Letta

Letta MCP Servers API

Remote Model Context Protocol tool servers.

GitHub OpenAPI

Documentation

📖
Documentation
https://docs.letta.com/guides/core-concepts/stateful-agents/
📖
APIReference
https://docs.letta.com/api-reference/agents/list
📖
Documentation
https://docs.letta.com/guides/core-concepts/messages/streaming/
📖
APIReference
https://docs.letta.com/api-reference/agents/messages/create
📖
Documentation
https://docs.letta.com/guides/core-concepts/memory/memory-blocks/
📖
APIReference
https://docs.letta.com/api-reference/blocks/list
📖
Documentation
https://docs.letta.com/guides/core-concepts/memory/archival-memory/
📖
APIReference
https://docs.letta.com/api-reference/archives/list-archives
📖
Documentation
https://docs.letta.com/guides/core-concepts/tools/server-tools/
📖
APIReference
https://docs.letta.com/api-reference/tools/list
📖
Documentation
https://docs.letta.com/guides/core-concepts/tools/mcp-tools/
📖
APIReference
https://docs.letta.com/api-reference/tools/list-mcp-servers
📖
Documentation
https://docs.letta.com/guides/core-concepts/filesystem/
📖
APIReference
https://docs.letta.com/api-reference/sources/list
📖
APIReference
https://docs.letta.com/api-reference/agents/identities/attach
📖
Documentation
https://docs.letta.com/guides/core-concepts/memory/shared-memory/
📖
APIReference
https://raw.githubusercontent.com/letta-ai/letta/main/fern/openapi.json
📖
Documentation
https://docs.letta.com/guides/build-with-letta/models/
📖
APIReference
https://docs.letta.com/api-reference/models/list
📖
Documentation
https://docs.letta.com/guides/observability/monitoring
📖
APIReference
https://docs.letta.com/api-reference/runs/list
📖
APIReference
https://docs.letta.com/api-reference/jobs/list
📖
Documentation
https://docs.letta.com/guides/templates/client-side-tokens/

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/letta-ai/refs/heads/main/openapi/letta-ai-mcp-servers-api-openapi.yml
⚙
AsyncAPI
https://raw.githubusercontent.com/api-evangelist/letta-ai/refs/heads/main/asyncapi/letta-ai-asyncapi.yml

OpenAPI Specification

letta-ai-mcp-servers-api-openapi.yml Raw ↑ 
openapi: 3.0.3
info:
  title: Letta Agent Templates MCP Servers API
  description: The Letta API creates and operates stateful AI agents whose memory - core context blocks and archival vector memory - persists across sessions. It configures the tools, data sources, identities, and multi-agent groups an agent uses, sends and streams messages to agents, and inspects the runs, jobs, and steps behind every agent response. The same OpenAPI-documented interface is served by the managed Letta Cloud API and by the open-source, self-hostable Letta server. All requests require a Bearer API key.
  version: 1.0.0
  contact:
    name: Letta
    url: https://www.letta.com
  license:
    name: Apache-2.0
    url: https://github.com/letta-ai/letta/blob/main/LICENSE
servers:
- url: https://api.letta.com/v1
  description: Letta Cloud
- url: http://localhost:8283/v1
  description: Self-hosted (default local port)
security:
- bearerAuth: []
tags:
- name: MCP Servers
  description: Remote Model Context Protocol tool servers.
paths:
  /v1/mcp-servers/:
    post:
      tags:
      - MCP Servers
      summary: Create Mcp Server
      description: Add a new MCP server to the Letta MCP server config
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/McpServerConfig'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
    get:
      tags:
      - MCP Servers
      summary: List Mcp Servers
      description: Get a list of all configured MCP servers
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/McpServerConfig'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v1/mcp-servers/{mcp_server_id}:
    get:
      tags:
      - MCP Servers
      summary: Retrieve Mcp Server
      description: Get a specific MCP server
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/McpServerConfig'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      tags:
      - MCP Servers
      summary: Delete Mcp Server
      description: Delete an MCP server by its ID
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    patch:
      tags:
      - MCP Servers
      summary: Update Mcp Server
      description: Update an existing MCP server configuration
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '422':
          $ref: '#/components/responses/ValidationError'
  /v1/mcp-servers/{mcp_server_id}/refresh:
    patch:
      tags:
      - MCP Servers
      summary: Refresh Mcp Server Tools
      description: 'Refresh tools for an MCP server by:

        1. Fetching current tools from the MCP server

        2. Deleting tools that no longer exist on the server

        3. Updating schemas for existing tools

        4. Adding new tools from the server'
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      - name: agent_id
        in: query
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '422':
          $ref: '#/components/responses/ValidationError'
  /v1/mcp-servers/{mcp_server_id}/tools:
    get:
      tags:
      - MCP Servers
      summary: List Tools For Mcp Server
      description: Get a list of all tools for a specific MCP server
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /v1/mcp-servers/{mcp_server_id}/tools/{tool_id}:
    get:
      tags:
      - MCP Servers
      summary: Retrieve Mcp Tool
      description: Get a specific MCP tool by its ID
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      - name: tool_id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /v1/mcp-servers/{mcp_server_id}/tools/{tool_id}/run:
    post:
      tags:
      - MCP Servers
      summary: Run Mcp Tool
      description: Execute a specific MCP tool
      parameters:
      - name: mcp_server_id
        in: path
        required: true
        schema:
          type: string
      - name: tool_id
        in: path
        required: true
        schema:
          type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '422':
          $ref: '#/components/responses/ValidationError'
components:
  responses:
    Unauthorized:
      description: Missing or invalid Bearer API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/HTTPValidationError'
  schemas:
    HTTPValidationError:
      type: object
      properties:
        detail:
          type: array
          items:
            type: object
            properties:
              loc:
                type: array
                items:
                  type: string
              msg:
                type: string
              type:
                type: string
    McpServerConfig:
      type: object
      description: A configured remote MCP (Model Context Protocol) tool server. Shape varies by transport (stdio, SSE, or Streamable HTTP).
      properties:
        id:
          type: string
        server_name:
          type: string
        type:
          type: string
          enum:
          - sse
          - stdio
          - streamable_http
        server_url:
          type: string
          format: uri
        command:
          type: string
        args:
          type: array
          items:
            type: string
        env:
          type: object
          additionalProperties:
            type: string
        custom_headers:
          type: object
          additionalProperties:
            type: string
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            code:
              type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'API key created at https://app.letta.com/api-keys, passed as `Authorization: Bearer YOUR_API_KEY`.'