skill-python-style-preferences/python-anyio-async/SKILL.md

name, description

name	description
python-anyio-async	Use when working on Python async code in repositories that already use or are explicitly standardizing on anyio. Apply task-group, cancellation, timeout, and async-boundary patterns without migrating established asyncio, trio, or synchronous code unless requested.

Python AnyIO Async

Use this skill for anyio-based async implementation work. It is not a general license to rewrite a repository's async model.

Priority Order

1. Explicit user instructions
2. Existing repository async conventions and verification workflow
3. This skill

Only apply this skill when the repository already uses anyio or the user explicitly asks to standardize on it.

Before Applying This Skill

Check the local project first:

• existing async imports and helpers
• current task runner and verification commands
• whether the code is anyio, asyncio, trio, or sync-only
• whether the CLI entrypoint is already established

If the repository is built around asyncio, trio, or synchronous code, keep that model unless the user asks for a migration.

Defaults

• Prefer anyio.create_task_group() over manual task orchestration.
• Prefer anyio.fail_after() or cancellation scopes for time-bounded work.
• Use anyio streams and synchronization primitives instead of mixing in raw asyncio APIs.
• For async CLIs that already use anyio, keep a synchronous entrypoint that calls anyio.run(...).
• When an asyncio boundary is unavoidable, isolate it and leave a short note.

from pathlib import Path

import anyio
import click


@click.command()
@click.argument("config_path", type=click.Path(path_type=Path))
def main(config_path: Path) -> None:
    anyio.run(run, config_path)


async def run(config_path: Path) -> None:
    async with await anyio.open_file(config_path) as fh:
        _ = await fh.read()

Verification

Use the repository's existing verification workflow first.

If no local workflow exists and the repository is already aligned with this stack:

1. run the configured type checker
2. run the async test suite or pytest
3. run a CLI or module smoke test that exercises the async boundary when relevant

Anti-Goals

• Do not replace an established asyncio or trio codebase with anyio unless asked.
• Do not mix manual event-loop management into anyio code without a forced integration boundary.
• Do not use this skill for synchronous code just because it contains a small async helper.