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SessionStart

SessionStart is a hook for coding agents from jmagar/swag-mcp. Its token cost is not measured, scanned A, a copy of SessionStart, MIT.

A session-start hook that runs two setup commands when a coding-agent session begins. The commands set up the plugin and synchronize its Python environment.

In plain words
What is it for?
Use it for automatic plugin initialization and environment synchronization when a session opens.
Why use it?
It removes the need to run those setup steps manually at the start of each session. The input does not describe any other behavior.

Hook

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 swag-mcp plugin — 1 skill, 2 hooks, 1 MCP server shipped together

One of 2 entries in hooks.json — they are configured in one file and arrive together.

not rated 5 4d ago A scan tokens not measured copy · 66% MIT
View the source file jmagar/swag-mcp
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 jmagar/swag-mcp
Claude Code
/plugin install swag-mcp

Or install swag-mcp, the plugin that ships this one along with the rest of its 1 skill, 2 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 SessionStart

README.md
[![agentmods](https://agentmods.dev/badge/hooks/jmagar/swag-mcp/session-start.svg)](https://agentmods.dev/hooks/jmagar/swag-mcp/session-start)
Your own site
<a href="https://agentmods.dev/hooks/jmagar/swag-mcp/session-start"><img src="https://agentmods.dev/badge/hooks/jmagar/swag-mcp/session-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. Scan, not verified.
Origin 66% 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 4d 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

66% identical to SessionStart — 9 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.

plugins/swag-mcp/hooks/hooks.json · 16 lines

What it actually says

{
  "SessionStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/scripts/plugin-setup.sh"
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/bin/sync-uv.sh"
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 2. 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. 4d ago First seen · 16 lines scan A 758bdcc013f0

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository jmagar/swag-mcp (5 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 66% identical to SessionStart, differing in 9 lines, and is treated as a copy.

LLMaifastmcpmcp-servermodel-context-protocol
Related

Other hooks, from other repositories

SessionStart

Runs when a session starts, executing session-start-staleness.sh. From malkreide/swiss-procurement-mcp.

malkreide/swiss-procurement-mcp · not measured

PreToolUse

Runs before the agent uses a tool for Edit, Write, MultiEdit, NotebookEdit, Read, Bash, Grep, mcp__precis__put, mcp__precis__edit, mcp__precis__delete and mcp__precis__tag tool calls, executing guard-worktree-path.py, guard-sealed-migration.py, rca-triage-nudge.py, guard-secret-read.py, guard-commit-on-main.py…

retospect/precis-mcp · not measured

SessionStart

Runs when a session starts, executing session-start-lock.sh, heal-primary-branch.sh, code-search-up.sh and memory-nudge.sh via bash with --for-hook (9 commands). From retospect/precis-mcp.

retospect/precis-mcp · not measured

PostToolUse

Runs after a tool call finishes for Write tool calls, executing map-staleness-reminder.py and session-size-nudge.py via python3 (2 commands). From retospect/precis-mcp.

retospect/precis-mcp · not measured

SessionEnd

Runs when a session ends, executing session-end-reap.sh. From retospect/precis-mcp.

retospect/precis-mcp · not measured

PreCompact

Runs before the context is compacted, executing precompact-persist.sh via bash. From retospect/precis-mcp.

retospect/precis-mcp · not measured