System Prompts Leaks is a collection of captured system instructions used to guide AI chatbots and coding agents before they receive user messages. It serves researchers and developers studying how different AI assistants are directed.
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.
npx skills add asgeirtj/system_prompts_leaks --skill init-newgit clone --depth 1 https://github.com/asgeirtj/system_prompts_leaksWrote 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.
[](https://agentmods.dev/skills/asgeirtj/system_prompts_leaks/init-new)<a href="https://agentmods.dev/skills/asgeirtj/system_prompts_leaks/init-new"><img src="https://agentmods.dev/badge/skills/asgeirtj/system_prompts_leaks/init-new/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/asgeirtj/system_prompts_leaks/init-new"><img src="https://agentmods.dev/badge/skills/asgeirtj/system_prompts_leaks/init-new.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00019 | $0.05173 |
| Opus 5 | $0.00010 | $0.02586 |
| Sonnet 5 | $0.00004 | $0.01035 |
| Haiku 4.5 | $0.00002 | $0.00517 |
Grade B, and why
init scanned grade B with 1 finding 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 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Reads agent configuration directoriesmediumAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
If Phase 2 found multiple git worktrees and the user confirmed they use sibling/external worktrees (not nested inside the main repo): the upward file walk won't find a single CLAUDE.local.md from all worktrees. Write the Copies of this mod
1 near-identical copy found in the catalogue:
- init-new — 89% identical, 18 lines differ
How it starts
The opening of the file, as written. The whole thing — 237 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Set up a minimal CLAUDE.md (and optionally skills and hooks) for this repo. CLAUDE.md is loaded into every Claude Code session, so it must be concise — only include what Claude would get wrong without it.
Phase 0: Check for an existing CLAUDE.md
Before asking anything, check if CLAUDE.md already exists at the project root (just cat ./CLAUDE.md — only the project-root file counts; don't explore the tree yet). This branches Phase 1.
Phase 1: Ask what to set up
Use AskUserQuestion to find out what the user wants. Which question you ask depends on Phase 0. Call AskUserQuestion with only Q1 — do NOT include Q2 in the same call. Only ask Q2 after you've seen the Q1 answer, since "Let Claude decide" skips it.
Before the first question, print this primer as normal assistant text so first-time users know the terms:
Quick context:
- CLAUDE.md files give Claude persistent instructions for a project, your personal workflow, or your organization. Claude reads them at the start of every session.
- Skills are packaged instructions Claude invokes automatically when a task matches, or that you trigger with a slash command (e.g.
/frontend-design,/commit-push-pr).- Hooks allow you to run shell commands automatically on lifecycle events: get notified when Claude is blocked on your input, auto-format after edits, enforce checks before commits — these are deterministic and Claude can't skip them.
If CLAUDE.md already exists, ask:
- "I found an existing CLAUDE.md. What would you like to do?"
Options: "Review and improve it" | "Leave it, set up other things" | "Start fresh (replace it)"
Description for improve: "Explore what's changed in the codebase and propose targeted edits to the existing file."
Description for leave it: "Skip CLAUDE.md. Go straight to skills and hooks."
Description for start fresh: "Discard it and write new file(s)."
Routing:
- "Review and improve" → skip Q1/Q2; explore (Phase 2), ask the single Phase 3-lite question, then go to Phase 4's diff-proposal, then Phase 8.
- "Leave it" → skip Q1, ask Q2 (rename its fourth option to "Neither — skip setup"). If they pick "Neither — skip setup", jump straight to Phase 8 with: "Nothing to set up — your CLAUDE.md is unchanged." Otherwise: Phase 2 → Phase 3 proposal (no gap-fill interview) → Phases 6/7 per queue → Phase 8. For Phase 7's hook target-file default, treat this path as "project" (
.claude/settings.json). - "Start fresh" → continue to Q1 below as if no file existed.
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.
- 2d ago First seen · 237 lines · 19 tokens per session scan B 906e211f39d8
init is a skill published in the GitHub repository asgeirtj/system_prompts_leaks (64,893 stars, last pushed 2d ago), licensed CC0-1.0. It adds 19 tokens to every session and 5,173 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-10.
Other skills, from other repositories
comps-analysis
Build comparable-company valuation workbooks in Excel.
p5js
Use when users request: p5.js sketches, creative coding, generative art, interactive visualizations, canvas animations, browser-based visual art, data viz, shader effects, or any p5.js project.
audiocraft-audio-generation
AudioCraft: MusicGen text-to-music, AudioGen text-to-sound.
pretext
Build creative browser demos with DOM-free text layout.
pinggy-tunnel
Zero-install localhost tunnels over SSH via Pinggy.
weights-and-biases
W&B: log ML experiments, sweeps, model registry, dashboards.