Claude Max API Proxy Setup

Overview

Replace per-token Claude API billing ($15-75/M tokens) with a flat-rate proxy through your Claude Max ($200/mo) or Pro ($20/mo) subscription. The claude-max-api-proxy package exposes your authenticated Claude Code CLI session as an OpenAI-compatible HTTP endpoint on localhost:3456.

How it works: The proxy uses your already-authenticated claude CLI session to forward requests. No API keys are stored or transmitted by the proxy — it relies on your local CLI login. Any OpenAI-compatible client (OpenClaw, LangChain, custom scripts) connects to localhost:3456.

Source code: github.com/atalovesyou/claude-max-api-proxy — review the source before installing.

When to Use

• Agent API costs exceed $20/month and you have a Claude Max or Pro subscription
• You want to run Claude Opus 4.6, Sonnet 4.6, or Haiku 4.5 without per-token charges
• You're configuring OpenClaw, LangChain, or any OpenAI-compatible client to use Claude

Do not use when:

• You don't have a Claude Max or Pro subscription (get one first at claude.ai)
• You need concurrent request throughput >5 (Max plan has rate limits)
• You're on a shared server where others could access port 3456

Security Notes

• The proxy binds to localhost only by default — it is not accessible from other machines
• It uses your authenticated claude CLI session, meaning anyone with access to port 3456 on your machine can make requests against your subscription
• Never expose port 3456 to the public internet — use firewall rules to restrict access
• Review the package source before installing

Setup Process

1. Prerequisites Check

# Verify Node.js 20+
node --version

# Verify Claude Code CLI is installed and authenticated
claude --version
claude --print "test"   # Should return a response without errors

If claude is not authenticated, run claude login and complete the browser flow.

2. Install and Start

# Review the package source first: https://github.com/atalovesyou/claude-max-api-proxy
npm install -g claude-max-api-proxy
claude-max-api   # Starts on localhost:3456 by default

# Verify:
curl http://localhost:3456/health
# => {"status":"ok","provider":"claude-code-cli",...}

3. Configure Your Client

For OpenClaw (~/.openclaw/openclaw.json):