Type Server Protocol

	Type Server Protocol(github.com)
	249 points by adamnemecek 18 hours ago \| 169 comments
	tl;dr: The Type Server Protocol (TSP) is a JSON-RPC protocol—borrowing conventions from LSP—for querying a Python type server about snapshots, import resolution, search paths, and type information (computed, declared, and expected types). It uses snapshot IDs to version analysis state, returns tagged JSON type objects with discriminators for built-ins, functions, classes, unions, etc., and supports an optional multi-connection mode for concurrent read-only queries over IPC. The current 0.4.1 spec appears aligned with Pylance 2026.4.1, suggesting Microsoft is formalizing an interface between editors and Python type checkers.
	HN Discussion: ~TSP is Microsoft's attempt at vendor lock-in disguised as an open protocol •Confusion about why TSP is needed when LSP could potentially be extended instead ~Protocol is too Python-specific to justify the generic 'Type Server Protocol' name ↑Positive that Astral's Ty will support TSP, enabling type checker/language server separation ↓Skepticism toward Microsoft-designed protocols based on prior LSP experience