# Auto Format On Edit

> Automatically format code files after every edit using Prettier and ESLint. Active in the background whenever Claude edits a file. Formatting is silent — no prompts, no output unless a formatter fails. Use when you want consistent formatting enforced automatically during a coding session.

- Skill: `davila7/auto-format-on-edit` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add davila7/auto-format-on-edit`
- Raw SKILL.md: https://api.skillmd.com/api/skills/davila7/auto-format-on-edit/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: davila7 (https://skillmd.com/u/davila7)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/davila7/auto-format-on-edit

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Formatting is applied automatically after every file edit via the PostToolUse hook defined in this skill's frontmatter. You do not need to run any formatter manually.

## What happens after each edit

When Claude uses the Edit or Write tool on any file, the PostToolUse hook fires and runs `scripts/format.sh`. That script:

1. Reads the edited file path from the hook input JSON
2. Checks whether the file has a recognized extension (.js, .ts, .jsx, .tsx, .css, .json, .md)
3. Runs `npx prettier --write` on the file if Prettier is available
4. Runs `npx eslint --fix` on the file if ESLint is available and the file is a script type (.js, .ts, .jsx, .tsx)
5. Exits 0 regardless of outcome — formatting failures are never allowed to block edits

## What is not formatted

- Binary files
- Files outside recognized extensions
- Files in node_modules, dist, .git, or similar directories
- Files where the formatter is not installed

## If the user asks why files look different after editing

Explain that `auto-format-on-edit` is active. It runs Prettier and ESLint after each edit to enforce consistent formatting. To disable it, remove or deactivate this skill.

## If a formatter produces unexpected results

Ask the user to check their `.prettierrc` or `.eslintrc` configuration files. The skill runs formatters with whatever project-level configuration is present — it does not override formatter settings.