fix(mcp): honor json schema openness in mcp output shapes

Objects without additionalProperties: false now keep their declared fields and
record that others are allowed, so references to undeclared fields lint clean
and resolve empty when missing. Arrays without items accept element paths.
Also documents the v2 execute 202 receipt returned after waitTimeoutSeconds.

Author: waleedlatif1

apps/docs/openapi-v2-workflows.json

@@ -3701,7 +3701,7 @@
       "post": {
         "operationId": "executeWorkflowV2",
         "summary": "Execute workflow",
-        "description": "Run the active deployment, or set `run.source: \"manual\"` to run the saved draft. Deployed execution requires workspace read access and OAuth `api:write` scope or an API key; public deployments also allow anonymous synchronous or streamed runs. Manual runs require personal-key or OAuth write access and cannot be async.\n\nUse `async: true` for a queue receipt, or `stream: true` for SSE. For a synchronous run with both flags false, send `Accept: application/x-ndjson` for heartbeat frames and a final frame containing `data`. Timeouts return `200` with `status: \"failed\"` and `error.code: \"TIMEOUT\"`; inspect run status. See [Streaming](/workflows/deployment/api#streaming) for event formats. Input descriptions specify compatible modes; invalid combinations return `400`.\n\nSupply `X-Run-Id` to prevent duplicate execution. Reuse returns `409`, without replaying results. A `503` with `error.details.code: \"ASYNC_ENQUEUE_AMBIGUOUS\"` omits `Retry-After` because the run may already have started. Reconcile using the returned run ID; do not start another run with a new or omitted ID.\n\nOAuth scope: `api:write`.",
+        "description": "Run the active deployment, or set `run.source: \"manual\"` to run the saved draft. Deployed execution requires workspace read access and OAuth `api:write` scope or an API key; public deployments also allow anonymous synchronous or streamed runs. Manual runs require personal-key or OAuth write access and cannot be async.\n\nUse `async: true` for a queue receipt, `waitTimeoutSeconds` to get one when a synchronous run outlasts the wait, or `stream: true` for SSE. For a synchronous run with both flags false, send `Accept: application/x-ndjson` for heartbeat frames and a final frame containing `data`. Timeouts return `200` with `status: \"failed\"` and `error.code: \"TIMEOUT\"`; inspect run status. See [Streaming](/workflows/deployment/api#streaming) for event formats. Input descriptions specify compatible modes; invalid combinations return `400`.\n\nSupply `X-Run-Id` to prevent duplicate execution. Reuse returns `409`, without replaying results. A `503` with `error.details.code: \"ASYNC_ENQUEUE_AMBIGUOUS\"` omits `Retry-After` because the run may already have started. Reconcile using the returned run ID; do not start another run with a new or omitted ID.\n\nOAuth scope: `api:write`.",
         "x-sim-operation": "workflows.execute",
         "x-oauth-scope": "api:write",
         "tags": ["Workflows"],
@@ -3891,7 +3891,7 @@
             }
           },
           "202": {
-            "description": "The asynchronous run was queued.",
+            "description": "The asynchronous run was queued, or the synchronous run was still running when `waitTimeoutSeconds` elapsed and continues in the background.",
             "headers": {
               "X-Run-Id": {
                 "$ref": "#/components/headers/X-Run-Id"
@@ -14267,7 +14267,7 @@
         "required": ["data"],
         "additionalProperties": false,
         "title": "Queued workflow execution response",
-        "description": "Receipt returned for an asynchronous workflow run.",
+        "description": "Receipt returned for an asynchronous workflow run, or for a synchronous run still running when `waitTimeoutSeconds` elapsed.",
         "examples": [
           {
             "data": {

apps/sim/executor/utils/block-reference.test.ts

@@ -144,6 +144,33 @@ describe('resolveBlockReference', () => {
       expect(result).toEqual({ value: undefined, blockId: 'block-1' })
     })
 
+    it('rejects an undeclared field under a json field that declares its properties', () => {
+      const ctx = createContext({
+        blockData: { 'block-1': { result: { summary: 'hello' } } },
+        blockOutputSchemas: {
+          'block-1': { result: { type: 'json', properties: { summary: { type: 'string' } } } },
+        },
+      })
+
+      expect(resolveBlockReference('start', ['result', 'summary'], ctx)?.value).toBe('hello')
+      expect(() => resolveBlockReference('start', ['result', 'typo'], ctx)).toThrow(
+        InvalidFieldError
+      )
+    })
+
+    it('accepts an undeclared field under an open json field that declares its properties', () => {
+      const ctx = createContext({
+        blockData: { 'block-1': { result: { summary: 'hello' } } },
+        blockOutputSchemas: {
+          'block-1': {
+            result: { type: 'json', properties: { summary: { type: 'string' } }, open: true },
+          },
+        },
+      })
+
+      expect(resolveBlockReference('start', ['result', 'extra'], ctx)?.value).toBeUndefined()
+    })
+
     it('should resolve values nested under json field on executed block', () => {
       const ctx = createContext({
         blockData: { 'block-1': { result: { summary: 'hello' } } },

apps/sim/executor/utils/block-reference.ts

@@ -15,6 +15,8 @@ interface SchemaNode {
   type?: string
   description?: string
   properties?: unknown
+  /** Fields beyond `properties` are allowed, so a path past them is not checked. */
+  open?: boolean
   items?: unknown
 }
 
@@ -101,6 +103,11 @@ function isOpaqueSchemaNode(value: unknown): boolean {
   return false
 }
 
+/** A node declaring its fields but allowing others, so a field it does not name is not an error. */
+function isOpenSchemaNode(value: unknown): boolean {
+  return asSchemaNode(value)?.open === true
+}
+
 /** Whether `pathParts` names a field the declared output schema has, the check a run makes. */
 export function isPathInSchema(schema: OutputSchema | undefined, pathParts: string[]): boolean {
   if (!schema || pathParts.length === 0) {
@@ -140,7 +147,7 @@ export function isPathInSchema(schema: OutputSchema | undefined, pathParts: stri
     if (arrayMatch) {
       const [, prop] = arrayMatch
       const fieldDef = lookupField(current, prop)
-      if (!fieldDef) return false
+      if (!fieldDef) return isOpenSchemaNode(current)
 
       if (isFileType(fieldDef)) {
         const nextPart = pathParts[i + 1]
@@ -194,9 +201,10 @@ export function isPathInSchema(schema: OutputSchema | undefined, pathParts: stri
         current = itemField
         continue
       }
+      return isOpenSchemaNode(items)
     }
 
-    return false
+    return isOpenSchemaNode(current)
   }
 
   return true

apps/sim/lib/api/contracts/v2/openapi/workflows.ts

@@ -223,7 +223,7 @@ const executeQueuedResponseSchema = documentedSchema(
   v2ExecuteWorkflowQueuedResponseSchema,
   'ExecuteWorkflowQueuedResponse',
   'Queued workflow execution response',
-  'Receipt returned for an asynchronous workflow run.',
+  'Receipt returned for an asynchronous workflow run, or for a synchronous run still running when `waitTimeoutSeconds` elapsed.',
   [QUEUED_RUN_EXAMPLE]
 )
 
@@ -1194,7 +1194,7 @@ const declaredRoutes = [
       applicationOperation: workflowOperations.execute,
       operationId: 'executeWorkflowV2',
       summary: 'Execute workflow',
-      description: `Run the active deployment, or set \`run.source: "manual"\` to run the saved draft. Deployed execution requires workspace read access and OAuth \`api:write\` scope or an API key; public deployments also allow anonymous synchronous or streamed runs. Manual runs require personal-key or OAuth write access and cannot be async.\n\nUse \`async: true\` for a queue receipt, or \`stream: true\` for SSE. For a synchronous run with both flags false, send \`Accept: application/x-ndjson\` for heartbeat frames and a final frame containing \`data\`. Timeouts return \`200\` with \`status: "failed"\` and \`error.code: "TIMEOUT"\`; inspect run status. See [Streaming](/workflows/deployment/api#streaming) for event formats. ${EXECUTE_OPTION_CONSTRAINTS}\n\nSupply \`X-Run-Id\` to prevent duplicate execution. Reuse returns \`409\`, without replaying results. A \`503\` with \`error.details.code: "ASYNC_ENQUEUE_AMBIGUOUS"\` omits \`Retry-After\` because the run may already have started. Reconcile using the returned run ID; do not start another run with a new or omitted ID.`,
+      description: `Run the active deployment, or set \`run.source: "manual"\` to run the saved draft. Deployed execution requires workspace read access and OAuth \`api:write\` scope or an API key; public deployments also allow anonymous synchronous or streamed runs. Manual runs require personal-key or OAuth write access and cannot be async.\n\nUse \`async: true\` for a queue receipt, \`waitTimeoutSeconds\` to get one when a synchronous run outlasts the wait, or \`stream: true\` for SSE. For a synchronous run with both flags false, send \`Accept: application/x-ndjson\` for heartbeat frames and a final frame containing \`data\`. Timeouts return \`200\` with \`status: "failed"\` and \`error.code: "TIMEOUT"\`; inspect run status. See [Streaming](/workflows/deployment/api#streaming) for event formats. ${EXECUTE_OPTION_CONSTRAINTS}\n\nSupply \`X-Run-Id\` to prevent duplicate execution. Reuse returns \`409\`, without replaying results. A \`503\` with \`error.details.code: "ASYNC_ENQUEUE_AMBIGUOUS"\` omits \`Retry-After\` because the run may already have started. Reconcile using the returned run ID; do not start another run with a new or omitted ID.`,
       errors: [
         'BadRequest',
         'Unauthorized',
@@ -1218,7 +1218,8 @@ const declaredRoutes = [
             additionalContentTypes: ['application/x-ndjson', 'text/event-stream'],
           },
           202: {
-            description: 'The asynchronous run was queued.',
+            description:
+              'The asynchronous run was queued, or the synchronous run was still running when `waitTimeoutSeconds` elapsed and continues in the background.',
             headers: ['X-Run-Id', ...RATE_LIMIT_HEADERS],
           },
         },

apps/sim/lib/api/mcp/generated/v2-operations.ts

@@ -1246,7 +1246,7 @@ export const V2_MCP_OPERATIONS = {
     contract: v2ExecuteWorkflowContract,
     summary: 'Execute workflow',
     description:
-      'Run the active deployment, or set `run.source: "manual"` to run the saved draft. Deployed execution requires workspace read access and OAuth `api:write` scope or an API key; public deployments also allow anonymous synchronous or streamed runs. Manual runs require personal-key or OAuth write access and cannot be async.\n\nUse `async: true` for a queue receipt, or `stream: true` for SSE. For a synchronous run with both flags false, send `Accept: application/x-ndjson` for heartbeat frames and a final frame containing `data`. Timeouts return `200` with `status: "failed"` and `error.code: "TIMEOUT"`; inspect run status. See [Streaming](/workflows/deployment/api#streaming) for event formats. Input descriptions specify compatible modes; invalid combinations return `400`.\n\nSupply `X-Run-Id` to prevent duplicate execution. Reuse returns `409`, without replaying results. A `503` with `error.details.code: "ASYNC_ENQUEUE_AMBIGUOUS"` omits `Retry-After` because the run may already have started. Reconcile using the returned run ID; do not start another run with a new or omitted ID.\n\nOAuth scope: `api:write`.',
+      'Run the active deployment, or set `run.source: "manual"` to run the saved draft. Deployed execution requires workspace read access and OAuth `api:write` scope or an API key; public deployments also allow anonymous synchronous or streamed runs. Manual runs require personal-key or OAuth write access and cannot be async.\n\nUse `async: true` for a queue receipt, `waitTimeoutSeconds` to get one when a synchronous run outlasts the wait, or `stream: true` for SSE. For a synchronous run with both flags false, send `Accept: application/x-ndjson` for heartbeat frames and a final frame containing `data`. Timeouts return `200` with `status: "failed"` and `error.code: "TIMEOUT"`; inspect run status. See [Streaming](/workflows/deployment/api#streaming) for event formats. Input descriptions specify compatible modes; invalid combinations return `400`.\n\nSupply `X-Run-Id` to prevent duplicate execution. Reuse returns `409`, without replaying results. A `503` with `error.details.code: "ASYNC_ENQUEUE_AMBIGUOUS"` omits `Retry-After` because the run may already have started. Reconcile using the returned run ID; do not start another run with a new or omitted ID.\n\nOAuth scope: `api:write`.',
     handler: () =>
       import('@/app/api/v2/workflows/[workflowId]/execute/route').then((route) => route.POST),
   },

apps/sim/lib/mcp/output-schema.ts

@@ -15,15 +15,21 @@ const MAX_SHAPE_DEPTH = 8
 const MAX_SHAPE_NODES = 500
 
 /**
- * The structure of a declared output schema: types, properties and array items
- * only. Descriptions, enums and examples are dropped because the snapshot is a
- * block input, and the executor and lint read every string in a block's inputs
- * as a possible `<block.path>` reference.
+ * The structure of a declared output schema: types, properties, openness and
+ * array items only. Descriptions, enums and examples are dropped because the
+ * snapshot is a block input, and the executor and lint read every string in a
+ * block's inputs as a possible `<block.path>` reference.
  */
 export interface McpToolOutputShape {
   type: 'object' | 'array' | 'string' | 'number' | 'boolean' | 'any'
-  /** Declared fields of a closed object; absent when the object is open or undeclared. */
+  /** Declared fields of an object; absent when it declares none, which leaves every field allowed. */
   properties?: Record<string, McpToolOutputShape>
+  /**
+   * The object allows fields beyond `properties`, as JSON Schema reads any object
+   * not declaring `additionalProperties: false`. A snapshot saved before this was
+   * recorded lacks it and stays closed until the operation is picked again.
+   */
+  open?: true
   items?: McpToolOutputShape
 }
 
@@ -67,23 +73,28 @@ function reduceNode(node: unknown, depth: number, budget: { nodes: number }): Mc
 
   switch (declaredType(node)) {
     case 'object': {
-      const open =
-        (node.additionalProperties !== undefined && node.additionalProperties !== false) ||
-        node.patternProperties !== undefined
-      if (open || !isRecordLike(node.properties)) return { type: 'object' }
+      if (!isRecordLike(node.properties)) return { type: 'object' }
       const entries: [string, McpToolOutputShape][] = []
       for (const [name, child] of Object.entries(node.properties)) {
-        /** Past the budget the object stays open: any field resolves, none is saved. */
+        /** Past the budget the object is saved untyped: any field resolves, none is declared. */
         if (budget.nodes <= 0) return { type: 'object' }
         entries.push([name, reduceNode(child, depth + 1, budget)])
       }
-      /** `fromEntries` keeps every declared name, `__proto__` included, as an own field. */
-      return { type: 'object', properties: Object.fromEntries(entries) }
+      const closed = node.additionalProperties === false && node.patternProperties === undefined
+      return {
+        type: 'object',
+        /** `fromEntries` keeps every declared name, `__proto__` included, as an own field. */
+        properties: Object.fromEntries(entries),
+        ...(!closed && { open: true }),
+      }
     }
     case 'array':
-      return isRecordLike(node.items)
-        ? { type: 'array', items: reduceNode(node.items, depth + 1, budget) }
-        : { type: 'array' }
+      return {
+        type: 'array',
+        items: isRecordLike(node.items)
+          ? reduceNode(node.items, depth + 1, budget)
+          : { type: 'any' },
+      }
     case 'string':
       return { type: 'string' }
     case 'number':
@@ -139,6 +150,7 @@ function isShape(value: unknown, depth = 0): value is McpToolOutputShape {
     return false
   }
   if (depth > MAX_SHAPE_DEPTH + 1) return false
+  if (value.open !== undefined && value.open !== true) return false
   if (value.items !== undefined && !isShape(value.items, depth + 1)) return false
   if (value.properties === undefined) return true
   return (

apps/sim/lib/workflows/blocks/outputs.ts

@@ -437,6 +437,8 @@ export function getEvaluatorMetricOutputs(
 interface DeclaredOutputNode {
   type: PrimitiveValueType
   properties?: Record<string, DeclaredOutputNode>
+  /** Fields beyond `properties` are allowed: a reference to one checks like any `json` path. */
+  open?: true
   items?: DeclaredOutputNode
 }
 
@@ -449,6 +451,7 @@ function toOutputNode(shape: McpToolOutputShape): DeclaredOutputNode {
             properties: Object.fromEntries(
               Object.entries(shape.properties).map(([name, child]) => [name, toOutputNode(child)])
             ),
+            ...(shape.open && { open: true }),
           }
         : { type: 'json' }
     case 'array':

apps/sim/lib/workflows/editing/dangling-refs.test.ts

@@ -284,8 +284,13 @@ describe('collectDanglingBlockOutputReferences', () => {
       type: 'object' as const,
       properties: {
         role: { type: 'string' },
-        person: { type: 'object', properties: { id: { type: 'string' } } },
+        person: {
+          type: 'object',
+          properties: { id: { type: 'string' } },
+          additionalProperties: false,
+        },
       },
+      additionalProperties: false,
     }
 
     function mcpGraph(
@@ -366,7 +371,11 @@ describe('collectDanglingBlockOutputReferences', () => {
             type: 'array',
             items: {
               type: 'array',
-              items: { type: 'object', properties: { id: { type: 'string' } } },
+              items: {
+                type: 'object',
+                properties: { id: { type: 'string' } },
+                additionalProperties: false,
+              },
             },
           },
         },
@@ -382,6 +391,35 @@ describe('collectDanglingBlockOutputReferences', () => {
       expect(finding?.reason).toContain('Declared fields: structuredContent.rows.id')
     })
 
+    it('accepts an undeclared field of an object the schema leaves open', () => {
+      const open = createMcpToolOutputSnapshot('server-1', 'on_call', {
+        type: 'object',
+        properties: {
+          role: { type: 'string' },
+          person: { type: 'object', properties: { id: { type: 'string' } } },
+        },
+        additionalProperties: false,
+      })
+      expect(
+        collectDanglingBlockOutputReferences(
+          mcpGraph('<oncall.structuredContent.person.email>', open)
+        )
+      ).toEqual([])
+    })
+
+    it('accepts a path inside the elements of an array that declares no items', () => {
+      const untypedItems = createMcpToolOutputSnapshot('server-1', 'on_call', {
+        type: 'object',
+        properties: { rows: { type: 'array' } },
+        additionalProperties: false,
+      })
+      expect(
+        collectDanglingBlockOutputReferences(
+          mcpGraph('<oncall.structuredContent.rows.0.id>', untypedItems)
+        )
+      ).toEqual([])
+    })
+
     it('keeps flagging structuredContent when the operation declares no schema', () => {
       for (const snapshot of [
         undefined,