agentmods.dev

PreToolUse

A set of automatic checks that run before an agent edits files or calls an external tool. The checks run shell scripts that protect logs, rules, the project root, and external actions.

In plain words
What is it for?
Use it to enforce project safety rules before edits, file writes, and external tool calls.
Why use it?
It catches or blocks unsafe actions before they change files or interact with outside services. This adds guardrails to routine agent work.

Hook

127 7d ago A scan tokens not measured original MIT
View the source file alivecontext/alive
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/alivecontext/alive/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/alivecontext/alive
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. Scan, not verified.
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 2d 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/alive/hooks/hooks.json · 34 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Edit|Write",
      "hooks": [
        {
          "type": "command",
          "command": "bash ${CLAUDE_PLUGIN_ROOT}/hooks/scripts/alive-log-guardian.sh",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "bash ${CLAUDE_PLUGIN_ROOT}/hooks/scripts/alive-rules-guardian.sh",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "bash ${CLAUDE_PLUGIN_ROOT}/hooks/scripts/alive-root-guardian.sh",
          "timeout": 5
        }
      ]
    },
    {
      "matcher": "mcp__.*",
      "hooks": [
        {
          "type": "command",
          "command": "bash ${CLAUDE_PLUGIN_ROOT}/hooks/scripts/alive-external-guard.sh",
          "timeout": 5
        }
      ]
    }
  ]
}
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. 2d ago First seen · 34 lines scan A ff96235ca49b

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository alivecontext/alive (127 stars, last pushed 7d 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 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

ai-toolsclaude-codeclaude-code-pluginclicontext-managementmarkdown
Related

Other hooks, from other repositories

PostCompact

Runs after the context is compacted, running echo 'REMINDERS (things linters dont catch): 1) Verify all s. From tomasz-tomczyk/crit.

tomasz-tomczyk/crit · not measured

PermissionRequest

Runs when the agent asks permission for an action for ExitPlanMode tool calls, running crit plan-hook. From tomasz-tomczyk/crit.

tomasz-tomczyk/crit · not measured

PostToolUse

Runs after a tool call finishes for Edit, Write, Bash, Read, Edit, Write, Glob, Grep, Agent and mcp__.* tool calls, executing read-cache.js and tracker.js (2 commands). From egorfedorov/claude-context-optimizer.

egorfedorov/claude-context-optimizer · not measured

PreToolUse

Runs before the agent uses a tool for Read tool calls, executing read-cache.js and context-shield.js (2 commands). From egorfedorov/claude-context-optimizer.

egorfedorov/claude-context-optimizer · not measured

PreCompact

Runs before the context is compacted, executing read-cache.js and tracker.js (2 commands). From egorfedorov/claude-context-optimizer.

egorfedorov/claude-context-optimizer · not measured

SessionEnd

Runs when a session ends, executing tracker.js. From egorfedorov/claude-context-optimizer.

egorfedorov/claude-context-optimizer · not measured