> ## Documentation Index
> Fetch the complete documentation index at: https://www.agentcommercekit.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ACK-ID Agent Demo

> Detailed step-by-step guide demonstrating ACK-ID identity verification between agents.

## Overview

**ACK-ID** is a protocol built on W3C Standards designed to ensure verifiable, secure, and compliant identity, reputation, and service discovery for autonomous agents.

This interactive command-line demo guides you through:

* **Owner Identity Creation**: Establish unique decentralized identifiers (DIDs) for entities (individuals or organizations) that offer AI agents.
* **Agent Identity Creation**: Assign distinct DIDs to AI agents, linked to their respective owners.
* **Verifiable Credential (VC) Issuance**: Generate digitally signed, tamper-proof credentials proving agent ownership.
* **Agent-to-Agent Verification**: Demonstrate secure verification of agent identities before or during interactions.

## Demo Video

<iframe width="560" height="315" src="https://www.youtube.com/embed/CDJ8pm_KlOw" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen />

## Getting Started

Before running this demo, follow the [Quickstart Guide](./quickstart) to ensure you are set up properly.

This demo requires either an Anthropic API key or an OpenAI API key.

You may set them in your `<root>/demos/identity/.env` file:

```env theme={null}
ANTHROPIC_API_KEY=your_anthropic_key
OPENAI_API_KEY=your_openai_key
```

## Running the Demo

Execute the following from the repository root:

```sh theme={null}
pnpm run demo:identity
```

Alternatively, from within the demo directory (`./demos/identity`):

```sh theme={null}
pnpm run demo
```

## Demo Walkthrough

The interactive CLI guides you through these steps:

<Steps>
  <Step title="Agent Setup">
    Two agents (Client and Server) and their "Owners" are created, each with their own public/private keypairs. DIDs represent their public keys, and each Agent DID points to its Owner.
  </Step>

  <Step title="Ownership Proof">
    Owners issue Verifiable Credentials (`ControllerCredential`) asserting their
    control over their respective agents.
  </Step>

  <Step title="Communication Initiation">
    Client and Server Agents start HTTP servers. The Client attempts
    communication; the Server demands identity verification first.
  </Step>

  <Step title="DID Exchange">
    The Server requests the Client's DID (`did:web:...`) for verification.
  </Step>

  <Step title="Identity Verification">
    Server performs a DID lookup, finds the Client's service endpoint, and
    privately requests the `ControllerCredential`. The Server verifies these
    credentials.
  </Step>

  <Step title="Interaction Fulfillment">
    After verification, the Server fulfills the Client's initial request.
  </Step>
</Steps>

## Example DID Methods Supported

ACK-ID supports multiple DID resolution methods, notably:

* **did:web**: Web-hosted DID Documents secured via SSL (e.g., `did:web:catenalabs.com`).
* **did:key**: DID Documents with embedded public keys (e.g., `did:key:zQ3shg46zUAV...`). No key rotation supported.
* **did:pkh**: Uses blockchain addresses (e.g., `did:pkh:eip155:84532:0xED89...`). No key rotation supported.

View a comprehensive list of DID methods [here](https://w3c.github.io/did-extensions/methods/#did-methods).

## DID Documents Explained

DID Documents broadcast public keys and essential metadata:

### Minimal `did:key` Document Example:

```json theme={null}
{
  "@context": ["https://www.w3.org/ns/did/v1"],
  "id": "did:key:zQ3shg46zUAV...",
  "verificationMethod": [
    {
      "id": "did:key:zQ3shg46zUAV...#jwk-1",
      "type": "JsonWebKey2020",
      "controller": "did:key:zQ3shg46zUAV...",
      "publicKeyJwk": { "kty": "EC", "crv": "secp256k1" }
    }
  ]
}
```

### Complete `did:web` Document Example:

```json theme={null}
{
  "@context": ["https://www.w3.org/ns/did/v1"],
  "id": "did:web:agent.example.com",
  "verificationMethod": [
    {
      "id": "did:web:agent.example.com#jwk-1",
      "type": "JsonWebKey2020",
      "controller": "did:web:agent.example.com",
      "publicKeyJwk": { "kty": "EC", "crv": "secp256k1" }
    }
  ],
  "controller": "did:key:zQ3shg46zUAV...",
  "service": [
    {
      "id": "did:web:agent.example.com/v1/messages",
      "type": "MessagingEndpoint",
      "serviceEndpoint": "http://agent.example.com/v1/messages"
    },
    {
      "id": "did:web:agent.example.com/identity",
      "type": "IdentityService",
      "serviceEndpoint": "http://agent.example.com/identity"
    }
  ]
}
```

**Note**: DID methods must support custom attributes for enhanced DID Documents (e.g., `did:web`). Methods like `did:key` and `did:pkh` are more restrictive.

***

## Further Exploration

* [View Identity Demo Source Code](https://github.com/agentcommercekit/ack/tree/main/demos/identity)
* [ACK Documentation](https://agentcommercekit.com)
* [ACK-ID Protocol Details](/ack-id/introduction)