Messages API

Create Claude conversations through the Anthropic native protocol. OfoxAI is fully compatible with the Anthropic Messages API, so you can use the official SDK directly.

Endpoint


POST https://api.ofox.ai/anthropic/v1/messages

Authentication

The Anthropic protocol uses the x-api-key header:


x-api-key: <your OFOXAI_API_KEY>
anthropic-version: 2023-06-01

Request Parameters

Parameter	Type	Required	Description
`model`	string	✅	Model identifier, e.g. `anthropic/claude-sonnet-5.5`
`max_tokens`	number	✅	Maximum tokens to generate
`messages`	array	✅	Message array
`system`	string	—	System prompt
`temperature`	number	—	Sampling temperature 0-1
`top_p`	number	—	Nucleus sampling parameter
`top_k`	number	—	Top-K sampling
`stream`	boolean	—	Enable streaming response
`tools`	array	—	Tool definitions
`tool_choice`	object	—	Tool selection strategy

Message Format


interface Message {
  role: 'user' | 'assistant'
  content: string | ContentBlock[]
}
 
type ContentBlock =
  | { type: 'text'; text: string }
  | { type: 'image'; source: { type: 'base64'; media_type: string; data: string } }
  | { type: 'tool_use'; id: string; name: string; input: object }
  | { type: 'tool_result'; tool_use_id: string; content: string }

Request Examples

cURL

Terminal


curl https://api.ofox.ai/anthropic/v1/messages \
  -H "x-api-key: $OFOX_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-sonnet-5.5",
    "max_tokens": 1024,
    "system": "You are a professional programming assistant.",
    "messages": [
      {"role": "user", "content": "Write a quicksort in Python"}
    ]
  }'

Python

anthropic_chat.py


import anthropic
 
client = anthropic.Anthropic(
    base_url="https://api.ofox.ai/anthropic",
    api_key="<your OFOXAI_API_KEY>"
)
 
message = client.messages.create(
    model="anthropic/claude-sonnet-5.5",
    max_tokens=1024,
    system="You are a professional programming assistant.",
    messages=[
        {"role": "user", "content": "Write a quicksort in Python"}
    ]
)
 
print(message.content[0].text)

TypeScript

anthropic_chat.ts


import Anthropic from '@anthropic-ai/sdk'
 
const client = new Anthropic({
  baseURL: 'https://api.ofox.ai/anthropic',
  apiKey: '<your OFOXAI_API_KEY>'
})
 
const message = await client.messages.create({
  model: 'anthropic/claude-sonnet-5.5',
  max_tokens: 1024,
  system: 'You are a professional programming assistant.',
  messages: [
    { role: 'user', content: 'Write a quicksort in Python' }
  ]
})
 
console.log(message.content[0].text)

Response Format


{
  "id": "msg_abc123",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "Here's a Python quicksort implementation..."
    }
  ],
  "model": "anthropic/claude-sonnet-5.5",
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 25,
    "output_tokens": 200
  }
}

Streaming

Python

anthropic_stream.py


with client.messages.stream(
    model="anthropic/claude-sonnet-5.5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Tell me a story"}]
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)

Supported Models

Model	Description
`anthropic/claude-opus-5.5`	Claude Opus 5.5 — Most capable
`anthropic/claude-sonnet-5.5`	Claude Sonnet 5.5 — Balanced performance
`anthropic/claude-haiku-5.5`	Claude Haiku 5.5 — Fast responses

OfoxAI’s Anthropic protocol supports all native features, including Vision, Tool Use, Prompt Caching, Extended Thinking, and more.