UserPromptSubmit

UserPromptSubmit is a hook for coding agents from langchain-ai/langsmith-claude-code-plugins. Its token cost is not measured, scanned A, a copy of UserPromptSubmit, MIT.

A hook that runs a Node.js script whenever you submit a prompt, before the coding agent receives it.

In plain words
What is it for?
Running the bundled user-prompt-submit script on each submitted prompt.
Why use it?
It allows submitted prompts to be processed automatically before the agent starts working.

Hook

Part of the langsmith-claude-code-plugins plugin — 9 hooks shipped together

One of 9 entries in hooks.json — they are configured in one file and arrive together.

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/langchain-ai/langsmith-claude-code-plugins/user-prompt-submit
Clone the repo
git clone --depth 1 https://github.com/langchain-ai/langsmith-claude-code-plugins

Or install langsmith-claude-code-plugins, the plugin that ships this one along with the rest of its 9 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 UserPromptSubmit

README.md
[![agentmods](https://agentmods.dev/badge/hooks/langchain-ai/langsmith-claude-code-plugins/user-prompt-submit.svg)](https://agentmods.dev/hooks/langchain-ai/langsmith-claude-code-plugins/user-prompt-submit)
Your own site
<a href="https://agentmods.dev/hooks/langchain-ai/langsmith-claude-code-plugins/user-prompt-submit"><img src="https://agentmods.dev/badge/hooks/langchain-ai/langsmith-claude-code-plugins/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. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 3d 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

100% identical to UserPromptSubmit — 0 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.

hooks/hooks.json · 13 lines

What it actually says

{
  "UserPromptSubmit": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/bundle/user-prompt-submit.js\"",
          "timeout": 30
        }
      ]
    }
  ]
}
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. 3d ago First seen · 13 lines scan A 075c6936a642

Subscribe to this mod's changes

UserPromptSubmit is a hook published in the GitHub repository langchain-ai/langsmith-claude-code-plugins (67 stars, last pushed 7d 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 100% identical to UserPromptSubmit, differing in 0 lines, and is treated as a copy.