Claude Messages API for AI Chat and Text Generation

The Claude Messages API lets you interact with Claude and GPT models using the native Anthropic request format. It is fully compatible with the official Anthropic SDK and documentation, so you can point your existing Anthropic integrations at GlobalAI OPC with minimal changes. Base URL: http://apillm.globalaiopc.com/gw_llm_power Endpoint: POST /v1/messages

Authentication

Authenticate every request using the Authorization header with your API key:

Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

Supported Models

Claude Models

Standard	`-official`	`-hc`	`-fd`
`claude-haiku-4-5`	`claude-haiku-4-5-official`	`claude-haiku-4-5-hc`	`claude-haiku-4-5-fd`
`claude-opus-4-5`	`claude-opus-4-5-official`	`claude-opus-4-5-hc`	`claude-opus-4-5-fd`
`claude-opus-4-6`	`claude-opus-4-6-official`	`claude-opus-4-6-hc`	`claude-opus-4-6-fd`
`claude-opus-4-7`	`claude-opus-4-7-official`	`claude-opus-4-7-hc`	`claude-opus-4-7-fd`
`claude-sonnet-4-5`	`claude-sonnet-4-5-official`	`claude-sonnet-4-5-hc`	`claude-sonnet-4-5-fd`
`claude-sonnet-4-6`	`claude-sonnet-4-6-official`	`claude-sonnet-4-6-hc`	`claude-sonnet-4-6-fd`

GPT Models (via Claude Protocol)

GPT models are also accessible through the Claude Messages API using the same request format.

Standard	`-official`	`-hc`	`-fd`	`-low`
`gpt-5.4`	`gpt-5.4-official`	`gpt-5.4-hc`	`gpt-5.4-fd`	`gpt-5.4-low`
`gpt-5.5`	`gpt-5.5-official`	`gpt-5.5-hc`	`gpt-5.5-fd`	`gpt-5.5-low`

GPT models accessed through this endpoint do not support image analysis. For image input with GPT models, use the OpenAI Chat API endpoint instead.

Model Suffix Reference

Suffix	Description
(none)	Standard version
`-official`	Official version
`-hc`	High-quality pool (AWS or premium account pool)
`-fd`	Proxy pool / mixed account pool
`-low`	Budget version

Request Parameters

string

required

The name of the model to use. For example: claude-opus-4-6, claude-sonnet-4-5, or gpt-5.5.

integer

required

The maximum number of tokens the model may generate in its response. This field is required by the Claude protocol.

array

required

An array of message objects representing the conversation history, following the Claude Messages protocol.

string

required

The role of the message author. Accepted values: user or assistant.

string | array

required

The content of the message. Pass a plain text string for standard text input, or a Claude native content block array for multimodal input.

string

An optional system prompt that sets the context and behavior for the model throughout the conversation.

boolean

When set to true, the response is returned as a stream of Claude-style SSE events.

number

Controls the randomness of the model’s output. Lower values produce more focused, deterministic responses; higher values produce more varied output.

Response Fields

string

A unique identifier for the message response.

string

The type of the returned object. Always message.

string

The role of the generated message. Always assistant.

string

The type of the content block. Typically text for standard text responses.

string

The text content generated by the model.

string

The reason the model stopped generating. Common values include end_turn (natural end) and max_tokens (token limit reached).

integer

The number of tokens in the input messages and system prompt.

integer

The number of tokens in the generated response.

Code Examples

curl -X POST http://apillm.globalaiopc.com/gw_llm_power/v1/messages \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-4-6",
    "max_tokens": 1024,
    "system": "You are a professional writing assistant.",
    "messages": [
      {"role": "user", "content": "Write a product description for a coffee maker."}
    ]
  }'

import requests

response = requests.post(
    "http://apillm.globalaiopc.com/gw_llm_power/v1/messages",
    headers={
        "Authorization": "Bearer YOUR_API_KEY",
        "Content-Type": "application/json"
    },
    json={
        "model": "claude-opus-4-6",
        "max_tokens": 1024,
        "system": "You are a professional writing assistant.",
        "messages": [
            {"role": "user", "content": "Write a product description for a coffee maker."}
        ]
    }
)
print(response.json()["content"][0]["text"])

Example Response

{
  "id": "msg_01ABC123",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "Introducing the BrewMaster Pro — your perfect morning companion. With precision temperature control and a 12-cup capacity, it delivers rich, barista-quality coffee every time."
    }
  ],
  "model": "claude-opus-4-6",
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 18,
    "output_tokens": 42
  }
}

This endpoint is fully compatible with the Anthropic Messages API protocol. For complete details on request options — including extended thinking, tool use, and vision — refer to the Anthropic Messages API documentation.

Overview

Text APIs

Image APIs

Video APIs

Asset Management

Claude Messages API for AI Chat and Text Generation

Authentication

Supported Models

Claude Models

GPT Models (via Claude Protocol)

Model Suffix Reference

Request Parameters

Response Fields

Code Examples

Example Response

​Authentication

​Supported Models

​Claude Models

​GPT Models (via Claude Protocol)

​Model Suffix Reference

​Request Parameters

​Response Fields

​Code Examples

​Example Response

Authentication

Supported Models

Claude Models

GPT Models (via Claude Protocol)

Model Suffix Reference

Request Parameters

Response Fields

Code Examples

Example Response