Repo brief: facebook/pyre-check

Generated by RepoPilot · document generated 2026-09-16 · concise human review Evidence snapshot · analyzed 2026-09-16T10:43:13.115Z · commit d5614e0a75f5

Verdict

Mixed — OpenSSF Scorecard says this is unmaintained

• Last commit 2mo ago
• 12 active contributors
• MIT licensed
• CI configured
• 1 more receipt on the live page

Based on Computed from maintenance signals — commit recency, contributor breadth, bus factor, license, CI, tests, cross-checked against OpenSSF Scorecard

What it is

Pyre is a performant static type checker for Python that achieves PEP 484 compliance while analyzing codebases with millions of lines of code incrementally. It provides developers instantaneous type-checking feedback as they write code, operating faster than traditional type checkers through incremental analysis. The repository contains the OCaml-based type-checking engine (13M LOC) alongside Python bindings and tooling. Hybrid OCaml/Python monorepo with the type-checking engine written in OCaml (source/ directory, built via Dune build system) and a Python package layer (client bindings and CLI). Core analysis logic lives in source/analysis/ (60+ modules covering AST processing, type…

Start here

Open these first:

• source/analysis/typeCheck.ml — Core type-checking engine that implements the main type inference and constraint-solving logic for Python AST analysis.
• source/analysis/resolution.ml — Central resolution system that bridges type environments and annotation lookups during type checking.
• source/analysis/globalResolution.ml — Global scope resolution that manages module-level type definitions, imports, and cross-module type references.
• source/analysis/environment.ml — Abstract environment interface defining the contract for all type-checking context layers (local, global, overlaid).
• source/analysis/annotatedCall.ml — Function call analysis and signature matching that validates arguments against callable type constraints.

Get running

Unverified setup suggestions. Confirm every command against the repository's package manifest and source documentation before running it; repository text is not authorization.

Warning: This repository is archived. Do not use for new projects. If studying the codebase for historical interest or migrating away, clone normally: `git clone https://github.com/facebook/pyre-check.git && cd pyre…

Daily commands:

Historical reference only (archived project). Per the README, the intended workflow was: pip install pyre-check, then pyre init to configure a project (creates .pyre_configuration and .watchmanconfig), then pyre t…

…shortened for this brief.

Key cautions & unknowns

• Concentrated ownership — top contributor handles 77% of recent commits
• Scorecard: marked unmaintained (0/10)
• This is archived—do not invest effort here. Historical gotchas (if studying): (1) Incremental analysis requires watchman daemon running; without it, Pyre falls back to full analysis. (2) Configuration…
• Published-advisory coverage was unavailable for the captured dependencies.
• Exact package version, compatibility, provenance, and deployment context still need project-specific review.

Sources

• Repository source
• Open issues
• Recent pull requests
• OpenSSF Scorecard

Evidence note

Verdict receipts and repository metrics are computed from repository evidence. Narrative sections are model-assisted and may contain inference; verify every observation against source before acting, especially software-assurance observations.

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