agentmods.dev

SessionStart

SessionStart is a hook for coding agents from GanyuanRan/Aegis. Its token cost is not measured, scanned A, a copy of SessionStart, MIT.

A startup hook that runs a command when a session starts, is cleared, or is compacted. Hooks are automated actions triggered by lifecycle events.

In plain words
What is it for?
It helps connect session lifecycle events to the configured run-hook command.
Why use it?
It lets a session perform a predefined startup action without someone running the command manually.

Hook

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the Aegis plugin — 22 skills, 3 commands, 1 hook shipped together

not rated 1.2k 5d ago A scan tokens not measured copy · 86% MIT
View the source file GanyuanRan/Aegis
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add GanyuanRan/Aegis
Claude Code
/plugin install Aegis

Or install Aegis, the plugin that ships this one along with the rest of its 22 skills, 3 commands, 1 hook.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for SessionStart

README.md
[![agentmods](https://agentmods.dev/badge/hooks/ganyuanran/aegis/session-start.svg)](https://agentmods.dev/hooks/ganyuanran/aegis/session-start)
Your own site
<a href="https://agentmods.dev/hooks/ganyuanran/aegis/session-start"><img src="https://agentmods.dev/badge/hooks/ganyuanran/aegis/session-start.svg" alt="Measured on agentmods" height="20"></a>
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 4d 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.

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. 4d ago First seen · 14 lines scan A 5d3b0000f9a6

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository GanyuanRan/Aegis (1,154 stars, last pushed 5d 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.

agent-skillsai-agentsai-codingarchitecture-driven-developmentclaude-codecodex
Related

Other hooks, from other repositories

SessionStart

Runs when a session starts, executing update-check.js via node. From KevinZai/commander.

KevinZai/commander · not measured

PreToolUse

Runs before the agent uses a tool for Write, Edit, Bash, Agent, Task, SendMessage and TaskStop tool calls, running bash (3 commands). From modu-ai/moai-adk.

modu-ai/moai-adk · not measured

PreToolUse

Runs before the agent uses a tool for Bash tool calls, running an inline shell check. From roboticforce/sugar.

roboticforce/sugar · not measured

BeforeTool

Runs on the BeforeTool event for write_file, replace, run_shell_command and shell tool calls, executing before-tool.js via node. From richardcb/oh-my-gemini.

richardcb/oh-my-gemini · not measured

SessionStart

Runs when a session starts, running "/path/to/shipworthy/hooks/session-start". From Vimalk0703/shipworthy.

Vimalk0703/shipworthy · not measured

PostCompact

Runs after the context is compacted, executing post-compact.sh. From luiseiman/dotforge.

luiseiman/dotforge · not measured