Letta Models and Providers API

openapi: 3.0.3
info:
  title: Letta Agent Templates Models and Providers 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: Models and Providers
  description: Available models and configured BYOK model providers.
paths:
  /v1/models/:
    get:
      tags:
      - Models and Providers
      summary: List Llm Models
      description: List available LLM models using the asynchronous implementation for improved performance.
      parameters:
      - name: provider_category
        in: query
        required: false
        schema:
          type: string
      - name: provider_name
        in: query
        required: false
        schema:
          type: string
      - name: provider_type
        in: query
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Model'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v1/models/embedding:
    get:
      tags:
      - Models and Providers
      summary: List Embedding Models
      description: List available embedding models using the asynchronous implementation for improved performance.
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Model'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v1/providers/:
    get:
      tags:
      - Models and Providers
      summary: List Providers
      description: Get a list of all custom providers.
      parameters:
      - name: before
        in: query
        required: false
        description: Provider ID cursor for pagination. Returns providers that come before this provider ID in the specified sort order
        schema:
          type: string
      - name: after
        in: query
        required: false
        description: Provider ID cursor for pagination. Returns providers that come after this provider ID in the specified sort order
        schema:
          type: string
      - name: limit
        in: query
        required: false
        description: Maximum number of providers to return
        schema:
          type: string
          default: 50
      - name: order
        in: query
        required: false
        description: Sort order for providers by creation time. 'asc' for oldest first, 'desc' for newest first
        schema:
          type: string
          default: desc
          enum:
          - asc
          - desc
      - name: order_by
        in: query
        required: false
        description: Field to sort by
        schema:
          type: string
          default: created_at
      - name: name
        in: query
        required: false
        description: Filter providers by name
        schema:
          type: string
      - name: provider_type
        in: query
        required: false
        description: Filter providers by type
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Provider'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      tags:
      - Models and Providers
      summary: Create Provider
      description: Create a new custom provider.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateProviderRequest'
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Provider'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /v1/providers/check:
    post:
      tags:
      - Models and Providers
      summary: Check Provider
      description: Verify the API key and additional parameters for a provider.
      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'
        '422':
          $ref: '#/components/responses/ValidationError'
  /v1/providers/{provider_id}:
    get:
      tags:
      - Models and Providers
      summary: Retrieve Provider
      description: Get a provider by ID.
      parameters:
      - name: provider_id
        in: path
        required: true
        description: The ID of the provider in the format 'provider-<uuid4>'
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Provider'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    patch:
      tags:
      - Models and Providers
      summary: Modify Provider
      description: Update an existing custom provider.
      parameters:
      - name: provider_id
        in: path
        required: true
        description: The ID of the provider in the format 'provider-<uuid4>'
        schema:
          type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateProviderRequest'
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Provider'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '422':
          $ref: '#/components/responses/ValidationError'
    delete:
      tags:
      - Models and Providers
      summary: Delete Provider
      description: Delete an existing custom provider.
      parameters:
      - name: provider_id
        in: path
        required: true
        description: The ID of the provider in the format 'provider-<uuid4>'
        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/providers/{provider_id}/check:
    post:
      tags:
      - Models and Providers
      summary: Check Existing Provider
      description: Verify the API key and additional parameters for an existing provider.
      parameters:
      - name: provider_id
        in: path
        required: true
        description: The ID of the provider in the format 'provider-<uuid4>'
        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/providers/{provider_id}/refresh:
    patch:
      tags:
      - Models and Providers
      summary: Refresh Provider Models
      description: 'Refresh models for a BYOK provider by querying the provider''s API.

        Adds new models and removes ones no longer available.'
      parameters:
      - name: provider_id
        in: path
        required: true
        description: The ID of the provider in the format 'provider-<uuid4>'
        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'
components:
  schemas:
    CreateProviderRequest:
      type: object
      required:
      - name
      - provider_type
      - api_key
      properties:
        name:
          type: string
        provider_type:
          type: string
        api_key:
          type: string
        base_url:
          type: string
    Provider:
      type: object
      description: A bring-your-own-key model provider configured on a Letta deployment.
      properties:
        id:
          type: string
        name:
          type: string
        provider_type:
          type: string
          example: anthropic
        provider_category:
          type: string
          enum:
          - base
          - byok
        api_key:
          type: string
          writeOnly: true
        base_url:
          type: string
        region:
          type: string
        updated_at:
          type: string
          format: date-time
        last_synced:
          type: string
          format: date-time
    HTTPValidationError:
      type: object
      properties:
        detail:
          type: array
          items:
            type: object
            properties:
              loc:
                type: array
                items:
                  type: string
              msg:
                type: string
              type:
                type: string
    Model:
      type: object
      description: An LLM or embedding model available on Letta.
      properties:
        handle:
          type: string
          example: openai/gpt-4o
        name:
          type: string
        display_name:
          type: string
        provider_type:
          type: string
        provider_name:
          type: string
        model_type:
          type: string
        context_window:
          type: integer
        max_tokens:
          type: integer
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            code:
              type: string
  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'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'API key created at https://app.letta.com/api-keys, passed as `Authorization: Bearer YOUR_API_KEY`.'