# Overview

Self Agent ID is an on-chain identity registry that binds AI agent identities to Self Protocol human proofs. Each agent receives a **soulbound ERC-721 NFT** backed by a ZK passport verification, enabling trustless proof-of-human for autonomous agents.

The system implements the [ERC-8004 Proof-of-Human extension](https://eips.ethereum.org/EIPS/eip-8004) and provides SDK implementations in TypeScript, Python, and Rust with identical feature parity.

## Who This Is For

| Audience                 | What You Do                                                                  |
| ------------------------ | ---------------------------------------------------------------------------- |
| **Agent builders**       | Register an agent identity, sign outbound requests with `SelfAgent`          |
| **Service/API teams**    | Verify inbound agent signatures with `SelfAgentVerifier` middleware          |
| **Protocol/infra teams** | Gate smart contracts, query on-chain state, compose with registry interfaces |

## How It Works

1. **Human scans passport** with the Self app (ZK proof generated locally on phone)
2. **Hub V2 verifies the proof** on-chain and calls back to the registry
3. **Registry mints a soulbound NFT** binding the agent key to a unique human nullifier
4. **Agent signs requests** using the SDK; services verify signatures against the on-chain registry

{% hint style="info" %}
No personal data ever leaves the user's device. Only a ZK proof and nullifier are submitted on-chain.
{% endhint %}

## Key Properties

* **Trustless**: On-chain verification with no central authority
* **Private**: ZK proofs reveal nothing about the human's identity
* **Composable**: A single registry call integrates into any EVM contract, backend, or agent framework
* **Sybil-resistant**: Each human maps to a unique nullifier, preventing unlimited agent registration
* **Time-bounded**: Proofs expire (default: 1 year or document expiry), requiring periodic re-authentication
* **ERC-8004 compliant**: Implements the standard Identity Registry interface with a Proof-of-Human extension

## Networks

| Network                | Chain ID   | Registry Address                             | Passport Required           |
| ---------------------- | ---------- | -------------------------------------------- | --------------------------- |
| Celo Mainnet (default) | `42220`    | `0xaC3DF9ABf80d0F5c020C06B04Cced27763355944` | Real passport via Self app  |
| Celo Sepolia (testnet) | `11142220` | `0x043DaCac8b0771DD5b444bCC88f2f8BBDBEdd379` | Mock documents via Self app |

{% hint style="warning" %}
**Mainnet is the default.** Registration requires a real passport scanned with the Self app. Testnet also requires the Self app, but you can generate mock documents within the app instead of using a real passport. Testnet is for development and testing only.
{% endhint %}

{% hint style="warning" %}
Celo Sepolia chain ID is **11142220**, not 44787 (deprecated Alfajores).
{% endhint %}

## Live Deployment

* Web app: <https://selfagentid.xyz>
* GitHub: <https://github.com/selfxyz/self-agent-id>

## A2A Protocol

Agents can interact programmatically via the A2A JSON-RPC endpoint at `/api/a2a`. This supports registration, verification, lookup, deregistration, and proof freshness checks — all through structured intents or natural language.

Send `{ "intent": "help" }` to get a full list of capabilities and a decision guide for choosing the right registration mode.

## Architecture

The system consists of three on-chain registries:

* **SelfAgentRegistry** — Core identity registry (ERC-8004 + Proof-of-Human extension, soulbound ERC-721)
* **SelfReputationRegistry** — ERC-8004 Reputation Registry for aggregated feedback with document-type weighted signals
* **SelfValidationRegistry** — ERC-8004 Validation Registry for on-demand third-party validation

Plus SDKs in TypeScript, Python, and Rust with identical feature parity for signing requests, verifying agents, and interacting with the registry.

## Next Steps

* [Registration Modes](https://docs.self.xyz/self-agent-id/registration-modes) — Choose how to register your agent
* [SDK Integration](https://docs.self.xyz/self-agent-id/sdk-integration) — Sign and verify agent requests
* [Smart Contracts](https://docs.self.xyz/self-agent-id/smart-contracts) — On-chain gating, queries, and the full ERC-8004 interface
* [A2A Protocol & REST API](https://docs.self.xyz/self-agent-id/rest-api) — Programmatic agent interaction via JSON-RPC