What is SessionStart?

A startup hook that runs a Python script when an agent session starts, resumes, is cleared, compacted, or forked.

Use it to run session-start context loading automatically across new and resumed sessions.

It loads PowerContext context at those session events so the agent can restore relevant information.

SessionStart — Hook for Claude Code by oceanbase/powercontext

About the project

oceanbase/powercontext is a system for preserving useful work context across conversations, people, and AI agents. It stores durable memories, current task state, handoffs, reusable experiences, sources, and revisions so work can resume without rereading its full history. The catalogue add-ons provide agent workflows and integrations for recording and using this context.

oceanbase/powercontext · 1,486 stars · on GitHub · powercontext.oceanbase.io

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 oceanbase/powercontext

Claude Code

/plugin install powercontext

Made for: Claude Code.

Or install powercontext, the plugin that ships this one along with the rest of its 2 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.

README.md

[![agentmods](https://agentmods.dev/badge/hooks/oceanbase/powercontext/session-start/github.svg)](https://agentmods.dev/hooks/oceanbase/powercontext/session-start)

Your own site

<a href="https://agentmods.dev/hooks/oceanbase/powercontext/session-start"><img src="https://agentmods.dev/badge/hooks/oceanbase/powercontext/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.

Your own site · 80×15

<a href="https://agentmods.dev/hooks/oceanbase/powercontext/session-start"><img src="https://agentmods.dev/badge/hooks/oceanbase/powercontext/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 23d 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.

integrations/claude-code/plugins/powercontext/hooks/hooks.json · 18 lines

What it actually says

{
  "SessionStart": [
    {
      "matcher": "startup|resume|clear|compact|fork",
      "hooks": [
        {
          "type": "command",
          "command": "python3",
          "args": [
            "${CLAUDE_PLUGIN_ROOT}/hooks/session_start.py"
          ],
          "timeout": 10,
          "statusMessage": "Loading PowerContext context"
        }
      ]
    }
  ]
}

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.

Hook UserPromptSubmit A not measured

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.

23d ago First seen · 18 lines scan A abd7ecd004b9

Subscribe to this mod's changes

SessionStart is a hook published in the GitHub repository oceanbase/powercontext (1,486 stars, last pushed yesterday), licensed Apache-2.0. 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 2026-10-15.

Building agents Claude Code Memory and context agent-memory codex handoff long-term-memory self-evolving

SessionStart next to 6 hooks from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
SessionStartoceanbase/powercontext	Hook	1.5k	yesterday	Apache-2.0	A	—	Claude Code
PostToolUsemoorcheh-ai/memanto	Hook	2.4k	yesterday	MIT	A	—	Claude Code
PreCompactmoorcheh-ai/memanto	Hook	2.4k	yesterday	MIT	A	—	Claude Code
SessionStartmoorcheh-ai/memanto	Hook	2.4k	yesterday	MIT	A	—	Claude Code
UserPromptSubmitkitfunso/hippo-memory	Hook	790	yesterday	MIT	A	—	Claude Code
PreCompactkitfunso/hippo-memory	Hook	790	yesterday	MIT	A	—	Claude Code
PostCompactkitfunso/hippo-memory	Hook	790	yesterday	MIT	A	—	Claude Code

SessionStart