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 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).

POST

anthropic

messages

JavaScript

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);

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)

package main

import (
	"context"
	"fmt"

	"github.com/team-telnyx/telnyx-go"
	"github.com/team-telnyx/telnyx-go/option"
)

func main() {
	client := telnyx.NewClient(
		option.WithAPIKey("My API Key"),
	)
	response, err := client.AI.Anthropic.V1.Messages(
		context.TODO(),
		telnyx.AIAnthropicV1MessagesParams{
			MaxTokens: 1,
			Messages:  "messages",
			Model:     "model",
		},
	)
	if err != nil {
		panic(err.Error())
	}
	fmt.Printf("%+v\n", response.Data)
}

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);
    }
}

<?php

require_once dirname(__DIR__) . '/vendor/autoload.php';

use Telnyx\Client;
use Telnyx\Core\Exceptions\APIException;

$client = new Client(apiKey: getenv('TELNYX_API_KEY') ?: 'My API Key');

try {
  $response = $client->ai->anthropic->v1->messages(
    max_tokens: 0,
    messages: [],
    model: 'model',
  );

  var_dump($response);
} catch (APIException $e) {
  echo $e->getMessage();
}

curl --request POST \
  --url https://api.telnyx.com/v2/ai/anthropic/v1/messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "zai-org/GLM-5.3-Flash",
  "system": "You are a friendly chatbot.",
  "messages": [
    {
      "role": "user",
      "content": "Hello, world!"
    }
  ],
  "max_tokens": 1024
}
'

{
  "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
  }
}

{
  "detail": [
    {
      "loc": [
        "body",
        "name"
      ],
      "msg": "Field required",
      "type": "missing"
    }
  ]
}

Authorizations

Authorization

string

header

required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Body

application/json

Anthropic Messages-compatible request with Telnyx extensions.

model

string

required

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

object[]

required

The messages to send to the model, following the Anthropic Messages API format.

max_tokens

integer

required

The maximum number of tokens to generate in the response.

system

System prompt. Can be a string or an array of content blocks following the Anthropic API format.

stream

boolean

default:false

Whether to stream the response as Anthropic-format Server-Sent Events.

temperature

number

Amount of randomness injected into the response. Ranges from 0 to 1.

top_p

number

Nucleus sampling parameter. Use temperature or top_p, but not both.

top_k

integer

Top-k sampling parameter. Only sample from the top K options for each subsequent token.

stop_sequences

string[]

Custom sequences that will cause the model to stop generating.

metadata

object

An object describing metadata about the request.

tools

object[]

Definitions of tools that the model may use, following the Anthropic API format.

tool_choice

object

Controls how the model uses tools, following the Anthropic API format.

thinking

object

Extended thinking configuration for models that support it. Set type to enabled to turn on extended thinking.

api_key_ref

string

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 for your API key, pass the secret's identifier in this field.

mcp_servers

object[]

List of MCP (Model Context Protocol) servers to make available to the model.

fallback_config

object

Configuration for model fallback behavior when the primary model is unavailable.

billing_group_id

string<uuid>

The billing group ID to associate with this request.

timeout

number

default:300

Request timeout in seconds.

max_retries

integer

Maximum number of retries for the request.

service_tier

string

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

enum<string>

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.

Available options:

USA,

EU,

AUS,

UAE

mode

enum<string>

default:preferred

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.

Available options:

preferred,

strict

Response

Successful Response

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.

JavaScript

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);

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)

package main

import (
	"context"
	"fmt"

	"github.com/team-telnyx/telnyx-go"
	"github.com/team-telnyx/telnyx-go/option"
)

func main() {
	client := telnyx.NewClient(
		option.WithAPIKey("My API Key"),
	)
	response, err := client.AI.Anthropic.V1.Messages(
		context.TODO(),
		telnyx.AIAnthropicV1MessagesParams{
			MaxTokens: 1,
			Messages:  "messages",
			Model:     "model",
		},
	)
	if err != nil {
		panic(err.Error())
	}
	fmt.Printf("%+v\n", response.Data)
}

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);
    }
}

<?php

require_once dirname(__DIR__) . '/vendor/autoload.php';

use Telnyx\Client;
use Telnyx\Core\Exceptions\APIException;

$client = new Client(apiKey: getenv('TELNYX_API_KEY') ?: 'My API Key');

try {
  $response = $client->ai->anthropic->v1->messages(
    max_tokens: 0,
    messages: [],
    model: 'model',
  );

  var_dump($response);
} catch (APIException $e) {
  echo $e->getMessage();
}

curl --request POST \
  --url https://api.telnyx.com/v2/ai/anthropic/v1/messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "zai-org/GLM-5.3-Flash",
  "system": "You are a friendly chatbot.",
  "messages": [
    {
      "role": "user",
      "content": "Hello, world!"
    }
  ],
  "max_tokens": 1024
}
'

{
  "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
  }
}

{
  "detail": [
    {
      "loc": [
        "body",
        "name"
      ],
      "msg": "Field required",
      "type": "missing"
    }
  ]
}

Inference

Data Residency

Integrations

Tutorials

API Reference

For AI Agents

Create a message (Anthropic-compatible)

Authorizations

Body

Response