# THE VAULT

Nucleus CTF Challenge

## Can your AI agent break out of a secure sandbox?

You play the attacker. Craft tool calls the way an AI agent would, and watch a math-backed permission system block every attempt to steal the secret — no LLM guessing, just proofs. Runs entirely in your browser. No signup, no install.

Prefer to automate? Point your own agent at the JSON/MCP API ↓
7
Levels
5
Real Exploits
113
Kani Proofs
<1ms
In-Browser Verdict

What's a "formally verified sandbox"? The rules that decide whether a tool call is allowed aren't written by an AI — they're a small set of mathematical functions whose safety properties are proven with Lean 4 and machine-checked with Kani. The same code runs here and in production.

### How It Works

01
Submit tool calls
Craft an attack as a sequence of JSON tool calls — read_file, run_bash, web_fetch, git_push, and more — exactly like a real AI agent would. An example is pre-loaded for every level.
02
Hit the permission lattice
Your calls run against the same formally verified permission system that guards production AI agents. Not an LLM deciding — math.
03
Watch defenses fire
See exactly which defense layer catches each attempt, with a link to the proof obligation (Lean 4 + Kani) that backs the denial.
04
Beat every layer
Progress through levels grounded in real 2024-2025 exploits. The final level: trigger every defense at once to prove you understand the system.
Open source · MIT Real 2024-2025 CVEs & exploits 113 Kani proofs + ~277 Lean theorems Runs in WASM · zero infra
★ Star on GitHub · Read the verified claims · Play via API / MCP

## Attack Console

## Available Tools

Hover a tool to see what it does.

## Tool Calls (JSON)

An example attack for this level is loaded below — edit it, then run it.

## Defense Visualizer

Private Data
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Untrusted Content
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Exfil Vector
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## Results

Submit an attack to see results.