# DetachHead/basedpyright

pyright fork with various type checking improvements, improved vscode support and pylance features built into the language server

Repository: https://github.com/DetachHead/basedpyright
Canonical: https://ross.abutalabs.com/products/basedpyright
Homepage: https://docs.basedpyright.com
Language: TypeScript
License: NOASSERTION
License Family: other
Topics: based, pylance, pyright, python, typing
Last push: 2026-08-21T09:04:42+00:00

## Health v2 (maintenance only)
Score: 88/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 98, release rhythm 85, longevity 71
- inputs: {"age_days": 1006, "days_push": 12, "days_rel": 20, "gap_med": 7.0, "n_releases_24m": 75}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3557, forks 135 (observed 2026-08-28T04:08:09.710102+00:00)

## What it is
basedpyright is a fork of Microsoft's pyright static type checker for Python with additional type checking improvements and pylance features built into the language server. It ships as a CLI, a language server, and editor extensions for VS Code, Sublime Text, and other LSP-capable editors.

## Use cases
- static type checking for python code
- get pylance features without vscode
- run a python type checker in ci
- improve python type checking beyond pyright
- python language server for sublime text
- check python typing errors in the editor

## When to choose
- you want pyright with stricter and more configurable type checking
- you need pylance-like features in editors other than vscode
- you want a free, self-hosted alternative to pylance

## When to avoid
- you want the officially supported microsoft pyright
- you need a runtime type checker rather than static analysis
- you rely on pylance's proprietary closed-source features exactly as shipped

## Facets
- artifact type: cli-tool
- maturity: active
- function: linter, type-system, editor, developer-tools
- domain: programming-languages, developer-tools, text-editors
- platform: python, cli, editor-plugin, cross-platform
- tags: pyright-fork, pylance, language-server, static-type-checking, vscode-extension, python-typing, nodejs

## Member repositories
- DetachHead/basedpyright (main) score 88

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:09.710102+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:34:15.276491+00:00, confidence not recorded.
  - readme: https://github.com/DetachHead/basedpyright (fetched 2026-08-28T04:08:09.710102+00:00, sha 8cb2108b48be)
  - homepage: https://docs.basedpyright.com (fetched 2026-08-29T09:28:20.412464+00:00, sha 36c6c3c2e4f9)
- Data as of 2026-08-30T08:39:29.467469+00:00.