Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add buildomator/buildomator/plugin install gsdWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/hooks/buildomator/buildomator/pre-tool-use)<a href="https://agentmods.dev/hooks/buildomator/buildomator/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/buildomator/buildomator/pre-tool-use.svg" alt="Measured on agentmods" height="20"></a>Grade A, and why
PreToolUse 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 4d ago.
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 f=require('fs'),p=require('path'),o=require('os'),cp=require('child_process'),c=[];if(process.env.CLAUDE_PLUGIN_ROOT)c.push(p.join(process.env.CLAUDE_PLUGIN_ROOT,'hooks/run-bash-hook.cjs'));co This is a copy
91% identical to SessionStart — 26 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.
How it starts
The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.
{
"PreToolUse": [
{
"matcher": "Edit|Write",
"hooks": [
{
"type": "command",
"command": "node -e \"const f=require('fs'),p=require('path'),o=require('os'),c=[];if(process.env.CLAUDE_PLUGIN_ROOT)c.push(p.join(process.env.CLAUDE_PLUGIN_ROOT,'bin/gsd-tools.cjs'));const b=p.join(o.homedir(),'.claude/plugins/cache'),g='gsd',t=[];try{for(const m of f.readdirSync(b)){try{for(const v of f.readdirSync(p.join(b,m,g)))if(/^\\d+\\.\\d+\\.\\d+$/.test(v))t.push([v,p.join(b,m,g,v,'bin/gsd-tools.cjs')]);}catch(e){}}}catch(e){}t.sort((a,z)=>{const A=a[0].split('.').map(Number),B=z[0].split('.').map(Number);return B[0]-A[0]||B[1]-A[1]||B[2]-A[2];});for(const e of t)c.push(e[1]);for(const x of c){if(!f.existsSync(x))continue;if(process.env.CLAUDE_PLUGIN_ROOT&&x!==c[0])process.stderr.write('GSD: plugin path stale, using '+x+'\\n');process.argv.splice(1,0,x);require(x);break;}\" hook pre-tool-use",
"timeout": 3000
}
]
},
{
"matcher": "Edit|Write",
"hooks": [
{
"type": "command",
"command": "node -e \"const f=require('fs'),p=require('path'),o=require('os'),c=[];if(process.env.CLAUDE_PLUGIN_ROOT)c.push(p.join(process.env.CLAUDE_PLUGIN_ROOT,'hooks/gsd-prompt-guard.js'));const b=p.join(o.homedir(),'.claude/plugins/cache'),g='gsd',t=[];try{for(const m of f.readdirSync(b)){try{for(const v of f.readdirSync(p.join(b,m,g)))if(/^\\d+\\.\\d+\\.\\d+$/.test(v))t.push([v,p.join(b,m,g,v,'hooks/gsd-prompt-guard.js')]);}catch(e){}}}catch(e){}t.sort((a,z)=>{const A=a[0].split('.').map(Number),B=z[0].split('.').map(Number);return B[0]-A[0]||B[1]-A[1]||B[2]-A[2];});for(const e of t)c.push(e[1]);for(const x of c){if(!f.existsSync(x))continue;if(process.env.CLAUDE_PLUGIN_ROOT&&x!==c[0])process.stderr.write('GSD: plugin path stale, using '+x+'\\n');process.argv.splice(1,0,x);require(x);break;}\"",
"timeout": 3000
}
]
},
{
"matcher": "Edit|Write",
"hoWhat else hooks.json configures
This page is one entry in a file that holds 6. Installing the file brings all of them; each is measured and scanned on its own page.
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.
- 4d ago First seen · 54 lines scan A de2223a08b26
PreToolUse is a hook published in the GitHub repository buildomator/buildomator (86 stars, last pushed yesterday), 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 SessionStart, differing in 26 lines, and is treated as a copy.
Other hooks, from other repositories
PostToolUse
Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.
SessionStart
Runs when a session starts, executing on-start.js via node. From google-gemini/gemini-cli.
SessionStart
Runs when a session starts on startup, executing install_pkgs.sh. From supabase/supabase.
PreToolUse
Runs before the agent uses a tool for Bash tool calls, running an inline shell check. From apache/superset.
PreToolUse
Runs before the agent uses a tool, executing pre-write.sh and pre-bash.sh (2 commands). From anthropics/claude-cookbooks.
SessionStart
Runs when a session starts, executing session-start.sh. From anthropics/claude-cookbooks.