agentmods.dev

PreToolUse

A safety hook that runs before the agent edits files or executes shell commands.

In plain words
What is it for?
Use it to run guard scripts before Edit, Write, NotebookEdit, or Bash actions.
Why use it?
It checks actions that could affect the repository, including work on the main branch, shared stashes, and file-tree enumeration.

Hook for Claude Code

45 yesterday A scan tokens not measured original Apache-2.0
View the source file objectstack-ai/objectstack
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/objectstack-ai/objectstack/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/objectstack-ai/objectstack

Made for: 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 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 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.

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.claude/settings.json · 30 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Edit|Write|NotebookEdit",
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR/.claude/hooks/guard-main-checkout.sh\""
        }
      ]
    },
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR/.claude/hooks/guard-shared-stash.sh\""
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR/.claude/hooks/guard-main-checkout-bash.sh\""
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR/.claude/hooks/guard-tree-enum.sh\""
        }
      ]
    }
  ]
}
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 · 30 lines scan A 11e86a5246b8

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository objectstack-ai/objectstack (45 stars, last pushed yesterday), 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 2026-08-30.

E-commercefdefde-enablementmetadata-drivenontologyontology-driven-developmentontology-engineering
Related

Other hooks, from other repositories

PreToolUse

Runs before the agent uses a tool for Bash, Edit, Write, MultiEdit and NotebookEdit tool calls, executing block-npm-publish.sh, block-unsafe-git.sh and block-generated-edit.sh (3 commands). From wlsdks/ontology-atlas.

wlsdks/ontology-atlas · not measured

Stop

Runs when the agent finishes a response, running an inline shell check. From jameywarren/shopify-claude-quickstart.

jameywarren/shopify-claude-quickstart · not measured

PostToolUse

Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.

supabase/supabase · not measured

SessionStart

Runs when a session starts on startup, executing install_pkgs.sh. From supabase/supabase.

supabase/supabase · not measured

SessionStart

Runs when a session starts, executing on-start.js via node. From google-gemini/gemini-cli.

google-gemini/gemini-cli · not measured

PreToolUse

Runs before the agent uses a tool, executing pre-write.sh and pre-bash.sh (2 commands). From anthropics/claude-cookbooks.

anthropics/claude-cookbooks · not measured