Windows-Copilot-API; Access GPT-4 and GPT-5 models without API keys or billing A new open-source project called Windows-Copilot-API allows developers to access GPT-4 and GPT-5 models through Microsoft Copilot without API keys or billing by turning the free Copilot web interface into an API. The tool provides a Python library and an OpenAI-compatible local server, requiring only a Microsoft or Google account sign-in. It is an unofficial project not affiliated with Microsoft. Using your own Microsoft Copilot account. No API key, no credits, no paid plan: it turns the free chat at copilot.microsoft.com https://copilot.microsoft.com into an API you can call from code. You can use it in two ways: - 🐍 As a Python library: just call client.chat "Hi" . Supports streaming and multi-turn conversations. - πŸ”Œ As a local OpenAI-compatible API: runs a server at http://localhost:8000/v1 that speaks the OpenAI format, so the official openai SDK and any OpenAI-compatible app works as a drop-in, with localhost in place of OpenAI. You sign in once in a browser with your Microsoft or Google account; your session is saved and refreshed automatically after that. Unofficial project.Not affiliated with or endorsed by Microsoft. It automates the consumer Copilot web experience for personal use, so use it responsibly and within Microsoft's terms. Why use this? why-use-this Requirements requirements Setup 2 minutes setup-2-minutes Run with Docker optional run-with-docker-optional Usage 1: In Python no server usage-1-in-python-no-server Usage 2: As an OpenAI-compatible server usage-2-as-an-openai-compatible-server Command line command-line Concurrency & stress test concurrency--stress-test Rate limiting rate-limiting Project layout project-layout Notes & limitations notes--limitations Troubleshooting troubleshooting Collaboration & support collaboration--support License license Star History star-history Free: uses your normal signed-in Copilot, no API billing. Drop-in OpenAI replacement: point any OpenAI client at localhost and it just works. Works everywhere you're signed in: the signed-in path works even in regions where anonymous Copilot is blocked e.g. India . Streaming + conversations: token-by-token output and multi-turn threads addressed by conversation id . Python 3.9+ - A Microsoft account the free one you use for Copilot is fine - Works on Windows, macOS, and Linux 1. Clone the project git clone