Repo brief: microsoft/pyright

Generated by RepoPilot · document generated 2026-09-16 · concise human review Evidence snapshot · analyzed 2026-09-16T04:53:03.463Z · commit e690634a94ab

Verdict

Healthy — Healthy across all four use cases

• Last commit today
• 20 active contributors
• Distributed ownership (top contributor 26% of recent commits)
• MIT licensed
• 2 more receipts on the live page

Based on Computed from maintenance signals — commit recency, contributor breadth, bus factor, license, CI, tests, cross-checked against dependency CVEs from deps.dev and OpenSSF Scorecard

What it is

Pyright is a fast, standards-based static type checker for Python written in TypeScript that performs ahead-of-time type analysis without running code. It provides both a command-line tool and VS Code extension, enabling developers to catch type errors, enforce PEP 484 type hints, and integrate type checking into CI/CD pipelines for large Python codebases. Monorepo managed by Lerna and pnpm with three main packages: packages/pyright (CLI entry point in langserver.ts and pyright.ts), packages/pyright-internal (core analysis engine under src/analyzer/ with ~50 specialized modules), and packages/vscode-pyright (VS Code extension). The analyzer directory contains semantic analysis,…

Start here

Open these first:

• packages/pyright-internal/src/analyzer/typeEvaluator.ts — Core type inference engine that evaluates Python AST nodes and derives type information; understanding this is essential…
• packages/pyright-internal/src/analyzer/program.ts — Central orchestrator for the analysis pipeline; manages file dependency graphs, scheduling, and coordinates all analyzer…
• packages/pyright-internal/src/analyzer/binder.ts — Binds declarations to symbols and establishes scope relationships; foundational for semantic analysis before type evaluation.
• packages/pyright-internal/src/analyzer/checker.ts — Performs diagnostic checks and produces error/warning reports post-type-evaluation; critical for end-user feedback.
• packages/pyright-internal/src/analyzer/importResolver.ts — Resolves Python import statements to actual files; essential for handling cross-file dependencies and typeshed integration.

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.

git clone https://github.com/microsoft/pyright.git
cd pyright
pnpm install:all

(The root package.json specifies pnpm@10.12.2 as the required package manager.)

Daily commands:

pnpm test                          # Run test suite (pyright-internal)
pnpm build:cli:dev                 # Build CLI for development
pnpm build:extension:dev           # Build VS Code extension
pnpm watch:extension               # Watch mode for extension development
pnpm watch:testserver              # Watch mode for test server
pnpm check                          # Run linting, formatting, and syncpack checks
pnpm typecheck                      # Type-check TypeScript source

Key cautions & unknowns

• PYRIGHT_TMPDIR environment variable: Required in remote/server environments where the OS temp directory is unavailable or read-only; set this to an absolute path before running Pyright. **Monorepo dependency…
• Exact package version, compatibility, provenance, and deployment context still need project-specific review.

Sources

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

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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