---
name: pc-run
description: >
Use when the user wants to run pre-commit hooks, wire them into git, bump hook
revs, maintain the cache, or diagnose why a hook fails or never fires. Not
creating or editing the pre-commit config -> `pc-author`.
compatibility: Requires pre-commit installed and available on PATH.
metadata:
category: devtools
source_keys:
- context7-pre-commit-com
- pre-commit-com
allowed-tools: Bash Read
---
## Gotchas
- The `SKIP` env var takes exact hook `id` values, comma-separated with no spaces: `SKIP=check-yaml,gitleaks git commit -m "msg"`. A space after a comma silently skips nothing instead of erroring.
- Never bypass a failing hook with `git commit --no-verify` (or `-n`). Hooks are the automated QA gate, so a bypassed commit pushes the failure downstream where it costs more — diagnose it instead.
- `- files were modified by this hook` is not a bug. A fixer hook (`trailing-whitespace`, `end-of-file-fixer`, `pretty-format-json --autofix`) rewrote a staged file, so the staged snapshot is stale and the commit is blocked on purpose. The fix is to re-stage and re-run the same commit: `git add -u && git commit`. Do NOT reach for `pre-commit install -f` here — that flag overwrites hook files in `.git/hooks/` and has nothing to do with re-staging.
## Gate — `pre-commit clean`
Confirm with the user before running `pre-commit clean`, on every path that reaches it — including when it turns up as the fix for a stale or broken environment. It wipes the whole cache at `~/.cache/pre-commit`, which is machine-wide and shared by every repo on the box, forcing every hook environment to be re-downloaded.
> "This will wipe the entire pre-commit cache. All hook environments will be re-downloaded on next run. Proceed?"
`pre-commit gc` drops only unused environments and needs no confirmation — prefer it when the goal is just to reclaim disk.
## Route
Determine intent from the user's request, then execute the matching operation. Where the matching row names a `references/` file, read that one file and no other — each flow file is self-contained.
| User intent | Operation |
|---|---|
| "run", "check", "verify", "test hooks" | `pre-commit run --all-files` (default) |
| "staged", "simulate commit" | `pre-commit run` (staged files only) |
| "CI", "changed files only", "diff range" | `pre-commit run --from-ref --to-ref ` — prefer this over `--all-files` on large repos |
| "install", "set up hooks", "wire into git" | `pre-commit install` — read `references/install.md` |
| "pre-create environments", "warm cache" | `pre-commit install-hooks` — builds every hook environment without running a hook |
| "remove hooks", "uninstall", "tear down" | `pre-commit uninstall` — removes pre-commit from `.git/hooks/` |
| "autoupdate", "update versions", "bump revs" | `pre-commit autoupdate` — read `references/autoupdate.md` |
| "gc", "garbage collect" | `pre-commit gc` — drops unused cached environments only, safe at any time |
| "clean", "wipe cache", "rebuild from scratch" | `pre-commit clean` — read `references/clean.md` |
| "hooks aren't running", "hook never fires", "why did a hook fail", a hook failure whose cause is unclear | Diagnose — read `references/failure-patterns.md` |
If the intent is ambiguous, default to `pre-commit run --all-files`.
## Run
Default to `pre-commit run --all-files`; never silently narrow to staged files. Run `pre-commit run` (staged only) or `pre-commit run ` (one named hook) when the user asks for it.
When hooks fail:
1. Name the hook and the specific cause. Be concrete — "gitleaks blocked `config.json` (high-entropy string on line 12)", not "gitleaks failed".
2. Suggest one concrete next step. Common causes and their concrete fixes are in `references/failure-patterns.md` — read it whenever the output does not already name the fix.
3. Do not auto-fix code files, and do not edit `.pre-commit-config.yaml` — those belong to the user or to `pc-author`.