vexjoy-agent: Hook for Claude Code

.claude/settings.json

SubagentStart is a hook for Claude Code from notque/vexjoy-agent. Its token cost is not measured, scanned A, original, MIT.

An automatic action that runs when a coding subagent starts and passes the parent session's context to it.

In plain words
What is it for?
It is for initializing subagents with shared session context before they work on their assigned task.
Why use it?
It helps the subagent begin with the information and working conditions already known by the main agent.

Hook for Claude Code

Written for Claude Code: PreToolUse hook event. Also seen: mentions subagents.

This is notque/vexjoy-agent's own configuration. It tells Claude Code how to work on vexjoy-agent itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything vexjoy-agent configures →

One of 11 entries in settings.json upstream. Installing this one merges just its entry into your config; the other 10 are separate, each on its own page.

Reuse

Borrowing it

Nothing to install: this file belongs to notque/vexjoy-agent. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/notque/vexjoy-agent/main/.claude/settings.json
Clone the repo
git clone --depth 1 https://github.com/notque/vexjoy-agent

Made for: Claude Code.

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 SubagentStart

README.md
[![agentmods](https://agentmods.dev/badge/hooks/notque/vexjoy-agent/subagent-start/github.svg)](https://agentmods.dev/hooks/notque/vexjoy-agent/subagent-start)
Your own site
<a href="https://agentmods.dev/hooks/notque/vexjoy-agent/subagent-start"><img src="https://agentmods.dev/badge/hooks/notque/vexjoy-agent/subagent-start/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for SubagentStart

Your own site · 80×15
<a href="https://agentmods.dev/hooks/notque/vexjoy-agent/subagent-start"><img src="https://agentmods.dev/badge/hooks/notque/vexjoy-agent/subagent-start.svg" alt="Reviewed on agentmods" width="80" 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. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

SubagentStart 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 8d 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 · 15 lines

What it actually says

{
  "SubagentStart": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "sh \"$HOME/.claude/hooks/lib/pyrun.sh\" \"$HOME/.claude/hooks/subagent-start-warmstart.py\"",
          "description": "Inject parent session context into the subagent at start (SubagentStart lands in the subagent; PreToolUse:Agent lands in the parent, so this hook owns the warmstart block and PreToolUse must not re-register it)",
          "timeout": 5000
        }
      ]
    }
  ]
}
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. 8d ago Changed 876e04b92f64
  2. 1mo ago First seen · 15 lines scan A cfb82024eb8a

Subscribe to this mod's changes

SubagentStart is a hook published in the GitHub repository notque/vexjoy-agent (443 stars, last pushed today), 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.