Better Bots via Hooks

Table of Contents

It can be tedious trying to get your bot to do exactly what you want to do, but it’s not always necessary. If there are hard conventions that you need to enforce (like tidying, not committing certain kinds of changes), try enforcing these at the git pre-commit hook level. The advantage of this is that you don’t need to go through contortions to put certain kinds of requirements in AGENT.md files, skill instructions etc. If you let your agent commit your code, the pre-commit hook can prevent them from committing until they play by the rules.

"Captain Hook Topiary at Epcot Flower & Garden Festival 2014" by Austin Kirk is licensed under CC BY 2.0 .

Caveat Emptor
#

It’s always possible that your agent decides to commit with --no-verify or even deletes your hooks, so consider this part of a belt and suspenders approach to getting the results you want.

Show Me the Hooks
#

Here’s an example of a pre-commit hook that I’m using for https://mymindisracing.com. It

prevents commits to main
prevents updates to a scaffolding file that I keep under version control but don’t want changed
enforces tidying and linting:

#!/bin/sh
# Pre-commit hook to run precious lint on staged files

# Check if we're on main branch
branch=$(git symbolic-ref --short HEAD 2>/dev/null)
if [ "$branch" = "main" ]; then
    echo "ERROR: Direct commits to 'main' branch are not allowed."
    echo "Please create a feature branch instead:"
    echo "  git checkout -b feature/your-feature-name"
    exit 1
fi

# Block commits that include .serena/project.yml (tool artifact, never commit)
if git diff --cached --name-only | grep -q '^\.serena/project\.yml$'; then
    echo "ERROR: .serena/project.yml is staged for commit."
    echo "This file is a local tool artifact and should not be committed."
    echo "  git reset HEAD .serena/project.yml"
    exit 1
fi

# Run precious lint on staged files
precious lint -q --staged

# Capture the exit code
RESULT=$?

# If precious lint failed, prevent the commit
if [ $RESULT -ne 0 ]; then
    echo "pre-commit hook failed: precious lint found issues with staged files"
    echo "Please run 'precious tidy -q --staged' and try again"
    exit 1
fi

exit 0

Agents can do a lot of things really well, but they do tend to perform better when given guardrails. Adding this kind of basic safeguard can save a lot of tedium in your day to day work.