A command hook that runs after the agent's conversation context is shortened and displays a fixed list of coding reminders. Context compaction is the process of reducing earlier conversation details to make room for new work.

Use it to remind the agent to verify mapped fields, check fetch responses, reset navigation state, prevent duplicate asynchronous operations, and define CSS variables in all four theme blocks.

It brings back checks that may be easy to forget after context is shortened, including response handling, navigation state, duplicate prevention, and CSS variables.

PostCompact — Hook by tomasz-tomczyk

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/tomasz-tomczyk/crit/post-compact

Clone the repo

git clone --depth 1 https://github.com/tomasz-tomczyk/crit

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 original No closer match found in the catalogue.

Security

Grade A, and why

PostCompact 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.

.claude/settings.json · 13 lines

What it actually says

{
  "PostCompact": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "echo 'REMINDERS (things linters dont catch): 1) Verify all struct fields mapped. 2) Check response.ok after fetch(). 3) Reset nav state on context changes. 4) Dedup guards for multi-source async ops. 5) Define CSS vars in all 4 theme blocks.'"
        }
      ]
    }
  ]
}

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 · 13 lines scan A 631b16c28154

Subscribe to this mod's changes

PostCompact is a hook published in the GitHub repository tomasz-tomczyk/crit (979 stars, last pushed 3d 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.

Code review Data and AI Frontend LLM agentic-coding ai-tools cli markdown

PostCompact

Getting it into your agent

Grade A, and why

Nothing flagged

What it actually says

What this file has done since we first saw it

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