# Understanding ERC-8001, ERC-8004, and x402: The Building Blocks of AI Agent Economies

*The future of the internet isn't just humans clicking buttons—it's AI agents autonomously discovering services, paying for them, and coordinating with each other*

By [Capminal](https://paragraph.com/@capminal) · 2025-10-29

---

The future of the internet isn't just humans clicking buttons—it's AI agents autonomously discovering services, paying for them, and coordinating with each other. Three new standards make this possible: ERC-8004 for trust, x402 for payments, and ERC-8001 for coordination. This article explains what each one does and how they work together.

TL;DR
=====

1.  What is ERC-8004? The Trust & Discovery Layer
    
2.  What is x402? The Payment Layer
    
3.  What is ERC-8001? The Coordination Layer
    
4.  How They Work Together: A Complete Example
    
5.  The Bigger Picture
    
6.  Why This Matters for the Future
    
7.  Current Status & Adoption
    

What is ERC-8004? The Trust & Discovery Layer
=============================================

ERC-8004 is an Ethereum standard (proposed August 2025) that helps AI agents find and trust each other across organizations without pre-existing relationships.​

Think of it as a "business directory and credit bureau" for AI agents. It consists of three main components:

### 1\. Identity Registry

Every agent gets a **unique, portable ID** stored as an NFT (ERC-721). This ID links to a registration file containing:​

*   The agent's name and description
    
*   How to communicate with it (API endpoints)
    
*   Which protocols it supports (A2A, MCP, etc.)
    
*   Its wallet addresses
    

**Why this matters**: Just like you trust a business with a verified identity, agents need verifiable identities to interact safely.​

### 2\. Validation Registry

For high-stakes tasks, agents can request **cryptographic verification** of their work through:​

*   **Stake-secured re-execution**: Validators re-run the task and stake funds on the result
    
*   **zkML proofs**: Zero-knowledge machine learning proofs that work was done correctly
    
*   **TEE attestations**: Trusted Execution Environment guarantees
    

**Simple analogy**: It's like having a third-party inspector verify a contractor's work before paying them.

What is x402? The Payment Layer
===============================

**x402** is an open payment protocol (launched May 2025 by Coinbase) that enables **instant, automatic payments over the internet** using the HTTP 402 status code.​

### How x402 Works: A Simple Example

Imagine an AI agent needs weather data from an API:

**Step 1**: Agent requests data from weather API  
**Step 2**: Server responds: `HTTP 402 Payment Required` with details:

    {
      "amount": "0.01 USDC",
      "payTo": "0xABC123...",
      "network": "base"
    }

**Step 3**: Agent's wallet **automatically signs and sends** 0.01 USDC  
**Step 4**: Payment confirms in **2 seconds**  
**Step 5**: Server delivers the weather data

**The entire process happens without human intervention**.

What is ERC-8001? The Coordination Layer
========================================

**ERC-8001** (proposed August 2025) enables **multiple agents to agree and act together** using cryptographic signatures.​

Unlike single-party intent standards (like ERC-7521), ERC-8001 handles situations where **multiple parties must coordinate** before taking action.​

### How ERC-8001 Works

**Core concept**: Group consensus through signed attestations​

**Step 1**: **Initiator** posts an **AgentIntent** (signed with EIP-712)

*   Describes what needs to happen
    
*   Lists all required participants
    
*   Sets expiration time
    

**Step 2**: Each **participant** reviews and signs an **AcceptanceAttestation**

*   Confirms they agree to participate
    
*   Adds their conditions (optional)
    
*   Signs with their private key
    

**Step 3**: When **all required signatures** are collected and still valid, the intent becomes **executable**​

**Step 4**: Anyone can trigger execution, and the action happens **atomically** (all-or-nothing)

### Simple Example: Multi-Validator Approval

Three AI validators must approve a transaction before it executes:

    Intent: "Transfer $10,000 if all 3 validators approve"
    Participants: [ValidatorA, ValidatorB, ValidatorC]
    Expiry: 1 hour
    
    ValidatorA signs ✓
    ValidatorB signs ✓
    ValidatorC signs ✓
    
    → Intent becomes READY
    → Execute transaction
    → Status: EXECUTED

How They Work Together: A Complete Example
==========================================

Let's see how all three standards combine in a real scenario:

### Scenario: AI Agent Hiring a Data Analyst

**1\. Discovery (ERC-8004)**

*   Your trading agent searches the Identity Registry for "data analysts"
    
*   Finds AgentID #247 with a **95/100 reputation score** based on 200 completed tasks
    
*   Reviews validation proofs showing accurate work history
    

**2\. Payment Negotiation (x402)**

*   Your agent contacts the analyst's API
    
*   Server responds: `HTTP 402 Payment Required: $5 USDC for full market analysis`
    
*   Your agent automatically sends $5 USDC via signed transaction
    
*   Payment settles in 2 seconds, data is delivered​
    

**3\. Multi-Party Validation (ERC-8001)**

*   High-stakes trade requires approval from 3 risk management agents
    
*   Your agent creates an Intent: "Execute trade if RiskAgentA, RiskAgentB, RiskAgentC approve"
    
*   Each risk agent analyzes the data and signs their acceptance
    
*   When all 3 signatures collected, trade executes automatically​
    

**4\. Reputation Update (ERC-8004)**

*   After successful trade, your agent submits feedback (score: 98/100)
    
*   Includes **x402 payment proof** showing $5 was actually paid
    
*   Analyst's reputation increases, making them more discoverable
    

The Bigger Picture
==================

These three standards create a **complete economy** where AI agents can:

*   **Discover** trusted service providers (ERC-8004)
    
*   **Pay** for services instantly (x402)
    
*   **Coordinate** complex multi-party actions (ERC-8001)
    
*   **Build reputation** for future interactions (ERC-8004)
    

All of this happens **autonomously, without human intervention**, at the speed of code.

Why This Matters for the Future
===============================

Traditional internet infrastructure was built for **humans** to consume free content or pay subscriptions. The AI agent economy needs something different:

*   **Micropayments**: AI agents might make thousands of $0.001 API calls per day
    
*   **No accounts**: Agents can't fill out signup forms or remember passwords
    
*   **Instant trust**: Agents need to verify counterparties in milliseconds
    
*   **Autonomous coordination**: Complex tasks require multiple agents working together
    

**ERC-8004 + x402 + ERC-8001** provide the missing infrastructure for this new economy.​

Current Status & Adoption
=========================

*   **ERC-8004**: Proposed by MetaMask, Google, Coinbase, and Ethereum Foundation in August 2025. Working demos already exist.​
    
*   **x402**: Launched May 2025 by Coinbase. The x402 Foundation (formed October 2025) includes Coinbase, Cloudflare, Google, AWS, Circle, and Anthropic. Over 500,000 weekly transactions as of October 2025.​
    
*   **ERC-8001**: Proposed August 2025. Still in draft stage but actively being developed alongside ERC-8004.​

---

*Originally published on [Capminal](https://paragraph.com/@capminal/erc-8001-erc-8004-and-x402)*