PostToolUse

A hook that runs after selected coding-agent actions, such as shell commands, builds or edits to JavaScript and TypeScript files. The shown configuration also reports a pull-request link after a GitHub pull request is created.

In plain words
What is it for?
Use it to trigger commands after matching tool calls, monitor build-related actions, inspect code edits, or print review instructions when a pull request is created.
Why use it?
It adds automatic follow-up messages to routine development actions, so useful checks or reminders do not depend on someone remembering them manually.

Hook

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add hooks/codelably/harmony-claude-code/post-tool-use
Clone the repo
git clone --depth 1 https://github.com/codelably/harmony-claude-code
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 1 finding. Scan, not verified.
Origin 91% copy Near-identical to another mod in the catalogue.
Security

Grade A, and why

PostToolUse scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the commands this hook runs, not an audit. A hook is shell that executes on your machine at the event it names, which is why every command in it is printed with what was found.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

"command": "node -e \"const{execFileSync}=require('child_process');const fs=require('fs');let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{const i=JSON.parse(d);const p=i.tool_input?.file_path;if(p&&
Origin

This is a copy

91% identical to AfterTool — 12 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

hooks/hooks.json · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "PostToolUse": [
    {
      "matcher": "tool == \"Bash\"",
      "hooks": [
        {
          "type": "command",
          "command": "node -e \"let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{const i=JSON.parse(d);const cmd=i.tool_input?.command||'';if(/gh pr create/.test(cmd)){const out=i.tool_output?.output||'';const m=out.match(/https:\\/\\/github.com\\/[^/]+\\/[^/]+\\/pull\\/\\d+/);if(m){console.error('[Hook] PR created: '+m[0]);const repo=m[0].replace(/https:\\/\\/github.com\\/([^/]+\\/[^/]+)\\/pull\\/\\d+/,'$1');const pr=m[0].replace(/.*\\/pull\\/(\\d+)/,'$1');console.error('[Hook] To review: gh pr review '+pr+' --repo '+repo)}}console.log(d)})\""
        }
      ],
      "description": "Log PR URL and provide review command after PR creation"
    },
    {
      "matcher": "tool == \"Bash\" && tool_input.command matches \"(npm run build|pnpm build|yarn build)\"",
      "hooks": [
        {
          "type": "command",
          "command": "node -e \"let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{console.error('[Hook] Build completed - async analysis running in background');console.log(d)})\"",
          "async": true,
          "timeout": 30
        }
      ],
      "description": "Example: async hook for build analysis (runs in background without blocking)"
    },
    {
      "matcher": "tool == \"Edit\" && tool_input.file_path matches \"\\\\.(ts|tsx|js|jsx)$\"",
      "hooks": [
        {
          "type": "command",
          "command": "node -e \"const{execFileSync}=require('child_process');const fs=require('fs');let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{const i=JSON.parse(d);const p=i.tool_input?.file_path;if(p&&fs.existsSync(p)){try{execFileSync('npx',['prettier','--write',p],{stdio:['pipe','pipe','pipe']})}catch(e){}}console.log(d)})\""
        }
      ],
      "description": "Auto-format JS/TS files with Prettier after edits"
    },
    {
      "matcher": "tool == \"Edit\"

Read the full file on GitHub · 56 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 56 lines scan A 0ec1b06ee7a7

Subscribe to this mod's changes

PostToolUse is a hook published in the GitHub repository codelably/harmony-claude-code (42 stars, last pushed 6mo ago), licensed MIT. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it A with 1 finding (runs shell commands). It is 91% identical to AfterTool, differing in 12 lines, and is treated as a copy.