What is SessionStart?

A group of checks that runs when an agent session starts or is compacted. It can load project and Git context, check dependencies, inspect branch state, load agent instructions, check staleness, and prepare the worktree environment.

Use it at session startup to load instructions and GitHub context, check dependencies and stale information, warn about stashed work, and prepare the working environment.

It gives the agent current project context and surfaces repository or setup issues before work begins.

SessionStart — Hook by steve-magne

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/steve-magne/hookstack/session-start

Clone the repo

git clone --depth 1 https://github.com/steve-magne/hookstack

Made for: Claude Code.

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 44% 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 yesterday.

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

44% identical to SessionStart — 70 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/settings.json · 77 lines

How it starts

The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "SessionStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/load-git-context.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/setup-check-deps.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/session-start-pull-if-main.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/session-start-worktree-if-main.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/session-start-stash-warning.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/agents-md-loader.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/session-start-github-context.mjs"
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/okf-staleness-check.mjs"
        }
      ]
    },
    {
      "hooks": [
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/setup-worktree-env.mjs",
          "statusMessage": "Copie des .env du worktree au démarrage de session..."
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/worktree-create-update-deps.mjs",
          "statusMessage": "Mise à jour des dépendances du worktree..."
        },
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/setup-install-deps.mjs"
        }
      ],
      "matcher": "startup"
    },
    {
      "hooks": [
        {
          "type": "command",
          "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/reinject-after-compact.mjs"
        }
      ],
      "matcher": "com

Read the full file on GitHub · 77 lines

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.

yesterday First seen · 77 lines scan A c03a71a16097

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository steve-magne/hookstack (7 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. It is 44% identical to SessionStart, differing in 70 lines, and is treated as a copy.

Git and workflow ai ai-agents anthropic claude claude-code cli

SessionStart

Getting it into your agent

Grade A, and why

Nothing flagged

This is a copy

How it starts

What this file has done since we first saw it

Other hooks, from other repositories

PostToolUse

SessionStart

SessionStart

PreToolUse

SessionStart

SessionStart