agentmods.dev

SessionStart

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

A startup hook that runs the command `bd prime` when an agent session begins. A hook is an automatic action triggered by a session event.

In plain words
What is it for?
Use it to initialize or prepare the environment through `bd prime` whenever a session starts.
Why use it?
It ensures the project’s prescribed preparation command runs at the start of each session without manual setup.

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 octo plugin — 70 skills, 108 commands, 10 agents, 18 hooks shipped together

One of 18 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 17 are separate, each on its own page.

not rated 4.3krepo +47 changed 20d ago A scan tokens not measured original MIT

Good fit Use it to initialize or prepare the environment through bd prime whenever a session starts.

Compare 6 hooks from other repositories ↓
View source ↗ nyldn/claude-octopus reddit.com
About the project

Claude Octopus is an orchestration project that sends research, design, and coding tasks to Claude Code and other AI model providers so their results can be compared. Developers use it for multi-model work, disagreement detection, reviews, persistent context, and an optional workflow that moves from discovery through delivery. The catalogue entries are its commands, skills, agents, instructions, hooks, plugins, and settings.

nyldn/claude-octopus · 4,258 stars · on GitHub · reddit.com

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 nyldn/claude-octopus
Claude Code
/plugin install octo

Made for: Claude Code.

Or install octo, the plugin that ships this one along with the rest of its 70 skills, 108 commands, 10 agents, 18 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/nyldn/claude-octopus/session-start/github.svg)](https://agentmods.dev/hooks/nyldn/claude-octopus/session-start)
Your own site
<a href="https://agentmods.dev/hooks/nyldn/claude-octopus/session-start"><img src="https://agentmods.dev/badge/hooks/nyldn/claude-octopus/session-start/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for SessionStart

Your own site · 80×15
<a href="https://agentmods.dev/hooks/nyldn/claude-octopus/session-start"><img src="https://agentmods.dev/badge/hooks/nyldn/claude-octopus/session-start.svg" alt="Reviewed on agentmods" width="80" 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 20d 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

Copies of this mod

8 near-identical copies found in the catalogue:

hooks/hooks.json · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "SessionStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/scripts/helpers/ensure-plugin-root.sh",
          "commandWindows": "cmd /d /c exit 0",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/context-reinforcement.sh",
          "commandWindows": "cmd /d /c exit 0",
          "timeout": 30
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/auto-router-inject.sh",
          "commandWindows": "cmd /d /c exit 0",
          "timeout": 3
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/session-start-memory.sh",
          "commandWindows": "cmd /d /c exit 0",
          "additionalContext": "Restore persisted user preferences and session sync from auto-memory",
          "timeout": 30
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/statusline-auto-repair.sh",
          "commandWindows": "cmd /d /c exit 0",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/version-advisory.sh",
          "commandWindows": "cmd /d /c exit 0",
          "additionalContext": "One-line advisory when plugin version changes between sessions",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/plugin-update-advisory.sh",
          "commandWindows": "cmd /d /c exit 0",
          "additionalContext": "Local-only plugin update health advisory; never runs an updater or network request",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/hooks/fable5-inject.sh",
          "commandWindows": "cmd /d /c exit 0",
          "additionalContext": "Inject Fable dispatch guards and prompt hygiene when a Fable 5

Read the full file on GitHub · 70 lines

Same file

What else hooks.json configures

This page is one entry in a file that holds 18. 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. 20d ago Changed · +9 lines fd9235dba9ac
  2. 1mo ago Changed · +48 lines 2c6c52c36c8a
  3. 1mo ago First seen · 13 lines scan A 35e69b8b59f2

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository nyldn/claude-octopus (4,258 stars, last pushed today), 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.

Claude Codeai-agentsai-orchestrationclaude-code-plugincodexcopilot
Related

Other hooks, from other repositories

PreCompact

Runs before the context is compacted for manual and auto tool calls, executing compaction-state.sh via bash. From jikig-ai/soleur.

jikig-ai/soleur · not measured

SessionStart

Runs when a session starts on startup, executing install_pkgs.sh. From supabase/supabase.

supabase/supabase · not measured

PostToolUse

Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.

supabase/supabase · not measured

PreToolUse

Runs before the agent uses a tool for Bash tool calls, running an inline shell check. From apache/superset.

apache/superset · not measured

PreToolUse

Runs before the agent uses a tool, executing pre-write.sh and pre-bash.sh (2 commands). From anthropics/claude-cookbooks.

anthropics/claude-cookbooks · not measured

PostToolUse

Runs after a tool call finishes for Bash tool calls, executing hooks.sh via sh (3 commands). From anthropics/claude-plugins-official.

anthropics/claude-plugins-official · not measured