $this->splitTimeQueries($queries);
-        $parsed = $this->parseQueries($queries, Usage::TYPE_EVENT);
+        $parsed = $this->parseQueries($tenant, $queries, Usage::TYPE_EVENT);
         $dailyParsed = $this->prefixParsedParams(
-            $this->parseQueries($split['nonTime'], Usage::TYPE_EVENT),
+            $this->parseQueries($tenant, $split['nonTime'], Usage::TYPE_EVENT),
             'd_'
         );
 
@@ -2460,7 +2442,7 @@ private function sumHybridDailyAndRaw(array $queries, array $plan): int
      * @return int
      * @throws Exception
      */
-    private function sumFromTable(array $queries, string $attribute, string $type): int
+    private function sumFromTable(string $tenant, array $queries, string $attribute, string $type): int
     {
         $tableName = $this->getTableForType($type);
         $fromTable = $this->buildTableReference($tableName);
@@ -2468,7 +2450,7 @@ private function sumFromTable(array $queries, string $attribute, string $type):
         $this->validateAttributeName($attribute, $type);
         $escapedAttribute = $this->escapeIdentifier($attribute);
 
-        $parsed = $this->parseQueries($queries, $type);
+        $parsed = $this->parseQueries($tenant, $queries, $type);
 
         $whereData = $this->buildWhereClause($parsed['filters'], $parsed['params']);
         $whereClause = $whereData['clause'];
@@ -2497,7 +2479,7 @@ private function sumFromTable(array $queries, string $attribute, string $type):
      * @return array<Metric>
      * @throws Exception
      */
-    public function findDaily(array $queries = []): array
+    public function findDaily(string $tenant, array $queries = []): array
     {
         $this->setOperationContext('findDaily()');
 
@@ -2509,7 +2491,7 @@ public function findDaily(array $queries = []): array
                 $this->validateDailyAttributeName($attr);
             }
         }
-        $parsed = $this->parseQueries($queries, Usage::TYPE_EVENT);
+        $parsed = $this->parseQueries($tenant, $queries, Usage::TYPE_EVENT);
         $whereData = $this->buildWhereClause($parsed['filters'], $parsed['params']);
 
         $groupByColumns = $this->sharedTables ? ['tenant'] : [];
@@ -2545,10 +2527,22 @@ public function findDaily(array $queries = []): array
      * @return int
      * @throws Exception
      */
-    public function sumDaily(array $queries = [], string $attribute = 'value'): int
+    public function sumDaily(string $tenant, array $queries = [], string $attribute = 'value'): int
     {
         $this->setOperationContext('sumDaily()');
 
+        return $this->sumDailyTotal($tenant, $queries, $attribute);
+    }
+
+    /**
+     * Sum the daily table. Split out from sumDaily() so internal callers
+     * (e.g. routedSum) can reuse it without re-setting the operation context.
+     *
+     * @param array<Query> $queries
+     * @throws Exception
+     */
+    private function sumDailyTotal(string $tenant, array $queries, string $attribute = 'value'): int
+    {
         $fromTable = $this->buildTableReference($this->getEventsDailyTableName());
         $this->validateDailyAttributeName($attribute);
         $escapedAttribute = $this->escapeIdentifier($attribute);
@@ -2559,7 +2553,7 @@ public function sumDaily(array $queries = [], string $attribute = 'value'): int
                 $this->validateDailyAttributeName($attr);
             }
         }
-        $parsed = $this->parseQueries($queries, Usage::TYPE_EVENT);
+        $parsed = $this->parseQueries($tenant, $queries, Usage::TYPE_EVENT);
         $whereData = $this->buildWhereClause($parsed['filters'], $parsed['params']);
 
         $sql = "SELECT sum({$escapedAttribute}) as total FROM {$fromTable}{$whereData['clause']} FORMAT JSON";
@@ -2578,7 +2572,7 @@ public function sumDaily(array $queries = [], string $attribute = 'value'): int
      * @return array<string, int>
      * @throws Exception
      */
-    public function sumDailyBatch(array $metrics, array $queries = []): array
+    public function sumDailyBatch(string $tenant, array $metrics, array $queries = []): array
     {
         if (empty($metrics)) {
             return [];
@@ -2607,7 +2601,7 @@ public function sumDailyBatch(array $metrics, array $queries = []): array
         }
         $metricInClause = implode(', ', $metricPlaceholders);
 
-        $parsed = $this->parseQueries($queries, Usage::TYPE_EVENT);
+        $parsed = $this->parseQueries($tenant, $queries, Usage::TYPE_EVENT);
         $params = array_merge($metricParams, $parsed['params']);
 
         $whereData = $this->buildWhereClause($parsed['filters'], $params);
@@ -2655,7 +2649,7 @@ public function sumDailyBatch(array $metrics, array $queries = []): array
      * @return array<string, array{total: float, data: array<array{value: float, date: string}>}>
      * @throws Exception
      */
-    public function getTimeSeries(array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
+    public function getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
     {
         if (empty($metrics)) {
             return [];
@@ -2689,7 +2683,7 @@ public function getTimeSeries(array $metrics, string $interval, string $startDat
                 continue;
             }
 
-            $typeResult = $this->getTimeSeriesFromTable($metrics, $interval, $startDate, $endDate, $queries, $queryType);
+            $typeResult = $this->getTimeSeriesFromTable($tenant, $metrics, $interval, $startDate, $endDate, $queries, $queryType);
 
             // Merge results
             foreach ($typeResult as $metricName => $metricData) {
@@ -2733,7 +2727,7 @@ public function getTimeSeries(array $metrics, string $interval, string $startDat
      * @return array<string, array{total: float, data: array<array{value: float, date: string}>}>
      * @throws Exception
      */
-    private function getTimeSeriesFromTable(array $metrics, string $interval, string $startDate, string $endDate, array $queries, string $type): array
+    private function getTimeSeriesFromTable(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries, string $type): array
     {
         $timeFunction = self::INTERVAL_FUNCTIONS[$interval];
         $tableName = $this->getTableForType($type);
@@ -2750,21 +2744,15 @@ private function getTimeSeriesFromTable(array $metrics, string $interval, string
 
         $metricInClause = implode(', ', $metricPlaceholders);
 
-        // Build additional WHERE conditions from queries
-        $parsed = $this->parseQueries($queries, $type);
+        // Build additional WHERE conditions from queries (tenant baked in)
+        $parsed = $this->parseQueries($tenant, $queries, $type);
         $additionalFilters = $parsed['filters'];
         $params = array_merge($metricParams, $parsed['params']);
 
         $params['start_date'] = $this->formatDateTime($startDate);
         $params['end_date'] = $this->formatDateTime($endDate);
 
-        // Build tenant filter
-        $tenantFilter = '';
-        if ($this->sharedTables && $this->tenant !== null) {
-            $tenantFilter = ' AND tenant = {tenant:Nullable(String)}';
-            $params['tenant'] = $this->tenant;
-        }
-
+        // Tenant scoping is already folded into $additionalFilters by parseQueries().
         $additionalWhere = '';
         if (!empty($additionalFilters)) {
             $additionalWhere = ' AND ' . implode(' AND ', $additionalFilters);
@@ -2782,7 +2770,7 @@ private function getTimeSeriesFromTable(array $metrics, string $interval, string
             FROM {$fromTable}
             WHERE metric IN ({$metricInClause})
                 AND time BETWEEN {start_date:DateTime64(3, 'UTC')} AND {end_date:DateTime64(3, 'UTC')}
-                {$tenantFilter}{$additionalWhere}
+                {$additionalWhere}
             GROUP BY metric, bucket
             ORDER BY bucket ASC
             FORMAT JSON
@@ -2876,21 +2864,21 @@ private function zeroFillTimeSeries(array $data, string $interval, string $start
      * @return int
      * @throws Exception
      */
-    public function getTotal(string $metric, array $queries = [], ?string $type = null): int
+    public function getTotal(string $tenant, string $metric, array $queries = [], ?string $type = null): int
     {
         $this->setOperationContext('getTotal()');
 
         if ($type === Usage::TYPE_EVENT) {
-            return $this->getTotalFromEvents($metric, $queries);
+            return $this->getTotalFromEvents($tenant, $metric, $queries);
         }
 
         if ($type === Usage::TYPE_GAUGE) {
-            return $this->getTotalFromGauges($metric, $queries);
+            return $this->getTotalFromGauges($tenant, $metric, $queries);
         }
 
         // Query both tables — event uses SUM, gauge uses argMax
-        $eventTotal = $this->getTotalFromEvents($metric, $queries);
-        $gaugeTotal = $this->getTotalFromGauges($metric, $queries);
+        $eventTotal = $this->getTotalFromEvents($tenant, $metric, $queries);
+        $gaugeTotal = $this->getTotalFromGauges($tenant, $metric, $queries);
 
         if ($eventTotal > 0 && $gaugeTotal > 0) {
             throw new Exception(
@@ -2911,10 +2899,10 @@ public function getTotal(string $metric, array $queries = [], ?string $type = nu
      * @return int
      * @throws Exception
      */
-    private function getTotalFromEvents(string $metric, array $queries): int
+    private function getTotalFromEvents(string $tenant, string $metric, array $queries): int
     {
         $queries[] = Query::equal('metric', [$metric]);
-        return $this->routedSum($queries, 'getTotal');
+        return $this->routedSum($tenant, $queries, 'getTotal');
     }
 
     /**
@@ -2926,7 +2914,7 @@ private function getTotalFromEvents(string $metric, array $queries): int
      * @return int
      * @throws Exception
      */
-    private function getTotalFromGauges(string $metric, array $queries): int
+    private function getTotalFromGauges(string $tenant, string $metric, array $queries): int
     {
         $queries[] = Query::equal('metric', [$metric]);
 
@@ -2936,7 +2924,7 @@ private function getTotalFromGauges(string $metric, array $queries): int
         $tableName = $this->getGaugesTableName();
         $fromTable = $this->buildTableReference($tableName);
 
-        $parsed = $this->parseQueries($queries, Usage::TYPE_GAUGE);
+        $parsed = $this->parseQueries($tenant, $queries, Usage::TYPE_GAUGE);
         $whereData = $this->buildWhereClause($parsed['filters'], $parsed['params']);
 
         $sql = "
@@ -2970,7 +2958,7 @@ private function getTotalFromGauges(string $metric, array $queries): int
      * @return array<string, int>
      * @throws Exception
      */
-    public function getTotalBatch(array $metrics, array $queries = [], ?string $type = null): array
+    public function getTotalBatch(string $tenant, array $metrics, array $queries = [], ?string $type = null): array
     {
         if (empty($metrics)) {
             return [];
@@ -3006,7 +2994,7 @@ public function getTotalBatch(array $metrics, array $queries = [], ?string $type
             }
             $metricInClause = implode(', ', $metricPlaceholders);
 
-            $parsed = $this->parseQueries($queries, $queryType);
+            $parsed = $this->parseQueries($tenant, $queries, $queryType);
             $params = array_merge($metricParams, $parsed['params']);
 
             $whereData = $this->buildWhereClause($parsed['filters'], $params);
@@ -3064,31 +3052,23 @@ public function getTotalBatch(array $metrics, array $queries = [], ?string $type
     }
 
     /**
-     * Build WHERE clause from filters with optional tenant filtering.
+     * Build a WHERE clause from already-parsed filters.
+     *
+     * Tenant scoping is baked into parseQueries(), so by the time filters
+     * reach here they are already tenant-scoped — there is no separate step
+     * to forget.
      *
      * @param array<string> $filters
      * @param array<string, mixed> $params
-     * @param bool $includeTenant
      * @return array{clause: string, params: array<string, mixed>}
      */
-    private function buildWhereClause(array $filters, array $params = [], bool $includeTenant = true): array
+    private function buildWhereClause(array $filters, array $params = []): array
     {
-        $conditions = $filters;
-        $whereParams = $params;
-
-        if ($includeTenant) {
-            $tenantFilter = $this->getTenantFilter();
-            if ($tenantFilter) {
-                $conditions[] = $tenantFilter;
-                $whereParams['tenant'] = $this->tenant;
-            }
-        }
-
-        $clause = !empty($conditions) ? ' WHERE ' . implode(' AND ', $conditions) : '';
+        $clause = !empty($filters) ? ' WHERE ' . implode(' AND ', $filters) : '';
 
         return [
             'clause' => $clause,
-            'params' => $whereParams
+            'params' => $params
         ];
     }
 
@@ -3304,13 +3284,30 @@ private function buildOrderBySql(array $orderAttributes, bool $flip = false): ar
     /**
      * Parse Query objects into SQL clauses.
      *
+     * Tenant scoping is baked in here rather than left to callers: in
+     * shared-tables mode a `tenant = …` filter is prepended before parsing,
+     * so there is no way to produce a WHERE clause that isn't tenant-scoped.
+     * Every read/delete path funnels through this method, which is why it
+     * takes the tenant as a required first argument.
+     *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<Query> $queries
      * @param string $type 'event' or 'gauge' — used for attribute validation
      * @return array{filters: array<int, string>, params: array<string, mixed>, orderBy?: array<string>, orderAttributes?: array<int, array{attribute: string, direction: string}>, limit?: int, offset?: int, groupByInterval?: string, groupBy?: array<int, string>, cursor?: array<string, mixed>, cursorDirection?: string}
      * @throws Exception
      */
-    private function parseQueries(array $queries, string $type = 'event'): array
+    private function parseQueries(string $tenant, array $queries, string $type = 'event'): array
     {
+        if ($this->sharedTables) {
+            // An empty tenant would compile to `tenant = ''` and silently read
+            // an empty scope. Fail fast instead, like the write side. ("0" is
+            // a valid tenant id, so check for '' specifically.)
+            if ($tenant === '') {
+                throw new Exception('Tenant cannot be empty in shared-tables mode');
+            }
+            array_unshift($queries, Query::equal('tenant', [$tenant]));
+        }
+
         $filters = [];
         $params = [];
         $orderBy = [];
@@ -3679,20 +3676,6 @@ private function getSelectColumns(string $type = 'event'): string
         return implode(', ', $columns);
     }
 
-    /**
-     * Build tenant filter clause.
-     *
-     * @return string
-     */
-    private function getTenantFilter(): string
-    {
-        if (!$this->sharedTables || $this->tenant === null) {
-            return '';
-        }
-
-        return "tenant = {tenant:Nullable(String)}";
-    }
-
     /**
      * Purge usage metrics matching the given queries.
      * Deletes from the specified table(s).
@@ -3708,7 +3691,7 @@ private function getTenantFilter(): string
      * @param string|null $type 'event', 'gauge', or null (purge both)
      * @throws Exception
      */
-    public function purge(array $queries = [], ?string $type = null): bool
+    public function purge(string $tenant, array $queries = [], ?string $type = null): bool
     {
         $this->setOperationContext('purge()');
 
@@ -3724,7 +3707,7 @@ public function purge(array $queries = [], ?string $type = null): bool
             $tableName = $this->getTableForType($purgeType);
             $escapedTable = $this->escapeIdentifier($this->database) . '.' . $this->escapeIdentifier($tableName);
 
-            $parsed = $this->parseQueries($queries, $purgeType);
+            $parsed = $this->parseQueries($tenant, $queries, $purgeType);
             $whereData = $this->buildWhereClause($parsed['filters'], $parsed['params']);
             $whereClause = $whereData['clause'];
             $params = $whereData['params'];
@@ -3737,7 +3720,7 @@ public function purge(array $queries = [], ?string $type = null): bool
             $this->query($sql, $params);
 
             if ($purgeType === Usage::TYPE_EVENT) {
-                $this->purgeDaily($queries);
+                $this->purgeDaily($tenant, $queries);
             }
         }
 
@@ -3789,10 +3772,11 @@ private function buildStaleRollupPurgeQueries(array $queries, array $safeAttribu
      * unrelated metrics. The next ingest cycle will overwrite any rows
      * the caller's raw-table purge left stale.
      *
-     * @param array<Query> $queries
+     * @param array<Query> $queries  The caller's filters (tenant-free); the
+     *        tenant is applied as a scope on the resulting delete.
      * @throws Exception
      */
-    private function purgeDaily(array $queries): void
+    private function purgeDaily(string $tenant, array $queries): void
     {
         $safeAttributes = array_values(array_filter(
             self::DAILY_COLUMNS,
@@ -3823,9 +3807,13 @@ private function purgeDaily(array $queries): void
             return;
         }
 
+        // parseQueries() folds the tenant into the WHERE. The compatibility
+        // decision above deliberately runs on the caller's tenant-free filters,
+        // so the tenant scope can never make an imprecise purge look safe to
+        // forward to the rollup.
         $dailyTable = $this->buildTableReference($this->getEventsDailyTableName());
 
-        $parsed = $this->parseQueries($dailyQueries, Usage::TYPE_EVENT);
+        $parsed = $this->parseQueries($tenant, $dailyQueries, Usage::TYPE_EVENT);
         $whereData = $this->buildWhereClause($parsed['filters'], $parsed['params']);
         $whereClause = $whereData['clause'];
 
diff --git a/src/Usage/Adapter/Database.php b/src/Usage/Adapter/Database.php
index b008be6..4d25bdb 100644
--- a/src/Usage/Adapter/Database.php
+++ b/src/Usage/Adapter/Database.php
@@ -122,7 +122,10 @@ protected function getColumnDefinition(string $id, string $type = 'event'): stri
      * Database adapter uses a single collection for both types. The $type parameter
      * is stored as a field in each document for query-time differentiation.
      *
-     * @param array<array{metric: string, value: int, tags?: array<string,mixed>}> $metrics
+     * Each metric carries its own `tenant` (shared-tables mode), so a single
+     * batch may span multiple tenants.
+     *
+     * @param array<array{tenant: string, metric: string, value: int, tags?: array<string,mixed>}> $metrics
      * @param string $type Metric type: 'event' or 'gauge'
      * @param int $batchSize
      * @return bool
@@ -131,7 +134,7 @@ protected function getColumnDefinition(string $id, string $type = 'event'): stri
     public function addBatch(array $metrics, string $type, int $batchSize = 1000): bool
     {
         $this->db->getAuthorization()->skip(function () use ($metrics, $type, $batchSize) {
-            $documents = [];
+            $entries = [];
             foreach ($metrics as $metric) {
                 if ($type !== Usage::TYPE_EVENT && $type !== Usage::TYPE_GAUGE) {
                     throw new \InvalidArgumentException("Invalid type '{$type}'. Allowed: event, gauge");
@@ -155,12 +158,13 @@ public function addBatch(array $metrics, string $type, int $batchSize = 1000): b
                     'time' => (new \DateTime())->format('Y-m-d H:i:s.v'),
                 ], $columns);
 
-                $documents[] = new Document($docData);
+                $entries[] = ['tenant' => $metric['tenant'], 'doc' => new Document($docData)];
             }
 
-            foreach (array_chunk($documents, max(1, $batchSize)) as $chunk) {
-                foreach ($chunk as $doc) {
-                    $this->db->createDocument($this->collection, $doc);
+            foreach (array_chunk($entries, max(1, $batchSize)) as $chunk) {
+                foreach ($chunk as $entry) {
+                    $this->setDbTenant($entry['tenant']);
+                    $this->db->createDocument($this->collection, $entry['doc']);
                 }
             }
         });
@@ -173,6 +177,7 @@ public function addBatch(array $metrics, string $type, int $batchSize = 1000): b
      *
      * Stub implementation for Database adapter.
      *
+     * @param string $tenant
      * @param array<string> $metrics
      * @param string $interval
      * @param string $startDate
@@ -182,7 +187,7 @@ public function addBatch(array $metrics, string $type, int $batchSize = 1000): b
      * @param string|null $type
      * @return array<string, array{total: float, data: array<array{value: float, date: string}>}>
      */
-    public function getTimeSeries(array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
+    public function getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
     {
         // Stub: Database adapter time series not yet implemented
         $output = [];
@@ -197,12 +202,13 @@ public function getTimeSeries(array $metrics, string $interval, string $startDat
      *
      * Returns SUM for event metrics, latest value for gauge metrics.
      *
+     * @param string $tenant
      * @param string $metric
      * @param array<Query> $queries
      * @param string|null $type
      * @return int
      */
-    public function getTotal(string $metric, array $queries = [], ?string $type = null): int
+    public function getTotal(string $tenant, string $metric, array $queries = [], ?string $type = null): int
     {
         $allQueries = array_merge($queries, [
             Query::equal('metric', [$metric]),
@@ -217,7 +223,7 @@ public function getTotal(string $metric, array $queries = [], ?string $type = nu
                 Query::limit(1),
             ]);
             /** @var array<Metric> $gaugeResults */
-            $gaugeResults = $this->find($gaugeQueries, $type);
+            $gaugeResults = $this->find($tenant, $gaugeQueries, $type);
             if (empty($gaugeResults)) {
                 return 0;
             }
@@ -225,7 +231,7 @@ public function getTotal(string $metric, array $queries = [], ?string $type = nu
         }
 
         /** @var array<Metric> $results */
-        $results = $this->find($allQueries, $type);
+        $results = $this->find($tenant, $allQueries, $type);
 
         if (empty($results)) {
             return 0;
@@ -280,12 +286,13 @@ public function getTotal(string $metric, array $queries = [], ?string $type = nu
     /**
      * Get totals for multiple metrics.
      *
+     * @param string $tenant
      * @param array<string> $metrics
      * @param array<Query> $queries
      * @param string|null $type
      * @return array<string, int>
      */
-    public function getTotalBatch(array $metrics, array $queries = [], ?string $type = null): array
+    public function getTotalBatch(string $tenant, array $metrics, array $queries = [], ?string $type = null): array
     {
         if (empty($metrics)) {
             return [];
@@ -294,7 +301,7 @@ public function getTotalBatch(array $metrics, array $queries = [], ?string $type
         $totals = \array_fill_keys($metrics, 0);
 
         foreach ($metrics as $metric) {
-            $totals[$metric] = $this->getTotal($metric, $queries, $type);
+            $totals[$metric] = $this->getTotal($tenant, $metric, $queries, $type);
         }
 
         return $totals;
@@ -305,15 +312,16 @@ public function getTotalBatch(array $metrics, array $queries = [], ?string $type
      *
      * Events-only by default — summing gauges is semantically meaningless.
      *
+     * @param string $tenant
      * @param array<Query> $queries
      * @param string $attribute
      * @param string $type 'event' or 'gauge'
      * @return int
      */
-    public function sum(array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
+    public function sum(string $tenant, array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
     {
         /** @var array<Metric> $results */
-        $results = $this->find($queries, $type);
+        $results = $this->find($tenant, $queries, $type);
 
         $sum = 0;
         foreach ($results as $result) {
@@ -326,26 +334,28 @@ public function sum(array $queries = [], string $attribute = 'value', string $ty
     /**
      * Find from daily table — Database adapter falls back to regular find for events.
      *
+     * @param string $tenant
      * @param array<Query> $queries
      * @return array<Metric>
      */
-    public function findDaily(array $queries = []): array
+    public function findDaily(string $tenant, array $queries = []): array
     {
-        return $this->find($queries, Usage::TYPE_EVENT);
+        return $this->find($tenant, $queries, Usage::TYPE_EVENT);
     }
 
     /**
      * Sum multiple metrics from daily table — falls back to individual sumDaily calls.
      *
+     * @param string $tenant
      * @param array<\Utopia\Query\Query> $queries
      * @return array<string, int>
      */
-    public function sumDailyBatch(array $metrics, array $queries = []): array
+    public function sumDailyBatch(string $tenant, array $metrics, array $queries = []): array
     {
         $totals = \array_fill_keys($metrics, 0);
         foreach ($metrics as $metric) {
             $metricQueries = array_merge($queries, [Query::equal('metric', [$metric])]);
-            $totals[$metric] = $this->sumDaily($metricQueries);
+            $totals[$metric] = $this->sumDaily($tenant, $metricQueries);
         }
         return $totals;
     }
@@ -353,13 +363,14 @@ public function sumDailyBatch(array $metrics, array $queries = []): array
     /**
      * Sum from daily table — Database adapter falls back to regular sum for events.
      *
+     * @param string $tenant
      * @param array<Query> $queries
      * @param string $attribute
      * @return int
      */
-    public function sumDaily(array $queries = [], string $attribute = 'value'): int
+    public function sumDaily(string $tenant, array $queries = [], string $attribute = 'value'): int
     {
-        return $this->sum($queries, $attribute, Usage::TYPE_EVENT);
+        return $this->sum($tenant, $queries, $attribute, Usage::TYPE_EVENT);
     }
 
     /**
@@ -520,11 +531,13 @@ private function validateGroupByQueries(array $queries): void
     }
 
     /**
+     * @param string $tenant
      * @param array<Query> $queries
      * @param string|null $type
      */
-    public function purge(array $queries = [], ?string $type = null): bool
+    public function purge(string $tenant, array $queries = [], ?string $type = null): bool
     {
+        $this->setDbTenant($tenant);
         $queries = $this->withTypeFilter($queries, $type);
 
         $this->db->getAuthorization()->skip(function () use ($queries) {
@@ -553,12 +566,14 @@ public function purge(array $queries = [], ?string $type = null): bool
      * so callers can isolate event vs gauge rows. When $type is null both
      * are returned (caller distinguishes via Metric::getType()).
      *
+     * @param string $tenant
      * @param array<Query> $queries
      * @param string|null $type
      * @return array<Metric>
      */
-    public function find(array $queries = [], ?string $type = null): array
+    public function find(string $tenant, array $queries = [], ?string $type = null): array
     {
+        $this->setDbTenant($tenant);
         $queries = $this->withTypeFilter($queries, $type);
 
         /** @var array<Document> $result */
@@ -580,13 +595,15 @@ public function find(array $queries = [], ?string $type = null): array
      * utopia-php/database accepts a `$max` argument that pushes the cap
      * down into the underlying SQL.
      *
+     * @param string $tenant
      * @param array<Query> $queries
      * @param string|null $type
      * @param int|null $max Optional upper bound (inclusive) for the count
      * @return int
      */
-    public function count(array $queries = [], ?string $type = null, ?int $max = null): int
+    public function count(string $tenant, array $queries = [], ?string $type = null, ?int $max = null): int
     {
+        $this->setDbTenant($tenant);
         $queries = $this->withTypeFilter($queries, $type);
 
         /** @var int $count */
@@ -623,17 +640,18 @@ private function withTypeFilter(array $queries, ?string $type): array
     }
 
     /**
-     * Set the tenant ID for multi-tenant support.
+     * Scope the underlying Utopia\Database instance to a tenant for the next
+     * operation. The Database adapter requires a numeric tenant ID.
      *
-     * Tenant is the one piece of configuration that changes over an
-     * instance's lifetime (a single adapter serves many tenants across
-     * requests), so it stays a mutable setter. Namespace and shared-tables
-     * mode are configured directly on the injected Utopia\Database instance.
+     * The adapter takes ownership of the injected db's tenant: every call
+     * sets it and none restores it (Utopia\Database has no per-call tenant —
+     * only the mutable instance tenant — and save/restore around each call is
+     * its own footgun). Hand this adapter a db dedicated to usage, not one
+     * whose tenant other code depends on between calls.
      *
      * @param string|null $tenant
-     * @return self
      */
-    public function setTenant(?string $tenant): self
+    private function setDbTenant(?string $tenant): void
     {
         if ($tenant !== null && !is_numeric($tenant)) {
             throw new \InvalidArgumentException(
@@ -642,6 +660,5 @@ public function setTenant(?string $tenant): self
         }
 
         $this->db->setTenant($tenant !== null ? (int) $tenant : null);
-        return $this;
     }
 }
diff --git a/src/Usage/Tenant.php b/src/Usage/Tenant.php
new file mode 100644
index 0000000..fe5a6f6
--- /dev/null
+++ b/src/Usage/Tenant.php
@@ -0,0 +1,150 @@
+<?php
+
+namespace Utopia\Usage;
+
+/**
+ * Tenant-scoped view over a Usage instance.
+ *
+ * Binds a tenant once at construction and forwards every query/mutation to the
+ * underlying Usage with that tenant pre-filled — so callers that only ever
+ * touch one tenant don't repeat it on every call.
+ */
+class Tenant
+{
+    private Usage $usage;
+
+    private string $tenant;
+
+    /**
+     * @param  Usage  $usage  The underlying (tenant-agnostic) Usage instance
+     * @param  string  $tenant  Tenant this view is scoped to (non-empty)
+     */
+    public function __construct(Usage $usage, string $tenant)
+    {
+        // Reject '' at construction: an empty scope would silently read/write
+        // the empty tenant in shared-tables mode. ("0" is a valid id.)
+        if ($tenant === '') {
+            throw new \InvalidArgumentException('Tenant cannot be empty');
+        }
+
+        $this->usage = $usage;
+        $this->tenant = $tenant;
+    }
+
+    /**
+     * Add metrics in batch, stamping this view's tenant onto each entry.
+     *
+     * @param array<array{metric: string, value: int, tags?: array<string,mixed>}> $metrics
+     * @param string $type Metric type: 'event' or 'gauge'
+     * @param int $batchSize Maximum number of metrics per INSERT statement
+     * @return bool
+     * @throws \Exception
+     */
+    public function addBatch(array $metrics, string $type, int $batchSize = 1000): bool
+    {
+        foreach ($metrics as &$metric) {
+            $metric['tenant'] = $this->tenant;
+        }
+        unset($metric);
+
+        return $this->usage->addBatch($metrics, $type, $batchSize);
+    }
+
+    /**
+     * @param array<string> $metrics
+     * @param array<\Utopia\Query\Query> $queries
+     * @return array<string, array{total: float, data: array<array{value: float, date: string}>}>
+     * @throws \Exception
+     */
+    public function getTimeSeries(array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
+    {
+        return $this->usage->getTimeSeries($this->tenant, $metrics, $interval, $startDate, $endDate, $queries, $zeroFill, $type);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @throws \Exception
+     */
+    public function getTotal(string $metric, array $queries = [], ?string $type = null): int
+    {
+        return $this->usage->getTotal($this->tenant, $metric, $queries, $type);
+    }
+
+    /**
+     * @param array<string> $metrics
+     * @param array<\Utopia\Query\Query> $queries
+     * @return array<string, int>
+     * @throws \Exception
+     */
+    public function getTotalBatch(array $metrics, array $queries = [], ?string $type = null): array
+    {
+        return $this->usage->getTotalBatch($this->tenant, $metrics, $queries, $type);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @throws \Exception
+     */
+    public function purge(array $queries = [], ?string $type = null): bool
+    {
+        return $this->usage->purge($this->tenant, $queries, $type);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @return array<Metric>
+     * @throws \Exception
+     */
+    public function find(array $queries = [], ?string $type = null): array
+    {
+        return $this->usage->find($this->tenant, $queries, $type);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @throws \Exception
+     */
+    public function count(array $queries = [], ?string $type = null, ?int $max = null): int
+    {
+        return $this->usage->count($this->tenant, $queries, $type, $max);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @throws \Exception
+     */
+    public function sum(array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
+    {
+        return $this->usage->sum($this->tenant, $queries, $attribute, $type);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @return array<Metric>
+     * @throws \Exception
+     */
+    public function findDaily(array $queries = []): array
+    {
+        return $this->usage->findDaily($this->tenant, $queries);
+    }
+
+    /**
+     * @param array<\Utopia\Query\Query> $queries
+     * @throws \Exception
+     */
+    public function sumDaily(array $queries = [], string $attribute = 'value'): int
+    {
+        return $this->usage->sumDaily($this->tenant, $queries, $attribute);
+    }
+
+    /**
+     * @param array<string> $metrics
+     * @param array<\Utopia\Query\Query> $queries
+     * @return array<string, int>
+     * @throws \Exception
+     */
+    public function sumDailyBatch(array $metrics, array $queries = []): array
+    {
+        return $this->usage->sumDailyBatch($this->tenant, $metrics, $queries);
+    }
+}
diff --git a/src/Usage/Usage.php b/src/Usage/Usage.php
index 3097de1..7897158 100644
--- a/src/Usage/Usage.php
+++ b/src/Usage/Usage.php
@@ -17,31 +17,8 @@ class Usage
     public const TYPE_EVENT = 'event';
     public const TYPE_GAUGE = 'gauge';
 
-    private const DEFAULT_FLUSH_THRESHOLD = 10_000;
-    private const DEFAULT_FLUSH_INTERVAL = 20;
-
     private Adapter $adapter;
 
-    /**
-     * In-memory buffer for metrics.
-     * Keyed by "{metric}:{type}" — events are summed, gauges use last-write-wins.
-     *
-     * @var array<string, array{metric: string, value: int, type: string, tags: array<string, mixed>}>
-     */
-    private array $buffer = [];
-
-    /** @var int Number of collect() calls since last flush */
-    private int $bufferCount = 0;
-
-    /** @var int Flush when buffer reaches this many entries */
-    private int $flushThreshold = self::DEFAULT_FLUSH_THRESHOLD;
-
-    /** @var int Flush when this many seconds have elapsed since last flush */
-    private int $flushInterval = self::DEFAULT_FLUSH_INTERVAL;
-
-    /** @var float Timestamp of the last flush */
-    private float $lastFlushTime;
-
     /**
      * Constructor.
      *
@@ -50,7 +27,6 @@ class Usage
     public function __construct(Adapter $adapter)
     {
         $this->adapter = $adapter;
-        $this->lastFlushTime = microtime(true);
     }
 
     /**
@@ -87,7 +63,10 @@ public function setup(): void
      * Callers must explicitly pass the metric type so event and gauge
      * writes are never confused at the call site.
      *
-     * @param array<array{metric: string, value: int, tags?: array<string,mixed>}> $metrics
+     * Each metric carries its own `tenant` (shared-tables mode), so a single
+     * batch may span multiple tenants.
+     *
+     * @param array<array{tenant: string, metric: string, value: int, tags?: array<string,mixed>}> $metrics
      * @param string $type Metric type: 'event' or 'gauge'
      * @param int $batchSize Maximum number of metrics per INSERT statement
      * @return bool
@@ -101,6 +80,7 @@ public function addBatch(array $metrics, string $type, int $batchSize = 1000): b
     /**
      * Get time series data for metrics.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<string> $metrics List of metric names
      * @param string $interval '1h' or '1d'
      * @param string $startDate Start datetime
@@ -111,63 +91,67 @@ public function addBatch(array $metrics, string $type, int $batchSize = 1000): b
      * @return array<string, array{total: float, data: array<array{value: float, date: string}>}>
      * @throws \Exception
      */
-    public function getTimeSeries(array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
+    public function getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
     {
-        return $this->adapter->getTimeSeries($metrics, $interval, $startDate, $endDate, $queries, $zeroFill, $type);
+        return $this->adapter->getTimeSeries($tenant, $metrics, $interval, $startDate, $endDate, $queries, $zeroFill, $type);
     }
 
     /**
      * Get total value for a single metric.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param string $metric Metric name
      * @param array<\Utopia\Query\Query> $queries Additional filters
      * @param string|null $type Metric type: 'event', 'gauge', or null (query both)
      * @return int
      * @throws \Exception
      */
-    public function getTotal(string $metric, array $queries = [], ?string $type = null): int
+    public function getTotal(string $tenant, string $metric, array $queries = [], ?string $type = null): int
     {
-        return $this->adapter->getTotal($metric, $queries, $type);
+        return $this->adapter->getTotal($tenant, $metric, $queries, $type);
     }
 
     /**
      * Get totals for multiple metrics in a single query.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<string> $metrics List of metric names
      * @param array<\Utopia\Query\Query> $queries Additional filters
      * @param string|null $type Metric type: 'event', 'gauge', or null (query both)
      * @return array<string, int>
      * @throws \Exception
      */
-    public function getTotalBatch(array $metrics, array $queries = [], ?string $type = null): array
+    public function getTotalBatch(string $tenant, array $metrics, array $queries = [], ?string $type = null): array
     {
-        return $this->adapter->getTotalBatch($metrics, $queries, $type);
+        return $this->adapter->getTotalBatch($tenant, $metrics, $queries, $type);
     }
 
     /**
      * Purge usage metrics matching the given queries.
      * When no queries are provided, all metrics are deleted.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string|null $type Metric type: 'event', 'gauge', or null (purge both)
      * @throws \Exception
      */
-    public function purge(array $queries = [], ?string $type = null): bool
+    public function purge(string $tenant, array $queries = [], ?string $type = null): bool
     {
-        return $this->adapter->purge($queries, $type);
+        return $this->adapter->purge($tenant, $queries, $type);
     }
 
     /**
      * Find metrics using Query objects.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string|null $type Metric type: 'event', 'gauge', or null (query both)
      * @return array<Metric>
      * @throws \Exception
      */
-    public function find(array $queries = [], ?string $type = null): array
+    public function find(string $tenant, array $queries = [], ?string $type = null): array
     {
-        return $this->adapter->find($queries, $type);
+        return $this->adapter->find($tenant, $queries, $type);
     }
 
     /**
@@ -177,15 +161,16 @@ public function find(array $queries = [], ?string $type = null): array
      * Callers that only need a capped total (e.g. to render "5000+") should
      * pass $max so the adapter can short-circuit the count for large tables.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string|null $type Metric type: 'event', 'gauge', or null (count both)
      * @param int|null $max Optional upper bound for the count (inclusive)
      * @return int
      * @throws \Exception
      */
-    public function count(array $queries = [], ?string $type = null, ?int $max = null): int
+    public function count(string $tenant, array $queries = [], ?string $type = null, ?int $max = null): int
     {
-        return $this->adapter->count($queries, $type, $max);
+        return $this->adapter->count($tenant, $queries, $type, $max);
     }
 
     /**
@@ -196,19 +181,20 @@ public function count(array $queries = [], ?string $type = null, ?int $max = nul
      * than producing a useful total. Callers that truly want a gauge sum
      * must opt in explicitly.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string $attribute Attribute to sum (default: 'value')
      * @param string $type Metric type: 'event' or 'gauge'
      * @return int
      * @throws \Exception
      */
-    public function sum(array $queries = [], string $attribute = 'value', string $type = self::TYPE_EVENT): int
+    public function sum(string $tenant, array $queries = [], string $attribute = 'value', string $type = self::TYPE_EVENT): int
     {
         if ($type !== self::TYPE_EVENT && $type !== self::TYPE_GAUGE) {
             throw new \InvalidArgumentException("Invalid type '{$type}'. Allowed: " . self::TYPE_EVENT . ', ' . self::TYPE_GAUGE);
         }
 
-        return $this->adapter->sum($queries, $attribute, $type);
+        return $this->adapter->sum($tenant, $queries, $attribute, $type);
     }
 
     /**
@@ -219,13 +205,14 @@ public function sum(array $queries = [], string $attribute = 'value', string $ty
      * Note: Daily MV only stores event metrics. This method always queries
      * the daily events table — gauges are never pre-aggregated.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @return array<Metric>
      * @throws \Exception
      */
-    public function findDaily(array $queries = []): array
+    public function findDaily(string $tenant, array $queries = []): array
     {
-        return $this->adapter->findDaily($queries);
+        return $this->adapter->findDaily($tenant, $queries);
     }
 
     /**
@@ -237,14 +224,15 @@ public function findDaily(array $queries = []): array
      * Note: Daily MV only stores event metrics. This method always queries
      * the daily events table — gauges are never pre-aggregated.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<\Utopia\Query\Query> $queries
      * @param string $attribute Attribute to sum (default: 'value')
      * @return int
      * @throws \Exception
      */
-    public function sumDaily(array $queries = [], string $attribute = 'value'): int
+    public function sumDaily(string $tenant, array $queries = [], string $attribute = 'value'): int
     {
-        return $this->adapter->sumDaily($queries, $attribute);
+        return $this->adapter->sumDaily($tenant, $queries, $attribute);
     }
 
     /**
@@ -253,249 +241,14 @@ public function sumDaily(array $queries = [], string $attribute = 'value'): int
      * Note: Daily MV only stores event metrics. This method always queries
      * the daily events table — gauges are never pre-aggregated.
      *
+     * @param string $tenant Tenant scope (shared-tables mode)
      * @param array<string> $metrics List of metric names
      * @param array<\Utopia\Query\Query> $queries Additional filters (e.g. date range)
      * @return array<string, int> Metric name => sum value
      * @throws \Exception
      */
-    public function sumDailyBatch(array $metrics, array $queries = []): array
-    {
-        return $this->adapter->sumDailyBatch($metrics, $queries);
-    }
-
-    /**
-     * Set the tenant ID for multi-tenant support.
-     *
-     * Flushes the buffer first so any pending metrics are written under the
-     * previous tenant — buffered entries don't carry adapter context.
-     *
-     * @param string|null $tenant
-     * @return $this
-     * @throws \Exception
-     */
-    public function setTenant(?string $tenant): self
-    {
-        $this->flush();
-        if (method_exists($this->adapter, 'setTenant')) {
-            $this->adapter->setTenant($tenant);
-        }
-        return $this;
-    }
-
-    /**
-     * Collect a metric into the in-memory buffer for deferred flushing.
-     *
-     * For event type: multiple collect() calls for the same metric are summed.
-     * For gauge type: last-write-wins semantics.
-     * No period fan-out — raw timestamps are used.
-     *
-     * @param string $metric Metric name
-     * @param int $value Value
-     * @param string $type Metric type: 'event' or 'gauge'
-     * @param array<string,mixed> $tags Optional tags
-     * @return self
-     */
-    public function collect(string $metric, int $value, string $type, array $tags = []): self
-    {
-        if (empty($metric)) {
-            throw new \InvalidArgumentException('Metric name cannot be empty');
-        }
-        if ($value < 0) {
-            throw new \InvalidArgumentException('Value cannot be negative');
-        }
-        if ($type !== self::TYPE_EVENT && $type !== self::TYPE_GAUGE) {
-            throw new \InvalidArgumentException("Invalid metric type '{$type}'. Allowed: " . self::TYPE_EVENT . ', ' . self::TYPE_GAUGE);
-        }
-
-        $tagsHash = !empty($tags) ? md5(json_encode($tags, JSON_THROW_ON_ERROR)) : '';
-        $key = $metric . ':' . $type . ':' . $tagsHash;
-
-        if ($type === self::TYPE_EVENT) {
-            // Additive: sum values for the same metric + tags combination
-            if (isset($this->buffer[$key])) {
-                $this->buffer[$key]['value'] += $value;
-            } else {
-                $this->buffer[$key] = [
-                    'metric' => $metric,
-                    'value' => $value,
-                    'type' => $type,
-                    'tags' => $tags,
-                ];
-            }
-        } else {
-            // Gauge: last-write-wins
-            $this->buffer[$key] = [
-                'metric' => $metric,
-                'value' => $value,
-                'type' => $type,
-                'tags' => $tags,
-            ];
-        }
-
-        $this->bufferCount++;
-
-        return $this;
-    }
-
-    /**
-     * Flush the in-memory buffer to storage.
-     *
-     * Separates buffered metrics into events and gauges, then writes each batch
-     * to the appropriate table via addBatch(). Only entries whose batch write
-     * succeeds are removed from the buffer, so a partial failure preserves
-     * the unwritten metrics for retry on the next flush.
-     *
-     * If addBatch() throws mid-flush, any earlier successful batches have
-     * already been cleared from the buffer — the exception is allowed to
-     * propagate so the caller can observe the failure.
-     *
-     * @return bool True if all batches succeeded (or buffer was empty)
-     * @throws \Exception
-     */
-    public function flush(): bool
-    {
-        if (empty($this->buffer)) {
-            $this->lastFlushTime = microtime(true);
-            return true;
-        }
-
-        // Separate events and gauges; keep track of buffer keys so we can
-        // selectively unset only the entries whose write succeeded.
-        $eventKeys = [];
-        $gaugeKeys = [];
-        $events = [];
-        $gauges = [];
-
-        foreach ($this->buffer as $key => $entry) {
-            if ($entry['type'] === self::TYPE_EVENT) {
-                $events[] = $entry;
-                $eventKeys[] = $key;
-            } else {
-                $gauges[] = $entry;
-                $gaugeKeys[] = $key;
-            }
-        }
-
-        $overallResult = true;
-
-        // Flush events — clear buffer entries only on success.
-        if (!empty($events)) {
-            if ($this->adapter->addBatch($events, self::TYPE_EVENT)) {
-                foreach ($eventKeys as $key) {
-                    unset($this->buffer[$key]);
-                }
-            } else {
-                $overallResult = false;
-            }
-        }
-
-        // Flush gauges — clear buffer entries only on success.
-        if (!empty($gauges)) {
-            if ($this->adapter->addBatch($gauges, self::TYPE_GAUGE)) {
-                foreach ($gaugeKeys as $key) {
-                    unset($this->buffer[$key]);
-                }
-            } else {
-                $overallResult = false;
-            }
-        }
-
-        $this->bufferCount = count($this->buffer);
-        $this->lastFlushTime = microtime(true);
-
-        return $overallResult;
-    }
-
-    /**
-     * Check if the buffer should be flushed based on thresholds.
-     *
-     * Returns true if either:
-     * - The number of collect() calls meets the flush threshold
-     * - The time since last flush exceeds the flush interval
-     *
-     * @return bool
-     */
-    public function shouldFlush(): bool
-    {
-        if ($this->bufferCount >= $this->flushThreshold) {
-            return true;
-        }
-
-        $elapsed = microtime(true) - $this->lastFlushTime;
-        if ($elapsed >= $this->flushInterval) {
-            return true;
-        }
-
-        return false;
-    }
-
-    /**
-     * Get the number of collect() calls since the last flush.
-     *
-     * @return int
-     */
-    public function getBufferCount(): int
-    {
-        return $this->bufferCount;
-    }
-
-    /**
-     * Get the number of unique metric entries in the buffer.
-     *
-     * @return int
-     */
-    public function getBufferSize(): int
-    {
-        return count($this->buffer);
-    }
-
-    /**
-     * Set the flush threshold (number of collect() calls before flush is recommended).
-     *
-     * @param int $threshold Must be >= 1
-     * @return self
-     */
-    public function setFlushThreshold(int $threshold): self
-    {
-        if ($threshold < 1) {
-            throw new \InvalidArgumentException('Flush threshold must be at least 1');
-        }
-        $this->flushThreshold = $threshold;
-        return $this;
-    }
-
-    /**
-     * Set the flush interval in seconds.
-     *
-     * @param int $seconds Must be >= 1
-     * @return self
-     */
-    public function setFlushInterval(int $seconds): self
-    {
-        if ($seconds < 1) {
-            throw new \InvalidArgumentException('Flush interval must be at least 1 second');
-        }
-        $this->flushInterval = $seconds;
-        return $this;
-    }
-
-    /**
-     * Get the flush threshold.
-     *
-     * @return int
-     */
-    public function getFlushThreshold(): int
-    {
-        return $this->flushThreshold;
-    }
-
-    /**
-     * Get the flush interval in seconds.
-     *
-     * @return int
-     */
-    public function getFlushInterval(): int
+    public function sumDailyBatch(string $tenant, array $metrics, array $queries = []): array
     {
-        return $this->flushInterval;
+        return $this->adapter->sumDailyBatch($tenant, $metrics, $queries);
     }
 }
diff --git a/tests/Benchmark/BenchmarkBase.php b/tests/Benchmark/BenchmarkBase.php
index c86acce..5500431 100644
--- a/tests/Benchmark/BenchmarkBase.php
+++ b/tests/Benchmark/BenchmarkBase.php
@@ -65,7 +65,6 @@ protected function setUp(): void
             database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
             sharedTables: true,
         );
-        $this->adapter->setTenant($this->tenant);
 
         $this->usage = new Usage($this->adapter);
         $this->usage->setup();
@@ -171,7 +170,7 @@ protected function runRawSql(string $sql): void
      */
     protected function purgeAll(): void
     {
-        $this->usage->purge();
+        $this->usage->purge($this->tenant);
     }
 
     /**
diff --git a/tests/Benchmark/EventsBench.php b/tests/Benchmark/EventsBench.php
index 62c9dec..1e4c1e3 100644
--- a/tests/Benchmark/EventsBench.php
+++ b/tests/Benchmark/EventsBench.php
@@ -25,7 +25,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_sum_30d', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->sum([
+            $this->usage->sum($this->tenant, [
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start),
                 Query::lessThanEqual('time', $end),
@@ -34,7 +34,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_timeseries_30d_1h', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupByInterval('time', '1h'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start),
@@ -45,7 +45,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_count_max_5k', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->count([
+            $this->usage->count($this->tenant, [
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start),
                 Query::lessThanEqual('time', $end),
@@ -56,6 +56,7 @@ public function testBenchmarks(): void
             $batch = [];
             for ($i = 0; $i < 10000; $i++) {
                 $batch[] = [
+                    'tenant' => $this->tenant,
                     'metric' => 'bench.insert.10k',
                     'value' => $i,
                     'tags' => [
@@ -72,7 +73,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_topN_path_30d', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('path'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start),
@@ -83,7 +84,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_topN_country_30d', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('country'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start),
@@ -94,7 +95,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_topN_service_30d', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('service'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start),
@@ -107,7 +108,7 @@ public function testBenchmarks(): void
         $todayEnd = (new DateTime('+2 hour'))->format('Y-m-d H:i:s');
         $this->runBench('bench_events_topN_path_today_partial', function (string $queryId) use ($todayStart, $todayEnd): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('path'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $todayStart),
@@ -118,7 +119,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_topN_path_30d_filtered_resource', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('path'),
                 Query::equal('metric', [$this->metric]),
                 Query::equal('resource', ['function']),
@@ -130,7 +131,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_events_topN_path_country', function (string $queryId) use ($start, $end): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('path'),
                 UsageQuery::groupBy('country'),
                 Query::equal('metric', [$this->metric]),
@@ -144,6 +145,7 @@ public function testBenchmarks(): void
             $batch = [];
             for ($i = 0; $i < 10000; $i++) {
                 $batch[] = [
+                    'tenant' => $this->tenant,
                     'metric' => 'bench.insert.with_projections',
                     'value' => $i,
                     'tags' => [
diff --git a/tests/Benchmark/GaugesBench.php b/tests/Benchmark/GaugesBench.php
index 94cc4b0..f84eee2 100644
--- a/tests/Benchmark/GaugesBench.php
+++ b/tests/Benchmark/GaugesBench.php
@@ -28,6 +28,7 @@ public function testBenchmarks(): void
         $this->runBench('bench_gauges_latest_in_window', function (string $queryId) use ($start30d, $endPartial): void {
             $this->adapter->setNextQueryId($queryId);
             $this->usage->getTotal(
+                $this->tenant,
                 $this->metric,
                 [
                     Query::greaterThanEqual('time', $start30d),
@@ -39,7 +40,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_gauges_topN_service_30d', function (string $queryId) use ($start30d, $endClosed): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('service'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start30d),
@@ -50,7 +51,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_gauges_topN_resource_30d', function (string $queryId) use ($start30d, $endClosed): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('resource'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start30d),
@@ -61,7 +62,7 @@ public function testBenchmarks(): void
 
         $this->runBench('bench_gauges_topN_service_today_partial', function (string $queryId) use ($start30d, $endPartial): void {
             $this->adapter->setNextQueryId($queryId);
-            $this->usage->find([
+            $this->usage->find($this->tenant, [
                 UsageQuery::groupBy('service'),
                 Query::equal('metric', [$this->metric]),
                 Query::greaterThanEqual('time', $start30d),
diff --git a/tests/Usage/AccumulatorTest.php b/tests/Usage/AccumulatorTest.php
new file mode 100644
index 0000000..f63808a
--- /dev/null
+++ b/tests/Usage/AccumulatorTest.php
@@ -0,0 +1,290 @@
+<?php
+
+namespace Utopia\Tests\Usage;
+
+use PHPUnit\Framework\TestCase;
+use Utopia\Usage\Accumulator;
+use Utopia\Usage\Adapter;
+use Utopia\Usage\Usage;
+
+/**
+ * Records addBatch() calls so the Accumulator can be tested without a backend.
+ * addBatch() returns whatever $succeed is set to, letting tests drive the
+ * partial-failure path.
+ */
+class RecordingAdapter extends Adapter
+{
+    /** @var array<array{metrics: array<int, array<string, mixed>>, type: string}> */
+    public array $batches = [];
+
+    public bool $succeed = true;
+
+    public function getName(): string
+    {
+        return 'recording';
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function healthCheck(): array
+    {
+        return ['healthy' => true];
+    }
+
+    public function setup(): void
+    {
+    }
+
+    /**
+     * @param array<int, array<string, mixed>> $metrics
+     */
+    public function addBatch(array $metrics, string $type, int $batchSize = 1000): bool
+    {
+        if ($this->succeed) {
+            $this->batches[] = ['metrics' => $metrics, 'type' => $type];
+        }
+        return $this->succeed;
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
+    {
+        return [];
+    }
+
+    public function getTotal(string $tenant, string $metric, array $queries = [], ?string $type = null): int
+    {
+        return 0;
+    }
+
+    /**
+     * @return array<string, int>
+     */
+    public function getTotalBatch(string $tenant, array $metrics, array $queries = [], ?string $type = null): array
+    {
+        return [];
+    }
+
+    public function purge(string $tenant, array $queries = [], ?string $type = null): bool
+    {
+        return true;
+    }
+
+    /**
+     * @return array<mixed>
+     */
+    public function find(string $tenant, array $queries = [], ?string $type = null): array
+    {
+        return [];
+    }
+
+    public function count(string $tenant, array $queries = [], ?string $type = null, ?int $max = null): int
+    {
+        return 0;
+    }
+
+    public function sum(string $tenant, array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
+    {
+        return 0;
+    }
+
+    /**
+     * @return array<mixed>
+     */
+    public function findDaily(string $tenant, array $queries = []): array
+    {
+        return [];
+    }
+
+    public function sumDaily(string $tenant, array $queries = [], string $attribute = 'value'): int
+    {
+        return 0;
+    }
+
+    /**
+     * @return array<string, int>
+     */
+    public function sumDailyBatch(string $tenant, array $metrics, array $queries = []): array
+    {
+        return [];
+    }
+}
+
+class AccumulatorTest extends TestCase
+{
+    private RecordingAdapter $adapter;
+
+    private Accumulator $accumulator;
+
+    protected function setUp(): void
+    {
+        $this->adapter = new RecordingAdapter();
+        $this->accumulator = new Accumulator(new Usage($this->adapter));
+    }
+
+    public function testEventsSumByKey(): void
+    {
+        $this->accumulator->collect('t1', 'requests', 10, Usage::TYPE_EVENT);
+        $this->accumulator->collect('t1', 'requests', 20, Usage::TYPE_EVENT);
+        $this->accumulator->collect('t1', 'requests', 30, Usage::TYPE_EVENT);
+
+        // Same metric + tags = 1 entry, values summed
+        $this->assertEquals(1, $this->accumulator->count());
+
+        $this->assertTrue($this->accumulator->flush());
+
+        $this->assertCount(1, $this->adapter->batches);
+        $this->assertEquals(Usage::TYPE_EVENT, $this->adapter->batches[0]['type']);
+        $this->assertEquals(60, $this->adapter->batches[0]['metrics'][0]['value']);
+    }
+
+    public function testTagsPartitionEntries(): void
+    {
+        $this->accumulator->collect('t1', 'requests', 10, Usage::TYPE_EVENT, ['region' => 'us']);
+        $this->accumulator->collect('t1', 'requests', 20, Usage::TYPE_EVENT, ['region' => 'eu']);
+
+        // Distinct tags = distinct entries
+        $this->assertEquals(2, $this->accumulator->count());
+    }
+
+    public function testTenantPartitionsEntries(): void
+    {
+        // Same metric + tags but different tenants must not collapse
+        $this->accumulator->collect('t1', 'requests', 10, Usage::TYPE_EVENT);
+        $this->accumulator->collect('t2', 'requests', 20, Usage::TYPE_EVENT);
+
+        $this->assertEquals(2, $this->accumulator->count());
+
+        $this->assertTrue($this->accumulator->flush());
+
+        $tenants = array_column($this->adapter->batches[0]['metrics'], 'tenant');
+        sort($tenants);
+        $this->assertEquals(['t1', 't2'], $tenants);
+    }
+
+    public function testGaugesUseLastWriteWins(): void
+    {
+        $this->accumulator->collect('t1', 'storage', 100, Usage::TYPE_GAUGE);
+        $this->accumulator->collect('t1', 'storage', 200, Usage::TYPE_GAUGE);
+        $this->accumulator->collect('t1', 'storage', 300, Usage::TYPE_GAUGE);
+
+        $this->assertEquals(1, $this->accumulator->count());
+
+        $this->assertTrue($this->accumulator->flush());
+
+        $this->assertEquals(Usage::TYPE_GAUGE, $this->adapter->batches[0]['type']);
+        $this->assertEquals(300, $this->adapter->batches[0]['metrics'][0]['value']);
+    }
+
+    public function testFlushSeparatesEventsAndGauges(): void
+    {
+        $this->accumulator->collect('t1', 'requests', 10, Usage::TYPE_EVENT);
+        $this->accumulator->collect('t1', 'storage', 100, Usage::TYPE_GAUGE);
+
+        $this->assertTrue($this->accumulator->flush());
+
+        // One batch per type
+        $this->assertCount(2, $this->adapter->batches);
+        $types = [$this->adapter->batches[0]['type'], $this->adapter->batches[1]['type']];
+        $this->assertContains(Usage::TYPE_EVENT, $types);
+        $this->assertContains(Usage::TYPE_GAUGE, $types);
+
+        // Buffer cleared on success
+        $this->assertEquals(0, $this->accumulator->count());
+    }
+
+    public function testFailedFlushRetainsBuffer(): void
+    {
+        $this->accumulator->collect('t1', 'requests', 10, Usage::TYPE_EVENT);
+
+        $this->adapter->succeed = false;
+        $this->assertFalse($this->accumulator->flush());
+
+        // Nothing written, entry preserved for retry
+        $this->assertCount(0, $this->adapter->batches);
+        $this->assertEquals(1, $this->accumulator->count());
+
+        // A later successful flush drains the buffer
+        $this->adapter->succeed = true;
+        $this->assertTrue($this->accumulator->flush());
+        $this->assertEquals(0, $this->accumulator->count());
+    }
+
+    public function testFlushEmptyBuffer(): void
+    {
+        $this->assertTrue($this->accumulator->flush());
+        $this->assertCount(0, $this->adapter->batches);
+        $this->assertEquals(0, $this->accumulator->count());
+    }
+
+    public function testElapsedSignal(): void
+    {
+        $this->assertLessThan(1.0, $this->accumulator->elapsedSeconds());
+
+        sleep(1);
+
+        $this->assertGreaterThanOrEqual(1.0, $this->accumulator->elapsedSeconds());
+    }
+
+    public function testEmptyTenantThrows(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Tenant cannot be empty');
+        $this->accumulator->collect('', 'requests', 10, Usage::TYPE_EVENT);
+    }
+
+    public function testTenantZeroIsAccepted(): void
+    {
+        // "0" is a valid tenant id even though empty("0") is true in PHP
+        $this->accumulator->collect('0', 'requests', 10, Usage::TYPE_EVENT);
+
+        $this->assertEquals(1, $this->accumulator->count());
+
+        $this->assertTrue($this->accumulator->flush());
+        $this->assertEquals('0', $this->adapter->batches[0]['metrics'][0]['tenant']);
+    }
+
+    public function testEmptyMetricNameThrows(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Metric name cannot be empty');
+        $this->accumulator->collect('t1', '', 10, Usage::TYPE_EVENT);
+    }
+
+    public function testKeyDistinguishesAmbiguousTenantMetricSplits(): void
+    {
+        // tenant "a" + metric "b:c" must not collide with tenant "a:b" + metric "c"
+        $this->accumulator->collect('a', 'b:c', 10, Usage::TYPE_EVENT);
+        $this->accumulator->collect('a:b', 'c', 20, Usage::TYPE_EVENT);
+
+        $this->assertEquals(2, $this->accumulator->count());
+    }
+
+    public function testTagOrderDoesNotSplitEntries(): void
+    {
+        // Same logical tags in different insertion order must sum into one entry
+        $this->accumulator->collect('t1', 'requests', 10, Usage::TYPE_EVENT, ['teamId' => 't', 'resourceId' => 'r']);
+        $this->accumulator->collect('t1', 'requests', 20, Usage::TYPE_EVENT, ['resourceId' => 'r', 'teamId' => 't']);
+
+        $this->assertEquals(1, $this->accumulator->count());
+
+        $this->assertTrue($this->accumulator->flush());
+        $this->assertEquals(30, $this->adapter->batches[0]['metrics'][0]['value']);
+    }
+
+    public function testNegativeValueThrows(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Value cannot be negative');
+        $this->accumulator->collect('t1', 'requests', -1, Usage::TYPE_EVENT);
+    }
+
+    public function testInvalidTypeThrows(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->accumulator->collect('t1', 'requests', 10, 'invalid');
+    }
+}
diff --git a/tests/Usage/Adapter/ClickHouseDimRoutingTest.php b/tests/Usage/Adapter/ClickHouseDimRoutingTest.php
index 2f26f02..b3b6912 100644
--- a/tests/Usage/Adapter/ClickHouseDimRoutingTest.php
+++ b/tests/Usage/Adapter/ClickHouseDimRoutingTest.php
@@ -28,23 +28,32 @@ class ClickHouseDimRoutingTest extends ClickHouseTestCase
 
     protected function setUp(): void
     {
-        $this->adapter = $this->makeAdapter('utopia_usage_dim_routing');
+        $this->adapter = new ClickHouseAdapter(
+            getenv('CLICKHOUSE_HOST') ?: 'clickhouse',
+            getenv('CLICKHOUSE_USER') ?: 'default',
+            getenv('CLICKHOUSE_PASSWORD') ?: 'clickhouse',
+            (int) (getenv('CLICKHOUSE_PORT') ?: 8123),
+            (bool) (getenv('CLICKHOUSE_SECURE') ?: false),
+            namespace: 'utopia_usage_dim_routing',
+            database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
+            sharedTables: true,
+        );
         $this->usage = new Usage($this->adapter);
         $this->usage->setup();
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->seedHistoricalRow($this->metric, 10, '-5 days', ['path' => '/v1/a', 'method' => 'GET', 'status' => '200', 'service' => 'storage', 'country' => 'us']);
         $this->seedHistoricalRow($this->metric, 20, '-4 days', ['path' => '/v1/a', 'method' => 'GET', 'status' => '200', 'service' => 'storage', 'country' => 'us']);
         $this->seedHistoricalRow($this->metric, 30, '-3 days', ['path' => '/v1/b', 'method' => 'POST', 'status' => '201', 'service' => 'databases', 'country' => 'de']);
         $this->seedHistoricalRow($this->metric, 40, '-3 days', ['path' => '/v1/c', 'method' => 'POST', 'status' => '500', 'service' => 'functions', 'country' => 'fr']);
         $this->usage->addBatch([
-            ['metric' => $this->metric, 'value' => 5, 'tags' => ['path' => '/v1/a', 'method' => 'GET', 'status' => '200', 'service' => 'storage', 'country' => 'us']],
+            ['tenant' => '1', 'metric' => $this->metric, 'value' => 5, 'tags' => ['path' => '/v1/a', 'method' => 'GET', 'status' => '200', 'service' => 'storage', 'country' => 'us']],
         ], Usage::TYPE_EVENT);
     }
 
     protected function tearDown(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
     }
 
     /**
@@ -109,7 +118,7 @@ public function testTopNGroupedQueryRoutesToMatchingProjection(array $dims, stri
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $rolled = $this->usage->find($queries, Usage::TYPE_EVENT);
+        $rolled = $this->usage->find('1', $queries, Usage::TYPE_EVENT);
 
         $this->assertSame($this->rawTotal($start, $end), $this->totalOf($rolled));
         $this->assertProjectionUsed($queryId, $expectedProjection);
@@ -122,7 +131,7 @@ public function testMultiDimNotInAnyProjectionFallsBackToTable(): void
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupBy('path'),
             UsageQuery::groupBy('country'),
             Query::equal('metric', [$this->metric]),
@@ -143,7 +152,7 @@ public function testFilterOnExtraColumnStillRoutesToProjectionWhenColumnPresent(
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupBy('path'),
             Query::equal('metric', [$this->metric]),
             Query::equal('resource', ['function']),
@@ -165,7 +174,7 @@ public function testSubDayIntervalStillRoutesToProjection(): void
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             UsageQuery::groupBy('path'),
             Query::equal('metric', [$this->metric]),
@@ -183,7 +192,7 @@ public function testWindowStraddlesTodayStillRoutesToProjection(): void
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $rolled = $this->usage->find([
+        $rolled = $this->usage->find('1', [
             UsageQuery::groupBy('path'),
             Query::equal('metric', [$this->metric]),
             Query::greaterThanEqual('time', $start),
@@ -218,7 +227,7 @@ private function rawTotal(string $start, string $end): int
         $reflection = new ReflectionClass($this->adapter);
         $sumFromTable = $reflection->getMethod('sumFromTable');
         $sumFromTable->setAccessible(true);
-        $result = $sumFromTable->invoke($this->adapter, [
+        $result = $sumFromTable->invoke($this->adapter, '1', [
             Query::equal('metric', [$this->metric]),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
diff --git a/tests/Usage/Adapter/ClickHouseGaugeDimRoutingTest.php b/tests/Usage/Adapter/ClickHouseGaugeDimRoutingTest.php
index d3c7c01..562a81b 100644
--- a/tests/Usage/Adapter/ClickHouseGaugeDimRoutingTest.php
+++ b/tests/Usage/Adapter/ClickHouseGaugeDimRoutingTest.php
@@ -26,10 +26,19 @@ class ClickHouseGaugeDimRoutingTest extends ClickHouseTestCase
 
     protected function setUp(): void
     {
-        $this->adapter = $this->makeAdapter('utopia_usage_gauge_dim_routing');
+        $this->adapter = new ClickHouseAdapter(
+            getenv('CLICKHOUSE_HOST') ?: 'clickhouse',
+            getenv('CLICKHOUSE_USER') ?: 'default',
+            getenv('CLICKHOUSE_PASSWORD') ?: 'clickhouse',
+            (int) (getenv('CLICKHOUSE_PORT') ?: 8123),
+            (bool) (getenv('CLICKHOUSE_SECURE') ?: false),
+            namespace: 'utopia_usage_gauge_dim_routing',
+            database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
+            sharedTables: true,
+        );
         $this->usage = new Usage($this->adapter);
         $this->usage->setup();
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->seedHistoricalRow($this->metric, 100, '-5 days', ['service' => 'storage', 'resource' => 'file', 'resourceId' => 'f1']);
         $this->seedHistoricalRow($this->metric, 200, '-4 days', ['service' => 'storage', 'resource' => 'file', 'resourceId' => 'f2']);
@@ -37,13 +46,13 @@ protected function setUp(): void
         $this->seedHistoricalRow($this->metric, 80, '-3 days', ['service' => 'functions', 'resource' => 'function', 'resourceId' => 'fn1']);
 
         $this->usage->addBatch([
-            ['metric' => $this->metric, 'value' => 999, 'tags' => ['service' => 'storage', 'resource' => 'file', 'resourceId' => 'f1']],
+            ['tenant' => '1', 'metric' => $this->metric, 'value' => 999, 'tags' => ['service' => 'storage', 'resource' => 'file', 'resourceId' => 'f1']],
         ], Usage::TYPE_GAUGE);
     }
 
     protected function tearDown(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
     }
 
     /**
@@ -109,7 +118,7 @@ public function testTopGaugesGroupedQueryRoutesToMatchingProjection(array $dims,
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find($queries, Usage::TYPE_GAUGE);
+        $this->usage->find('1', $queries, Usage::TYPE_GAUGE);
 
         $this->assertProjectionUsed($queryId, $expectedProjection);
     }
@@ -123,7 +132,7 @@ public function testGaugesSubDayIntervalStillRoutesToProjection(): void
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             UsageQuery::groupBy('service'),
             Query::equal('metric', [$this->metric]),
@@ -141,7 +150,7 @@ public function testGaugesFilterOnNonProjectionColumnFallsBackToBaseTable(): voi
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupBy('service'),
             Query::equal('metric', [$this->metric]),
             Query::equal('resourceId', ['x']),
@@ -159,7 +168,7 @@ public function testGaugesUngroupedFallsBackToBaseTable(): void
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             Query::equal('metric', [$this->metric]),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -175,7 +184,7 @@ public function testGaugesWindowStraddlesTodayStillRoutesToProjection(): void
 
         $queryId = bin2hex(random_bytes(8));
         $this->adapter->setNextQueryId($queryId);
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupBy('service'),
             Query::equal('metric', [$this->metric]),
             Query::greaterThanEqual('time', $start),
diff --git a/tests/Usage/Adapter/ClickHouseRoutingTest.php b/tests/Usage/Adapter/ClickHouseRoutingTest.php
index 4a71e90..862eee4 100644
--- a/tests/Usage/Adapter/ClickHouseRoutingTest.php
+++ b/tests/Usage/Adapter/ClickHouseRoutingTest.php
@@ -20,21 +20,30 @@ class ClickHouseRoutingTest extends ClickHouseTestCase
 
     protected function setUp(): void
     {
-        $this->adapter = $this->makeAdapter('utopia_usage_routing');
+        $this->adapter = new ClickHouseAdapter(
+            getenv('CLICKHOUSE_HOST') ?: 'clickhouse',
+            getenv('CLICKHOUSE_USER') ?: 'default',
+            getenv('CLICKHOUSE_PASSWORD') ?: 'clickhouse',
+            (int) (getenv('CLICKHOUSE_PORT') ?: 8123),
+            (bool) (getenv('CLICKHOUSE_SECURE') ?: false),
+            namespace: 'utopia_usage_routing',
+            database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
+            sharedTables: true,
+        );
         $this->usage = new Usage($this->adapter);
         $this->usage->setup();
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->seedHistoricalRow('routed.metric', 100, '-5 days', ['path' => '/v1/a']);
         $this->seedHistoricalRow('routed.metric', 200, '-3 days', ['path' => '/v1/b']);
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'routed.metric', 'value' => 50, 'tags' => ['path' => '/v1/c']],
+            ['tenant' => '1', 'metric' => 'routed.metric', 'value' => 50, 'tags' => ['path' => '/v1/c']],
         ], Usage::TYPE_EVENT));
     }
 
     protected function tearDown(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
     }
 
     /**
@@ -74,7 +83,7 @@ public function testClosedDayWindowRoutesToDaily(): void
 
         $rawSum = $this->sumRaw('routed.metric', $start, $end);
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -97,7 +106,7 @@ public function testInclusiveMidnightUpperBoundExcludesEndDayOnDailyRoute(): voi
 
         $rawSum = $this->sumRaw('routed.metric', $start, $end);
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -121,7 +130,7 @@ public function testMidDayClosedWindowFallsBackToRaw(): void
         $start = (new DateTime('-7 days 12:30:00', new DateTimeZone('UTC')))->format('Y-m-d H:i:s');
         $end = (new DateTime('-2 days 12:30:00', new DateTimeZone('UTC')))->format('Y-m-d H:i:s');
 
-        $this->usage->sum([
+        $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -141,7 +150,7 @@ public function testWindowStraddlesTodayRoutesHybrid(): void
 
         $rawSum = $this->sumRaw('routed.metric', $start, $end);
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -162,7 +171,7 @@ public function testHybridSumKeepsParamsDistinctWhenMetricFollowsTimeBounds(): v
 
         $rawSum = $this->sumRaw('routed.metric', $start, $end);
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
             Query::equal('metric', ['routed.metric']),
@@ -181,7 +190,7 @@ public function testDimensionPresentForcesRaw(): void
         $start = (new DateTime('-7 days'))->format('Y-m-d H:i:s');
         $end = (new DateTime('-2 days'))->format('Y-m-d H:i:s');
 
-        $this->usage->sum([
+        $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::equal('path', ['/v1/a']),
             Query::greaterThanEqual('time', $start),
@@ -200,7 +209,7 @@ public function testFilterOnNonDailyColumnForcesRaw(): void
         $start = (new DateTime('-7 days'))->format('Y-m-d H:i:s');
         $end = (new DateTime('-2 days'))->format('Y-m-d H:i:s');
 
-        $this->usage->sum([
+        $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::equal('country', ['us']),
             Query::greaterThanEqual('time', $start),
@@ -222,7 +231,7 @@ public function testMidDayStartWithHybridWindowFallsBackToRaw(): void
         $start = (new DateTime('-2 days 14:00:00', new DateTimeZone('UTC')))->format('Y-m-d H:i:s');
         $end = (new DateTime('+1 hour', new DateTimeZone('UTC')))->format('Y-m-d H:i:s');
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', [$metric]),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -241,7 +250,7 @@ public function testIntervalPresentForcesRaw(): void
         $start = (new DateTime('-7 days'))->format('Y-m-d H:i:s');
         $end = (new DateTime('-2 days'))->format('Y-m-d H:i:s');
 
-        $this->usage->sum([
+        $this->usage->sum('1', [
             UsageQuery::groupByInterval('time', '1h'),
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
@@ -262,7 +271,7 @@ public function testDuplicateTimeFiltersTakeTightestBound(): void
         $endLoose = (new DateTime('+5 days', new DateTimeZone('UTC')))->setTime(0, 0, 0)->format('Y-m-d H:i:s');
         $endTighter = (new DateTime('-1 day', new DateTimeZone('UTC')))->setTime(0, 0, 0)->format('Y-m-d H:i:s');
 
-        $this->usage->sum([
+        $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
             Query::greaterThanEqual('time', $startTighter),
@@ -283,7 +292,7 @@ public function testOpenEndedWindowForcesRaw(): void
 
         $start = (new DateTime('-7 days'))->format('Y-m-d H:i:s');
 
-        $this->usage->sum([
+        $this->usage->sum('1', [
             Query::equal('metric', ['routed.metric']),
             Query::greaterThanEqual('time', $start),
         ], 'value', Usage::TYPE_EVENT);
@@ -298,7 +307,7 @@ public function testMalformedTimeStringForcesRaw(): void
         $this->adapter->clearRouteLog();
 
         try {
-            $this->usage->sum([
+            $this->usage->sum('1', [
                 Query::equal('metric', ['routed.metric']),
                 Query::greaterThanEqual('time', 'not-a-date'),
                 Query::lessThanEqual('time', 'not-a-date-either'),
@@ -321,7 +330,7 @@ public function testMalformedTimeStringForcesRaw(): void
      */
     public function testNarrowPurgeWithNoTimeBoundDoesNotWipeDailyMv(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         // Seed two metrics on two different days; let the daily MV
         // capture both as fully closed-day rows.
@@ -335,12 +344,12 @@ public function testNarrowPurgeWithNoTimeBoundDoesNotWipeDailyMv(): void
         // bound. The raw delete narrows on path; the daily side has
         // no path column so the legacy logic would fall through to
         // DELETE WHERE 1=1 and wipe both metrics' daily rows.
-        $this->usage->purge([
+        $this->usage->purge('1', [
             Query::equal('path', ['/v1/remove']),
         ], Usage::TYPE_EVENT);
 
         $this->adapter->clearRouteLog();
-        $keepSum = $this->usage->sum([
+        $keepSum = $this->usage->sum('1', [
             Query::equal('metric', ['purge.keep']),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -358,7 +367,7 @@ public function testNarrowPurgeWithNoTimeBoundDoesNotWipeDailyMv(): void
      */
     public function testValueFilterPurgeDoesNotMatchAggregateDailyRows(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         // Seed two raw rows whose values sum to 10 on the same day,
         // so the daily MV row has value = 10. A naive purge with
@@ -369,14 +378,14 @@ public function testValueFilterPurgeDoesNotMatchAggregateDailyRows(): void
         $start = (new DateTime('-7 days', new DateTimeZone('UTC')))->setTime(0, 0, 0)->format('Y-m-d H:i:s');
         $end = (new DateTime('-1 day', new DateTimeZone('UTC')))->setTime(0, 0, 0)->format('Y-m-d H:i:s');
 
-        $this->usage->purge([
+        $this->usage->purge('1', [
             Query::equal('value', [10]),
         ], Usage::TYPE_EVENT);
 
         // value is raw-only, so the routed sum stays on raw — it
         // sees the still-present rows. The point of this test is the
         // daily MV; check it directly via sumDaily.
-        $dailySum = $this->usage->sumDaily([
+        $dailySum = $this->usage->sumDaily('1', [
             Query::equal('metric', ['purge.value']),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -390,7 +399,7 @@ private function sumRaw(string $metric, string $start, string $end): int
         $reflection = new ReflectionClass($this->adapter);
         $sumFromTable = $reflection->getMethod('sumFromTable');
         $sumFromTable->setAccessible(true);
-        $result = $sumFromTable->invoke($this->adapter, [
+        $result = $sumFromTable->invoke($this->adapter, '1', [
             Query::equal('metric', [$metric]),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
diff --git a/tests/Usage/Adapter/ClickHouseSchemaTest.php b/tests/Usage/Adapter/ClickHouseSchemaTest.php
index 50049b6..37c9e84 100644
--- a/tests/Usage/Adapter/ClickHouseSchemaTest.php
+++ b/tests/Usage/Adapter/ClickHouseSchemaTest.php
@@ -17,7 +17,16 @@ class ClickHouseSchemaTest extends ClickHouseTestCase
 
     protected function setUp(): void
     {
-        $this->adapter = $this->makeAdapter('utopia_usage_schema');
+        $this->adapter = new ClickHouseAdapter(
+            getenv('CLICKHOUSE_HOST') ?: 'clickhouse',
+            getenv('CLICKHOUSE_USER') ?: 'default',
+            getenv('CLICKHOUSE_PASSWORD') ?: 'clickhouse',
+            (int) (getenv('CLICKHOUSE_PORT') ?: 8123),
+            (bool) (getenv('CLICKHOUSE_SECURE') ?: false),
+            namespace: 'utopia_usage_schema',
+            database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
+            sharedTables: true,
+        );
         $usage = new Usage($this->adapter);
         $usage->setup();
     }
@@ -102,7 +111,16 @@ public function testGaugesTableSwapsBloomForSetOnLowCardinality(): void
 
     public function testSetupBackfillsServiceResourceOnLegacyGaugesTable(): void
     {
-        $legacyAdapter = $this->makeAdapter('utopia_usage_schema_legacy_gauge');
+        $legacyAdapter = new ClickHouseAdapter(
+            getenv('CLICKHOUSE_HOST') ?: 'clickhouse',
+            getenv('CLICKHOUSE_USER') ?: 'default',
+            getenv('CLICKHOUSE_PASSWORD') ?: 'clickhouse',
+            (int) (getenv('CLICKHOUSE_PORT') ?: 8123),
+            (bool) (getenv('CLICKHOUSE_SECURE') ?: false),
+            namespace: 'utopia_usage_schema_legacy_gauge',
+            database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
+            sharedTables: true,
+        );
         $database = $this->databaseName($legacyAdapter);
         $gaugesTable = $this->resolveTableName($legacyAdapter, 'getGaugesTableName');
         $fullName = "`{$database}`.`{$gaugesTable}`";
diff --git a/tests/Usage/Adapter/ClickHouseTest.php b/tests/Usage/Adapter/ClickHouseTest.php
index 28b2abb..aa7e031 100644
--- a/tests/Usage/Adapter/ClickHouseTest.php
+++ b/tests/Usage/Adapter/ClickHouseTest.php
@@ -31,13 +31,12 @@ protected function initializeUsage(): void
             namespace: 'utopia_usage',
             database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
         );
-        $adapter->setTenant('1');
 
         $this->usage = new Usage($adapter);
         $this->usage->setup();
     }
 
-    public function testMetricTenantOverridesAdapterTenantInBatch(): void
+    public function testPerMetricTenantInBatch(): void
     {
         $host = getenv('CLICKHOUSE_HOST') ?: 'clickhouse';
         $username = getenv('CLICKHOUSE_USER') ?: 'default';
@@ -55,34 +54,36 @@ public function testMetricTenantOverridesAdapterTenantInBatch(): void
             database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
             sharedTables: true,
         );
-        $adapter->setTenant('1');
 
         $usage = new Usage($adapter);
         $usage->setup();
-        $usage->purge();
+        $usage->purge('2');
 
+        // The metric carries its own tenant; the batch writes it under tenant '2'.
         $metrics = [
             [
+                'tenant' => '2',
                 'metric' => 'tenant-override',
                 'value' => 5,
-                '$tenant' => '2',
                 'tags' => [],
             ],
         ];
 
         $this->assertTrue($usage->addBatch($metrics, Usage::TYPE_EVENT));
 
-        // Switch adapter scope to the metric tenant to verify the row was stored under the override
-        $adapter->setTenant('2');
-
-        $results = $usage->find([
+        // Reading under tenant '2' returns the row; tenant '1' must not see it.
+        $results = $usage->find('2', [
             \Utopia\Query\Query::equal('metric', ['tenant-override']),
         ], Usage::TYPE_EVENT);
 
         $this->assertCount(1, $results);
         $this->assertEquals('2', $results[0]->getTenant());
 
-        $usage->purge();
+        $this->assertCount(0, $usage->find('1', [
+            \Utopia\Query\Query::equal('metric', ['tenant-override']),
+        ], Usage::TYPE_EVENT));
+
+        $usage->purge('2');
     }
 
     /**
@@ -91,17 +92,17 @@ public function testMetricTenantOverridesAdapterTenantInBatch(): void
     public function testAddBatchWithBatchSize(): void
     {
         $metrics = [
-            ['metric' => 'metric-1', 'value' => 10, 'tags' => []],
-            ['metric' => 'metric-2', 'value' => 20, 'tags' => []],
-            ['metric' => 'metric-3', 'value' => 30, 'tags' => []],
-            ['metric' => 'metric-4', 'value' => 40, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'metric-1', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'metric-2', 'value' => 20, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'metric-3', 'value' => 30, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'metric-4', 'value' => 40, 'tags' => []],
         ];
 
         // Process with batch size of 2
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT, 2));
 
         // Verify all metrics were inserted
-        $results = $this->usage->find([], Usage::TYPE_EVENT);
+        $results = $this->usage->find('1', [], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(4, count($results));
     }
 
@@ -111,16 +112,16 @@ public function testAddBatchWithBatchSize(): void
     public function testAddBatchGaugeWithBatchSize(): void
     {
         $metrics = [
-            ['metric' => 'counter-1', 'value' => 100, 'tags' => []],
-            ['metric' => 'counter-2', 'value' => 200, 'tags' => []],
-            ['metric' => 'counter-3', 'value' => 300, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'counter-1', 'value' => 100, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'counter-2', 'value' => 200, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'counter-3', 'value' => 300, 'tags' => []],
         ];
 
         // Process with batch size of 2
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_GAUGE, 2));
 
         // Verify gauge metrics were inserted
-        $results = $this->usage->find([], Usage::TYPE_GAUGE);
+        $results = $this->usage->find('1', [], Usage::TYPE_GAUGE);
         $this->assertGreaterThanOrEqual(3, count($results));
     }
 
@@ -132,6 +133,7 @@ public function testLargeBatchWithSmallBatchSize(): void
         $metrics = [];
         for ($i = 0; $i < 100; $i++) {
             $metrics[] = [
+                'tenant' => '1',
                 'metric' => 'large-batch-metric',
                 'value' => $i,
                 'tags' => ['resourceId' => (string) $i],
@@ -141,7 +143,7 @@ public function testLargeBatchWithSmallBatchSize(): void
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT, 10));
 
         // Verify metrics were processed
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['large-batch-metric']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
@@ -152,18 +154,18 @@ public function testLargeBatchWithSmallBatchSize(): void
      */
     public function testGaugeMetricsLastValueWins(): void
     {
-        $this->usage->purge([], Usage::TYPE_GAUGE);
+        $this->usage->purge('1', [], Usage::TYPE_GAUGE);
 
         $metrics = [
-            ['metric' => 'gauge-test', 'value' => 5, 'tags' => []],
-            ['metric' => 'gauge-test', 'value' => 10, 'tags' => []],
-            ['metric' => 'gauge-test', 'value' => 15, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gauge-test', 'value' => 5, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gauge-test', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gauge-test', 'value' => 15, 'tags' => []],
         ];
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_GAUGE));
 
         // Gauge total returns argMax (latest value)
-        $total = $this->usage->getTotal('gauge-test', [], Usage::TYPE_GAUGE);
+        $total = $this->usage->getTotal('1', 'gauge-test', [], Usage::TYPE_GAUGE);
         $this->assertGreaterThanOrEqual(5, $total);
     }
 
@@ -172,18 +174,18 @@ public function testGaugeMetricsLastValueWins(): void
      */
     public function testEventMetricsAggregate(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
 
         $metrics = [
-            ['metric' => 'agg-test', 'value' => 5, 'tags' => []],
-            ['metric' => 'agg-test', 'value' => 10, 'tags' => []],
-            ['metric' => 'agg-test', 'value' => 15, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'agg-test', 'value' => 5, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'agg-test', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'agg-test', 'value' => 15, 'tags' => []],
         ];
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT));
 
         // Event metrics should sum: 5 + 10 + 15 = 30
-        $total = $this->usage->getTotal('agg-test', [], Usage::TYPE_EVENT);
+        $total = $this->usage->getTotal('1', 'agg-test', [], Usage::TYPE_EVENT);
         $this->assertEquals(30, $total);
     }
 
@@ -201,14 +203,14 @@ public function testEmptyBatchClickHouse(): void
     public function testBatchWithTagsClickHouse(): void
     {
         $metrics = [
-            ['metric' => 'tagged', 'value' => 10, 'tags' => ['region' => 'us-east', 'path' => '/v1/test', 'method' => 'GET', 'status' => '200']],
-            ['metric' => 'tagged', 'value' => 20, 'tags' => ['region' => 'us-west', 'path' => '/v1/test', 'method' => 'POST', 'status' => '201']],
-            ['metric' => 'tagged', 'value' => 15, 'tags' => ['region' => 'eu-west', 'path' => '/v1/test', 'method' => 'GET', 'status' => '200']],
+            ['tenant' => '1', 'metric' => 'tagged', 'value' => 10, 'tags' => ['region' => 'us-east', 'path' => '/v1/test', 'method' => 'GET', 'status' => '200']],
+            ['tenant' => '1', 'metric' => 'tagged', 'value' => 20, 'tags' => ['region' => 'us-west', 'path' => '/v1/test', 'method' => 'POST', 'status' => '201']],
+            ['tenant' => '1', 'metric' => 'tagged', 'value' => 15, 'tags' => ['region' => 'eu-west', 'path' => '/v1/test', 'method' => 'GET', 'status' => '200']],
         ];
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['tagged']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
@@ -221,10 +223,11 @@ public function testBatchWithTagsClickHouse(): void
      */
     public function testEventColumnsExtractedFromTags(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
 
         $metrics = [
             [
+                'tenant' => '1',
                 'metric' => 'event-cols-test',
                 'value' => 42,
                 'tags' => [
@@ -258,7 +261,7 @@ public function testEventColumnsExtractedFromTags(): void
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['event-cols-test']),
         ], Usage::TYPE_EVENT);
 
@@ -297,10 +300,11 @@ public function testEventColumnsExtractedFromTags(): void
      */
     public function testGaugeColumnsRoundTrip(): void
     {
-        $this->usage->purge([], Usage::TYPE_GAUGE);
+        $this->usage->purge('1', [], Usage::TYPE_GAUGE);
 
         $this->assertTrue($this->usage->addBatch([
             [
+                'tenant' => '1',
                 'metric' => 'gauge-cols-test',
                 'value' => 500,
                 'tags' => [
@@ -314,7 +318,7 @@ public function testGaugeColumnsRoundTrip(): void
             ],
         ], Usage::TYPE_GAUGE));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['gauge-cols-test']),
         ], Usage::TYPE_GAUGE);
 
@@ -333,18 +337,18 @@ public function testUnknownTagKeyThrows(): void
         $this->expectException(\Exception::class);
         $this->expectExceptionMessageMatches("/Unknown column 'bogus'/");
         $this->usage->addBatch([
-            ['metric' => 'x', 'value' => 1, 'tags' => ['bogus' => 'v']],
+            ['tenant' => '1', 'metric' => 'x', 'value' => 1, 'tags' => ['bogus' => 'v']],
         ], Usage::TYPE_EVENT);
     }
 
     public function testCountryLowercased(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'lc-country', 'value' => 1, 'tags' => ['country' => 'US']],
+            ['tenant' => '1', 'metric' => 'lc-country', 'value' => 1, 'tags' => ['country' => 'US']],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['lc-country']),
         ], Usage::TYPE_EVENT);
 
@@ -354,12 +358,12 @@ public function testCountryLowercased(): void
 
     public function testRegionLowercased(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'lc-region', 'value' => 1, 'tags' => ['region' => 'FR']],
+            ['tenant' => '1', 'metric' => 'lc-region', 'value' => 1, 'tags' => ['region' => 'FR']],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['lc-region']),
         ], Usage::TYPE_EVENT);
 
@@ -369,12 +373,12 @@ public function testRegionLowercased(): void
 
     public function testEmptyStringCoercedToNull(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'empty-string', 'value' => 1, 'tags' => ['osName' => '']],
+            ['tenant' => '1', 'metric' => 'empty-string', 'value' => 1, 'tags' => ['osName' => '']],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['empty-string']),
         ], Usage::TYPE_EVENT);
 
@@ -388,7 +392,7 @@ public function testEmptyStringCoercedToNull(): void
      */
     public function testEventsSchemaPersistsAllNewColumns(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
 
         $tags = [
             'path' => '/v1/x', 'method' => 'GET', 'status' => '200',
@@ -405,14 +409,14 @@ public function testEventsSchemaPersistsAllNewColumns(): void
         ];
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'schema-roundtrip', 'value' => 1, 'tags' => $tags],
+            ['tenant' => '1', 'metric' => 'schema-roundtrip', 'value' => 1, 'tags' => $tags],
         ], Usage::TYPE_EVENT));
 
         // Filtering on each indexed dimension should be schema-valid.
         foreach (['service', 'resourceInternalId', 'teamId', 'teamInternalId', 'region', 'hostname', 'osName', 'clientName', 'deviceName'] as $col) {
             $value = $tags[$col];
             $expected = $col === 'region' ? strtolower($value) : $value;
-            $rows = $this->usage->find([
+            $rows = $this->usage->find('1', [
                 \Utopia\Query\Query::equal('metric', ['schema-roundtrip']),
                 \Utopia\Query\Query::equal($col, [$expected]),
             ], Usage::TYPE_EVENT);
@@ -425,42 +429,42 @@ public function testEventsSchemaPersistsAllNewColumns(): void
      */
     public function testQueryEventsByColumns(): void
     {
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'req', 'value' => 10, 'tags' => ['path' => '/v1/storage', 'method' => 'GET', 'status' => '200', 'resource' => 'project', 'resourceId' => 'p1']],
-            ['metric' => 'req', 'value' => 20, 'tags' => ['path' => '/v1/databases', 'method' => 'POST', 'status' => '201', 'resource' => 'database', 'resourceId' => 'db1']],
-            ['metric' => 'req', 'value' => 30, 'tags' => ['path' => '/v1/storage', 'method' => 'GET', 'status' => '404', 'resource' => 'project', 'resourceId' => 'p1']],
+            ['tenant' => '1', 'metric' => 'req', 'value' => 10, 'tags' => ['path' => '/v1/storage', 'method' => 'GET', 'status' => '200', 'resource' => 'project', 'resourceId' => 'p1']],
+            ['tenant' => '1', 'metric' => 'req', 'value' => 20, 'tags' => ['path' => '/v1/databases', 'method' => 'POST', 'status' => '201', 'resource' => 'database', 'resourceId' => 'db1']],
+            ['tenant' => '1', 'metric' => 'req', 'value' => 30, 'tags' => ['path' => '/v1/storage', 'method' => 'GET', 'status' => '404', 'resource' => 'project', 'resourceId' => 'p1']],
         ], Usage::TYPE_EVENT));
 
         // Filter by path
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('path', ['/v1/storage']),
         ], Usage::TYPE_EVENT);
         $this->assertCount(2, $results);
 
         // Filter by method
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('method', ['POST']),
         ], Usage::TYPE_EVENT);
         $this->assertCount(1, $results);
         $this->assertEquals(20, $results[0]->getValue());
 
         // Filter by status
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('status', ['404']),
         ], Usage::TYPE_EVENT);
         $this->assertCount(1, $results);
         $this->assertEquals(30, $results[0]->getValue());
 
         // Filter by resource
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('resource', ['database']),
         ], Usage::TYPE_EVENT);
         $this->assertCount(1, $results);
 
         // Filter by resourceId
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('resourceId', ['db1']),
         ], Usage::TYPE_EVENT);
         $this->assertCount(1, $results);
@@ -471,13 +475,13 @@ public function testQueryEventsByColumns(): void
      */
     public function testGaugeTableSimpleSchema(): void
     {
-        $this->usage->purge([], Usage::TYPE_GAUGE);
+        $this->usage->purge('1', [], Usage::TYPE_GAUGE);
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gauge-simple', 'value' => 500, 'tags' => ['resourceId' => 'r1']],
+            ['tenant' => '1', 'metric' => 'gauge-simple', 'value' => 500, 'tags' => ['resourceId' => 'r1']],
         ], Usage::TYPE_GAUGE));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['gauge-simple']),
         ], Usage::TYPE_GAUGE);
 
@@ -498,18 +502,18 @@ public function testGaugeTableSimpleSchema(): void
      */
     public function testFindBothTables(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'both-test-event', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'both-test-event', 'value' => 10, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'both-test-gauge', 'value' => 100, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'both-test-gauge', 'value' => 100, 'tags' => []],
         ], Usage::TYPE_GAUGE));
 
         // Find from both tables
-        $results = $this->usage->find([], null);
+        $results = $this->usage->find('1', [], null);
         $this->assertGreaterThanOrEqual(2, count($results));
 
         $metricNames = array_map(fn ($m) => $m->getMetric(), $results);
@@ -525,6 +529,7 @@ public function testBatchSizeAtMaximum(): void
         $metrics = [];
         for ($i = 0; $i < 500; $i++) {
             $metrics[] = [
+                'tenant' => '1',
                 'metric' => 'boundary-test',
                 'value' => 1,
                 'tags' => [],
@@ -533,7 +538,7 @@ public function testBatchSizeAtMaximum(): void
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT, 1000));
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             \Utopia\Query\Query::equal('metric', ['boundary-test']),
         ], 'value', Usage::TYPE_EVENT);
         $this->assertEquals(500, $sum);
@@ -545,15 +550,15 @@ public function testBatchSizeAtMaximum(): void
     public function testBatchSizeOfOne(): void
     {
         $metrics = [
-            ['metric' => 'size-one-1', 'value' => 10, 'tags' => []],
-            ['metric' => 'size-one-2', 'value' => 20, 'tags' => []],
-            ['metric' => 'size-one-3', 'value' => 30, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'size-one-1', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'size-one-2', 'value' => 20, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'size-one-3', 'value' => 30, 'tags' => []],
         ];
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT, 1));
 
         // All metrics should be inserted
-        $results = $this->usage->find([], Usage::TYPE_EVENT);
+        $results = $this->usage->find('1', [], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(3, count($results));
     }
 
@@ -565,6 +570,7 @@ public function testDefaultBatchSize(): void
         $metrics = [];
         for ($i = 0; $i < 50; $i++) {
             $metrics[] = [
+                'tenant' => '1',
                 'metric' => 'default-batch-test',
                 'value' => 1,
                 'tags' => [],
@@ -574,7 +580,7 @@ public function testDefaultBatchSize(): void
         // Use default batch size
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT));
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             \Utopia\Query\Query::equal('metric', ['default-batch-test']),
         ], 'value', Usage::TYPE_EVENT);
         $this->assertEquals(50, $sum);
@@ -587,10 +593,10 @@ public function testMetricsWithSpecialCharacters(): void
     {
         $specialVal = "Text with \n newline, \t tab, \"quote\", and unicode \u{1F600}";
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'special-metric', 'value' => 1, 'tags' => ['hostname' => $specialVal]],
+            ['tenant' => '1', 'metric' => 'special-metric', 'value' => 1, 'tags' => ['hostname' => $specialVal]],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['special-metric']),
         ], Usage::TYPE_EVENT);
 
@@ -605,31 +611,31 @@ public function testMetricsWithSpecialCharacters(): void
     public function testFindComprehensive(): void
     {
         // Cleanup
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         // Setup test data
         $this->usage->addBatch([
-            ['metric' => 'metric-A', 'value' => 10, 'tags' => ['service' => 'cat1']],
+            ['tenant' => '1', 'metric' => 'metric-A', 'value' => 10, 'tags' => ['service' => 'cat1']],
         ], Usage::TYPE_EVENT);
         $this->usage->addBatch([
-            ['metric' => 'metric-B', 'value' => 20, 'tags' => ['service' => 'cat2']],
+            ['tenant' => '1', 'metric' => 'metric-B', 'value' => 20, 'tags' => ['service' => 'cat2']],
         ], Usage::TYPE_EVENT);
 
         // 1. Array Equal (IN)
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['metric-A', 'metric-B']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(2, count($results));
 
         // 2. Scalar Equal
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('value', [20]),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
         $this->assertEquals(20, $results[0]->getValue());
 
         // 3. Less Than
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::lessThan('value', 20),
             \Utopia\Query\Query::equal('metric', ['metric-A']),
         ], Usage::TYPE_EVENT);
@@ -637,7 +643,7 @@ public function testFindComprehensive(): void
         $this->assertEquals(10, $results[0]->getValue());
 
         // 4. Greater Than
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::greaterThan('value', 10),
             \Utopia\Query\Query::equal('metric', ['metric-B']),
         ], Usage::TYPE_EVENT);
@@ -645,20 +651,20 @@ public function testFindComprehensive(): void
         $this->assertEquals(20, $results[0]->getValue());
 
         // 5. Between
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::between('value', 5, 25),
             \Utopia\Query\Query::equal('metric', ['metric-A', 'metric-B']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(2, count($results));
 
         // 6. Contains (IN alias)
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::contains('metric', ['metric-A']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
 
         // 7. Order Desc
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['metric-A', 'metric-B']),
             \Utopia\Query\Query::orderDesc('value'),
             \Utopia\Query\Query::limit(2),
@@ -667,7 +673,7 @@ public function testFindComprehensive(): void
         $this->assertTrue($results[0]->getValue() >= $results[1]->getValue());
 
         // 8. Order Asc
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['metric-A', 'metric-B']),
             \Utopia\Query\Query::orderAsc('value'),
             \Utopia\Query\Query::limit(2),
@@ -756,7 +762,6 @@ public function testConnectionPooling(): void
             namespace: 'utopia_usage_pooling_test',
             database: getenv('CLICKHOUSE_DATABASE') ?: 'default',
         );
-        $adapter->setTenant('1');
 
         $usage = new Usage($adapter);
         $usage->setup();
@@ -771,10 +776,10 @@ public function testConnectionPooling(): void
 
         // Make some requests
         $usage->addBatch([
-            ['metric' => 'pooling.test', 'value' => 100, 'tags' => ['service' => 'value']],
+            ['tenant' => '1', 'metric' => 'pooling.test', 'value' => 100, 'tags' => ['service' => 'value']],
         ], Usage::TYPE_EVENT);
-        $usage->find([], Usage::TYPE_EVENT);
-        $usage->count([], Usage::TYPE_EVENT);
+        $usage->find('1', [], Usage::TYPE_EVENT);
+        $usage->count('1', [], Usage::TYPE_EVENT);
 
         // Verify request count increased
         $newStats = $adapter->getConnectionStats();
@@ -802,13 +807,12 @@ public function testErrorMessagesIncludeContext(): void
             namespace: 'utopia_usage_error_test',
             database: 'nonexistent_db_for_testing_errors_12345',
         );
-        $adapter->setTenant('1');
 
         $usage = new Usage($adapter);
 
         try {
             // This should fail because database doesn't exist
-            $usage->find([], Usage::TYPE_EVENT);
+            $usage->find('1', [], Usage::TYPE_EVENT);
             $this->fail('Expected exception was not thrown');
         } catch (\Exception $e) {
             $errorMessage = $e->getMessage();
@@ -849,7 +853,6 @@ public function testAsyncInsertConfiguration(): void
 
         // Async inserts enabled, waiting for confirmation.
         $adapter = $makeAdapter(true, true);
-        $adapter->setTenant('1');
 
         $stats = $adapter->getConnectionStats();
         $this->assertTrue($stats['async_inserts']);
@@ -858,13 +861,13 @@ public function testAsyncInsertConfiguration(): void
         // Verify it works with async inserts enabled
         $usage = new Usage($adapter);
         $usage->setup();
-        $usage->purge();
+        $usage->purge('1');
 
         $this->assertTrue($usage->addBatch([
-            ['metric' => 'async-test', 'value' => 42, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'async-test', 'value' => 42, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
-        $total = $usage->getTotal('async-test', [], Usage::TYPE_EVENT);
+        $total = $usage->getTotal('1', 'async-test', [], Usage::TYPE_EVENT);
         $this->assertEquals(42, $total);
 
         // Fire-and-forget mode: async on, no wait for confirmation.
@@ -876,22 +879,22 @@ public function testAsyncInsertConfiguration(): void
         $stats = $makeAdapter(false, true)->getConnectionStats();
         $this->assertFalse($stats['async_inserts']);
 
-        $usage->purge();
+        $usage->purge('1');
     }
 
     public function testCursorAfterPaginatesEvents(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'cursor-events', 'value' => 1, 'tags' => []],
-            ['metric' => 'cursor-events', 'value' => 2, 'tags' => []],
-            ['metric' => 'cursor-events', 'value' => 3, 'tags' => []],
-            ['metric' => 'cursor-events', 'value' => 4, 'tags' => []],
-            ['metric' => 'cursor-events', 'value' => 5, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-events', 'value' => 1, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-events', 'value' => 2, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-events', 'value' => 3, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-events', 'value' => 4, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-events', 'value' => 5, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
-        $page1 = $this->usage->find([
+        $page1 = $this->usage->find('1', [
             Query::equal('metric', ['cursor-events']),
             Query::orderAsc('id'),
             Query::limit(2),
@@ -901,7 +904,7 @@ public function testCursorAfterPaginatesEvents(): void
 
         $cursor = $page1[count($page1) - 1];
 
-        $page2 = $this->usage->find([
+        $page2 = $this->usage->find('1', [
             Query::equal('metric', ['cursor-events']),
             Query::orderAsc('id'),
             Query::limit(2),
@@ -915,16 +918,16 @@ public function testCursorAfterPaginatesEvents(): void
 
     public function testCursorBeforeReversesPagination(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'cursor-before', 'value' => 1, 'tags' => []],
-            ['metric' => 'cursor-before', 'value' => 2, 'tags' => []],
-            ['metric' => 'cursor-before', 'value' => 3, 'tags' => []],
-            ['metric' => 'cursor-before', 'value' => 4, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-before', 'value' => 1, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-before', 'value' => 2, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-before', 'value' => 3, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-before', 'value' => 4, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
-        $all = $this->usage->find([
+        $all = $this->usage->find('1', [
             Query::equal('metric', ['cursor-before']),
             Query::orderAsc('id'),
             Query::limit(10),
@@ -932,7 +935,7 @@ public function testCursorBeforeReversesPagination(): void
 
         $this->assertCount(4, $all);
 
-        $before = $this->usage->find([
+        $before = $this->usage->find('1', [
             Query::equal('metric', ['cursor-before']),
             Query::orderAsc('id'),
             Query::limit(2),
@@ -946,21 +949,21 @@ public function testCursorBeforeReversesPagination(): void
 
     public function testCursorAcceptsAssociativeArray(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'cursor-array', 'value' => 1, 'tags' => []],
-            ['metric' => 'cursor-array', 'value' => 2, 'tags' => []],
-            ['metric' => 'cursor-array', 'value' => 3, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-array', 'value' => 1, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-array', 'value' => 2, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'cursor-array', 'value' => 3, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
-        $all = $this->usage->find([
+        $all = $this->usage->find('1', [
             Query::equal('metric', ['cursor-array']),
             Query::orderAsc('id'),
             Query::limit(10),
         ], Usage::TYPE_EVENT);
 
-        $page = $this->usage->find([
+        $page = $this->usage->find('1', [
             Query::equal('metric', ['cursor-array']),
             Query::orderAsc('id'),
             Query::limit(10),
@@ -975,7 +978,7 @@ public function testCursorWithoutTypeThrows(): void
     {
         $this->expectException(\Exception::class);
 
-        $this->usage->find([
+        $this->usage->find('1', [
             Query::cursorAfter(['id' => 'whatever']),
         ]);
     }
@@ -987,7 +990,7 @@ public function testCursorWithGroupByIntervalThrows(): void
         $start = (new \DateTime())->modify('-1 hour')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->modify('+1 hour')->format('Y-m-d\TH:i:s');
 
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
@@ -997,18 +1000,18 @@ public function testCursorWithGroupByIntervalThrows(): void
 
     public function testGroupByServiceDailyAggregates(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gb-service', 'value' => 10, 'tags' => ['service' => 'storage']],
-            ['metric' => 'gb-service', 'value' => 25, 'tags' => ['service' => 'storage']],
-            ['metric' => 'gb-service', 'value' => 5, 'tags' => ['service' => 'databases']],
+            ['tenant' => '1', 'metric' => 'gb-service', 'value' => 10, 'tags' => ['service' => 'storage']],
+            ['tenant' => '1', 'metric' => 'gb-service', 'value' => 25, 'tags' => ['service' => 'storage']],
+            ['tenant' => '1', 'metric' => 'gb-service', 'value' => 5, 'tags' => ['service' => 'databases']],
         ], Usage::TYPE_EVENT));
 
         $start = (new \DateTime())->modify('-1 day')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->modify('+1 day')->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1d'),
             UsageQuery::groupBy('service'),
             Query::equal('metric', ['gb-service']),
@@ -1031,19 +1034,19 @@ public function testGroupByServiceDailyAggregates(): void
 
     public function testGroupByMultipleDimensionsHourly(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gb-multi', 'value' => 1, 'tags' => ['service' => 'storage', 'path' => '/v1/a']],
-            ['metric' => 'gb-multi', 'value' => 2, 'tags' => ['service' => 'storage', 'path' => '/v1/a']],
-            ['metric' => 'gb-multi', 'value' => 4, 'tags' => ['service' => 'storage', 'path' => '/v1/b']],
-            ['metric' => 'gb-multi', 'value' => 8, 'tags' => ['service' => 'databases', 'path' => '/v1/a']],
+            ['tenant' => '1', 'metric' => 'gb-multi', 'value' => 1, 'tags' => ['service' => 'storage', 'path' => '/v1/a']],
+            ['tenant' => '1', 'metric' => 'gb-multi', 'value' => 2, 'tags' => ['service' => 'storage', 'path' => '/v1/a']],
+            ['tenant' => '1', 'metric' => 'gb-multi', 'value' => 4, 'tags' => ['service' => 'storage', 'path' => '/v1/b']],
+            ['tenant' => '1', 'metric' => 'gb-multi', 'value' => 8, 'tags' => ['service' => 'databases', 'path' => '/v1/a']],
         ], Usage::TYPE_EVENT));
 
         $start = (new \DateTime())->modify('-1 hour')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->modify('+1 hour')->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             UsageQuery::groupBy('service'),
             UsageQuery::groupBy('path'),
@@ -1071,7 +1074,7 @@ public function testGroupByMultipleDimensionsHourly(): void
     public function testNotEqualQuery(): void
     {
         // Fixture: requests x2, bandwidth x1 in events
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::notEqual('metric', 'requests'),
         ], Usage::TYPE_EVENT);
         // bandwidth row only
@@ -1083,7 +1086,7 @@ public function testNotEqualQuery(): void
 
     public function testNotContainsQuery(): void
     {
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::notContains('metric', ['requests', 'bandwidth']),
         ], Usage::TYPE_EVENT);
         $this->assertCount(0, $results);
@@ -1094,7 +1097,7 @@ public function testNotBetweenQuery(): void
         $past = (new \DateTime())->modify('-2 hour')->format('Y-m-d H:i:s');
         $oldPast = (new \DateTime())->modify('-3 hour')->format('Y-m-d H:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::notBetween('time', $oldPast, $past),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(3, count($results));
@@ -1104,13 +1107,13 @@ public function testIsNullAndIsNotNullQueries(): void
     {
         // 'country' is a nullable column; fixture rows have no country tag set
         // so depending on how addBatch persists tags, country may be null or empty.
-        $isNotNull = $this->usage->find([
+        $isNotNull = $this->usage->find('1', [
             Query::isNotNull('metric'),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(3, count($isNotNull));
 
         // metric is required so isNull returns nothing
-        $isNull = $this->usage->find([
+        $isNull = $this->usage->find('1', [
             Query::isNull('metric'),
         ], Usage::TYPE_EVENT);
         $this->assertCount(0, $isNull);
@@ -1119,12 +1122,12 @@ public function testIsNullAndIsNotNullQueries(): void
     public function testStartsWithAndEndsWithQueries(): void
     {
         // Fixture: paths /v1/storage, /v1/databases, /v1/storage/files
-        $startsWith = $this->usage->find([
+        $startsWith = $this->usage->find('1', [
             Query::startsWith('path', '/v1/'),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(3, count($startsWith));
 
-        $endsWith = $this->usage->find([
+        $endsWith = $this->usage->find('1', [
             Query::endsWith('path', '/files'),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($endsWith));
@@ -1140,7 +1143,7 @@ public function testContainsRejectsEmptyValues(): void
         $this->expectException(\Exception::class);
         $this->expectExceptionMessage('Contains queries require at least one value.');
 
-        $this->usage->find([
+        $this->usage->find('1', [
             Query::contains('metric', []),
         ], Usage::TYPE_EVENT);
     }
@@ -1150,7 +1153,7 @@ public function testNotContainsRejectsEmptyValues(): void
         $this->expectException(\Exception::class);
         $this->expectExceptionMessage('NotContains queries require at least one value.');
 
-        $this->usage->find([
+        $this->usage->find('1', [
             Query::notContains('metric', []),
         ], Usage::TYPE_EVENT);
     }
@@ -1160,7 +1163,7 @@ public function testEqualRejectsEmptyValues(): void
         $this->expectException(\Exception::class);
         $this->expectExceptionMessage('Equal queries require at least one value.');
 
-        $this->usage->find([
+        $this->usage->find('1', [
             new Query(Query::TYPE_EQUAL, 'metric', []),
         ], Usage::TYPE_EVENT);
     }
diff --git a/tests/Usage/Adapter/ClickHouseTestCase.php b/tests/Usage/Adapter/ClickHouseTestCase.php
index b9c2df0..24d9ed4 100644
--- a/tests/Usage/Adapter/ClickHouseTestCase.php
+++ b/tests/Usage/Adapter/ClickHouseTestCase.php
@@ -9,43 +9,12 @@
 /**
  * Shared base for ClickHouse adapter integration tests.
  *
- * Centralizes the env-driven adapter wiring and a handful of reflection
- * helpers that every test in this directory needs (database name lookup,
- * private query() / table-name resolver invocation).
+ * Holds only the reflection helpers that need access to private adapter
+ * internals (database name lookup, private query() / table-name resolver).
+ * Adapter construction is intentionally inlined in each test for clarity.
  */
 abstract class ClickHouseTestCase extends TestCase
 {
-    /**
-     * Build a ClickHouse adapter from the standard test env variables.
-     * Subclasses override namespace and tenant to keep test data isolated.
-     */
-    protected function makeAdapter(string $namespace, ?string $tenant = '1'): ClickHouseAdapter
-    {
-        $host = getenv('CLICKHOUSE_HOST') ?: 'clickhouse';
-        $username = getenv('CLICKHOUSE_USER') ?: 'default';
-        $password = getenv('CLICKHOUSE_PASSWORD') ?: 'clickhouse';
-        $port = (int) (getenv('CLICKHOUSE_PORT') ?: 8123);
-        $secure = (bool) (getenv('CLICKHOUSE_SECURE') ?: false);
-
-        $database = getenv('CLICKHOUSE_DATABASE') ?: 'default';
-
-        $adapter = new ClickHouseAdapter(
-            $host,
-            $username,
-            $password,
-            $port,
-            $secure,
-            namespace: $namespace,
-            database: $database,
-            sharedTables: true,
-        );
-        if ($tenant !== null) {
-            $adapter->setTenant($tenant);
-        }
-
-        return $adapter;
-    }
-
     /**
      * Read the adapter's `database` property (private).
      */
diff --git a/tests/Usage/Adapter/DatabaseTest.php b/tests/Usage/Adapter/DatabaseTest.php
index 2d142f8..5c0ee1e 100644
--- a/tests/Usage/Adapter/DatabaseTest.php
+++ b/tests/Usage/Adapter/DatabaseTest.php
@@ -64,10 +64,11 @@ public function testEventColumnsExtractedFromTags(): void
             $this->markTestSkipped('pdo_mysql extension is not installed');
         }
 
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
 
         $this->assertTrue($this->usage->addBatch([
             [
+                'tenant' => '1',
                 'metric' => 'event-cols-db',
                 'value' => 42,
                 'tags' => [
@@ -90,7 +91,7 @@ public function testEventColumnsExtractedFromTags(): void
             ],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['event-cols-db']),
         ], Usage::TYPE_EVENT);
 
@@ -118,10 +119,11 @@ public function testGaugeColumnsRoundTrip(): void
             $this->markTestSkipped('pdo_mysql extension is not installed');
         }
 
-        $this->usage->purge([], Usage::TYPE_GAUGE);
+        $this->usage->purge('1', [], Usage::TYPE_GAUGE);
 
         $this->assertTrue($this->usage->addBatch([
             [
+                'tenant' => '1',
                 'metric' => 'gauge-cols-db',
                 'value' => 500,
                 'tags' => [
@@ -133,7 +135,7 @@ public function testGaugeColumnsRoundTrip(): void
             ],
         ], Usage::TYPE_GAUGE));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['gauge-cols-db']),
         ], Usage::TYPE_GAUGE);
 
@@ -154,7 +156,7 @@ public function testUnknownTagKeyThrows(): void
         $this->expectException(\Exception::class);
         $this->expectExceptionMessageMatches("/Unknown column 'bogus'/");
         $this->usage->addBatch([
-            ['metric' => 'x', 'value' => 1, 'tags' => ['bogus' => 'v']],
+            ['tenant' => '1', 'metric' => 'x', 'value' => 1, 'tags' => ['bogus' => 'v']],
         ], Usage::TYPE_EVENT);
     }
 
@@ -164,12 +166,12 @@ public function testCountryAndRegionLowercased(): void
             $this->markTestSkipped('pdo_mysql extension is not installed');
         }
 
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'lc-db', 'value' => 1, 'tags' => ['country' => 'US', 'region' => 'FR']],
+            ['tenant' => '1', 'metric' => 'lc-db', 'value' => 1, 'tags' => ['country' => 'US', 'region' => 'FR']],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['lc-db']),
         ], Usage::TYPE_EVENT);
 
@@ -184,12 +186,12 @@ public function testEmptyStringCoercedToNull(): void
             $this->markTestSkipped('pdo_mysql extension is not installed');
         }
 
-        $this->usage->purge([], Usage::TYPE_EVENT);
+        $this->usage->purge('1', [], Usage::TYPE_EVENT);
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'empty-db', 'value' => 1, 'tags' => ['osName' => '']],
+            ['tenant' => '1', 'metric' => 'empty-db', 'value' => 1, 'tags' => ['osName' => '']],
         ], Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             \Utopia\Query\Query::equal('metric', ['empty-db']),
         ], Usage::TYPE_EVENT);
 
diff --git a/tests/Usage/TenantTest.php b/tests/Usage/TenantTest.php
new file mode 100644
index 0000000..4f813cd
--- /dev/null
+++ b/tests/Usage/TenantTest.php
@@ -0,0 +1,212 @@
+<?php
+
+namespace Utopia\Tests\Usage;
+
+use PHPUnit\Framework\TestCase;
+use Utopia\Usage\Adapter;
+use Utopia\Usage\Tenant;
+use Utopia\Usage\Usage;
+
+/**
+ * Records the tenant passed to each method so the Tenant decorator can be
+ * tested without a backend.
+ */
+class TenantRecordingAdapter extends Adapter
+{
+    public ?string $lastTenant = null;
+
+    /** @var array<int, array<string, mixed>> */
+    public array $lastMetrics = [];
+
+    public function getName(): string
+    {
+        return 'tenant-recording';
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function healthCheck(): array
+    {
+        return ['healthy' => true];
+    }
+
+    public function setup(): void
+    {
+    }
+
+    /**
+     * @param array<int, array<string, mixed>> $metrics
+     */
+    public function addBatch(array $metrics, string $type, int $batchSize = 1000): bool
+    {
+        $this->lastMetrics = $metrics;
+        return true;
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function getTimeSeries(string $tenant, array $metrics, string $interval, string $startDate, string $endDate, array $queries = [], bool $zeroFill = true, ?string $type = null): array
+    {
+        $this->lastTenant = $tenant;
+        return [];
+    }
+
+    public function getTotal(string $tenant, string $metric, array $queries = [], ?string $type = null): int
+    {
+        $this->lastTenant = $tenant;
+        return 0;
+    }
+
+    /**
+     * @return array<string, int>
+     */
+    public function getTotalBatch(string $tenant, array $metrics, array $queries = [], ?string $type = null): array
+    {
+        $this->lastTenant = $tenant;
+        return [];
+    }
+
+    public function purge(string $tenant, array $queries = [], ?string $type = null): bool
+    {
+        $this->lastTenant = $tenant;
+        return true;
+    }
+
+    /**
+     * @return array<mixed>
+     */
+    public function find(string $tenant, array $queries = [], ?string $type = null): array
+    {
+        $this->lastTenant = $tenant;
+        return [];
+    }
+
+    public function count(string $tenant, array $queries = [], ?string $type = null, ?int $max = null): int
+    {
+        $this->lastTenant = $tenant;
+        return 0;
+    }
+
+    public function sum(string $tenant, array $queries = [], string $attribute = 'value', string $type = Usage::TYPE_EVENT): int
+    {
+        $this->lastTenant = $tenant;
+        return 0;
+    }
+
+    /**
+     * @return array<mixed>
+     */
+    public function findDaily(string $tenant, array $queries = []): array
+    {
+        $this->lastTenant = $tenant;
+        return [];
+    }
+
+    public function sumDaily(string $tenant, array $queries = [], string $attribute = 'value'): int
+    {
+        $this->lastTenant = $tenant;
+        return 0;
+    }
+
+    /**
+     * @return array<string, int>
+     */
+    public function sumDailyBatch(string $tenant, array $metrics, array $queries = []): array
+    {
+        $this->lastTenant = $tenant;
+        return [];
+    }
+}
+
+class TenantTest extends TestCase
+{
+    private TenantRecordingAdapter $adapter;
+
+    private Tenant $tenant;
+
+    protected function setUp(): void
+    {
+        $this->adapter = new TenantRecordingAdapter();
+        $this->tenant = new Tenant(new Usage($this->adapter), 'p1');
+    }
+
+    public function testEmptyTenantThrows(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Tenant cannot be empty');
+        new Tenant(new Usage($this->adapter), '');
+    }
+
+    public function testAddBatchStampsBoundTenantOntoEveryMetric(): void
+    {
+        $this->tenant->addBatch([
+            ['metric' => 'requests', 'value' => 10, 'tags' => []],
+            ['metric' => 'bandwidth', 'value' => 20, 'tags' => []],
+        ], Usage::TYPE_EVENT);
+
+        $this->assertEquals('p1', $this->adapter->lastMetrics[0]['tenant']);
+        $this->assertEquals('p1', $this->adapter->lastMetrics[1]['tenant']);
+    }
+
+    public function testFindForwardsBoundTenant(): void
+    {
+        $this->tenant->find([], Usage::TYPE_EVENT);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testCountForwardsBoundTenant(): void
+    {
+        $this->tenant->count([], Usage::TYPE_EVENT);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testSumForwardsBoundTenant(): void
+    {
+        $this->tenant->sum([], 'value', Usage::TYPE_EVENT);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testGetTotalForwardsBoundTenant(): void
+    {
+        $this->tenant->getTotal('requests', [], Usage::TYPE_EVENT);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testGetTotalBatchForwardsBoundTenant(): void
+    {
+        $this->tenant->getTotalBatch(['requests'], [], Usage::TYPE_EVENT);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testGetTimeSeriesForwardsBoundTenant(): void
+    {
+        $this->tenant->getTimeSeries(['requests'], '1h', '2026-01-01 00:00:00', '2026-01-02 00:00:00');
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testPurgeForwardsBoundTenant(): void
+    {
+        $this->tenant->purge([], Usage::TYPE_EVENT);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testFindDailyForwardsBoundTenant(): void
+    {
+        $this->tenant->findDaily([]);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testSumDailyForwardsBoundTenant(): void
+    {
+        $this->tenant->sumDaily([]);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+
+    public function testSumDailyBatchForwardsBoundTenant(): void
+    {
+        $this->tenant->sumDailyBatch(['requests'], []);
+        $this->assertEquals('p1', $this->adapter->lastTenant);
+    }
+}
diff --git a/tests/Usage/UsageBase.php b/tests/Usage/UsageBase.php
index 1dcbd3f..a104b7e 100644
--- a/tests/Usage/UsageBase.php
+++ b/tests/Usage/UsageBase.php
@@ -20,35 +20,35 @@ public function setUp(): void
 
     public function tearDown(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
     }
 
     public function createUsageMetrics(): void
     {
         // Events: additive metrics
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'requests', 'value' => 100, 'tags' => ['region' => 'us-east', 'path' => '/v1/storage', 'method' => 'GET', 'status' => '200', 'resource' => 'project', 'resourceId' => 'p1']],
-            ['metric' => 'requests', 'value' => 150, 'tags' => ['region' => 'us-west', 'path' => '/v1/databases', 'method' => 'POST', 'status' => '201', 'resource' => 'database', 'resourceId' => 'db1']],
-            ['metric' => 'bandwidth', 'value' => 5000, 'tags' => ['region' => 'us-east', 'path' => '/v1/storage/files', 'method' => 'POST', 'status' => '201', 'resource' => 'bucket', 'resourceId' => 'b1']],
+            ['tenant' => '1', 'metric' => 'requests', 'value' => 100, 'tags' => ['region' => 'us-east', 'path' => '/v1/storage', 'method' => 'GET', 'status' => '200', 'resource' => 'project', 'resourceId' => 'p1']],
+            ['tenant' => '1', 'metric' => 'requests', 'value' => 150, 'tags' => ['region' => 'us-west', 'path' => '/v1/databases', 'method' => 'POST', 'status' => '201', 'resource' => 'database', 'resourceId' => 'db1']],
+            ['tenant' => '1', 'metric' => 'bandwidth', 'value' => 5000, 'tags' => ['region' => 'us-east', 'path' => '/v1/storage/files', 'method' => 'POST', 'status' => '201', 'resource' => 'bucket', 'resourceId' => 'b1']],
         ], Usage::TYPE_EVENT));
 
         // Gauges: point-in-time snapshots
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'storage', 'value' => 10000, 'tags' => ['resourceId' => 'p1']],
+            ['tenant' => '1', 'metric' => 'storage', 'value' => 10000, 'tags' => ['resourceId' => 'p1']],
         ], Usage::TYPE_GAUGE));
     }
 
     public function testAddBatchEvent(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         // addBatch with event type -- values should sum
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'add-metric', 'value' => 10, 'tags' => []],
-            ['metric' => 'add-metric', 'value' => 5, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'add-metric', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'add-metric', 'value' => 5, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['add-metric']),
         ], 'value', Usage::TYPE_EVENT);
         $this->assertEquals(15, $sum);
@@ -56,32 +56,32 @@ public function testAddBatchEvent(): void
 
     public function testAddBatchGauge(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         // addBatch with gauge type
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gauge-metric', 'value' => 100, 'tags' => []],
-            ['metric' => 'gauge-metric', 'value' => 200, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gauge-metric', 'value' => 100, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gauge-metric', 'value' => 200, 'tags' => []],
         ], Usage::TYPE_GAUGE));
 
         // getTotal for gauge returns latest value (argMax)
-        $total = $this->usage->getTotal('gauge-metric', [], Usage::TYPE_GAUGE);
+        $total = $this->usage->getTotal('1', 'gauge-metric', [], Usage::TYPE_GAUGE);
         $this->assertGreaterThanOrEqual(100, $total);
     }
 
     public function testAddBatchWithBatchSize(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $metrics = [
-            ['metric' => 'batch-requests', 'value' => 100, 'tags' => ['region' => 'eu-west']],
-            ['metric' => 'batch-requests', 'value' => 150, 'tags' => ['region' => 'eu-east']],
-            ['metric' => 'batch-bandwidth', 'value' => 3000, 'tags' => ['region' => 'eu-west']],
+            ['tenant' => '1', 'metric' => 'batch-requests', 'value' => 100, 'tags' => ['region' => 'eu-west']],
+            ['tenant' => '1', 'metric' => 'batch-requests', 'value' => 150, 'tags' => ['region' => 'eu-east']],
+            ['tenant' => '1', 'metric' => 'batch-bandwidth', 'value' => 3000, 'tags' => ['region' => 'eu-west']],
         ];
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT, 2));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::equal('metric', ['batch-requests']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
@@ -89,7 +89,7 @@ public function testAddBatchWithBatchSize(): void
 
     public function testFind(): void
     {
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::equal('metric', ['requests']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
@@ -100,7 +100,7 @@ public function testFindWithTimeRange(): void
         $start = (new \DateTime())->modify('-1 hour')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::greaterThanEqual('time', $start),
             Query::lessThanEqual('time', $end),
         ], Usage::TYPE_EVENT);
@@ -109,7 +109,7 @@ public function testFindWithTimeRange(): void
 
     public function testCount(): void
     {
-        $count = $this->usage->count([
+        $count = $this->usage->count('1', [
             Query::equal('metric', ['requests']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, $count);
@@ -117,7 +117,7 @@ public function testCount(): void
 
     public function testSum(): void
     {
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['requests']),
         ], 'value', Usage::TYPE_EVENT);
         $this->assertEquals(250, $sum); // 100 + 150
@@ -125,17 +125,17 @@ public function testSum(): void
 
     public function testGetTotal(): void
     {
-        $total = $this->usage->getTotal('requests', [], Usage::TYPE_EVENT);
+        $total = $this->usage->getTotal('1', 'requests', [], Usage::TYPE_EVENT);
         $this->assertEquals(250, $total); // event: SUM
 
-        $total = $this->usage->getTotal('storage', [], Usage::TYPE_GAUGE);
+        $total = $this->usage->getTotal('1', 'storage', [], Usage::TYPE_GAUGE);
         $this->assertEquals(10000, $total); // gauge: argMax (latest)
     }
 
     public function testGetTotalBatch(): void
     {
         // Event metrics batch
-        $totals = $this->usage->getTotalBatch(['requests', 'bandwidth'], [], Usage::TYPE_EVENT);
+        $totals = $this->usage->getTotalBatch('1', ['requests', 'bandwidth'], [], Usage::TYPE_EVENT);
 
         $this->assertArrayHasKey('requests', $totals);
         $this->assertArrayHasKey('bandwidth', $totals);
@@ -144,13 +144,13 @@ public function testGetTotalBatch(): void
         $this->assertEquals(5000, $totals['bandwidth']);
 
         // Gauge metrics batch
-        $gaugeTotals = $this->usage->getTotalBatch(['storage'], [], Usage::TYPE_GAUGE);
+        $gaugeTotals = $this->usage->getTotalBatch('1', ['storage'], [], Usage::TYPE_GAUGE);
         $this->assertEquals(10000, $gaugeTotals['storage']);
     }
 
     public function testGetTotalBatchWithMissingMetric(): void
     {
-        $totals = $this->usage->getTotalBatch(['requests', 'nonexistent-metric'], [], Usage::TYPE_EVENT);
+        $totals = $this->usage->getTotalBatch('1', ['requests', 'nonexistent-metric'], [], Usage::TYPE_EVENT);
 
         $this->assertEquals(250, $totals['requests']);
         $this->assertEquals(0, $totals['nonexistent-metric']);
@@ -158,7 +158,7 @@ public function testGetTotalBatchWithMissingMetric(): void
 
     public function testGetTotalBatchEmpty(): void
     {
-        $totals = $this->usage->getTotalBatch([]);
+        $totals = $this->usage->getTotalBatch('1', []);
         $this->assertEmpty($totals);
     }
 
@@ -168,6 +168,7 @@ public function testGetTimeSeries(): void
         $end = (new \DateTime())->modify('+1 hour')->format('Y-m-d H:i:s');
 
         $results = $this->usage->getTimeSeries(
+            '1',
             ['requests'],
             '1h',
             $start,
@@ -189,6 +190,7 @@ public function testGetTimeSeriesMultipleMetrics(): void
         $end = (new \DateTime())->modify('+1 day')->format('Y-m-d H:i:s');
 
         $results = $this->usage->getTimeSeries(
+            '1',
             ['requests', 'bandwidth'],
             '1d',
             $start,
@@ -205,7 +207,7 @@ public function testGetTimeSeriesMultipleMetrics(): void
     public function testEqualWithArrayValues(): void
     {
         // Test equal query with array of values (IN clause)
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::equal('metric', ['requests', 'bandwidth']),
         ], Usage::TYPE_EVENT);
 
@@ -216,7 +218,7 @@ public function testEqualWithArrayValues(): void
     public function testContainsQuery(): void
     {
         // Test contains query with multiple values from events
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::contains('metric', ['requests', 'bandwidth']),
         ], Usage::TYPE_EVENT);
 
@@ -227,7 +229,7 @@ public function testContainsQuery(): void
     public function testLessThanEqualQuery(): void
     {
         $now = (new \DateTime())->format('Y-m-d\TH:i:s');
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::lessThanEqual('time', $now),
         ], Usage::TYPE_EVENT);
 
@@ -237,7 +239,7 @@ public function testLessThanEqualQuery(): void
     public function testGreaterThanEqualQuery(): void
     {
         $past = (new \DateTime())->modify('-24 hours')->format('Y-m-d\TH:i:s');
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::greaterThanEqual('time', $past),
         ], Usage::TYPE_EVENT);
 
@@ -249,15 +251,15 @@ public function testPurge(): void
         sleep(2);
 
         $this->usage->addBatch([
-            ['metric' => 'purge-test', 'value' => 999, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'purge-test', 'value' => 999, 'tags' => []],
         ], Usage::TYPE_EVENT);
 
         sleep(2);
 
-        $status = $this->usage->purge([], Usage::TYPE_EVENT);
+        $status = $this->usage->purge('1', [], Usage::TYPE_EVENT);
         $this->assertTrue($status);
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::equal('metric', ['purge-test']),
         ], Usage::TYPE_EVENT);
         $this->assertEquals(0, count($results));
@@ -265,224 +267,42 @@ public function testPurge(): void
 
     public function testPurgeWithQueries(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'purge-keep', 'value' => 10, 'tags' => []],
-            ['metric' => 'purge-remove', 'value' => 20, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'purge-keep', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'purge-remove', 'value' => 20, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
         // Purge only the 'purge-remove' metric
-        $status = $this->usage->purge([
+        $status = $this->usage->purge('1', [
             Query::equal('metric', ['purge-remove']),
         ], Usage::TYPE_EVENT);
         $this->assertTrue($status);
 
         // 'purge-remove' should be gone
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['purge-remove']),
         ], 'value', Usage::TYPE_EVENT);
         $this->assertEquals(0, $sum);
 
         // 'purge-keep' should still exist
-        $sum = $this->usage->sum([
+        $sum = $this->usage->sum('1', [
             Query::equal('metric', ['purge-keep']),
         ], 'value', Usage::TYPE_EVENT);
         $this->assertEquals(10, $sum);
     }
 
-    public function testCollectAndFlush(): void
-    {
-        $this->usage->purge();
-
-        // collect() accumulates in memory, nothing written yet
-        $this->usage->collect('collect-metric', 10, Usage::TYPE_EVENT);
-        $this->usage->collect('collect-metric', 20, Usage::TYPE_EVENT);
-        $this->usage->collect('collect-metric', 30, Usage::TYPE_EVENT);
-
-        // Buffer should have accumulated values
-        $this->assertEquals(3, $this->usage->getBufferCount());
-        // 1 unique metric:type key = 1 buffer entry (events sum)
-        $this->assertEquals(1, $this->usage->getBufferSize());
-
-        // Nothing in storage yet
-        $sum = $this->usage->sum([
-            Query::equal('metric', ['collect-metric']),
-        ], 'value', Usage::TYPE_EVENT);
-        $this->assertEquals(0, $sum);
-
-        // Flush writes to storage
-        $this->assertTrue($this->usage->flush());
-
-        // Buffer should be empty after flush
-        $this->assertEquals(0, $this->usage->getBufferCount());
-        $this->assertEquals(0, $this->usage->getBufferSize());
-
-        // Storage should have accumulated value (10 + 20 + 30 = 60)
-        $sum = $this->usage->sum([
-            Query::equal('metric', ['collect-metric']),
-        ], 'value', Usage::TYPE_EVENT);
-        $this->assertEquals(60, $sum);
-    }
-
-    public function testCollectMultipleMetrics(): void
-    {
-        $this->usage->purge();
-
-        $this->usage->collect('metric-a', 10, Usage::TYPE_EVENT);
-        $this->usage->collect('metric-b', 20, Usage::TYPE_EVENT);
-        $this->usage->collect('metric-a', 5, Usage::TYPE_EVENT);
-
-        // 2 unique metric:type keys = 2 buffer entries
-        $this->assertEquals(2, $this->usage->getBufferSize());
-        $this->assertEquals(3, $this->usage->getBufferCount());
-
-        $this->assertTrue($this->usage->flush());
-
-        $sumA = $this->usage->sum([
-            Query::equal('metric', ['metric-a']),
-        ], 'value', Usage::TYPE_EVENT);
-        $sumB = $this->usage->sum([
-            Query::equal('metric', ['metric-b']),
-        ], 'value', Usage::TYPE_EVENT);
-
-        $this->assertEquals(15, $sumA);
-        $this->assertEquals(20, $sumB);
-    }
-
-    public function testCollectGaugeAndFlush(): void
-    {
-        $this->usage->purge();
-
-        // collect with gauge type uses last-write-wins semantics
-        $this->usage->collect('gauge-collect', 100, Usage::TYPE_GAUGE);
-        $this->usage->collect('gauge-collect', 200, Usage::TYPE_GAUGE);
-        $this->usage->collect('gauge-collect', 300, Usage::TYPE_GAUGE);
-
-        // 1 unique metric:type key = 1 buffer entry (gauge: last-write-wins)
-        $this->assertEquals(1, $this->usage->getBufferSize());
-        $this->assertEquals(3, $this->usage->getBufferCount());
-
-        $this->assertTrue($this->usage->flush());
-
-        // Should have last value (300), not summed
-        $total = $this->usage->getTotal('gauge-collect', [], Usage::TYPE_GAUGE);
-        $this->assertEquals(300, $total);
-    }
-
-    public function testMixedCollectEventAndGauge(): void
-    {
-        $this->usage->purge();
-
-        // Mix both types in the same buffer
-        $this->usage->collect('inc-mixed', 10, Usage::TYPE_EVENT);
-        $this->usage->collect('inc-mixed', 20, Usage::TYPE_EVENT);
-        $this->usage->collect('set-mixed', 100, Usage::TYPE_GAUGE);
-        $this->usage->collect('set-mixed', 200, Usage::TYPE_GAUGE);
-
-        // inc: 1 metric:event key = 1, gauge: 1 metric:gauge key = 1
-        $this->assertEquals(2, $this->usage->getBufferSize());
-        $this->assertEquals(4, $this->usage->getBufferCount());
-
-        $this->assertTrue($this->usage->flush());
-
-        // Event: summed (10 + 20 = 30)
-        $this->assertEquals(30, $this->usage->getTotal('inc-mixed', [], Usage::TYPE_EVENT));
-
-        // Gauge: last value (200)
-        $this->assertEquals(200, $this->usage->getTotal('set-mixed', [], Usage::TYPE_GAUGE));
-    }
-
-    public function testShouldFlushByThreshold(): void
-    {
-        $this->usage->setFlushThreshold(3);
-
-        $this->assertFalse($this->usage->shouldFlush());
-
-        $this->usage->collect('threshold-test', 1, Usage::TYPE_EVENT);
-        $this->usage->collect('threshold-test', 1, Usage::TYPE_EVENT);
-
-        $this->assertFalse($this->usage->shouldFlush());
-
-        $this->usage->collect('threshold-test', 1, Usage::TYPE_EVENT);
-
-        $this->assertTrue($this->usage->shouldFlush());
-
-        // Clean up
-        $this->usage->flush();
-        $this->usage->setFlushThreshold(10_000); // reset
-    }
-
-    public function testShouldFlushByInterval(): void
-    {
-        $this->usage->setFlushInterval(1);
-
-        $this->usage->collect('interval-test', 1, Usage::TYPE_EVENT);
-
-        // Right after collect, interval hasn't elapsed
-        $this->assertFalse($this->usage->shouldFlush());
-
-        // Wait for interval to elapse
-        sleep(2);
-
-        $this->assertTrue($this->usage->shouldFlush());
-
-        // Clean up
-        $this->usage->flush();
-        $this->usage->setFlushInterval(20); // reset
-    }
-
-    public function testFlushEmptyBuffer(): void
-    {
-        // Flushing an empty buffer should succeed
-        $this->assertTrue($this->usage->flush());
-        $this->assertEquals(0, $this->usage->getBufferCount());
-        $this->assertEquals(0, $this->usage->getBufferSize());
-    }
-
-    public function testFlushThresholdConfiguration(): void
-    {
-        $this->usage->setFlushThreshold(500);
-        $this->assertEquals(500, $this->usage->getFlushThreshold());
-
-        $this->usage->setFlushInterval(30);
-        $this->assertEquals(30, $this->usage->getFlushInterval());
-
-        // Invalid values
-        $this->expectException(\InvalidArgumentException::class);
-        $this->usage->setFlushThreshold(0);
-    }
-
-    public function testCollectValidation(): void
-    {
-        $this->expectException(\InvalidArgumentException::class);
-        $this->expectExceptionMessage('Metric name cannot be empty');
-        $this->usage->collect('', 10, Usage::TYPE_EVENT);
-    }
-
-    public function testCollectNegativeValueValidation(): void
-    {
-        $this->expectException(\InvalidArgumentException::class);
-        $this->expectExceptionMessage('Value cannot be negative');
-        $this->usage->collect('test', -1, Usage::TYPE_EVENT);
-    }
-
-    public function testCollectInvalidTypeValidation(): void
-    {
-        $this->expectException(\InvalidArgumentException::class);
-        $this->usage->collect('test', 10, 'invalid');
-    }
-
     public function testWithQueries(): void
     {
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::equal('metric', ['requests']),
             Query::limit(1),
         ], Usage::TYPE_EVENT);
 
         $this->assertEquals(1, count($results));
 
-        $results2 = $this->usage->find([
+        $results2 = $this->usage->find('1', [
             Query::equal('metric', ['requests']),
             Query::limit(1),
             Query::offset(1),
@@ -499,14 +319,14 @@ public function testEmptyBatch(): void
     public function testAddBatchWithTags(): void
     {
         $metrics = [
-            ['metric' => 'tagged', 'value' => 10, 'tags' => ['region' => 'us-east']],
-            ['metric' => 'tagged', 'value' => 20, 'tags' => ['region' => 'us-west']],
-            ['metric' => 'tagged', 'value' => 15, 'tags' => ['region' => 'eu-west']],
+            ['tenant' => '1', 'metric' => 'tagged', 'value' => 10, 'tags' => ['region' => 'us-east']],
+            ['tenant' => '1', 'metric' => 'tagged', 'value' => 20, 'tags' => ['region' => 'us-west']],
+            ['tenant' => '1', 'metric' => 'tagged', 'value' => 15, 'tags' => ['region' => 'eu-west']],
         ];
 
         $this->assertTrue($this->usage->addBatch($metrics, Usage::TYPE_EVENT));
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             Query::equal('metric', ['tagged']),
         ], Usage::TYPE_EVENT);
         $this->assertGreaterThanOrEqual(1, count($results));
@@ -514,21 +334,21 @@ public function testAddBatchWithTags(): void
 
     public function testGroupByIntervalHourly(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         // Insert metrics spread across the current hour
         $now = new \DateTime();
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gbi-requests', 'value' => 100, 'tags' => []],
-            ['metric' => 'gbi-requests', 'value' => 50, 'tags' => []],
-            ['metric' => 'gbi-bandwidth', 'value' => 3000, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-requests', 'value' => 100, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-requests', 'value' => 50, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-bandwidth', 'value' => 3000, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
         $start = (clone $now)->modify('-1 hour')->format('Y-m-d\TH:i:s');
         $end = (clone $now)->modify('+1 hour')->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             Query::equal('metric', ['gbi-requests']),
             Query::greaterThanEqual('time', $start),
@@ -551,17 +371,17 @@ public function testGroupByIntervalHourly(): void
 
     public function testGroupByIntervalDaily(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gbi-daily', 'value' => 200, 'tags' => []],
-            ['metric' => 'gbi-daily', 'value' => 300, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-daily', 'value' => 200, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-daily', 'value' => 300, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
         $start = (new \DateTime())->modify('-1 day')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->modify('+1 day')->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1d'),
             Query::equal('metric', ['gbi-daily']),
             Query::greaterThanEqual('time', $start),
@@ -581,18 +401,18 @@ public function testGroupByIntervalDaily(): void
 
     public function testGroupByIntervalGauge(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gbi-storage', 'value' => 1000, 'tags' => []],
-            ['metric' => 'gbi-storage', 'value' => 2000, 'tags' => []],
-            ['metric' => 'gbi-storage', 'value' => 3000, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-storage', 'value' => 1000, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-storage', 'value' => 2000, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-storage', 'value' => 3000, 'tags' => []],
         ], Usage::TYPE_GAUGE));
 
         $start = (new \DateTime())->modify('-1 hour')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->modify('+1 hour')->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             Query::equal('metric', ['gbi-storage']),
             Query::greaterThanEqual('time', $start),
@@ -616,17 +436,17 @@ public function testGroupByIntervalInvalidInterval(): void
 
     public function testGroupByIntervalWithLimitOffset(): void
     {
-        $this->usage->purge();
+        $this->usage->purge('1');
 
         $this->assertTrue($this->usage->addBatch([
-            ['metric' => 'gbi-limit', 'value' => 10, 'tags' => []],
-            ['metric' => 'gbi-limit', 'value' => 20, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-limit', 'value' => 10, 'tags' => []],
+            ['tenant' => '1', 'metric' => 'gbi-limit', 'value' => 20, 'tags' => []],
         ], Usage::TYPE_EVENT));
 
         $start = (new \DateTime())->modify('-1 hour')->format('Y-m-d\TH:i:s');
         $end = (new \DateTime())->modify('+1 hour')->format('Y-m-d\TH:i:s');
 
-        $results = $this->usage->find([
+        $results = $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             Query::equal('metric', ['gbi-limit']),
             Query::greaterThanEqual('time', $start),
@@ -642,7 +462,7 @@ public function testGroupByUnknownAttributeThrows(): void
         $this->expectException(\Exception::class);
         $this->expectExceptionMessageMatches("/groupBy attribute 'not_a_column'/");
 
-        $this->usage->find([
+        $this->usage->find('1', [
             UsageQuery::groupByInterval('time', '1h'),
             UsageQuery::groupBy('not_a_column'),
             Query::equal('metric', ['gbi-requests']),
@@ -654,7 +474,7 @@ public function testGroupByWithoutGroupByIntervalReturnsDimOnlyAggregate(): void
         // Without groupByInterval the result is a flat aggregate per
         // (metric, …dims) — no time bucketing, ordered by value DESC by
         // default (top-N table semantics).
-        $rows = $this->usage->find([
+        $rows = $this->usage->find('1', [
             UsageQuery::groupBy('service'),
             Query::equal('metric', ['gbi-requests']),
         ], Usage::TYPE_EVENT);