build-on-change — Claude Code hook: what it does, how to install
Runs your build pipeline automatically whenever Claude Code edits a file. Detects build setups for Node.js, Make, Rust, and Java projects.
npx claude-code-templates@latest --hook automation/build-on-changeWhat build-on-change does
The hook attaches to the PostToolUse event with an Edit matcher. As soon as Claude Code finishes modifying any file, it executes a shell script inside the workspace.
The script inspects root files to pick the right command. It looks into package.json for a build script to invoke npm run build or yarn build. If not found, it checks for Makefile (make), Cargo.toml (cargo build), pom.xml (mvn compile), or build.gradle (./gradlew build).
Standard error is suppressed via 2>/dev/null combined with || true. Because of this suppression, a broken compilation does not stop the agent or print failure logs back to the context.
What it helps with
- rebuild projects automatically after agent file changes
- compile Rust code via cargo on source edits
- trigger frontend bundle builds after script updates
- run make or gradle targets without manual console input
Example prompts for the agent
- Update the interface definitions in
src/index.ts - Add input validation to the parser in
src/main.rs
How to install build-on-change
1claude-code-templates
npx claude-code-templates@latest --hook automation/build-on-change2Manually: put the files in place
.claude/settings.jsonThe hooks block: event (PreToolUse, PostToolUse, Stop…) → command. Personal ones go to ~/.claude/settings.json
Step by step, with commands for each platform: Claude Code hooks: what they are, where to configure them, how to block a risky command
Questions about build-on-change
How to install build-on-change in Claude Code?
Run npx claude-code-templates@latest --hook automation/build-on-change or place the hook declaration inside .claude/settings.json.
Which build systems does build-on-change support?
It recognizes projects managed with package.json (npm or yarn), Makefile, Cargo.toml, pom.xml, and build.gradle.
How does the hook handle compilation failures?
The script discards errors using /dev/null and appends || true, ensuring broken builds do not block the active agent session.
Source text
build-on-change.json · MIT
{
"description": "Automatically trigger build processes when source files change. Detects common build tools and runs appropriate build commands.",
"hooks": {
"PostToolUse": [
{
"matcher": "Edit",
"hooks": [
{
"type": "command",
"command": "if [[ -f package.json ]] && grep -q '\"build\"' package.json; then npm run build 2>/dev/null || yarn build 2>/dev/null || true; elif [[ -f Makefile ]]; then make 2>/dev/null || true; elif [[ -f Cargo.toml ]]; then cargo build 2>/dev/null || true; elif [[ -f pom.xml ]]; then mvn compile 2>/dev/null || true; elif [[ -f build.gradle ]]; then ./gradlew build 2>/dev/null || true; fi"
}
]
}
]
}
}
© davila7 · MIT · davila7/claude-code-templates
