> ## Documentation Index > Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt > Use this file to discover all available pages before exploring further. # Create a message (Anthropic-compatible) > Send a message to a language model using the Anthropic Messages API format. This endpoint is compatible with the [Anthropic Messages API](https://docs.anthropic.com/en/api/messages) 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`). ## OpenAPI ````yaml /openapi/source/external/inference/inference-embedding.json post /ai/anthropic/v1/messages openapi: 3.1.0 info: version: 2.0.0 title: Telnyx API x-latency-category: responsive x-endpoint-cost: light 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: Chat description: Generate text with LLMs - name: Assistants description: Configure AI assistant specifications - name: Conversations description: Manage historical AI assistant conversations - name: File-based Text-to-Speech description: Turn audio into text or text into audio. - name: Embeddings description: Embed documents and perform text searches - name: Clusters description: Identify common themes and patterns in your embedded documents - name: Fine Tuning description: Customize LLMs for your unique needs - name: OpenAI Embeddings description: >- OpenAI-compatible embeddings endpoints for generating vector representations of text 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](https://docs.anthropic.com/en/api/messages) 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' x-codeSamples: - lang: JavaScript source: |- import Telnyx from 'telnyx'; const client = new Telnyx({ apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted }); const response = await client.ai.anthropic.v1.messages({ max_tokens: 0, messages: [], model: 'model', }); console.log(response.data); - lang: Python source: | import os from telnyx import Telnyx client = Telnyx( api_key=os.environ.get("TELNYX_API_KEY"), # This is the default and can be omitted ) response = client.ai.anthropic.v1.messages( max_tokens=0, messages=[], model="model", ) print(response.data) - lang: Go source: "package main\n\nimport (\n\t\"context\"\n\t\"fmt\"\n\n\t\"github.com/team-telnyx/telnyx-go\"\n\t\"github.com/team-telnyx/telnyx-go/option\"\n)\n\nfunc main() {\n\tclient := telnyx.NewClient(\n\t\toption.WithAPIKey(\"My API Key\"),\n\t)\n\tresponse, err := client.AI.Anthropic.V1.Messages(\n\t\tcontext.TODO(),\n\t\ttelnyx.AIAnthropicV1MessagesParams{\n\t\t\tMaxTokens: 1,\n\t\t\tMessages: \"messages\",\n\t\t\tModel: \"model\",\n\t\t},\n\t)\n\tif err != nil {\n\t\tpanic(err.Error())\n\t}\n\tfmt.Printf(\"%+v\\n\", response.Data)\n}\n" - lang: Java source: |- package com.telnyx.sdk.example; import com.telnyx.sdk.client.TelnyxClient; import com.telnyx.sdk.client.okhttp.TelnyxOkHttpClient; import com.telnyx.sdk.models.ai.anthropic.v1.V1MessagesParams; import java.util.List; public final class Main { private Main() {} public static void main(String[] args) { TelnyxClient client = TelnyxOkHttpClient.fromEnv(); V1MessagesParams params = V1MessagesParams.builder() .maxTokens(0) .messages(List.of()) .model("model") .build(); var response = client.ai().anthropic().v1().messages(params); } } - lang: Ruby source: >- require "telnyx" telnyx = Telnyx::Client.new(api_key: "My API Key") response = telnyx.ai.anthropic.v1.messages(max_tokens: 0, messages: [], model: "model") puts(response) - lang: PHP source: >- ai->anthropic->v1->messages( max_tokens: 0, messages: [], model: 'model', ); var_dump($response); } catch (APIException $e) { echo $e->getMessage(); } - lang: CLI source: |- telnyx ai:anthropic:v1 messages \ --api-key 'My API Key' \ --model model \ --messages messages \ --max-tokens 0 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: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError securitySchemes: bearerAuth: type: http scheme: bearer ````