Retell AI MCP Server

Instructions

Implementation Reference

• src/index.ts:1131-1134 (handler)

  Handler for retell_update_call: extracts call_id from arguments, sends PATCH request to Retell API /v2/update-call/{call_id} with remaining args as body.

  case "retell_update_call": {
    const { call_id, ...updateData } = args;
    return retellRequest(`/v2/update-call/${call_id}`, "PATCH", updateData as Record<string, unknown>);
  }

• src/index.ts:161-183 (schema)

  Tool schema definition including name, description, and inputSchema with properties call_id (required), metadata, data_storage_setting.

  {
    name: "retell_update_call",
    description: "Update call metadata or data storage settings for a specific call.",
    inputSchema: {
      type: "object",
      properties: {
        call_id: {
          type: "string",
          description: "The unique identifier of the call to update"
        },
        metadata: {
          type: "object",
          description: "New metadata to set for the call"
        },
        data_storage_setting: {
          type: "string",
          enum: ["everything", "everything_except_pii", "basic_attributes_only"],
          description: "Data retention policy for the call"
        }
      },
      required: ["call_id"]
    }
  },

• src/index.ts:1283-1285 (registration)

  Registers the list tools handler which returns the tools array containing the retell_update_call tool definition.

  server.setRequestHandler(ListToolsRequestSchema, async () => {
    return { tools };
  });