ty-lsp

claude-ty-lsp

A Claude Code plugin that wires up ty — Astral's fast Python type checker and language server — so Claude gets real code intelligence on Python projects: diagnostics after every edit, go to definition, find references, hover types, and symbol search.

This repository is both the plugin (ty-lsp) and a single-plugin marketplace (claude-ty-lsp).

Install

The plugin configures the connection to ty; it does not bundle the binary. Install ty first and make sure it's on your PATH:

uv tool install ty

Or as a project dev dependency:

uv add --dev ty

Then add the marketplace and install the plugin:

/plugin marketplace add jsperger/claude-ty-lsp
/plugin install ty-lsp@claude-ty-lsp

Verify with ty --version. If /plugin shows Executable not found in $PATH under its Errors tab, ty isn't installed or isn't visible to Claude Code.

Local development

git clone https://github.com/jsperger/claude-ty-lsp.git
claude --plugin-dir /path/to/claude-ty-lsp

What you get

Applies to .py and .pyi files.

Verified working against ty 0.0.56: diagnostics, go to definition / declaration / type definition, find references, document symbols, workspace symbols, call hierarchy, type hierarchy, hover, completions, inlay hints, signature help, document highlight, semantic tokens, folding, and rename.

Not provided by ty: go to implementation, code lens, document link, document color, rename-files. (Claude exposes a goToImplementation operation, but ty does not answer it.) Formatting is intentionally out of scope — use ruff format.

ty is in beta. Its navigation is dependable; its type system still has gaps, tracked in astral-sh/ty#1889. The most consequential one for day-to-day use is that return types of unannotated functions aren't inferred yet, which is why you'll see Unknown in hovers. Missing language-server features are tracked in astral-sh/ty#3588.

The plugin also ships a skill (ty-python-lsp) that teaches Claude when to reach for LSP navigation instead of grep, how to position requests so they don't silently miss, and which beta gaps to expect.

Layout

.claude-plugin/
  plugin.json        # plugin manifest
  marketplace.json   # marketplace listing
.lsp.json            # ty language server configuration
skills/
  ty-python-lsp/
    SKILL.md         # guidance for using ty effectively

More information

• ty language server features
• ty on GitHub
• ty on PyPI