Anthropic Messages API

POST https://api.bve.me/v1/messages
GET  https://api.bve.me/v1/messages/:message_id

Requires Authorization: Bearer sk-bve-YOUR_KEY.

BVE Gateway natively passes through the Anthropic Messages API. The response is in Anthropic format (not OpenAI format). This is useful when you want to use Anthropic-specific features like extended thinking or when targeting Claude models directly.

Request body

{
  "model": "claude-sonnet-4-6",
  "max_tokens": 1024,
  "messages": [
    { "role": "user", "content": "Hello, Claude!" }
  ]
}

Field	Type	Required	Description
`model`	string	Yes	Claude model ID (e.g. `claude-sonnet-4-6`)
`messages`	array	Yes	Array of `{role, content}` objects
`max_tokens`	integer	Yes	Maximum tokens to generate
`system`	string	No	System prompt
`temperature`	number	No	Sampling temperature 0–1
`top_p`	number	No	Nucleus sampling
`top_k`	integer	No	Top-k sampling
`stream`	boolean	No	Enable SSE streaming
`stop_sequences`	array	No	Stop sequences
`tools`	array	No	Tool definitions
`tool_choice`	object	No	Tool selection strategy
`thinking`	object	No	Extended thinking configuration
`metadata`	object	No	Request metadata

Response (Anthropic format)

{
  "id": "msg_01XFDUDYJgAACzvnptvVoYEL",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "Hello! How can I help you today?"
    }
  ],
  "model": "claude-sonnet-4-6-20250929",
  "stop_reason": "end_turn",
  "stop_sequence": null,
  "usage": {
    "input_tokens": 10,
    "output_tokens": 12
  }
}

cURL example

curl https://api.bve.me/v1/messages \
  -H "Authorization: Bearer sk-bve-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4-6",
    "max_tokens": 1024,
    "messages": [
      { "role": "user", "content": "Hello, Claude!" }
    ]
  }'

Streaming

curl https://api.bve.me/v1/messages \
  -H "Authorization: Bearer sk-bve-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4-6",
    "max_tokens": 1024,
    "messages": [{ "role": "user", "content": "Count to 5." }],
    "stream": true
  }'

Streaming returns Anthropic SSE events: message_start, content_block_start, content_block_delta, content_block_stop, message_delta, message_stop.

Anthropic SDK

import Anthropic from '@anthropic-ai/sdk';

const client = new Anthropic({
  apiKey: 'sk-bve-YOUR_KEY',
  baseURL: 'https://api.bve.me/v1',
});

const message = await client.messages.create({
  model: 'claude-sonnet-4-6',
  max_tokens: 1024,
  messages: [{ role: 'user', content: 'Hello, Claude!' }],
});

console.log(message.content[0].text);

Available Claude models

Model	ID
Claude Sonnet 4.6	`claude-sonnet-4-6`
Claude Sonnet 4.5	`claude-sonnet-4-5`
Claude Sonnet 4	`claude-sonnet-4`
Claude Haiku 4.5	`claude-haiku-4-5`
Claude Haiku 4	`claude-haiku-4`
Claude 3.7 Sonnet	`claude-3-7-sonnet`
Claude 3.5 Sonnet	`claude-3-5-sonnet`
Claude 3.5 Haiku	`claude-3-5-haiku`

See the Models page for the full list.

Notes

The anthropic-version header is optional but recommended.
The x-api-key header is NOT required — authentication uses the BVE Gateway Authorization: Bearer sk-bve-YOUR_KEY header only.
The request-id response header is passed through from the Anthropic upstream.
Extended thinking ("thinking": {"type": "enabled", "budget_tokens": N}) is forwarded if the model supports it.