agentmods.dev

SubagentStart

A startup hook that runs a command when another software agent begins work. It records which decision role started.

In plain words
What is it for?
Use it to run the supplied recording script whenever a subagent starts.
Why use it?
It creates a record of agent activity without requiring someone to do it manually.

Hook

Part of the founder-os plugin — 42 skills, 13 agents, 3 hooks, 1 MCP server shipped together

4 8d ago A scan tokens not measured original MIT
View the source file msolecki/founder-os
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/msolecki/founder-os/subagent-start
Clone the repo
git clone --depth 1 https://github.com/msolecki/founder-os

Or install founder-os, the plugin that ships this one along with the rest of its 42 skills, 13 agents, 3 hooks, 1 MCP server.

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

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 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.

founder-os/hooks/hooks.json · 13 lines

What it actually says

{
  "SubagentStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "python3 \"${CLAUDE_PLUGIN_ROOT}/hooks/record-agent.py\"",
          "statusMessage": "Recording Founder OS decision role"
        }
      ]
    }
  ]
}
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 · 13 lines scan A 42b3e7743ff7

Subscribe to this mod's changes

SubagentStart is a hook published in the GitHub repository msolecki/founder-os (4 stars, last pushed 8d 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 2026-08-31.

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SessionStart

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