---
source_keys:
  - context7-pre-commit-com
  - pre-commit-com
---

# Creating a `.pre-commit-config.yaml`

Reached from `SKILL.md`'s Route table when the repo has no config yet. Self-contained — the modify
flow's file is not needed here. `SKILL.md`'s three common gates still apply.

## Steps

1. Detect what languages are actually in the repo with a shallow extension scan, rather than
   inferring them from the project's name or README:

   ```bash
   git ls-files | grep -oE '\.[a-z]+$' | sort | uniq -c | sort -rn
   ```

2. Read `references/hooks-by-language.md` and map the detected extensions to recommended hooks.
   Take the repo URL, `rev` and args from that file rather than from memory — a `rev` that does not
   exist is the most common way a fresh config fails on its first run.

   For a deliberately minimal starting point instead of a full recommendation set,
   `pre-commit sample-config > .pre-commit-config.yaml` prints a small starter config to build on.

3. State the proposed config in full and wait for the user's confirmation.

4. Write `.pre-commit-config.yaml`, then run `pre-commit validate-config`. If it exits non-zero,
   show the error, fix it in place, and re-validate.