astral-sh/ty

View on GitHub

An extremely fast Python type checker and language server, written in Rust.

Stars: 19.7k
Forks: 331
Open beginner issues: 0
Indexed issues: 906
Avg merge: 15h 23m
Merged PRs (30d): 43

Dominant language: Python
License: MIT
Last GitHub push: Sep 9, 2026
Latest indexed: Sep 14, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

Open All

899 open issues indexed

consider building use-def map per-scope instead of per-module Open

performance

astral-sh/ty#246 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Merge tracing setup for CLI and LSP Open

cli internal server

astral-sh/ty#90 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
ensure that type inference on a high-durability file is also high durability Open

performance

astral-sh/ty#242 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
mdtest output in CI isn't colourised Open

ci internal testing

astral-sh/ty#235 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Improve test coverage for edge cases involving `--typeshed` Open

stubs testing

astral-sh/ty#234 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Properly model control flow through `finally` suites Open

control flow runtime semantics

astral-sh/ty#233 · 4 comments · 0 reactions · 1 assignee · Indexed Sep 14, 2026
Inconsistency between unbound and undeclared symbols Open

control flow

astral-sh/ty#229 · 1 comment · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Do not treat nominal types inheriting from `Any` as fully static Open

type properties

astral-sh/ty#227 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Control flow modelling error in `try` ... `else` Open

control flow runtime semantics

astral-sh/ty#225 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
simplify across intersections in a union Open

set-theoretic types

astral-sh/ty#224 · 11 comments · 2 reactions · 0 assignees · Indexed Sep 14, 2026
Document public parts of ty_extensions API Open

documentation needs-design

astral-sh/ty#223 · 10 comments · 2 reactions · 0 assignees · Indexed Sep 14, 2026
`type[Any]` is equivalent to `type & Any` Open

set-theoretic types type properties

astral-sh/ty#222 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
`AlwaysTruthy | bool` is equivalent to `AlwaysTruthy | Literal[False]` Open

bug literal-types set-theoretic types type properties

astral-sh/ty#216 · 12 comments · 1 reaction · 1 assignee · Indexed Sep 14, 2026
`tuple & AlwaysFalsy` should simplify to `tuple[()]` Open

bug set-theoretic types type properties

astral-sh/ty#215 · 5 comments · 0 reactions · 1 assignee · Indexed Sep 14, 2026
expression-level type coverage measurement Open

feature

astral-sh/ty#213 · 6 comments · 16 reactions · 0 assignees · Indexed Sep 14, 2026
make it easier to avoid accidental cross-module direct AST usage Open

internal performance

astral-sh/ty#208 · 2 comments · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Diagnostic for conflicting declared attribute types Open

attributes diagnostics help wanted typing semantics

astral-sh/ty#206 · 8 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
consider fixing spans related to relative imports Open

bug diagnostics imports

astral-sh/ty#204 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Disjointness of complements Open

set-theoretic types type properties

astral-sh/ty#202 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Warn about too old python-version Open

configuration

astral-sh/ty#201 · 0 comments · 3 reactions · 1 assignee · Indexed Sep 14, 2026
Add `implicit-reexport` rule for runtime files Open

imports typing semantics

astral-sh/ty#200 · 0 comments · 5 reactions · 0 assignees · Indexed Sep 14, 2026
Check the return type of dunder methods Open

runtime semantics

astral-sh/ty#196 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Change `Type::member` to return a `Result` and rename it to `try_member` Open

internal

astral-sh/ty#194 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 14, 2026
mdtest: implement auto-update for inline `# error: ` message assertions Open

internal testing

astral-sh/ty#192 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Path handling on non-case sensitive systems Open

cli server

astral-sh/ty#189 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Verify file watching with windows UNC paths Open

windows

astral-sh/ty#187 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Hierarchical configuration Open

configuration

astral-sh/ty#175 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 14, 2026
Change range for `unresolved-attribute` error to attribute Open

attributes diagnostics

astral-sh/ty#169 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Tracking issue for override-related checks (including the Liskov Substitution Principle) Open

overrides typing semantics

astral-sh/ty#166 · 15 comments · 6 reactions · 1 assignee · Indexed Sep 14, 2026
Multi-platform checking Open

wish

astral-sh/ty#160 · 12 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Advanced `TypedDict` support Open

conformance typeddict typing semantics

astral-sh/ty#154 · 20 comments · 42 reactions · 0 assignees · Indexed Sep 14, 2026
Typing guide, migration guide, and other documentation Open

documentation

astral-sh/ty#149 · 3 comments · 4 reactions · 0 assignees · Indexed Sep 14, 2026
Add an opt-in diagnostic warning about unsound calls to `type[]` Open

constructor-call diagnostics typing semantics

astral-sh/ty#145 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Goto-type and hover-type for non-expression nodes (identifiers in statements) Open

hover navigation server

astral-sh/ty#144 · 3 comments · 1 reaction · 0 assignees · Indexed Sep 14, 2026
add Type::TypeVar to property tests Open

generics testing

astral-sh/ty#137 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Default to 'concise' output format if stdout is not a TTY Open

cli diagnostics

astral-sh/ty#134 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Consider custom `getattr_static` method Open

internal

astral-sh/ty#132 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Return type inference Open

type-inference

astral-sh/ty#128 · 21 comments · 51 reactions · 1 assignee · Indexed Sep 14, 2026
model the possibility of mid-module external mutation of module globals? Open

runtime semantics

astral-sh/ty#126 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
validate incremental correctness by checking successive commits of real projects Open

internal testing

astral-sh/ty#125 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Add more tests for inference of async comprehensions with invalid syntax Open

async internal testing type-inference

astral-sh/ty#121 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Update `star.md` tests to avoid syntax errors Open

imports internal testing

astral-sh/ty#120 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 14, 2026
Avoid type inference diagnostics on nodes with invalid syntax Open

diagnostics type-inference

astral-sh/ty#119 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Subscripted generic classes should not be considered instances of `type` Open

bug generics type properties

astral-sh/ty#116 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Calling `is_file_open` degrades current query to durability LOW Open

performance

astral-sh/ty#114 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Type inferred as `Never` from cyclic * import Open

bug cycles imports type-inference

astral-sh/ty#113 · 11 comments · 4 reactions · 0 assignees · Indexed Sep 14, 2026
Check for overlapping overloads Open

overloads type properties typing semantics unsoundness

astral-sh/ty#103 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 14, 2026
Display of overloaded definitions Open

diagnostics needs-design overloads

astral-sh/ty#102 · 13 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Avoid re-indexing when new files are added Open

cli performance

astral-sh/ty#97 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Stack overflow for large chain of inter-dependent definitions Open

bug fatal non-determinism

astral-sh/ty#96 · 12 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026

astral-sh/ty

Get new issues in your inbox