ZKred Agent ID

In an increasingly digital and automated world, autonomous agents ranging from AI-powered software bots to IoT devices need a reliable way to establish identity and trust without relying on centralized authorities. Traditional identity systems, while effective for humans, are often ill-suited for these agents due to their dependence on central servers, susceptibility to single points of failure, and limited interoperability. This is where ZKred Agent ID comes in, providing a decentralized identity solution designed specifically for agents.

Why Agent ID? Trust is a fundamental requirement for any interaction in a digital ecosystem. Autonomous agents must communicate, transact, and share data securely, but without a verifiable identity, these interactions are vulnerable to impersonation, fraud, or unauthorized access. Centralized identity solutions create bottlenecks and increase systemic risk, making them unsuitable for a world where agents operate independently at scale. ZKred Agent ID addresses these challenges by leveraging decentralized technologies to provide a secure, verifiable, and tamper-resistant identity system.

What is ZKred Agent ID? ZKred Agent ID is a decentralized identity framework that allows agents to register themselves on a blockchain-based trust registry. Each agent receives a unique decentralized identifier (DID) linked to a cryptographic keypair, enabling secure authentication and verification. The on-chain trust registry ensures that every agent’s identity is publicly verifiable, auditable, and resistant to tampering, while maintaining privacy and autonomy for the agents themselves.

How does it work? Agents generate a cryptographic keypair and register their DID on the blockchain trust registry. This registration is immutable and accessible to anyone in the network for verification. When two agents interact, they can authenticate each other by proving ownership of their private keys corresponding to their DID, eliminating the need for intermediaries. This approach prevents impersonation attacks and ensures that only legitimate agents can participate in the ecosystem. By combining decentralized identifiers with a blockchain trust registry, Agent ID provides a robust, scalable, and interoperable solution for managing autonomous agent identities in the digital age.

Zkred Agent ID was built by extending the ERC-8004 registry standard to support Decentralized Identifiers (DIDs). This allows autonomous agents to register themselves on-chain with a DID, a description, and a service endpoint. The registry works across multiple networks, and for our prototype we deployed it on Polygon Amoy, Hedera, and OG chain chains we believe are particularly relevant for agentic ecosystems, with Polygon powering payments and Hedera/OG positioning themselves as AI-native infrastructures.

To make the registration process accessible, we built an SDK in TypeScript (with Python SDK coming soon). The SDK abstracts away blockchain complexity: developers can generate private keys, derive DIDs, register agents, and initiate handshakes without writing a single line of solidity or transaction boilerplate. This lets agentic developers, who may not be crypto-native, onboard seamlessly.

We also implemented an X402 payment server that accepts USDC. Here, agents can pay using stablecoins, and the server forwards the request to the registry contract. To keep things secure, we use EIP-712 typed signatures signed by the agent itself. This ensures the payment flow is cryptographically verifiable while still being lightweight and developer-friendly.

For handshakes between agents, we chose an off-chain in-memory session model. When one agent initiates a handshake, a session ID and challenge are generated. The receiving agent completes the handshake by signing the challenge, and the initiator validates the signature against the public key stored in the registry. This keeps the handshake fast while ensuring trust is anchored on-chain.

The “hacky” but fun part was stitching all of this together — adapting ERC-8004 to include DID metadata, wiring an EIP-712 signature server for X402 payments, and making the SDK feel chain-agnostic even though the backend logic spans Polygon, Hedera, and OG.

In short, we combined standards (ERC-8004, X402, DIDs), multi-chain deployments, and a developer-friendly SDK to make identity and payments a native part of the autonomous agent stack.