agent-library: Hook for Gemini CLI

.gemini/settings.json

BeforeTool is a hook for Gemini CLI from bl1nk-bot/agent-library. Its token cost is not measured, scanned A, original, CC0-1.0.

A pre-tool hook for shell commands that runs a Python check before the command is executed. The check is intended to run readiness checks before Git commits, including linting, tests, and a rebrand scan.

In plain words
What is it for?
Use it in a workflow where shell commands create Git commits and those checks should run first.
Why use it?
It can catch selected repository problems before a commit is made rather than after changes have been recorded.

Hook for Gemini CLI

Written for Gemini CLI: installed under .gemini/.

This is bl1nk-bot/agent-library's own configuration. It tells Gemini CLI how to work on agent-library itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agent-library configures →

One of 3 entries in settings.json upstream. Installing this one merges just its entry into your config; the other 2 are separate, each on its own page.

Reuse

Borrowing it

Nothing to install: this file belongs to bl1nk-bot/agent-library. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/bl1nk-bot/agent-library/main/.gemini/settings.json
Clone the repo
git clone --depth 1 https://github.com/bl1nk-bot/agent-library

Made for: Gemini CLI.

Wrote 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.

agentmods badge for BeforeTool

README.md
[![agentmods](https://agentmods.dev/badge/hooks/bl1nk-bot/agent-library/before-tool/github.svg)](https://agentmods.dev/hooks/bl1nk-bot/agent-library/before-tool)
Your own site
<a href="https://agentmods.dev/hooks/bl1nk-bot/agent-library/before-tool"><img src="https://agentmods.dev/badge/hooks/bl1nk-bot/agent-library/before-tool/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for BeforeTool

Your own site · 80×15
<a href="https://agentmods.dev/hooks/bl1nk-bot/agent-library/before-tool"><img src="https://agentmods.dev/badge/hooks/bl1nk-bot/agent-library/before-tool.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
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 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

BeforeTool scanned grade A with 0 findings 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 1mo 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.gemini/settings.json · 15 lines

What it actually says

{
  "BeforeTool": [
    {
      "matcher": "run_shell_command",
      "hooks": [
        {
          "name": "pre-commit-readiness-check",
          "type": "command",
          "command": "python3 .gemini/hooks/check-git-commit.py",
          "description": "Runs readiness checks (lint, test, rebrand sweep) before any git commit command."
        }
      ]
    }
  ]
}
Same file

What else settings.json configures

This page is one entry in a file that holds 3. Installing the file brings all of them; each is measured and scanned on its own page.

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. 1mo ago First seen · 15 lines scan A 69711ccf1aa4

Subscribe to this mod's changes

BeforeTool is a hook published in the GitHub repository bl1nk-bot/agent-library (2 stars, last pushed today), licensed CC0-1.0. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-07.