What is SessionStart?

A session-start hook configuration that runs a Node.js bridge program when a coding-agent session begins. A hook is an automated command tied to a lifecycle event.

Use it when a project relies on the wmux bridge during session startup. The configuration runs the bridge with the session-start event.

It removes the need to start that bridge manually at the beginning of each session.

SessionStart — Hook by openwong2kim

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/openwong2kim/wmux/session-start

Clone the repo

git clone --depth 1 https://github.com/openwong2kim/wmux

Or install claude, the plugin that ships this one along with the rest of its 5 hooks.

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 88% copy Near-identical to another mod 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 3d 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

88% identical to PostToolUse — 4 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.

integrations/claude/hooks/hooks.json · 13 lines

What it actually says

{
  "SessionStart": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/bin/wmux-bridge.mjs\" SessionStart"
        }
      ]
    }
  ]
}

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.

3d ago First seen · 13 lines scan A d470655de2a3

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository openwong2kim/wmux (362 stars, last pushed 3d 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 88% identical to PostToolUse, differing in 4 lines, and is treated as a copy.

ai-agents ai-coding browser-automation claude-code developer-tools electron

SessionStart

Getting it into your agent

Grade A, and why

Nothing flagged

This is a copy

What it actually says

What this file has done since we first saw it

Other hooks, from other repositories

SessionStart

UserPromptSubmit

Stop

PreToolUse

PostToolUse

Stop