SubagentStart

SubagentStart is a hook for Claude Code from dop-amine/tmux-claude-status. Its token cost is not measured, scanned A, a copy of SessionStart, MIT.

A start-time hook that runs a shell command when a subagent, or helper agent, begins work.

In plain words
What is it for?
It helps connect subagent starts to command-line checks or status updates, such as the tmux status command shown here.
Why use it?
It can announce or record the start of helper-agent activity automatically, making status tracking easier.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

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 tmux-claude-status plugin — 11 hooks shipped together

One of 11 entries in hooks.json — they are configured in one file and arrive together.

Good fit It helps connect subagent starts to command-line checks or status updates, such…

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 dop-amine/tmux-claude-status
Claude Code
/plugin install tmux-claude-status

Made for: Claude Code.

Or install tmux-claude-status, the plugin that ships this one along with the rest of its 11 hooks.

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/dop-amine/tmux-claude-status/subagent-start.svg)](https://agentmods.dev/hooks/dop-amine/tmux-claude-status/subagent-start)
Your own site
<a href="https://agentmods.dev/hooks/dop-amine/tmux-claude-status/subagent-start"><img src="https://agentmods.dev/badge/hooks/dop-amine/tmux-claude-status/subagent-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. A grade says what 26 rules found in the file — not that it is safe.
Origin 64% 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 6d 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

64% identical to SessionStart — 7 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.

claude-plugin/hooks/hooks.json · 12 lines

What it actually says

{
  "SubagentStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "\"${CLAUDE_PLUGIN_ROOT}/bin/claude-status\" agent-start"
        }
      ]
    }
  ]
}
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. 6d ago First seen · 12 lines scan A 0796ac4cb54b

Subscribe to this mod's changes

SubagentStart is a hook published in the GitHub repository dop-amine/tmux-claude-status (3 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 64% identical to SessionStart, differing in 7 lines, and is treated as a copy.