---
summary: "Community proxy to expose Claude subscription credentials as an OpenAI-compatible endpoint"
read_when:
  - You want to use Claude Max subscription with OpenAI-compatible tools
  - You want a local API server that wraps Claude Code CLI
  - You want to evaluate subscription-based vs API-key-based Anthropic access
title: "Claude Max API Proxy"
---

# Claude Max API Proxy

**claude-max-api-proxy** is a community tool that exposes your Claude Max/Pro subscription as an OpenAI-compatible API endpoint. This allows you to use your subscription with any tool that supports the OpenAI API format.

<Warning>
This path is technical compatibility only. Anthropic has blocked some subscription
usage outside Claude Code in the past. You must decide for yourself whether to use
it and verify Anthropic's current terms before relying on it.
</Warning>

## Why Use This?

| Approach                | Cost                                                | Best For                                   |
| ----------------------- | --------------------------------------------------- | ------------------------------------------ |
| Anthropic API           | Pay per token (~$15/M input, $75/M output for Opus) | Production apps, high volume               |
| Claude Max subscription | $200/month flat                                     | Personal use, development, unlimited usage |

If you have a Claude Max subscription and want to use it with OpenAI-compatible tools, this proxy may reduce cost for some workflows. API keys remain the clearer policy path for production use.

## How It Works

```
Your App → claude-max-api-proxy → Claude Code CLI → Anthropic (via subscription)
     (OpenAI format)              (converts format)      (uses your login)
```

The proxy:

1. Accepts OpenAI-format requests at `http://localhost:3456/v1/chat/completions`
2. Converts them to Claude Code CLI commands
3. Returns responses in OpenAI format (streaming supported)

## Installation

```bash
# Requires Node.js 20+ and Claude Code CLI
npm install -g claude-max-api-proxy

# Verify Claude CLI is authenticated
claude --version
```

## Usage

### Start the server

```bash
claude-max-api
# Server runs at http://localhost:3456
```

### Test it

```bash
# Health check
curl http://localhost:3456/health

# List models
curl http://localhost:3456/v1/models

# Chat completion
curl http://localhost:3456/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-4",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'
```

### With Gensparx

You can point gensparx at the proxy as a custom OpenAI-compatible endpoint:

```json5
{
  env: {
    OPENAI_API_KEY: "not-needed",
    OPENAI_BASE_URL: "http://localhost:3456/v1",
  },
  agents: {
    defaults: {
      model: { primary: "openai/claude-opus-4" },
    },
  },
}
```

## Available Models

| Model ID          | Maps To         |
| ----------------- | --------------- |
| `claude-opus-4`   | Claude Opus 4   |
| `claude-sonnet-4` | Claude Sonnet 4 |
| `claude-haiku-4`  | Claude Haiku 4  |

## Auto-Start on macOS

Create a LaunchAgent to run the proxy automatically:

```bash
cat > ~/Library/LaunchAgents/com.claude-max-api.plist << 'EOF'
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.claude-max-api</string>
  <key>RunAtLoad</key>
  <true/>
  <key>KeepAlive</key>
  <true/>
  <key>ProgramArguments</key>
  <array>
    <string>/usr/local/bin/node</string>
    <string>/usr/local/lib/node_modules/claude-max-api-proxy/dist/server/standalone.js</string>
  </array>
  <key>EnvironmentVariables</key>
  <dict>
    <key>PATH</key>
    <string>/usr/local/bin:/opt/homebrew/bin:~/.local/bin:/usr/bin:/bin</string>
  </dict>
</dict>
</plist>
EOF

launchctl bootstrap gui/$(id -u) ~/Library/LaunchAgents/com.claude-max-api.plist
```

## Links

- **npm:** [https://www.npmjs.com/package/claude-max-api-proxy](https://www.npmjs.com/package/claude-max-api-proxy)
- **GitHub:** [https://github.com/atalovesyou/claude-max-api-proxy](https://github.com/atalovesyou/claude-max-api-proxy)
- **Issues:** [https://github.com/atalovesyou/claude-max-api-proxy/issues](https://github.com/atalovesyou/claude-max-api-proxy/issues)

## Notes

- This is a **community tool**, not officially supported by Anthropic or Gensparx
- Requires an active Claude Max/Pro subscription with Claude Code CLI authenticated
- The proxy runs locally and does not send data to any third-party servers
- Streaming responses are fully supported

## See Also

- [Anthropic provider](/providers/anthropic) - Native gensparx integration with Claude setup-token or API keys
- [OpenAI provider](/providers/openai) - For OpenAI/Codex subscriptions
