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PreToolUse

PreToolUse is a hook for Claude Code from omar-y-abdi/furl-ctx. Its token cost is not measured, scanned A, original, Apache-2.0.

A pre-action hook that runs a context-checking script before the agent uses Bash, the command-line tool. It can be disabled through an environment setting and does not stop the command if the hook itself fails.

In plain words
What is it for?
Use it to run a Furl context check before Bash commands in Claude Code.
Why use it?
It gives commands an extra check before they run and can add context from the Furl tool without changing the command’s normal outcome.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the furl plugin — 3 hooks shipped together

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

not rated 4repo 6d ago A scan tokens not measured original Apache-2.0

Good fit Use it to run a Furl context check before Bash commands in Claude Code.

Compare 6 hooks from other repositories ↓
View source ↗ omar-y-abdi/furl-ctx furl-ctx.vercel.app
Install

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.

Claude Code
/plugin marketplace add omar-y-abdi/furl-ctx
Claude Code
/plugin install furl

Made for: Claude Code.

Or install furl, the plugin that ships this one along with the rest of its 3 hooks.

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 PreToolUse

README.md
[![agentmods](https://agentmods.dev/badge/hooks/omar-y-abdi/furl-ctx/pre-tool-use.svg)](https://agentmods.dev/hooks/omar-y-abdi/furl-ctx/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/omar-y-abdi/furl-ctx/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/omar-y-abdi/furl-ctx/pre-tool-use.svg" alt="Measured on agentmods" 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

PreToolUse 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 8d 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.

plugins/furl/hooks/hooks.json · 14 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "sh -c 'case \"$(printf %s \"$FURL_PRETOOL_PIPE\" | tr \"[:upper:]\" \"[:lower:]\" | tr -d \"[:space:]\")\" in 0|false|off|no|disabled) ;; *) o=$(PATH=\"$PATH:$HOME/.local/bin:$HOME/.cargo/bin:/opt/homebrew/bin:/usr/local/bin\" uv run --no-project --with \"furl-ctx[mcp]==1.4.0\" python3 \"${CLAUDE_PLUGIN_ROOT}/hooks/pretool_pipe.py\"); pre=${o%%\"{\"*}; case $o in *\"{\"*) printf %s \"${o#\"$pre\"}\" ;; *) printf %s \"$o\" ;; esac ;; esac; true'",
          "timeout": 30
        }
      ]
    }
  ]
}
Same file

What else hooks.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. 8d ago First seen · 14 lines scan A 483ecfc2f55c

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository omar-y-abdi/furl-ctx (4 stars, last pushed 6d ago), licensed Apache-2.0. 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 2026-08-31.

Claude Codeclaudeclaude-code-plugincompressioncontext-managementdeveloper-tools
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