fix: return full API response from get_call including messages/transcript

The get_call tool was only returning a subset of fields from the Vapi API.
This change updates transformCallOutput to pass through the complete API
response, including:

- messages (full transcript with role, content, timestamps)
- transcript (plain text transcript)
- recordingUrl and stereoRecordingUrl
- cost and costBreakdown
- analysis and artifact data
- Additional call metadata

The CallOutputSchema has been updated to document these fields while using
passthrough() to allow any additional fields from the API.

Fixes: PRISM-5

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Vapi Tasker

src/__tests__/transformers.test.ts

@@ -0,0 +1,113 @@
+import { transformCallOutput } from '../transformers/index.js';
+import { Vapi } from '@vapi-ai/server-sdk';
+
+describe('transformCallOutput', () => {
+  // Use type assertion to allow setting all fields including those returned by API
+  const mockCallWithMessages = {
+    id: 'call-123',
+    orgId: 'org-456',
+    createdAt: '2025-01-15T10:00:00.000Z',
+    updatedAt: '2025-01-15T10:05:00.000Z',
+    status: 'ended',
+    endedReason: 'assistant-ended-call',
+    assistantId: 'asst-789',
+    phoneNumberId: 'pn-012',
+    customer: {
+      number: '+15551234567',
+    },
+    messages: [
+      {
+        role: 'assistant',
+        message: 'Hello! How can I help you today?',
+        time: 1705312800000,
+        secondsFromStart: 0,
+      },
+      {
+        role: 'user',
+        message: 'I need help with my order.',
+        time: 1705312805000,
+        secondsFromStart: 5,
+      },
+      {
+        role: 'assistant',
+        message: 'Of course! Can you provide your order number?',
+        time: 1705312810000,
+        secondsFromStart: 10,
+      },
+    ],
+    transcript: 'Hello! How can I help you today?\nI need help with my order.\nOf course! Can you provide your order number?',
+    recordingUrl: 'https://example.com/recording.mp3',
+    stereoRecordingUrl: 'https://example.com/stereo-recording.mp3',
+    costBreakdown: {
+      stt: 0.01,
+      llm: 0.05,
+      tts: 0.02,
+      vapi: 0.03,
+      total: 0.11,
+    },
+    cost: 0.11,
+  } as Vapi.Call;
+
+  it('should include messages array in the output', () => {
+    const result = transformCallOutput(mockCallWithMessages);
+
+    // This test verifies that messages are included in the output
+    expect(result.messages).toBeDefined();
+    expect(Array.isArray(result.messages)).toBe(true);
+    expect(result.messages!).toHaveLength(3);
+    expect(result.messages![0]).toMatchObject({
+      role: 'assistant',
+      message: 'Hello! How can I help you today?',
+    });
+  });
+
+  it('should include transcript in the output', () => {
+    const result = transformCallOutput(mockCallWithMessages);
+
+    expect(result.transcript).toBeDefined();
+    expect(result.transcript).toContain('Hello! How can I help you today?');
+  });
+
+  it('should include recording URLs in the output', () => {
+    const result = transformCallOutput(mockCallWithMessages);
+
+    expect(result.recordingUrl).toBe('https://example.com/recording.mp3');
+    expect(result.stereoRecordingUrl).toBe('https://example.com/stereo-recording.mp3');
+  });
+
+  it('should include cost information in the output', () => {
+    const result = transformCallOutput(mockCallWithMessages);
+
+    expect(result.cost).toBe(0.11);
+    expect(result.costBreakdown).toBeDefined();
+    expect(result.costBreakdown!.total).toBe(0.11);
+  });
+
+  it('should still include basic call fields', () => {
+    const result = transformCallOutput(mockCallWithMessages);
+
+    expect(result.id).toBe('call-123');
+    expect(result.createdAt).toBe('2025-01-15T10:00:00.000Z');
+    expect(result.updatedAt).toBe('2025-01-15T10:05:00.000Z');
+    expect(result.status).toBe('ended');
+    expect(result.endedReason).toBe('assistant-ended-call');
+    expect(result.assistantId).toBe('asst-789');
+    expect(result.phoneNumberId).toBe('pn-012');
+    expect(result.customer?.number).toBe('+15551234567');
+  });
+
+  it('should handle calls without messages gracefully', () => {
+    const callWithoutMessages: Vapi.Call = {
+      id: 'call-no-messages',
+      orgId: 'org-456',
+      createdAt: '2025-01-15T10:00:00.000Z',
+      updatedAt: '2025-01-15T10:00:00.000Z',
+      status: 'queued',
+    };
+
+    const result = transformCallOutput(callWithoutMessages);
+
+    expect(result.id).toBe('call-no-messages');
+    expect(result.messages).toBeUndefined();
+  });
+});

src/schemas/index.ts

@@ -287,18 +287,54 @@ export const CallInputSchema = z.object({
     .describe('Overrides for the assistant configuration'),
 });
 
+// Message schema for call transcript messages
+const CallMessageSchema = z.object({
+  role: z.string(),
+  message: z.string().optional(),
+  time: z.number().optional(),
+  secondsFromStart: z.number().optional(),
+  content: z.string().optional(),
+}).passthrough();
+
+// Cost breakdown schema
+const CostBreakdownSchema = z.object({
+  stt: z.number().optional(),
+  llm: z.number().optional(),
+  tts: z.number().optional(),
+  vapi: z.number().optional(),
+  total: z.number().optional(),
+}).passthrough();
+
 export const CallOutputSchema = BaseResponseSchema.extend({
   status: z.string(),
   endedReason: z.string().optional(),
   assistantId: z.string().optional(),
   phoneNumberId: z.string().optional(),
   customer: z
     .object({
-      number: z.string(),
+      number: z.string().optional(),
     })
+    .passthrough()
     .optional(),
   scheduledAt: z.string().optional(),
-});
+  // Full transcript fields
+  messages: z.array(CallMessageSchema).optional(),
+  transcript: z.string().optional(),
+  // Recording URLs
+  recordingUrl: z.string().optional(),
+  stereoRecordingUrl: z.string().optional(),
+  // Cost information
+  cost: z.number().optional(),
+  costBreakdown: CostBreakdownSchema.optional(),
+  // Analysis and artifact data
+  analysis: z.any().optional(),
+  artifact: z.any().optional(),
+  // Additional call metadata
+  startedAt: z.string().optional(),
+  endedAt: z.string().optional(),
+  type: z.string().optional(),
+  // Allow any additional fields from the API
+}).passthrough();
 
 export const GetCallInputSchema = z.object({
   callId: z.string().describe('ID of the call to get'),

src/transformers/index.ts

@@ -211,21 +211,17 @@ export function transformCallInput(
 export function transformCallOutput(
   call: Vapi.Call
 ): z.infer<typeof CallOutputSchema> {
+  // Return the full call object to include all fields from the API response,
+  // including messages (transcript), cost, recording URLs, etc.
+  // Using type assertion since Vapi.Call contains all the fields we need
+  // and we want to pass through the complete response.
   return {
-    id: call.id,
-    createdAt: call.createdAt,
-    updatedAt: call.updatedAt,
+    ...call,
+    // Ensure required fields have default values
     status: call.status || '',
-    endedReason: call.endedReason,
-    assistantId: call.assistantId,
-    phoneNumberId: call.phoneNumberId,
-    customer: call.customer
-      ? {
-          number: call.customer.number || '',
-        }
-      : undefined,
+    // Map schedulePlan.earliestAt to scheduledAt for backward compatibility
     scheduledAt: call.schedulePlan?.earliestAt,
-  };
+  } as z.infer<typeof CallOutputSchema>;
 }
 
 // ===== Phone Number Transformers =====