feat(transports/newrelic): align encoder with TypeScript transport format

.changeset/new-relic-encoder-align.md

@@ -0,0 +1,5 @@
+---
+"transports/newrelic": minor
+---
+
+Align encoder with TypeScript transport format: emit `timestamp`, `level`, `log`, and `attributes` instead of the previous flat `logtype`/`loglevel`/`message` shape. Adds attribute validation at encode time (max 255 attributes, 255-char names, 4,094-char string values).

docs/src/transports/newrelic.md

@@ -7,7 +7,7 @@ description: Ship logs to the New Relic Log Ingest API.
 
 <ModuleBadges path="transports/newrelic" />
 
-Sends log entries to the [New Relic Log Ingest API](https://docs.newrelic.com/docs/logs/log-api/introduction-log-api/). Built on the [HTTP transport](/transports/http) with a New Relic-specific encoder, site-aware URL, and `api-key` header.
+Sends log entries to the [New Relic Log Ingest API](https://docs.newrelic.com/docs/logs/log-api/introduction-log-api/). Built on the [HTTP transport](/transports/http) with a New Relic-specific encoder (timestamp, level, log, attributes), site-aware URL, and `Api-Key` header. Includes attribute validation enforced at encode time (max 255 attributes, 255-char names, 4,094-char values). Log format matches the [TypeScript transport](https://loglayer.dev/transports/new-relic).
 
 ```sh
 go get go.loglayer.dev/transports/newrelic
@@ -134,47 +134,52 @@ See the [HTTP transport docs](/transports/http) for the full HTTP config surface
 
 ## Encoded Body Shape
 
-Each log entry becomes one object in a JSON array:
+Each log entry becomes one object in a JSON array. The format matches the [TypeScript New Relic transport](https://loglayer.dev/transports/new-relic):
 
 ```json
 [
   {
-    "logtype":    "LogEvent",
     "timestamp":  1745616000123,
-    "loglevel":   "info",
-    "message":    "served request",
-    "requestId":  "abc",
-    "durationMs": 42
+    "level":      "info",
+    "log":        "served request",
+    "attributes": {
+      "requestId":  "abc",
+      "durationMs": 42
+    }
   }
 ]
 ```
 
-Every object includes `logtype: "LogEvent"` and `timestamp` (epoch milliseconds) as required by the New Relic API. Persistent fields (`WithFields`) and metadata (`WithMetadata`) follow the [core placement rules](/configuration#fieldskey): when `FieldsKey` is empty, fields merge at the root of each log object; when `MetadataFieldName` is empty, map metadata merges at the root and non-map metadata nests under `metadata`. Fields and metadata are merged via `transport.MergeIntoMap` so they coexist cleanly with the system fields. Set either knob on `loglayer.Config` to nest under a configured key instead.
+Every object includes `timestamp` (epoch milliseconds), `level` (the log layer severity), and `log` (the message text). Persistent fields and metadata are merged under the `attributes` key with New Relic's API constraints enforced: maximum 255 attributes, 255-character attribute names, and string values truncated at 4,094 characters. Reserved fields (`timestamp`, `level`, `log`) are excluded from attributes to prevent collisions.
 
-## Level → loglevel Mapping
+## Level → level Mapping
 
-New Relic uses a `loglevel` string per entry. The transport maps loglayer levels:
+New Relic uses a `level` string per entry. The transport maps loglayer levels:
 
-| LogLayer Level   | New Relic loglevel |
-|------------------|--------------------|
-| `LogLevelTrace`  | `trace`            |
-| `LogLevelDebug`  | `debug`            |
-| `LogLevelInfo`   | `info`             |
-| `LogLevelWarn`   | `warn`             |
-| `LogLevelError`  | `error`            |
-| `LogLevelFatal`  | `critical`         |
-| `LogLevelPanic`  | `critical`         |
+| LogLayer Level   | New Relic level  |
+|------------------|------------------|
+| `LogLevelTrace`  | `trace`          |
+| `LogLevelDebug`  | `debug`          |
+| `LogLevelInfo`   | `info`           |
+| `LogLevelWarn`   | `warn`           |
+| `LogLevelError`  | `error`          |
+| `LogLevelFatal`  | `critical`       |
+| `LogLevelPanic`  | `critical`       |
 
 New Relic has no distinction between Fatal and Panic, so both map to `critical` (the highest-severity level in the Log Ingest API).
 
 ## API Limits
 
-New Relic enforces these restrictions on Log Ingest API requests ([reference](https://docs.newrelic.com/docs/logs/log-api/introduction-log-api/#limits)):
+The transport enforces these limits at encode time ([reference](https://docs.newrelic.com/docs/logs/log-api/introduction-log-api/#limits)):
+
+- 255 attributes maximum per event (excess attributes are dropped, not merged)
+- 255 characters maximum per attribute name (longer names are dropped silently)
+- String values truncated at 4,094 characters
+
+New Relic also enforces these on the server side:
 
 - 1MB maximum payload per POST (compression recommended)
 - Payload must be UTF-8 encoded
-- 255 attributes maximum per event
-- 255 characters maximum per attribute name
 - 4,094 characters stored in NRDB; longer values stored as a blob
 
 The default `BatchSize` of 100 stays well under the 1MB payload limit for typical entries. If you bump `BatchSize` for higher throughput or ship large attributes, watch for the boundary.

docs/src/whats-new.md

@@ -7,6 +7,12 @@ description: Latest features and improvements in LogLayer for Go.
 
 - See the [main `CHANGELOG.md`](https://github.com/loglayer/loglayer-go/blob/main/CHANGELOG.md) for the auto-generated per-release log.
 
+## May 11, 2026
+
+`transports/newrelic`:
+
+Encoder updated to match the [TypeScript transport format](https://loglayer.dev/transports/new-relic). Log entries now use `timestamp`, `level`, `log`, and `attributes` (nested) instead of the previous flat shape (`logtype`, `loglevel`, `message`, fields at root). Attribute validation added at encode time: maximum 255 attributes, 255-char names, 4,094-char string values.
+
 ## May 10, 2026
 
 `transports/newrelic`:

transports/betterstack/go.sum

@@ -2,7 +2,7 @@ github.com/goccy/go-json v0.10.6 h1:p8HrPJzOakx/mn/bQtjgNjdTcN+/S6FcG2CTtQOrHVU=
 github.com/goccy/go-json v0.10.6/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 go.loglayer.dev/transports/http/v2 v2.1.0 h1:+9kaawgxkbFYKvIliTWwSjj9WKUnG9Uzjm3dRmuCkRY=
 go.loglayer.dev/transports/http/v2 v2.1.0/go.mod h1:OeIaQoUHcT3Qeb8HI8CaY4OFhQwwpC/Pb0yXGTrHxIM=
-go.loglayer.dev/v2 v2.0.1 h1:B7oYpkfMky0UG/N8IdKeIiiTi6h7eyj5NvRyEth9DHI=
-go.loglayer.dev/v2 v2.0.1/go.mod h1:+BWhs5AyICvCLBz07qHnCE12W34tArUWfXOba0Ct/QI=
+go.loglayer.dev/v2 v2.1.0 h1:8/fq8Z1NNLtjfKgaPn6S0Hy7zWPnkjn9Gj3YgEDFk4w=
+go.loglayer.dev/v2 v2.1.0/go.mod h1:+BWhs5AyICvCLBz07qHnCE12W34tArUWfXOba0Ct/QI=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=

transports/newrelic/go.sum

@@ -6,8 +6,10 @@ github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRI
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
-go.loglayer.dev/v2 v2.0.1 h1:B7oYpkfMky0UG/N8IdKeIiiTi6h7eyj5NvRyEth9DHI=
-go.loglayer.dev/v2 v2.0.1/go.mod h1:+BWhs5AyICvCLBz07qHnCE12W34tArUWfXOba0Ct/QI=
+go.loglayer.dev/transports/http/v2 v2.1.0 h1:+9kaawgxkbFYKvIliTWwSjj9WKUnG9Uzjm3dRmuCkRY=
+go.loglayer.dev/transports/http/v2 v2.1.0/go.mod h1:OeIaQoUHcT3Qeb8HI8CaY4OFhQwwpC/Pb0yXGTrHxIM=
+go.loglayer.dev/v2 v2.1.0 h1:8/fq8Z1NNLtjfKgaPn6S0Hy7zWPnkjn9Gj3YgEDFk4w=
+go.loglayer.dev/v2 v2.1.0/go.mod h1:+BWhs5AyICvCLBz07qHnCE12W34tArUWfXOba0Ct/QI=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

transports/newrelic/newrelic.go

@@ -3,9 +3,8 @@
 // Wraps transports/http with New Relic-specific defaults:
 //   - Site-aware intake URL (US, EU)
 //   - Api-Key header from Config.LicenseKey
-//   - Encoder that emits New Relic's expected log shape (logtype,
-//     timestamp, loglevel, message) merged with the user's fields
-//     and metadata
+//   - Encoder that emits the New Relic log shape (timestamp, level, log,
+//     attributes) with attribute validation enforced at encode time
 //
 // API reference:
 // https://docs.newrelic.com/docs/logs/log-api/introduction-log-api/
@@ -155,25 +154,87 @@ func Build(cfg Config) (*Transport, error) {
 }
 
 // newEncoder produces the JSON-array encoder for New Relic's intake format.
-// Each entry is a JSON object with logtype, timestamp, loglevel, message,
-// plus any user fields and metadata.
+// Each entry is a JSON object with timestamp, level, log, and attributes
+// (merged data + metadata), matching the TypeScript transport format.
 func newEncoder() httptr.Encoder {
 	return httptr.EncoderFunc(func(entries []httptr.Entry) ([]byte, string, error) {
 		objs := make([]map[string]any, len(entries))
 		for i, e := range entries {
-			obj := make(map[string]any, 4+len(e.Data))
-			obj["logtype"] = "LogEvent"
-			obj["timestamp"] = e.Time.UnixMilli()
-			obj["loglevel"] = loglevelFor(e.Level)
-			obj["message"] = transport.JoinMessages(e.Messages)
-			transport.MergeIntoMap(obj, e.Data, e.Metadata, e.Schema.MetadataFieldName)
+			obj := map[string]any{
+				"timestamp": e.Time.UnixMilli(),
+				"level":     loglevelFor(e.Level),
+				"log":       transport.JoinMessages(e.Messages),
+			}
+			attrs := mergeAttributes(e)
+			if len(attrs) > 0 {
+				obj["attributes"] = attrs
+			}
 			objs[i] = obj
 		}
 		body, err := json.Marshal(objs)
 		return body, "application/json", err
 	})
 }
 
+const (
+	maxAttributes           = 255
+	maxAttributeNameLength  = 255
+	maxAttributeValueLength = 4094
+)
+
+// mergeAttributes merges entry data and metadata into a single attributes
+// map, enforcing New Relic's API constraints: max 255 attributes, max 255-
+// char attribute names, and values truncated at 4094 chars. Reserved fields
+// (timestamp, level, log) are excluded to prevent collisions.
+func mergeAttributes(e httptr.Entry) map[string]any {
+	attrs := make(map[string]any)
+	for k, v := range e.Data {
+		if reserved(k) {
+			continue
+		}
+		if len(attrs)+1 > maxAttributes {
+			break
+		}
+		setAttr(attrs, k, v)
+	}
+
+	if m, ok := transport.MetadataAsRootMap(e.Metadata); ok {
+		for k, v := range m {
+			if reserved(k) {
+				continue
+			}
+			if len(attrs)+1 > maxAttributes {
+				break
+			}
+			setAttr(attrs, k, v)
+		}
+	}
+
+	return attrs
+}
+
+// reserved returns true if k is a top-level New Relic log field that should
+// not appear inside the attributes map.
+func reserved(k string) bool {
+	switch k {
+	case "timestamp", "level", "log":
+		return true
+	}
+	return false
+}
+
+// setAttr validates and sets a single attribute, truncating string values
+// that exceed the New Relic limit.
+func setAttr(attrs map[string]any, key string, val any) {
+	if len(key) > maxAttributeNameLength {
+		return
+	}
+	if s, ok := val.(string); ok && len(s) > maxAttributeValueLength {
+		val = s[:maxAttributeValueLength]
+	}
+	attrs[key] = val
+}
+
 // loglevelFor maps a loglayer LogLevel to New Relic's loglevel string.
 // Fatal and Panic both map to "critical" (New Relic's highest-severity
 // log level).

transports/newrelic/newrelic_test.go

@@ -79,8 +79,8 @@ func TestNewRelic_BasicBatchOnClose(t *testing.T) {
 	}
 
 	// First entry should be "hello"
-	if arr[0]["message"] != "hello" {
-		t.Errorf("first message: got %v, want hello", arr[0]["message"])
+	if arr[0]["log"] != "hello" {
+		t.Errorf("first log: got %v, want hello", arr[0]["log"])
 	}
 }
 
@@ -292,9 +292,9 @@ func TestNewRelic_LevelFiltering(t *testing.T) {
 
 	// Check that no debug or info entries made it through.
 	for i, obj := range arr {
-		if loglevel, ok := obj["loglevel"].(string); ok {
-			if loglevel == "debug" || loglevel == "info" {
-				t.Errorf("entry %d should have been filtered, got loglevel %q", i, loglevel)
+		if level, ok := obj["level"].(string); ok {
+			if level == "debug" || level == "info" {
+				t.Errorf("entry %d should have been filtered, got level %q", i, level)
 			}
 		}
 	}
@@ -339,8 +339,8 @@ func TestNewRelic_EncodedBodyShape(t *testing.T) {
 
 	obj := arr[0]
 
-	if obj["logtype"] != "LogEvent" {
-		t.Errorf("logtype: got %v, want LogEvent", obj["logtype"])
+	if level, ok := obj["level"].(string); !ok || level == "" {
+		t.Errorf("level: missing or empty, got %v", obj["level"])
 	}
 
 	// Timestamp should be a number (epoch milliseconds).
@@ -350,12 +350,12 @@ func TestNewRelic_EncodedBodyShape(t *testing.T) {
 		t.Errorf("timestamp too small for a valid epoch-ms: %v", ts)
 	}
 
-	if obj["loglevel"] != "info" {
-		t.Errorf("loglevel: got %v, want info", obj["loglevel"])
+	if obj["level"] != "info" {
+		t.Errorf("level: got %v, want info", obj["level"])
 	}
 
-	if obj["message"] != "test body shape" {
-		t.Errorf("message: got %v, want 'test body shape'", obj["message"])
+	if obj["log"] != "test body shape" {
+		t.Errorf("log: got %v, want 'test body shape'", obj["log"])
 	}
 }
 
@@ -393,15 +393,19 @@ func TestNewRelic_FieldAndMetadataInBody(t *testing.T) {
 	_ = json.Unmarshal(cap.bodies[0], &arr)
 
 	obj := arr[0]
-	if obj["requestId"] != "req-42" {
-		t.Errorf("requestId: got %v", obj["requestId"])
+	attrs, ok := obj["attributes"].(map[string]any)
+	if !ok {
+		t.Fatal("expected attributes map")
+	}
+	if attrs["requestId"] != "req-42" {
+		t.Errorf("requestId: got %v", attrs["requestId"])
 	}
 	// JSON unmarshals numbers as float64.
-	if obj["durationMs"] != float64(123) {
-		t.Errorf("durationMs: got %v", obj["durationMs"])
+	if attrs["durationMs"] != float64(123) {
+		t.Errorf("durationMs: got %v", attrs["durationMs"])
 	}
-	if obj["endpoint"] != "/api/v1" {
-		t.Errorf("endpoint: got %v", obj["endpoint"])
+	if attrs["endpoint"] != "/api/v1" {
+		t.Errorf("endpoint: got %v", attrs["endpoint"])
 	}
 }
 
@@ -585,11 +589,11 @@ func TestNewRelic_GroupsWork(t *testing.T) {
 		t.Fatalf("expected 1 entry, got %d", len(arr))
 	}
 	obj := arr[0]
-	if obj["logtype"] != "LogEvent" {
-		t.Errorf("logtype: got %v", obj["logtype"])
+	if obj["level"] == nil {
+		t.Errorf("level: missing")
 	}
-	if obj["message"] != "grouped log" {
-		t.Errorf("message: got %v", obj["message"])
+	if obj["log"] != "grouped log" {
+		t.Errorf("log: got %v", obj["log"])
 	}
 }
 
@@ -650,9 +654,9 @@ func TestNewRelic_LevelMapping(t *testing.T) {
 		"critical": {},
 	}
 	for i, obj := range allEntries {
-		if lv, ok := obj["loglevel"].(string); ok {
+		if lv, ok := obj["level"].(string); ok {
 			if _, ok := wantMap[lv]; !ok {
-				t.Errorf("entry %d has unexpected loglevel %q", i, lv)
+				t.Errorf("entry %d has unexpected level %q", i, lv)
 			}
 		}
 	}