x402 & ERC-8004 Part 1: How x402 Gives AI Agents a Bank Account

What is the "Economic Paradox" of AI Agents?

Current AI Agents face a critical paradox: they possess intelligence surpassing humans but remain "economically disabled." While an Agent can write complex code, it cannot independently pay a $5 server fee or open a bank account.

To transition from chatboxes to a sovereign Agent Economy, the blockchain industry is developing two fundamental infrastructure layers:

• x402 (Money & Payment): A protocol reviving "HTTP 402" to give AI agents native wallets.
• ERC-8004 (Identity & Trust): A standard for on-chain identity and contract execution.

As the first part of this series, CoinEx Research will analyze x402, the protocol enabling machines to exchange value trustlessly.

What is the x402 Protocol? (Reviving HTTP 402)

In the Web2 era, HTTP 402 was a forgotten ghost code; today, in the fusion of Web3 and AI, x402 is the open protocol combining this standard with stablecoins to solve machine-to-machine payments. Simply put, x402 is an open protocol designed to solve how machines (Agents) natively pay for API, data, and content access.

• It enables Agents to perform trustless payments without bank accounts or credit cards.
• It breaks the limits of traditional payment gateways that cannot handle high-frequency, micro-transactions (as low as 1 cent).
• By being compatible with high-performance networks like Base and Solana, x402 makes "Pay-per-request" possible, establishing the underlying capital flow standard for the machine-to-machine economy.

x402 Ecosystem Architecture: The 4 Layers of Value

The x402 ecosystem architecture is clearly divided into four levels, which is crucial for determining value capture:

• Client: The Agent (consumer) that initiates the request.
• Server: The Agent (producer) that provides APIs or data.
• Facilitator: The sole entity that executes on-chain payments, controls the traffic entry point, and has the right to settle fees.
• Settlement: The underlying blockchain network (such as Base, Solana).

Among these four layers, the Facilitator is the core of value capture. It is the only role that actually executes on-chain payments and controls the traffic entry and settlement fee rights. Unlike the fragmented client and server sides, the Facilitator holds a position similar to Visa/Mastercard in traditional networks, with a high probability of a winner-take-all scenario in the future.Coinbase has gained an early advantage due to the compliance and stability advantages of CDPs, but multi-chain solutions such as PayAI offer greater flexibility.

x402 V2 Upgrades: Multi-chain Support & Credit Systems

While early x402 (V1) proved the process, it was limited by a "Base-first" strategy, making it difficult to carry network-wide liquidity. The core breakthroughs of V2 lie in two points:

• Default Multi-chain & Hybrid Rails: Bridges the gap between fiat and cryptocurrency. Agents pay in USDC, while traditional Web2 cloud providers can receive fiat directly.This is a crucial step for AI to move from "self-indulgent" on-chain activities to real-world procurement.
• Introduction of "Pay Later": Allows providers to establish accounting relationships with high-reputation Agents, reducing gas fee friction through post-payment settlement.This also foreshadows our later discussion of the "credit system".

Data Observations: Demos Fade, Real Demand Emerges

Based on data from x402scan and Artemis, we observed that the x402 ecosystem, after an initial period of frenzy, is returning to rationality and exhibiting significant structural changes:

• Squeezing out "Bubbles": After peaking in early November 2025, transaction counts, volume, and active addresses dropped sharply, indicating the retreat of "fake prosperity" meant for airdrops or testing.
• The Rivalry of Two Chains: Since mid-November, Solana has gradually encroached on or even surpassed Base in transaction counts, showing market recognition for Solana's high throughput in high-frequency inference and real-time API scenarios.

• Dominance of A2A (Agent-to-Agent): Breaking down by service category, service calls between agents dominate (the yellow bars in the graph), indicating that x402 is becoming the underlying language for "value exchange" between AI agents. Unlike traditional user-to-service (B2C), the current ecosystem growth is primarily driven by micro-payments and resource calls between agents to complete complex tasks. Dexter AI on Solana (providing agent services for MCP/ChatGPT) and Virtuals Protocol on Base are currently the frontrunners.

• Decrease in Cheating Rates: The proportions of Self-trading (A → A) and Wash-trading (A → B → A) have significantly decreased, marking a transition from team self-testing to authentic external calls.

CoinEx Research View: The "Trust Gap" Challenge

While x402 has successfully implemented payment functionality, CoinEx Research believes the current ecosystem remains largely demo-oriented. The biggest obstacle is the "trust gap."

Traditional credit card systems have robust dispute resolution mechanisms (such as chargeback refunds), while stablecoin payments on x402 are instant and irreversible. When hundreds or thousands of agents collaborate at high frequency, large-scale commercial applications will be difficult to implement without identity verification (KYA - Know Your Agent) and dispute resolution mechanisms. The current x402 ecosystem is like the early internet: it has TCP/IP (payment channels) but lacks SSL (security and identity).

This is why we need ERC-8004.

In the next report, we will delve into the technical core of ERC-8004 and explore its synergistic effects with protocols like x402 and underlying infrastructure. We will break down in detail how this standard, through organic integration, brings a new paradigm shift to the ecosystem.