agentmods.dev

SessionStart

A session-start hook that runs a Node.js script whenever an agent session begins.

In plain words
What is it for?
Automatically starting the configured stop-that-shit-claude.cjs script when a session opens.
Why use it?
It performs a predefined check or action at the start of each session without waiting for a separate prompt.

Hook

798 yesterday A scan tokens not measured copy · 61% MIT
View the source file lennney/stop-that-shit
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/lennney/stop-that-shit/session-start
Clone the repo
git clone --depth 1 https://github.com/lennney/stop-that-shit
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 61% copy Near-identical to another mod in the catalogue.
Security

Grade A, and why

SessionStart 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

This is a copy

61% identical to SessionStart — 7 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.

hooks/hooks.json · 14 lines

What it actually says

{
  "SessionStart": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/stop-that-shit-claude.cjs\"",
          "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. yesterday First seen · 14 lines scan A 8409ade82358

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository lennney/stop-that-shit (798 stars, last pushed yesterday), 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 61% identical to SessionStart, differing in 7 lines, and is treated as a copy.

agent-skillsai-agentscodexcodex-clicodex-plugindeveloper-tools
Related

Other hooks, from other repositories

PostToolUse

Runs after a tool call finishes for ^mcp__(plugin_[A-Za-z0-9_-]+_)?roboflow__.*$ tool calls, executing cta.js via node. From Borda/vision-delivery.

Borda/vision-delivery · not measured

SessionStart

Runs when a session starts, executing plugin-setup.sh via bash. From sasly2048/codex-atlas.

sasly2048/codex-atlas · not measured

SessionEnd

Runs when a session ends for startup and resume tool calls, executing session-lifecycle-hook.mjs via node with --show-toplevel. From nikuscs/codex-multitask.

nikuscs/codex-multitask · not measured

PostToolUse

Runs after a tool call finishes for TodoWrite, TaskCreate, TaskUpdate, TaskList, Write, Edit, MultiEdit, Bash, rp, RepoPrompt, Task and Agent tool calls, executing todo_tracker.py, edit_tracker.py and handoff_result.py via python3 (3 commands). From TerenceLiu98/prewalk.

TerenceLiu98/prewalk · not measured

SubagentStart

Runs when a subagent starts for ^(prewalk:)?prewalk-executor$ tool calls, executing handoff_lifecycle.py via python3. From TerenceLiu98/prewalk.

TerenceLiu98/prewalk · not measured

SubagentStop

Runs when a subagent finishes for ^(prewalk:)?prewalk-executor$ tool calls, executing handoff_lifecycle.py via python3. From TerenceLiu98/prewalk.

TerenceLiu98/prewalk · not measured