What is promptsign?
promptsign is a Claude Code mod by PromptSign that verifies signatures on the instruction files Claude Code loads, meaning CLAUDE.md, skills, and agent definitions, before they reach model context. It re-checks a skill bundle before the. It is listed under Context & memory and has no public popularity data yet.
| Type | Claude code mod |
|---|---|
| Author | PromptSign |
| Repository | PromptSign/promptsign-plugin |
| Popularity | no public popularity data yet |
| Category | Context & memory |
| Security | Review before installing (76/100) |
| Rank | #4,331 of 5,272 Claude Code mods; #407 in Context & memory |
| License | Apache-2.0 |
| Last commit | 2026-10-17 |
| Hooks | 3 events |
| Sees | every skill, the system prompt |
| Draws on | nothing |
Is promptsign safe to install?
promptsign scores 76/100 on the MCPMods security check: Review before installing. Things to review: starts processes outside the sandbox; reads environment variables. It passed 6 of 8 checks.
Mod footprints come from claude plugin validate, which lists every event a mod hooks and every API call it makes without running it.
| Check | Result |
|---|---|
| No network access | Pass |
| Starts processes outside the sandbox | Review |
| Writes no files or config | Pass |
| Reads environment variables | Review |
| Only sees the events it hooks | Pass |
| Doesn't drive Claude | Pass |
| Passes claude plugin validate | Pass |
| Has an open-source license | Pass |
API calls in its code
| Call | What it means |
|---|---|
$.env.get | reads env vars |
$.process.run | runs processes |
$.ui.toast | draws interface |
How do I install promptsign?
- Check your Claude Code version. Mods need Claude Code 2.1.287 or later and are on by default.
claude --version
- Read its footprint. This lists every event it hooks and every API call it makes, without running it.
git clone https://github.com/PromptSign/promptsign-plugin claude plugin validate ./promptsign-plugin/.
- Install it. Run this in your terminal, then /reload-plugins in an open session.
claude plugin marketplace add PromptSign/promptsign-plugin && claude plugin install promptsign@promptsign
Or ask Claude to set it up
Paste this into Claude Code and it installs promptsign for you:
Install the "promptsign" Claude Code mod from https://github.com/PromptSign/promptsign-plugin. Run claude plugin validate on it first and show me what it can access before you enable it.