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.

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 can save you significant money.

How It Works

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

The proxy:

Accepts OpenAI-format requests at http://localhost:3456/v1/chat/completions
Converts them to Claude Code CLI commands
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 Mayros

You can point Mayros 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

Notes

This is a community tool, not officially supported by Anthropic or Mayros
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