SessionStart

SessionStart is a hook for Claude Code from mhylle/claude-skills-collection. Its token cost is not measured, scanned A, original, MIT.

A session-start hook that runs shell checks when a coding-agent session begins and reports available learned patterns or project context.

In plain words
What is it for?
It checks for learned pattern files and context documents, then prints a short notice when they are found.
Why use it?
It makes relevant previously saved guidance and repository context visible at the start of a session.

Hook for Claude Code

Written for Claude Code: SessionStart hook event.

Part of the devflow plugin — 38 skills, 13 agents, 5 hooks shipped together

One of 5 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 4 are separate, each on its own page.

Good fit It checks for learned pattern files and context documents, then prints a short notice when they are found.

Compare 6 hooks from other repositories ↓
Install with agentmods
npx agentmods add hooks/mhylle/claude-skills-collection/session-start
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.

Clone the repo
git clone --depth 1 https://github.com/mhylle/claude-skills-collection

Made for: Claude Code.

Or install devflow, the plugin that ships this one along with the rest of its 38 skills, 13 agents, 5 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 SessionStart

README.md
[![agentmods](https://agentmods.dev/badge/hooks/mhylle/claude-skills-collection/session-start.svg)](https://agentmods.dev/hooks/mhylle/claude-skills-collection/session-start)
Your own site
<a href="https://agentmods.dev/hooks/mhylle/claude-skills-collection/session-start"><img src="https://agentmods.dev/badge/hooks/mhylle/claude-skills-collection/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. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found 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 8d 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.

hooks/hooks.json · 26 lines

What it actually says

{
  "SessionStart": [
    {
      "name": "load-learned-patterns",
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node -e \"const fs=require('fs');const path=require('path');const learnedDir=path.join(process.env.HOME,'.claude','skills','learned');if(fs.existsSync(learnedDir)){const files=fs.readdirSync(learnedDir).filter(f=>f.endsWith('.md'));if(files.length){console.error('[Hook] Learned patterns available: '+files.length);files.slice(0,5).forEach(f=>console.error('  - '+f.replace('.md','')));console.error('[Hook] Patterns will be applied automatically during this session')}}\""
        }
      ],
      "description": "Load learned patterns from previous sessions"
    },
    {
      "name": "load-context",
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node -e \"const fs=require('fs');const path=require('path');const contextDir=path.join(process.cwd(),'docs','context');if(fs.existsSync(contextDir)){const files=fs.readdirSync(contextDir).filter(f=>f.startsWith('CONTEXT-')&&f.endsWith('.md'));if(files.length){console.error('[Hook] Found '+files.length+' context file(s) in docs/context/');files.slice(0,3).forEach(f=>console.error('  - '+f));console.error('[Hook] Use: Read docs/context/'+files[0]+' to resume')}}\""
        }
      ],
      "description": "Detect saved context files on session start"
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 5. 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. 8d ago First seen · 26 lines scan A 4e819bc544da

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository mhylle/claude-skills-collection (18 stars, last pushed 5d 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 2026-08-30.