SubagentStart

SubagentStart is a hook for Claude Code from babamba2/superclaude-for-sap. Its token cost is not measured, scanned A, a copy of SessionStart, MIT.

A hook that runs when a subagent starts. A subagent is a helper agent working on part of a larger task.

In plain words
What is it for?
Use it to start tracking each subagent as soon as it begins.
Why use it?
It records when helper work begins, making subagent activity easier to track.

Hook for Claude Code

Written for Claude Code: $CLAUDE_PLUGIN_ROOT variable. Also seen: mentions subagents.

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 sc4sap plugin — 19 skills, 27 agents, 8 hooks, 1 MCP server shipped together

One of 8 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 7 are separate, each on its own page.

Good fit Use it to start tracking each subagent as soon as it begins.

Compare 6 hooks from other repositories ↓
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 babamba2/superclaude-for-sap
Claude Code
/plugin install sc4sap

Made for: Claude Code.

Or install sc4sap, the plugin that ships this one along with the rest of its 19 skills, 27 agents, 8 hooks, 1 MCP server.

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/babamba2/superclaude-for-sap/subagent-start/github.svg)](https://agentmods.dev/hooks/babamba2/superclaude-for-sap/subagent-start)
Your own site
<a href="https://agentmods.dev/hooks/babamba2/superclaude-for-sap/subagent-start"><img src="https://agentmods.dev/badge/hooks/babamba2/superclaude-for-sap/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/babamba2/superclaude-for-sap/subagent-start"><img src="https://agentmods.dev/badge/hooks/babamba2/superclaude-for-sap/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 77% copy Near-identical to another mod 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 1mo 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

77% identical to SessionStart — 46 lines 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

{
  "SubagentStart": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node \"$CLAUDE_PLUGIN_ROOT\"/scripts/subagent-tracker.mjs start",
          "timeout": 3
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 8. Installing the file brings all of them; each is measured and scanned on its own page.

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. 1mo ago Changed 7fb147327c62
  2. 1mo ago First seen · 14 lines scan A 5628f2a3eb13

Subscribe to this mod's changes

SubagentStart is a hook published in the GitHub repository babamba2/superclaude-for-sap (66 stars, last pushed 4d 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 77% identical to SessionStart, differing in 46 lines, and is treated as a copy.