Pyrefly Sublime LSP

Pyrefly LSP integrates Meta's Rust-based pyrefly type checker into Sublime Text via the LSP package, with automatic binary management. It gives Sublime users a fast, from-source type checker without leaving the editor.

The problem

Python type checkers in Sublime have historically meant wrestling with LSP configuration and binary paths by hand. Pyrefly is a new, Rust-based checker from Meta that is fast enough for interactive use, but there was no turnkey Sublime integration that handled binary download, version pinning, and LSP wiring.

The approach

The plugin manages the pyrefly binary lifecycle — downloading, versioning, and locating it — so the user only needs LSP installed and the package enabled. The LSP configuration is generated at runtime from the managed binary path, avoiding hardcoded settings that break on update. The 6-test suite covers binary resolution and LSP config emission.

What it demonstrates

Published at 0.7.0 with CI, pre-commit hooks, typed source, and 2 documentation pages. Six tests is a small surface, but the scope is correspondingly narrow: the contract is binary management and LSP config, not a general framework. Shipping an LSP integration with the same pipeline discipline as a standalone library keeps the ecosystem honest.