Retell AI MCP Server

Instructions

Implementation Reference

• src/index.ts:1201-1202 (handler)

  The handler logic for the 'retell_create_llm' tool in the executeTool switch statement. It forwards the request to Retell's API endpoint /create-retell-llm.

  case "retell_create_llm":
    return retellRequest("/create-retell-llm", "POST", args);

• src/index.ts:702-739 (registration)

  Registration of the 'retell_create_llm' tool in the tools array, including name, description, and inputSchema for validation.

  {
    name: "retell_create_llm",
    description: "Create a new Retell LLM configuration with custom prompts and settings.",
    inputSchema: {
      type: "object",
      properties: {
        model: {
          type: "string",
          description: "The base model (e.g., 'gpt-4o', 'claude-3.5-sonnet', 'gpt-4o-mini')"
        },
        general_prompt: {
          type: "string",
          description: "The main system prompt defining the agent's behavior and personality"
        },
        begin_message: {
          type: "string",
          description: "Optional: The greeting message the agent says when call starts"
        },
        general_tools: {
          type: "array",
          description: "Optional: Array of tool configurations for function calling",
          items: {
            type: "object"
          }
        },
        inbound_dynamic_variables_webhook_url: {
          type: "string",
          description: "Optional: Webhook URL to fetch dynamic variables for inbound calls"
        },
        knowledge_base_ids: {
          type: "array",
          items: { type: "string" },
          description: "Optional: Array of knowledge base IDs to use"
        }
      },
      required: ["model", "general_prompt"]
    }
  },