Telnyx Anthropic Messages API

openapi: 3.2.0
info:
  version: 2.0.0
  x-latency-category: responsive
  x-endpoint-cost: light
  title: Telnyx Anthropic Messages API
  description: SIP trunking, SMS, MMS, Call Control and Telephony Data Services.
  contact:
    email: support@telnyx.com
servers:
- url: https://api.telnyx.com/v2
  description: Version 2.0.0 of the Telnyx API
security:
- bearerAuth: []
tags:
- name: Anthropic Messages
paths:
  /ai/anthropic/v1/messages:
    post:
      tags:
      - Anthropic Messages
      summary: Create a message (Anthropic-compatible)
      description: 'Send a message to a language model using the Anthropic Messages API format. This endpoint is compatible with the Anthropic Messages API and may be used with the Anthropic JS or Python SDK by setting the base URL to `https://api.telnyx.com/v2/ai/anthropic`.


        The endpoint translates Anthropic-format requests into Telnyx''s inference internals, then translates the response back to the Anthropic message shape. Streaming responses use Anthropic SSE event types (`message_start`, `content_block_start`, `content_block_delta`, `content_block_stop`, `message_delta`, `message_stop`).'
      operationId: create_anthropic_message
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnthropicMessageRequest'
            example:
              model: zai-org/GLM-5.3-Flash
              system: You are a friendly chatbot.
              messages:
              - role: user
                content: Hello, world!
              max_tokens: 1024
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
                description: 'An Anthropic-format message response with `type: "message"`, `role`, `content`, `stop_reason`, `stop_sequence`, and `usage`. When `stream` is true, the response is a text/event-stream of Anthropic SSE events.'
              example:
                id: msg_01B8b1f2a3c9d4e5f6a
                type: message
                role: assistant
                model: zai-org/GLM-5.3-Flash
                content:
                - type: text
                  text: Telnyx provides carrier-grade voice, messaging, and AI inference through one API.
                stop_reason: end_turn
                stop_sequence: null
                usage:
                  input_tokens: 24
                  output_tokens: 18
            text/event-stream:
              schema:
                type: string
                description: Anthropic-format Server-Sent Events stream.
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    AnthropicMessageRequest:
      properties:
        model:
          type: string
          description: The model to use for generating the response, for example `zai-org/GLM-5.3-Flash` or another model available from the Telnyx models endpoint.
        messages:
          type: array
          items:
            type: object
            additionalProperties: true
          description: The messages to send to the model, following the [Anthropic Messages API](https://docs.anthropic.com/en/api/messages) format.
        max_tokens:
          type: integer
          description: The maximum number of tokens to generate in the response.
        system:
          description: System prompt. Can be a string or an array of content blocks following the Anthropic API format.
          oneOf:
          - type: string
          - type: array
            items:
              type: object
              additionalProperties: true
        stream:
          type: boolean
          default: false
          description: Whether to stream the response as Anthropic-format Server-Sent Events.
        temperature:
          type: number
          description: Amount of randomness injected into the response. Ranges from 0 to 1.
        top_p:
          type: number
          description: Nucleus sampling parameter. Use temperature or top_p, but not both.
        top_k:
          type: integer
          description: Top-k sampling parameter. Only sample from the top K options for each subsequent token.
        stop_sequences:
          type: array
          items:
            type: string
          description: Custom sequences that will cause the model to stop generating.
        metadata:
          type: object
          additionalProperties: true
          description: An object describing metadata about the request.
        tools:
          type: array
          items:
            type: object
            additionalProperties: true
          description: Definitions of tools that the model may use, following the Anthropic API format.
        tool_choice:
          type: object
          additionalProperties: true
          description: Controls how the model uses tools, following the Anthropic API format.
        thinking:
          type: object
          additionalProperties: true
          description: Extended thinking configuration for models that support it. Set `type` to `enabled` to turn on extended thinking.
        api_key_ref:
          type: string
          description: If you are using an external inference provider, this field allows you to pass along a reference to your API key. After creating an [integration secret](https://developers.telnyx.com/api-reference/integration-secrets/create-a-secret) for your API key, pass the secret's `identifier` in this field.
        mcp_servers:
          type: array
          items:
            type: object
            additionalProperties: true
          description: List of MCP (Model Context Protocol) servers to make available to the model.
        fallback_config:
          type: object
          additionalProperties: true
          description: Configuration for model fallback behavior when the primary model is unavailable.
        billing_group_id:
          type: string
          format: uuid
          description: The billing group ID to associate with this request.
        timeout:
          type: number
          default: 300
          description: Request timeout in seconds.
        max_retries:
          type: integer
          description: Maximum number of retries for the request.
        service_tier:
          type: string
          description: The service tier to use for this request. Supported values vary by model; use the Telnyx models endpoint and inspect the model's `service_tiers` field. If omitted, Telnyx-hosted models use `default`.
        region:
          type: string
          enum:
          - USA
          - EU
          - AUS
          - UAE
          description: 'Optional data-residency region the request should be served from, using the same vocabulary as your account''s Data Locality setting. Behavior depends on `mode`. Supported for Telnyx-hosted models only: a request routed to an external provider never passes through Telnyx model routing, so a region cannot be enforced for it. Omit for today''s latency-based routing.'
        mode:
          type: string
          enum:
          - preferred
          - strict
          default: preferred
          description: 'How strictly `region` is applied. `preferred` (the default when `region` is set) tries that region first and falls back to another when the model cannot be served there, so a request that would have succeeded still succeeds. `strict` pins the request: it is served from that region or it fails with a 422, never redirected to another region. Requires `region`.'
      type: object
      required:
      - model
      - messages
      - max_tokens
      title: AnthropicMessageRequest
      additionalProperties: true
      description: Anthropic Messages-compatible request with Telnyx extensions.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
      example:
        detail:
        - loc:
          - body
          - name
          msg: Field required
          type: missing
    ValidationError:
      title: ValidationError
      required:
      - loc
      - msg
      - type
      type: object
      properties:
        loc:
          title: Location
          type: array
          items:
            anyOf:
            - type: string
            - type: integer
        msg:
          title: Message
          type: string
        type:
          title: Error Type
          type: string
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API key
      description: 'Telnyx API key supplied as `Authorization: Bearer <token>`. In production, auth may be validated by the API gateway and forwarded via Telnyx auth headers.'
    Payment:
      type: apiKey
      in: header
      name: Authorization
      description: 'Machine Payment Protocol credential used on paid retries, sent as `Authorization: Payment ...`. Obtained by paying a challenge returned in the `WWW-Authenticate` header of a 402 response. This is not a Telnyx API key; initial challenge requests use standard bearer authentication instead.'
    agent-memory_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key
    bearerAuth:
      type: http
      scheme: bearer
    branded-calling_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key. Generate one at https://portal.telnyx.com/#/app/api-keys.
    collections_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key. Collections and results are automatically scoped to the authenticated user's organization.
    number-reputation_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key. Generate one at https://portal.telnyx.com/#/app/api-keys.
    oauthClientAuth:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: https://api.telnyx.com/v2/oauth/token
          scopes:
            admin: Administrative access to Telnyx resources
        authorizationCode:
          authorizationUrl: https://api.telnyx.com/v2/oauth/authorize
          tokenUrl: https://api.telnyx.com/v2/oauth/token
          refreshUrl: https://api.telnyx.com/v2/oauth/token
          scopes:
            admin: Administrative access to Telnyx resources
      description: OAuth 2.0 authentication for Telnyx API and MCP integrations
    outbound-voice-profiles_bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
    pronunciation-dicts_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API v2 key. Obtain from https://portal.telnyx.com
    rcs-registration_bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API key
    stored-payment-transactions_bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
    transcriptions-search_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key. Results are automatically scoped to the authenticated user's organization.
    web-search_bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key
x-service-info:
  categories:
  - communication
  - developer-tools
  docs:
    apiReference: https://developers.telnyx.com
    homepage: https://telnyx.com
    llms: https://telnyx.com/llms.txt