API Documentation

Quick Start

Get up and running in under a minute.

curl -X POST https://api.unlimitedclaude.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "claude-sonnet-4.6",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Authentication

All API requests require an API key. You can pass it via the x-api-key header or the Authorization: Bearer header. You can find your key in the Dashboard.

curl https://api.unlimitedclaude.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{"model": "claude-sonnet-4.6", "messages": [...]}'

Base URL

All endpoints are relative to this base URL.

https://api.unlimitedclaude.com/v1

Chat Completions

Works with any SDK or tool that supports the OpenAI chat format.

Request Body

Example

curl -X POST https://api.unlimitedclaude.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "claude-sonnet-4.6",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "What is the capital of France?"}
    ],
    "max_tokens": 256
  }'

{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "model": "claude-sonnet-4.6",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "The capital of France is Paris."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 25,
    "completion_tokens": 8,
    "total_tokens": 33
  }
}

Messages API

Use this if your tooling expects the native Anthropic format.

Headers

Example

curl -X POST https://api.unlimitedclaude.com/v1/messages \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4.6",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Explain quantum computing in simple terms."}
    ]
  }'

{
  "id": "msg_abc123",
  "type": "message",
  "role": "assistant",
  "model": "claude-sonnet-4.6",
  "content": [
    {
      "type": "text",
      "text": "Quantum computing uses quantum bits (qubits) that can exist in multiple states simultaneously..."
    }
  ],
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 15,
    "output_tokens": 64
  }
}

Streaming

Set "stream": true in your request body to receive Server-Sent Events (SSE). The response streams token-by-token instead of waiting for the full completion.

curl -X POST https://api.unlimitedclaude.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "claude-sonnet-4.6",
    "stream": true,
    "messages": [{"role": "user", "content": "Write a haiku about coding."}]
  }'

data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","choices":[{"delta":{"content":"Silent"},"index":0}]}

data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","choices":[{"delta":{"content":" keys"},"index":0}]}

data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","choices":[{"delta":{},"index":0,"finish_reason":"stop"}]}

data: [DONE]

Models

Available models depend on your plan. All models are accessed through the same endpoints.

Rate Limits

Limits are applied per-user based on your plan. Exceeding limits returns a 429 status.

Error Codes

Standard HTTP status codes indicate success or failure.

Error Response Format

{
  "error": "Daily request limit reached. Upgrade your plan for more requests."
}

Claude Code Setup

Use UnlimitedClaude as the backend for Claude Code across CLI, VS Code, and other editors.

1. Terminal (CLI)

Set these environment variables to route Claude Code CLI requests through UnlimitedClaude.

export ANTHROPIC_BASE_URL=https://api.unlimitedclaude.com
export ANTHROPIC_API_KEY=YOUR_API_KEY

# To persist, add to your shell profile:
echo 'export ANTHROPIC_BASE_URL=https://api.unlimitedclaude.com' >> ~/.bashrc
echo 'export ANTHROPIC_API_KEY=YOUR_API_KEY' >> ~/.bashrc
source ~/.bashrc

2. VS Code Extension

If you use the Claude Code VS Code extension, configure it through VS Code settings.

// settings.json
{
  "claudeCode.environmentVariables": [
    {
      "name": "ANTHROPIC_BASE_URL",
      "value": "https://api.unlimitedclaude.com"
    },
    {
      "name": "ANTHROPIC_API_KEY",
      "value": "YOUR_API_KEY"
    }
  ]
}

3. Cursor / Other Editors

For Cursor or any editor that supports Claude, set the same environment variables in your system or shell profile. Most editors pick them up automatically.

// Cursor: Settings > Models > Claude
// Set the API Base URL to:
https://api.unlimitedclaude.com

// Set the API Key to:
YOUR_API_KEY

Coding Agents

Use UnlimitedClaude with popular coding agents like Cline, Continue, Aider, and more via the OpenAI-compatible API.

Cline (VS Code)

Base URL:  https://api.unlimitedclaude.com/v1
API Key:   YOUR_API_KEY
Model:     claude-sonnet-4.6

Continue (VS Code / JetBrains)

Add this to your ~/.continue/config.json:

{
  "models": [
    {
      "provider": "openai",
      "title": "UnlimitedClaude",
      "model": "claude-sonnet-4.6",
      "apiBase": "https://api.unlimitedclaude.com/v1",
      "apiKey": "YOUR_API_KEY"
    }
  ]
}

Aider

Set environment variables and run Aider with the OpenAI-compatible flag:

export OPENAI_API_BASE=https://api.unlimitedclaude.com/v1
export OPENAI_API_KEY=YOUR_API_KEY

aider --model openai/claude-sonnet-4.6