Pyright LSP

---
name: pyright-lsp
description: |
  Always active when working in Python projects. Runs Pyright diagnostics
  after edits to catch type errors. Trigger: any .py file edit.
allowed-tools:
  - Bash(npx pyright *)
  - Bash(pip install pyright *)
  - Read
  - Glob
---

# Pyright LSP

Python type checking and diagnostics via Pyright language server. Catches
type errors, import issues, and missing annotations.

## Prerequisites

- `pyright` installed: `pip install pyright` or `npm install -g pyright`
- Python project with `pyrightconfig.json` or `pyproject.toml` (optional)

## Steps

1. After any Python file edit, run diagnostics:
   ```bash
   npx pyright --outputjson 2>/dev/null | python3 -c "
   import json, sys
   data = json.load(sys.stdin)
   for d in data.get('generalDiagnostics', [])[:20]:
       print(f\"{d['file']}:{d['range']['start']['line']}: {d['message']}\")
   "
   ```

2. Or for simple output:
   ```bash
   npx pyright 2>&1 | tail -30
   ```

3. Common fixes:
   - Add type annotations to function signatures
   - Use `Optional[T]` or `T | None` for nullable params
   - Add `py.typed` marker for library packages
   - Use `TYPE_CHECKING` imports to avoid circular dependencies

4. Configure strictness in `pyrightconfig.json`:
   ```json
   {
     "typeCheckingMode": "basic",
     "reportMissingTypeStubs": false
   }
   ```