list_calls

Instructions

Implementation Reference

• src/tools/call.ts:19-22 (handler)

  The main handler for the 'list_calls' tool. It calls vapiClient.calls.list({ limit: 10 }) and transforms the output using transformCallOutput.

  createToolHandler(async () => {
    const calls = await vapiClient.calls.list({ limit: 10 });
    return calls.map(transformCallOutput);
  })

• src/tools/call.ts:15-23 (registration)

  Registration of the 'list_calls' tool via server.tool(), which registers it with name 'list_calls', description 'Lists all Vapi calls', an empty schema (no input params), and the handler.

  server.tool(
    'list_calls',
    'Lists all Vapi calls',
    {},
    createToolHandler(async () => {
      const calls = await vapiClient.calls.list({ limit: 10 });
      return calls.map(transformCallOutput);
    })
  );

• src/tools/utils.ts:44-72 (helper)

  The createToolHandler wrapper used by list_calls. It handles auth checking (valid token, auth flow), calls the actual handler, and wraps results in success/error responses.

  export function createToolHandler<T>(
    handler: (params: T) => Promise<any>
  ): (params: T) => Promise<ToolResponse> {
    return async (params: T) => {
      // Check auth first
      if (!hasValidToken()) {
        // Start auth if not already in progress
        if (!isAuthInProgress()) {
          try {
            await startAuthFlow();
          } catch (error) {
            // Ignore - we'll show the auth URL below
          }
        }
        const url = getAuthUrl();
        if (url) {
          return createAuthRequiredResponse(url);
        }
        return createErrorResponse('Authentication required. Please use vapi_login tool first.');
      }
  
      try {
        const result = await handler(params);
        return createSuccessResponse(result);
      } catch (error) {
        return createErrorResponse(error);
      }
    };
  }

• src/schemas/index.ts:290-301 (schema)

  The CallOutputSchema used by transformCallOutput to validate the structure of call data returned from list_calls.

  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(),
      })
      .optional(),
    scheduledAt: z.string().optional(),
  });

• src/tools/index.ts:9-14 (registration)

  The registerAllTools function that calls registerCallTools, which in turn registers the list_calls tool on the MCP server.

  export const registerAllTools = (server: McpServer, vapiClient: VapiClient) => {
    registerAssistantTools(server, vapiClient);
    registerCallTools(server, vapiClient);
    registerPhoneNumberTools(server, vapiClient);
    registerToolTools(server, vapiClient);
  };