retell_get_phone_number

Retrieve details for a specific phone number to verify availability and configuration for AI voice agents.

Instructions

Retrieve details of a specific phone number.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`phone_number`	Yes	The phone number in E.164 format to retrieve

Implementation Reference

src/index.ts:1155-1156 (handler)
The switch case handler that executes the tool logic by calling the Retell API's GET /get-phone-number/{phone_number} endpoint with URL-encoded phone number.
```
case "retell_get_phone_number":
  return retellRequest(`/get-phone-number/${encodeURIComponent(args.phone_number as string)}`, "GET");
```

src/index.ts:342-351 (schema)

Input schema definition specifying the required 'phone_number' parameter as a string.

inputSchema: {
  type: "object",
  properties: {
    phone_number: {
      type: "string",
      description: "The phone number in E.164 format to retrieve"
    }
  },
  required: ["phone_number"]
}

src/index.ts:1283-1285 (registration)
MCP registration of the ListToolsRequestHandler, which returns the full tools array including 'retell_get_phone_number'.
```
server.setRequestHandler(ListToolsRequestSchema, async () => {
  return { tools };
});
```

src/index.ts:1288-1293 (registration)

MCP registration of the CallToolRequestHandler, which dispatches tool execution to executeTool based on name, invoking the handler for 'retell_get_phone_number'.

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const { name, arguments: args } = request.params;

  try {
    const result = await executeTool(name, args as Record<string, unknown>);
    return {

src/index.ts:23-57 (helper)

Core helper function for making authenticated API requests to Retell AI, used by the retell_get_phone_number handler and all other tools.

async function retellRequest(
  endpoint: string,
  method: string = "GET",
  body?: Record<string, unknown>
): Promise<unknown> {
  const apiKey = getApiKey();

  const headers: Record<string, string> = {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  };

  const options: RequestInit = {
    method,
    headers,
  };

  if (body && method !== "GET") {
    options.body = JSON.stringify(body);
  }

  const response = await fetch(`${RETELL_API_BASE}${endpoint}`, options);

  if (!response.ok) {
    const errorText = await response.text();
    throw new Error(`Retell API error (${response.status}): ${errorText}`);
  }

  // Handle 204 No Content
  if (response.status === 204) {
    return { success: true };
  }

  return response.json();
}

Retell AI MCP Server