What is UserPromptSubmit?

A prompt-submission hook that runs a Python script before the coding agent receives your request.

Running prompt preprocessing such as vocabulary glossing before each request reaches the agent.

It lets a script process or change submitted prompts automatically, without requiring a separate manual step.

UserPromptSubmit — Hook for Claude Code by OleksandrHavuka

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.

Clone the repo

git clone --depth 1 https://github.com/OleksandrHavuka/shadowling

Made for: Claude Code.

Or install shadowling, the plugin that ships this one along with the rest of its 8 skills, 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/oleksandrhavuka/shadowling/user-prompt-submit.svg)](https://agentmods.dev/hooks/oleksandrhavuka/shadowling/user-prompt-submit)

Your own site

<a href="https://agentmods.dev/hooks/oleksandrhavuka/shadowling/user-prompt-submit"><img src="https://agentmods.dev/badge/hooks/oleksandrhavuka/shadowling/user-prompt-submit.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 unknown No closer match found in the catalogue.

Security

Grade A, and why

UserPromptSubmit 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 6d 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.

plugins/shadowling/hooks/hooks.json · 12 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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 Stop 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.

6d ago First seen · 12 lines scan A 8ce124642ae8

Subscribe to this mod's changes

UserPromptSubmit is a hook published in the GitHub repository OleksandrHavuka/shadowling (2 stars, last pushed 2mo ago), licensed AGPL-3.0. 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 2026-08-31.

Claude Code claude-code-plugin english-learning language-learning translation vocabulary

UserPromptSubmit