agents-observe: Hook for Claude Code

.claude/settings.json

UserPromptExpansion is a hook for Claude Code from simple10/agents-observe. Its token cost is not measured, scanned A, a copy of SessionStart, MIT.

A hook that runs a shell script to expand a user’s prompt before the coding agent receives it.

In plain words
What is it for?
Running a project-defined prompt-expansion script before agent work begins.
Why use it?
It can add or transform prompt context automatically, so the agent receives the prepared request without the user having to write everything out each time.

Hook for Claude Code

Written for Claude Code: $CLAUDE_PROJECT_DIR variable.

This is simple10/agents-observe's own configuration. It tells Claude Code how to work on agents-observe itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agents-observe configures →

Part of the agents-observe plugin — 1 skill, 28 hooks, 1 MCP server shipped together

One of 29 entries in settings.json — they are configured in one file and arrive together.

Reuse

Borrowing it

Nothing to install: this file belongs to simple10/agents-observe. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/simple10/agents-observe/main/.claude/settings.json
Clone the repo
git clone --depth 1 https://github.com/simple10/agents-observe

Made for: Claude Code.

Or install agents-observe, the plugin that ships this one along with the rest of its 1 skill, 28 hooks, 1 MCP server.

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 UserPromptExpansion

README.md
[![agentmods](https://agentmods.dev/badge/hooks/simple10/agents-observe/user-prompt-expansion.svg)](https://agentmods.dev/hooks/simple10/agents-observe/user-prompt-expansion)
Your own site
<a href="https://agentmods.dev/hooks/simple10/agents-observe/user-prompt-expansion"><img src="https://agentmods.dev/badge/hooks/simple10/agents-observe/user-prompt-expansion.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 50% copy Near-identical to another mod in the catalogue.
Security

Grade A, and why

UserPromptExpansion 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 7d 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

This is a copy

50% identical to SessionStart — 8 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 · 13 lines

What it actually says

{
  "UserPromptExpansion": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "bash $CLAUDE_PROJECT_DIR/hooks/scripts/hook.sh"
        }
      ]
    }
  ]
}
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. 7d ago First seen · 13 lines scan A 0ac2bfd5c2e3

Subscribe to this mod's changes

UserPromptExpansion is a hook published in the GitHub repository simple10/agents-observe (666 stars, last pushed 2d 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 50% identical to SessionStart, differing in 8 lines, and is treated as a copy.