A pre-tool hook that runs Node.js checks before selected ComfyUI actions, including workflow execution and stopping or restarting ComfyUI.

Running safety checks before enqueueing workflows or changing the ComfyUI service state.

It checks video-memory use before work and warns about saving before ComfyUI is stopped or restarted.

PreToolUse — Hook by sandyup

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/sandyup/comfyui-mcp/pre-tool-use

Clone the repo

git clone --depth 1 https://github.com/sandyup/comfyui-mcp

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 58% copy Near-identical to another mod 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.

Origin

This is a copy

58% identical to SessionStart — 17 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.

plugin/hooks/hooks.json · 22 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "mcp__plugin_comfy_comfyui__enqueue_workflow",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/vram-check.mjs\""
        }
      ]
    },
    {
      "matcher": "mcp__plugin_comfy_comfyui__(stop|restart)_comfyui",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/save-warning.mjs\""
        }
      ]
    }
  ]
}

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.

2d ago First seen · 22 lines scan A 21cc0748e938

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository sandyup/comfyui-mcp (1 stars, last pushed 1mo 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. It is 58% identical to SessionStart, differing in 17 lines, and is treated as a copy.

PreToolUse

Getting it into your agent

Grade A, and why

Nothing flagged

This is a copy

What it actually says

What this file has done since we first saw it

Other hooks, from other repositories

PostToolUse

SessionStart

SessionStart

PreToolUse

PreToolUse

SessionStart