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.

Why use this?

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)

Getting started

Install the proxy

Requires Node.js 20+ and Claude Code CLI.

```bash
npm install -g claude-max-api-proxy

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

Start the server

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

Test the proxy

```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!"}]
  }'
```

Configure Genesis

Point Genesis 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" },
    },
  },
}
```

Built-in catalog

Advanced configuration

Proxy-style OpenAI-compatible notes

This path uses the same proxy-style OpenAI-compatible route as other custom
`/v1` backends:

- Native OpenAI-only request shaping does not apply
- No `service_tier`, no Responses `store`, no prompt-cache hints, and no
  OpenAI reasoning-compat payload shaping
- Hidden Genesis attribution headers (`originator`, `version`, `User-Agent`)
  are not injected on the proxy URL

Auto-start on macOS with LaunchAgent

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
• GitHub: 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 Genesis
• 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

Related

• Anthropic provider Native Genesis integration with Claude CLI or API keys.

• OpenAI provider For OpenAI/Codex subscriptions.

• Model selection Overview of all providers, model refs, and failover behavior.

• Configuration Full config reference.