{"slug": "pylance-pyrefly-python-type-checker-is-now-swappable", "title": "Pylance + Pyrefly: Python Type Checker Is Now Swappable", "summary": "Microsoft has decoupled Pylance from Pyright via the Type Server Protocol (TSP), a new open standard that lets Pylance accept any compliant type checker as its backend, with Meta's Rust-powered Pyrefly the first to plug in. The change means VS Code Python users can now pair Pylance's IDE features — completions, Quick Info, and Copilot integration — with a type checker other than Pyright, which previously handled all type analysis underneath Pylance.", "body_md": "Microsoft broke Pylance’s exclusive relationship with Pyright last week. The Type Server Protocol (TSP) is a new open standard that lets Pylance accept any compliant type checker as its backend — and Pyrefly, Meta’s Rust-powered type checker, is the first to plug in. If you use VS Code for Python, this changes how type checking works in your editor. What the Type Server Protocol Changes Until now, Pylance and Pyright were inseparable. Pylance handled IDE features like completions, Quick Info, and Copilot integration; Pyright did the type analysis underneath. You got one without a say in the other. TSP draws […]\n\nThe post", "url": "https://wpnews.pro/news/pylance-pyrefly-python-type-checker-is-now-swappable", "canonical_source": "https://byteiota.com/pylance-type-server-protocol-pyrefly/", "published_at": "2026-10-27 10:16:44+00:00", "updated_at": "2026-10-27 11:15:10.275312+00:00", "lang": "en", "topics": ["developer-tools", "ai-tools"], "entities": ["Microsoft", "Pylance", "Pyright", "Type Server Protocol", "Pyrefly", "Meta", "VS Code", "Copilot"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/pylance-pyrefly-python-type-checker-is-now-swappable", "markdown": "https://wpnews.pro/news/pylance-pyrefly-python-type-checker-is-now-swappable.md", "text": "https://wpnews.pro/news/pylance-pyrefly-python-type-checker-is-now-swappable.txt", "jsonld": "https://wpnews.pro/news/pylance-pyrefly-python-type-checker-is-now-swappable.jsonld"}}