agentmods.dev

SessionStart

A startup hook that runs a command when a coding-agent session starts, resumes, is cleared, or is compacted.

In plain words
What is it for?
It helps run setup or session-initialization tasks through the included hook script.
Why use it?
It lets a command run automatically at these session events, so you do not have to start it by hand.

Hook

155 6d ago A scan tokens not measured copy · 86% MIT
View the source file ericlitman/open-pstack
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/ericlitman/open-pstack/session-start
Clone the repo
git clone --depth 1 https://github.com/ericlitman/open-pstack
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 86% 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 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

86% identical to SessionStart — 1 line 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.

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

What it actually says

{
  "SessionStart": [
    {
      "matcher": "startup|clear|compact",
      "hooks": [
        {
          "type": "command",
          "command": "\"${CLAUDE_PLUGIN_ROOT}/hooks/run-hook.cmd\" session-start",
          "async": false
        }
      ]
    }
  ]
}
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 · 14 lines scan A 5d3b0000f9a6

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository ericlitman/open-pstack (155 stars, last pushed 6d 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 86% identical to SessionStart, differing in 1 line, and is treated as a copy.

Related

Other hooks, from other repositories

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

SessionStart

Runs when a session starts, executing session-start.sh. From anthropics/claude-cookbooks.

anthropics/claude-cookbooks · not measured

SessionStart

Runs when a session starts on startup, clear and compact, executing run-hook.cmd. From obra/superpowers.

obra/superpowers · not measured