Problem

Remembering to run prek auto-update regularly to keep pre-commit hooks up to date is a common challenge. Without regular updates, hooks can become stale, missing important bug fixes, performance improvements, or new features.

Existing solutions in the pre-commit ecosystem

• pre-commit.ci — auto-creates weekly PRs with updates (GitHub only)
• pre-commit-update — a hook that checks for updates during normal pre-commit runs
• Scheduled CI jobs — run autoupdate on a cron and open PRs
• Crontab — local scheduled updates

Prek's current state

Prek already has:

• prek auto-update command with a nice --cooldown-days flag for supply chain security
• repo: builtin for fast, zero-setup Rust-native hooks

What's missing is a built-in hook to check/remind developers about outdated hook versions during normal workflow.

Proposal

Add a repo: builtin hook (e.g., check-hook-updates) that runs during commits or pushes and warns when hook versions are outdated.

Example configuration

repos:
  - repo: builtin
    hooks:
      - id: check-hook-updates
        # Optional: only warn if updates are older than N days
        # (leveraging the existing --cooldown-days concept)
        args: [--cooldown-days=7]

Behavior

• On commit/push, check if any configured hooks have newer versions available
• If updates are found, print a warning (but don't fail the commit by default)
• Optionally, allow --fail-on-updates to make the hook fail if updates are available
• Respect --cooldown-days to avoid alerting about very recent releases (supply chain security)

Why this fits prek's philosophy

This aligns well with prek's "batteries included" approach—providing zero-setup, Rust-native solutions that don't require external dependencies or services. Unlike pre-commit.ci (GitHub-only) or cron jobs (requires system setup), this would work everywhere prek runs, right out of the box.

Related

• This is different from Feature: Hook version sync #1054 which focuses on syncing hook versions with local project dependencies (e.g., matching ruff version in pre-commit config with pyproject.toml). This proposal is specifically about alerting when upstream hooks have newer releases available.
• This is also different from prek.ci #621 (prek.ci) which discusses a hosted CI service. This proposal is for a local built-in hook that works without any external service.