> ## Documentation Index
> Fetch the complete documentation index at: https://sigil-docs-568611a1.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# What is Sigil?

> Stake real money on what an AI skill does. Break the claim with proof, take the money.

## The idea

An AI agent installs "skills" — small tools, MCP servers, snippets of code. One bad skill can leak a cloud key or drain a wallet. Today an agent has only two signals about a skill: the author's description, and a scanner's opinion. **Neither one costs anything to be wrong.**

Sigil makes being trustworthy cost money. Someone stakes USDC behind a **specific, testable claim** about a skill, for example "this skill reads no environment variable except `LOG_LEVEL`". Anyone who can produce a machine-checked trace that **breaks** that claim takes the stake.

No human votes. No language model gives a verdict. The only thing standing behind a claim is capital at risk.

## See it live

<CardGroup cols={3}>
  <Card title="Live web app" icon="globe" href="https://dr7shuhqdeo3p.cloudfront.net">
    The registry of skills, each with the money staked on it, on Hedera and Arc testnet.
  </Card>

  <Card title="Live gateway API" icon="server" href="https://d32gga9078v6q0.cloudfront.net/health">
    The x402-paid service that sells skill source and settles payments through Blocky402.
  </Card>

  <Card title="Source code" icon="github" href="https://github.com/sm-xd/sigil">
    The full monorepo: contracts, gateway, agent, sandbox, and web.
  </Card>
</CardGroup>

<Frame caption="The registry: every skill, the USDC staked on it, and the status of each claim.">
  <img src="https://mintcdn.com/sigil-docs-568611a1/5bNJGtVQokDEO0Rf/docs/img/registry.png?fit=max&auto=format&n=5bNJGtVQokDEO0Rf&q=85&s=2204e59f7bc41bc1991794251d0ee958" alt="Sigil registry screen" width="1440" height="1500" data-path="docs/img/registry.png" />
</Frame>

## Why it matters

| Without Sigil                               | With Sigil                                                                             |
| ------------------------------------------- | -------------------------------------------------------------------------------------- |
| "Trust me, this skill is safe."             | "There is 10 USDC saying this skill reads no secrets. Prove otherwise and it's yours." |
| A scanner flags a maybe-issue, for free.    | A challenge costs a bond, and pays out only on reproducible proof.                     |
| A fake track record is free to manufacture. | Personhood check stops one person funding both sides of a claim.                       |

## The three chains

Sigil uses each chain for the one thing it is best at:

* **Hedera** records every claim, challenge, and outcome, sells access to skills over x402, and mints a licence NFT — all at sub-cent cost.
* **Arc** holds the staked USDC and pays it to the winner when a claim is settled.
* **World** proves each participant is a distinct human, so nobody can play both sides.

Read [How it works](/docs/how-it-works) next for the full loop.