agentmods.dev

SessionStart

A session-start hook that runs two Node.js commands when a coding session begins. One keeps the project path canonical, and the other checks for updates.

In plain words
What is it for?
Use it to enforce the expected project path and run an update check whenever a session starts.
Why use it?
It automates routine setup and update checks at the beginning of each session, so they do not have to be remembered or run manually.

Hook

8.9k 2d ago A scan tokens not measured original MIT
View the source file open-gsd/gsd-core
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/open-gsd/gsd-core/session-start
Clone the repo
git clone --depth 1 https://github.com/open-gsd/gsd-core
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

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.

hooks/hooks.json · 17 lines

What it actually says

{
  "SessionStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/gsd-ensure-canonical-path.js\"",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/gsd-check-update.js\""
        }
      ]
    }
  ]
}
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 · 17 lines scan A 7fe1d59ce84c

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository open-gsd/gsd-core (8,909 stars, last pushed 2d 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.

Planningclaude-codecontext-engineeringmeta-promptingspec-driven-development
Related

Other hooks, from other repositories

SessionEnd

Runs when a session ends, executing state-save.sh. From noahrasheta/director.

noahrasheta/director · not measured

SessionStart

Runs when a session starts, executing session-start.sh. From noahrasheta/director.

noahrasheta/director · not measured

PostToolUse

Runs after a tool call finishes for Bash, Write, Edit, Read, Glob, Grep, WebFetch and WebSearch tool calls, executing get-posttool-output.py, detect-assistant-giving-up.sh, get-bash-posttool-output.py, remind-restart-after-skill-modification.sh and get-read-posttool-output.py via python3 (5 commands). From cowwoc/cat.

cowwoc/cat · not measured

SessionStart

Runs when a session starts, executing check-upgrade.sh, check-update-available.sh, echo-session-id.sh, check-retrospective-due.sh and inject-session-instructions.sh (5 commands). From cowwoc/cat.

cowwoc/cat · not measured

UserPromptSubmit

Runs when you submit a prompt, before the agent sees it, executing get-skill-output.py and detect-giving-up.sh via python3 (2 commands). From cowwoc/cat.

cowwoc/cat · 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