Claude (Anthropic) Compatibility Guide

Important Note: We provide API services compatible with Anthropic standards. Therefore, we strongly recommend directly referring to the official Anthropic API documentation to obtain the most comprehensive, up-to-date parameter details and examples. The following is an overview of the simplified interface, focusing on core fields and usage instructions.

Overview

UModelverse platform provides a Messages interface compatible with the Anthropic Claude API, allowing developers to directly invoke models on Modelverse using the Anthropic SDK or other supported tools.

Request Method: POST
Endpoint: https://api.umodelverse.ai/v1/messages
Authentication: Use API key, pass through x-api-key: {api_key} or Authorization: Bearer {api_key}

Note: The /v1/messages endpoint only supports the Claude series models. For other models (such as GPT, Gemini, DeepSeek, etc.), use the OpenAI-compatible /v1/chat/completions endpoint. Although Claude and OpenAI both use /v1/models to obtain a list of models, the call interfaces are different.

Key Core Fields

Request Fields

Field	Type	Required	Default	Description
model	string	Yes	None	Model ID, such as `claude-sonnet-4-5-20250929`. Specifies the model for generating responses.
messages	array	Yes	None	List of conversation messages. Each message includes `role` (user/assistant) and `content` (text/image).
max_tokens	integer	Yes	None	Maximum number of tokens to generate. Controls the response length to prevent overly lengthy outputs.
system	string/array	No	None	System prompts. Defines model behavior and roles.
temperature	number	No	1.0	Sampling temperature (0 to 1). Controls randomness, with higher values being more creative and lower values being more deterministic.
top_p	number	No	None	Nucleus sampling (0 to 1). Controls diversity.
top_k	integer	No	None	Top-K sampling. Samples only from the top K tokens with the highest probabilities.
stop_sequences	array	No	None	List of stop sequences. Stops generation upon reaching these sequences.
stream	boolean	No	false	Whether to stream responses. Returns content incrementally in real-time.
metadata	object	No	None	Metadata object, which can include `user_id` for tracking.
tools	array	No	None	List of available tools. Enables function calling features.
tool_choice	object	No	auto	Tool selection strategy. For example, `{"type": "auto"}` lets the model decide to invoke tools.

Response Fields

Field	Type	Description
id	string	Response ID. Uniquely identifies this completion.
type	string	Object type: `message`.
role	string	Role: `assistant`.
content	array	List of content blocks. Each block contains `type` and corresponding content (such as `text`).
model	string	The model ID used.
stop_reason	string	Stop reason: `end_turn`, `max_tokens`, `stop_sequence`, `tool_use`.
stop_sequence	string	Sequence that triggered the stop (if applicable).
usage	object	Usage statistics. Includes `input_tokens` and `output_tokens`.

Quick Start

Install Anthropic SDK


pip install anthropic

Sample Code

Python


import anthropic
 
client = anthropic.Anthropic(
    api_key="<MODELVERSE_API_KEY>",
    base_url="https://api.umodelverse.ai"
)
 
message = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Hello, how are you?"}
    ]
)
 
print(message.content[0].text)

Python Streaming


import anthropic
 
client = anthropic.Anthropic(
    api_key="<MODELVERSE_API_KEY>",
    base_url="https://api.umodelverse.ai"
)
 
with client.messages.stream(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Write a short story about AI."}
    ]
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)

curl


curl https://api.umodelverse.ai/v1/messages \
  -H "Content-Type: application/json" \
  -H "x-api-key: $MODELVERSE_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Hello, how are you?"}
    ]
  }'

curl Streaming


curl https://api.umodelverse.ai/v1/messages \
  -H "Content-Type: application/json" \
  -H "x-api-key: $MODELVERSE_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "max_tokens": 1024,
    "stream": true,
    "messages": [
      {"role": "user", "content": "Hello, how are you?"}
    ]
  }'

Multimodal Support

Claude-compatible interfaces support image input, which can be delivered via base64 encoding or URL:

Using URL


import anthropic
 
client = anthropic.Anthropic(
    api_key="<MODELVERSE_API_KEY>",
    base_url="https://api.umodelverse.ai"
)
 
# Using URL to pass image
message = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": [
                {
                    "type": "image",
                    "source": {
                        "type": "url",
                        "url": "https://umodelverse-inference.cn-wlcb.ufileos.com/ucloud-maxcot.jpg"
                    }
                },
                {
                    "type": "text",
                    "text": "What's in this image?"
                }
            ]
        }
    ]
)
 
print(message.content[0].text)

Using base64 Encoding


import anthropic
import base64
 
client = anthropic.Anthropic(
    api_key="<MODELVERSE_API_KEY>",
    base_url="https://api.umodelverse.ai"
)
 
# Using base64 to encode image
with open("image.png", "rb") as f:
    image_data = base64.standard_b64encode(f.read()).decode("utf-8")
 
message = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": [
                {
                    "type": "image",
                    "source": {
                        "type": "base64",
                        "media_type": "image/png",
                        "data": image_data
                    }
                },
                {
                    "type": "text",
                    "text": "What's in this image?"
                }
            ]
        }
    ]
)
 
print(message.content[0].text)

Tool Calling (Function Calling)


import anthropic
 
client = anthropic.Anthropic(
    api_key="<MODELVERSE_API_KEY>",
    base_url="https://api.umodelverse.ai"
)
 
tools = [
    {
        "name": "get_weather",
        "description": "Get the current weather in a given location",
        "input_schema": {
            "type": "object",
            "properties": {
                "location": {
                    "type": "string",
                    "description": "The city and state, e.g. San Francisco, CA"
                }
            },
            "required": ["location"]
        }
    }
]
 
message = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    tools=tools,
    messages=[
        {"role": "user", "content": "What's the weather like in Beijing?"}
    ]
)
 
print(message.content)

Model List

For more supported Claude-compatible models, please see [Get Model List] or visit the UModelverse Model Center .

For more details on the fields, see the official Anthropic documentation