SessionStart

Automatic actions that run when a coding session starts, such as loading project context, detecting the shell, and checking repository information.

In plain words
What is it for?
They help load shared instructions, discover agents across repositories, detect the working environment, and provide session or GitHub context.
Why use it?
They prepare the agent with relevant background and checks before it begins responding or editing files.

Hook for Claude Code

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/notque/vexjoy-agent/session-start
Clone the repo
git clone --depth 1 https://github.com/notque/vexjoy-agent

Made for: Claude Code.

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 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.

.claude/settings.json · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "SessionStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/sync-to-user-claude.py\"",
          "description": "Sync agents/skills/hooks/commands to ~/.claude",
          "timeout": 20000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/afk-mode.py\"",
          "description": "Inject autonomous behavioral posture for SSH/tmux/headless sessions",
          "timeout": 1000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/session-context.py\"",
          "description": "Inject the pre-built overnight dream payload and dream notice (ADR-147)",
          "timeout": 5000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/cross-repo-agents.py\"",
          "description": "Discover custom agents in working directory",
          "timeout": 3000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/fish-shell-detector.py\"",
          "description": "Auto-detect Fish shell users and inject shell-config skill",
          "timeout": 1000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/zsh-shell-detector.py\"",
          "description": "Auto-detect Zsh shell users and inject shell-config skill",
          "timeout": 1000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/sapcc-go-detector.py\"",
          "description": "Auto-detect SAP CC Go projects and inject go-patterns skill",
          "timeout": 1000,
          "once": true
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/operator-context-detector.

Read the full file on GitHub · 106 lines

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 · 106 lines scan A fd9bdba950f4

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository notque/vexjoy-agent (417 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.