fix: complete tool calls with server results

.changeset/server-tool-results-complete.md

@@ -0,0 +1,7 @@
+---
+'@tanstack/ai': patch
+'@tanstack/ai-client': patch
+'@tanstack/ai-event-client': patch
+---
+
+Populate server-executed tool results on the matching `tool-call` part and mark successful tool calls as `complete`.

packages/typescript/ai-client/src/types.ts

@@ -25,6 +25,7 @@ export type ToolCallState =
   | 'input-complete' // All arguments received
   | 'approval-requested' // Waiting for user approval
   | 'approval-responded' // User has approved/denied
+  | 'complete' // Result is complete
 
 /**
  * Tool result states - track the lifecycle of a tool result

packages/typescript/ai-event-client/src/index.ts

@@ -112,6 +112,7 @@ export type ToolCallState =
   | 'input-complete' // All arguments received
   | 'approval-requested' // Waiting for user approval
   | 'approval-responded' // User has approved/denied
+  | 'complete' // Result is complete
 
 /**
  * Tool result states - track the lifecycle of a tool result

packages/typescript/ai/src/activities/chat/messages.ts

@@ -200,6 +200,7 @@ function createSegment(): AssistantSegment {
 function isToolCallIncluded(part: ToolCallPart): boolean {
   return (
     part.state === 'input-complete' ||
+    part.state === 'complete' ||
     part.state === 'approval-responded' ||
     part.output !== undefined
   )

packages/typescript/ai/src/activities/chat/stream/message-updaters.ts

@@ -217,11 +217,7 @@ export function updateToolCallWithOutput(
 
     if (toolCallPart) {
       toolCallPart.output = errorText ? { error: errorText } : output
-      if (state) {
-        toolCallPart.state = state
-      } else {
-        toolCallPart.state = 'input-complete'
-      }
+      toolCallPart.state = state ?? (errorText ? 'input-complete' : 'complete')
     }
 
     return { ...msg, parts }

packages/typescript/ai/src/activities/chat/stream/processor.ts

@@ -378,6 +378,7 @@ export class StreamProcessor {
     // 3. It has a corresponding tool-result part (server tool completed)
     return toolParts.every(
       (part) =>
+        part.state === 'complete' ||
         part.state === 'approval-responded' ||
         (part.output !== undefined && !part.approval) ||
         toolResultIds.has(part.id),

packages/typescript/ai/src/types.ts

@@ -40,6 +40,7 @@ export type ToolCallState =
   | 'input-complete' // All arguments received
   | 'approval-requested' // Waiting for user approval
   | 'approval-responded' // User has approved/denied
+  | 'complete' // Result is complete
 
 /**
  * Tool result states - track the lifecycle of a tool result

packages/typescript/ai/tests/message-updaters.test.ts

@@ -538,7 +538,7 @@ describe('message-updaters', () => {
   })
 
   describe('updateToolCallWithOutput', () => {
-    it('should update tool call with output', () => {
+    it('should update tool call with output and complete state', () => {
       const messages = [
         createMessage('msg-1', 'assistant', [
           {
@@ -558,7 +558,7 @@ describe('message-updaters', () => {
         id: 'call-1',
         name: 'getWeather',
         arguments: '{}',
-        state: 'input-complete',
+        state: 'complete',
         output,
       })
     })
@@ -588,7 +588,7 @@ describe('message-updaters', () => {
       expect(part?.output).toEqual(output)
     })
 
-    it('should default to input-complete state when not provided', () => {
+    it('should default to complete state when not provided', () => {
       const messages = [
         createMessage('msg-1', 'assistant', [
           {
@@ -604,7 +604,7 @@ describe('message-updaters', () => {
       const result = updateToolCallWithOutput(messages, 'call-1', output)
 
       const part = result[0]?.parts[0] as ToolCallPart | undefined
-      expect(part?.state).toBe('input-complete')
+      expect(part?.state).toBe('complete')
     })
 
     it('should handle error output', () => {
@@ -629,6 +629,7 @@ describe('message-updaters', () => {
 
       const part = result[0]?.parts[0] as ToolCallPart | undefined
       expect(part?.output).toEqual({ error: 'Tool execution failed' })
+      expect(part?.state).toBe('input-complete')
     })
 
     it('should search across all messages', () => {

packages/typescript/ai/tests/stream-processor.test.ts

@@ -917,6 +917,7 @@ describe('StreamProcessor', () => {
         (p) => p.type === 'tool-call',
       ) as ToolCallPart
       expect((toolCallPart as any).output).toEqual({ temp: 72 })
+      expect(toolCallPart.state).toBe('complete')
 
       const toolResultPart = messages[0]?.parts.find(
         (p) => p.type === 'tool-result',
@@ -981,6 +982,7 @@ describe('StreamProcessor', () => {
         (p) => p.type === 'tool-call',
       ) as ToolCallPart
       expect((toolCallPart as any).output).toEqual({ temp: 72 })
+      expect(toolCallPart.state).toBe('complete')
 
       const toolResultPart = messages[0]!.parts.find(
         (p) => p.type === 'tool-result',
@@ -1020,6 +1022,7 @@ describe('StreamProcessor', () => {
         .getMessages()[0]!
         .parts.find((p) => p.type === 'tool-call') as ToolCallPart
       expect((toolCallPart as any).output).toEqual({ error: 'Network error' })
+      expect(toolCallPart.state).toBe('input-complete')
 
       const toolResultPart = processor
         .getMessages()[0]!
@@ -3326,6 +3329,7 @@ describe('StreamProcessor', () => {
         (p) => p.type === 'tool-call',
       ) as ToolCallPart
       expect((toolCallPart as any).output).toEqual({ temp: 72 })
+      expect(toolCallPart.state).toBe('complete')
 
       const toolResultPart = messages[0]?.parts.find(
         (p) => p.type === 'tool-result',

testing/e2e/tests/tools-test/helpers.ts

@@ -180,6 +180,21 @@ export async function getToolCalls(
   })
 }
 
+/**
+ * Parse the full UIMessage array from #messages-json-content.
+ */
+export async function getMessages(page: Page): Promise<Array<any>> {
+  return page.evaluate(() => {
+    const el = document.getElementById('messages-json-content')
+    if (!el) return []
+    try {
+      return JSON.parse(el.textContent || '[]')
+    } catch {
+      return []
+    }
+  })
+}
+
 /**
  * Extract tool-call parts with parsed arguments from #messages-json-content.
  */

testing/e2e/tests/tools-test/server-client-sequence.spec.ts

@@ -6,6 +6,7 @@ import {
   getMetadata,
   getEventLog,
   getToolCalls,
+  getMessages,
 } from './helpers'
 
 /**
@@ -58,6 +59,73 @@ test.describe('Server-Client Sequence E2E Tests', () => {
     expect(chartExecution).toBeTruthy()
   })
 
+  test('server and client tool results populate tool-call output and complete state', async ({
+    page,
+    testId,
+    aimockPort,
+  }) => {
+    await selectScenario(page, 'sequence-server-client', testId, aimockPort)
+    await runTest(page)
+
+    await waitForTestComplete(page, 15000, 2)
+
+    await page.waitForFunction(
+      () => {
+        const messagesEl = document.getElementById('messages-json-content')
+        const messages = JSON.parse(messagesEl?.textContent || '[]')
+        const toolCalls = messages.flatMap((msg: any) =>
+          (msg.parts || []).filter((part: any) => part.type === 'tool-call'),
+        )
+
+        const fetchData = toolCalls.find(
+          (part: any) => part.name === 'fetch_data',
+        )
+        const displayChart = toolCalls.find(
+          (part: any) => part.name === 'display_chart',
+        )
+
+        return (
+          fetchData?.state === 'complete' &&
+          fetchData.output !== undefined &&
+          displayChart?.state === 'complete' &&
+          displayChart.output !== undefined
+        )
+      },
+      { timeout: 10000 },
+    )
+
+    const messages = await getMessages(page)
+    const toolCalls = messages.flatMap((msg) =>
+      (msg.parts || []).filter((part: any) => part.type === 'tool-call'),
+    )
+    const toolResults = messages.flatMap((msg) =>
+      (msg.parts || []).filter((part: any) => part.type === 'tool-result'),
+    )
+
+    const fetchData = toolCalls.find((part) => part.name === 'fetch_data')
+    expect(fetchData).toMatchObject({
+      state: 'complete',
+      output: {
+        source: 'api',
+        data: [1, 2, 3, 4, 5],
+      },
+    })
+
+    const displayChart = toolCalls.find((part) => part.name === 'display_chart')
+    expect(displayChart?.state).toBe('complete')
+    expect(displayChart?.output).toMatchObject({ rendered: true })
+    expect(typeof displayChart?.output?.chartId).toBe('string')
+
+    expect(
+      toolResults.some(
+        (part) =>
+          part.toolCallId === fetchData?.id &&
+          part.state === 'complete' &&
+          JSON.parse(part.content).source === 'api',
+      ),
+    ).toBe(true)
+  })
+
   test('server then two client tools in sequence', async ({
     page,
     testId,
@@ -162,10 +230,7 @@ test.describe('Server-Client Sequence E2E Tests', () => {
     const toolCalls = await getToolCalls(page)
     const weatherTool = toolCalls.find((tc) => tc.name === 'get_weather')
     expect(weatherTool).toBeTruthy()
-    // Server tools stay at 'input-complete' state but are tracked as complete via tool-result parts
-    expect(['complete', 'input-complete', 'output-available']).toContain(
-      weatherTool?.state,
-    )
+    expect(weatherTool?.state).toBe('complete')
   })
 
   test('text only scenario has no tool calls', async ({