cloudflare-worker-api-proxylisted

# Zero-Cost Serverless OpenAI API Proxy on Cloudflare Workers ## Overview A high-performance, edge-native API proxy deployed on Cloudflare Workers. It enables zero-cost routing, token authentication, custom rate-limiting, and header rewriting for OpenAI, Claude, and Google Gemini API endpoints, bypassing regional network blocks with global edge caching and SSE streaming support. ## When to Use & When NOT to Use ### When to Use - Bypassing geographic IP restrictions on AI provider APIs (e.g. OpenAI / Anthropic). - Adding custom Bearer token authentication in front of self-hosted or shared LLM gateways. - Injecting custom user agents or security headers into upstream requests. ### When NOT to Use - Heavy video/audio encoding or streaming workloads exceeding Cloudflare Worker CPU limits (50ms free / 30s paid). - Caching multi-gigabyte files (use Cloudflare R2 instead). ## Production Worker Implementation ```javascript export default { async fetch(request, env) { const url = new URL(request.url); // 1. CORS Preflight if (request.method === "OPTIONS") { return new Response(null, { headers: { "Access-Control-Allow-Origin": "*", "Access-Control-Allow-Methods": "GET, POST, OPTIONS", "Access-Control-Allow-Headers": "Content-Type, Authorization", } }); } // 2. Upstream Target Configuration const UPSTREAM_TARGET = env.UPSTREAM_URL || "https://api.openai.com"; const targetUrl = new URL(ur