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

# Agents

> Pair AI agents with verified humans, check that pairing in your app, and use it to price or gate paid APIs.

Billions links an AI agent to the verified human behind it, and gives services a way to check that link before they trust the agent.

## Pick a task

<CardGroup cols={2}>
  <Card title="Pair an agent" icon="link" href="/agents/identity-skill">
    Give your agent a DID and pair it with you. Two chat messages.
  </Card>

  <Card title="Verify an agent in my app" icon="user-shield" href="/agents/verify-human-agent-pairing">
    Check that a caller controls an agent DID and that a verified human is paired with it.
  </Card>

  <Card title="Protect an x402 endpoint" icon="server" href="/agents/protect-x402-endpoint">
    Offer paired agents a different price or limit on a paid API.
  </Card>

  <Card title="Inspect attestations" icon="eye" href="/agents/attestation-production-lookup">
    Read a real pairing in the Explorer and the API, field by field.
  </Card>
</CardGroup>

Each guide has its prerequisites, the exact commands, the response you should see, and the page to read next.

## What's involved

Three parts work together. You don't need to know them to start a task above, but the guides refer to them.

| Part | What it does |
| - | - |
| **Verified Agent Identity skill** | Runs on the agent. Creates the agent's DID from a key pair the agent holds, then pairs that DID with a person who has a Proof of Uniqueness credential. |
| **Attestation Registry and Explorer** | Records each pairing on-chain as an ownership attestation. Anyone can look it up in a browser or over an API. |
| **x402 Human Proof SDKs** | Let a paid API check the pairing on each request and offer paired agents a different price or limit. |

## What a pairing proves

A pairing proves that a person with a Proof of Uniqueness credential paired with a specific agent DID, and the ownership attestation records it on-chain.

It does **not** prove:

* **That the caller is that agent.** DIDs and attestations are public, so anyone can quote one. Your application has to check a signature from the agent, which is called proof of control.
* **That the agent behaves well.** A paired agent can still send spam. Pairing lets you set limits per person.
* **Which agent did something**, unless that request was signed with the agent's key.

## Production and testnet

Production holds real pairings and is what a live application should query. Testnet is for practice: creating and revoking your own records. Records never move between them. See [Environments](/agents/environments) for every URL and address.


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