diff --git a/.changeset/map-node-config-schema.md b/.changeset/map-node-config-schema.md
new file mode 100644
index 0000000000..0cea361c3b
--- /dev/null
+++ b/.changeset/map-node-config-schema.md
@@ -0,0 +1,22 @@
+---
+"@objectstack/service-automation": patch
+---
+
+feat(automation): publish a configSchema for the `map` node (flow designer parity, #3304)
+
+The `map` (sequential multi-instance) node shipped no `configSchema`, so the flow
+designer fell back to its hardcoded field group online and to raw Advanced-JSON
+where that wasn't present. Its descriptor now carries a structured `configSchema`
+that mirrors the objectui hardcoded `map` field group field-for-field —
+`collection` (marked `xExpression: 'template'`, an `interpolate()` `{items}`
+template, same as `loop.collection`), `flowName` + `itemObject` as typed
+references (`xRef`), and `iteratorVariable` / `outputVariable` as plain text — so
+the online (schema-driven) and offline forms match.
+
+`map` is the one previously-schemaless flow node whose fields are all scalars and
+typed references, so it maps cleanly through objectui's `jsonSchemaToFlowFields`
+with zero regression. The remaining schemaless nodes lean on editor kinds the
+schema→fields adapter does not yet reproduce (`keyValue` maps, the decision
+virtual `target` column, `wait`'s top-level block), and are deferred to #3304
+until that adapter is extended. Additive and backward-compatible: no runtime
+behavior change; an older designer that ignores the schema is unaffected.
diff --git a/packages/services/service-automation/src/builtin/map-node.test.ts b/packages/services/service-automation/src/builtin/map-node.test.ts
index 8a245faa4e..c236acb082 100644
--- a/packages/services/service-automation/src/builtin/map-node.test.ts
+++ b/packages/services/service-automation/src/builtin/map-node.test.ts
@@ -164,3 +164,27 @@ describe('map node executor (sequential multi-instance)', () => {
     expect(await store.list()).toHaveLength(0);
   });
 });
+
+describe('map descriptor configSchema (objectui #2670 Phase 3 / #3304)', () => {
+  it('publishes a structured config form matching the objectui `map` field group', () => {
+    // `map` is the one previously-schemaless node whose fields all map cleanly
+    // through jsonSchemaToFlowFields (scalars + typed references, no keyValue /
+    // virtual columns), so shipping this schema makes the online designer form
+    // match the offline hardcoded one with zero regression.
+    const engine = new AutomationEngine(silentLogger());
+    registerMapNode(engine, ctx());
+    const schema = engine.getActionDescriptor('map')?.configSchema as
+      | { properties?: Record<string, { xExpression?: unknown; xRef?: { kind?: string } }>; required?: string[] }
+      | undefined;
+    expect(schema).toBeDefined();
+    // `collection` is an interpolate() `{items}` template (mono editor + `{var}`
+    // picker, no CEL brace-trap) — the same marker as loop.collection.
+    expect(schema?.properties?.collection?.xExpression).toBe('template');
+    // `flowName` / `itemObject` are typed references → pickers, not free text.
+    expect(schema?.properties?.flowName?.xRef?.kind).toBe('flow');
+    expect(schema?.properties?.itemObject?.xRef?.kind).toBe('object');
+    // Plain scalar text fields carry no authoring marker.
+    expect(schema?.properties?.iteratorVariable?.xExpression).toBeUndefined();
+    expect(schema?.properties?.outputVariable?.xExpression).toBeUndefined();
+  });
+});
diff --git a/packages/services/service-automation/src/builtin/map-node.ts b/packages/services/service-automation/src/builtin/map-node.ts
index 845dcb6c53..9f92e52555 100644
--- a/packages/services/service-automation/src/builtin/map-node.ts
+++ b/packages/services/service-automation/src/builtin/map-node.ts
@@ -49,6 +49,25 @@ export function registerMapNode(engine: AutomationEngine, ctx: PluginContext): v
       // Each item's subflow may pause, so the map suspends and resumes per item.
       supportsPause: true,
       isAsync: true,
+      // Structured config form for the flow designer (ADR-0018). Mirrors the
+      // objectui hardcoded `map` field group field-for-field, so the online
+      // (schema-driven) form matches the offline one (objectui #2670 Phase 3 /
+      // #3304). `map` is the one previously-schemaless node whose fields are all
+      // scalars / typed references — no `keyValue` map, no virtual columns — so
+      // it maps cleanly through `jsonSchemaToFlowFields` with zero regression.
+      configSchema: {
+        type: 'object',
+        properties: {
+          // interpolate() single-brace `{items}` template, not bare CEL — same
+          // marker + rationale as loop.collection.
+          collection: { type: 'string', title: 'Collection', description: 'Expression resolving to the array to process, one item at a time.', xExpression: 'template' },
+          flowName: { type: 'string', title: 'Per-item flow', description: 'Subflow run for each item — it may pause (e.g. an approval).', xRef: { kind: 'flow' } },
+          iteratorVariable: { type: 'string', title: 'Item variable' },
+          itemObject: { type: 'string', title: 'Item object', description: 'When items are records, the object they belong to (exposes each item as the child’s record).', xRef: { kind: 'object' } },
+          outputVariable: { type: 'string', title: 'Output variable', description: 'Each item’s subflow output, collected in order.' },
+        },
+        required: ['collection', 'flowName'],
+      },
     }),
     async execute(node, variables, context) {
       const cfg = (node.config ?? {}) as Record<string, unknown>;