## Summary
- On every CLI command invocation (except `update`/`upgrade`/`mcp`), a
detached subprocess checks PyPI for newer versions (throttled to once
per 4 hours) and caches the result at `~/.arcade/update_cache.json`
- On the next invocation, if a newer version is known, a yellow
one-liner notification is printed suggesting `arcade update`
- Respects `ARCADE_DISABLE_AUTOUPDATE=1` environment variable to opt out
entirely
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Adds a background PyPI version check that spawns detached subprocesses
and may print update notifications on most CLI invocations; mistakes
could impact CLI reliability or corrupt MCP stdio output (mitigated by
explicit command exclusions).
>
> **Overview**
> Adds `arcade update` (and hidden `arcade upgrade` alias) to
self-upgrade the `arcade-mcp` CLI by detecting the original install
method (`uv tool`, `pipx`, `uv pip`, or `pip`) and running the
appropriate upgrade command.
>
> Introduces a **throttled background update check** on most CLI
invocations: a detached subprocess queries PyPI, writes
`~/.arcade/update_cache.json`, and on subsequent runs prints a one-line
notification when a newer version is cached; this is disabled via
`ARCADE_DISABLE_AUTOUPDATE=1` and explicitly skipped for
`update`/`upgrade`/`mcp` to avoid MCP stdio output corruption.
>
> Bumps the package version to `1.13.0`, adds a `packaging` dependency,
and includes comprehensive tests covering PyPI/yanked/prerelease
handling, install-method detection, caching, and callback integration.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
2d9646ecc2211e8cfecd6e4901d14b1f5b7bb306. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>