With the Ethereum mainnet about to launch the ERC-8004 standard, the ecosystem of AI agents is on the brink of explosive growth. ERC-8004 and x402, as two complementary protocols, are regarded by the community as the foundational closed loop of the agent economy: ERC-8004 provides the 'trust layer,' while x402 provides the 'payment layer.' The combination of the two enables AI agents to discover, collaborate, and automatically settle in an environment without pre-established trust, opening up a truly decentralized global AI service market.

ERC-8004: The Trust Infrastructure from 'Stranger' to 'Trusted Partner'

ERC-8004: The Trust Infrastructure for AI Agents ERC-8004 (officially EIP-8004) is an Ethereum improvement proposal. It expands the Agent-to-Agent (A2A) protocol, with the core aim of establishing an on-chain registry to achieve identity recognition, portable reputation, and verifiable capabilities for AI agents. Key features include:

  • Agent discovery and selection: Any AI agent can register on-chain, publicly displaying its capabilities, historical performance, and reputation scores, allowing other agents to query and decide whether to collaborate based on this information.

  • Trustless collaboration: Through on-chain proofs, agents can safely interact in cross-organizational and cross-chain scenarios without the need for centralized intermediaries.

  • Reputation portability: The reputation of agents is not bound to a single platform and can migrate across ecologies, avoiding 'reputation islands'.

The significance of ERC-8004 lies in providing AI agents with 'identity + credit record', addressing the biggest pain point of current AI systems: how to judge whether a stranger agent is reliable in an open environment.

x402: A payment protocol that allows every collaboration to achieve 'instant monetization'.

x402: The internet-native agent payment protocol x402 (the on-chain implementation of HTTP 402 Payment Required) is led by Coinbase and is an open instant micropayment protocol designed specifically for AI agents. Key features:

  • Automatic micropayments: Supports pay-per-use (pay-per-prompt, pay-per-inference), and can automatically settle stablecoin payments during interactions between agents without manual authorization or pre-opening accounts.

  • Low friction: Low transaction delay and minimal fees, suitable for high-frequency micropayment scenarios.

  • Internet native: Compatible with HTTP standards, easy to integrate with existing web services.

By January 2026, the annualized payment volume of x402 on the Base chain has exceeded $600 million (Base accounts for 60%), proving its viability in real-world scenarios.

Dual protocol closed loop: A perfect synergy of trust + payment.

The complementary closed loops of the dual protocols ERC-8004 and x402 are not competitive but highly synergistic:

  • ERC-8004 allows agents to 'dare to interact' (knowing the other party is trustworthy).

  • x402 enables interactions to 'monetize' (automatically completes payments).

  • Closed loop process: Discovery (reputation → collaborative execution → automatic settlement → update reputation).

The community often metaphorically compares the two as the 'trust + payment' dual engines, both indispensable. The Agent Commerce Protocol (ACP) of the Virtuals Protocol has been seen as one of the practical application layer extensions of x402. The ecological chain and the main blockchain ERC-8004 ecology mainly focus on high performance and low fees of Layer 2 chains:

  • Base (Coinbase ecology): The highest adoption rate, with x402 payment volume being the largest, with core projects like Virtuals Protocol primarily deployed here.

  • Linea, Polygon, Taiko, etc.: Provide infrastructure support, with some projects deployed across chains.

  • Phala Network: Provides privacy computing and supplements the security layer.

These chains together form the underlying operational environment of the agency economy, and more L2s are expected to join after the mainnet goes live.

The latest ecological panorama: A mature network of diverse coexistence.

Ecological panorama: A thriving agency world, the ERC-8004 ecology is mainly rooted in high-performance Layer 2 chains.

The chains to be deployed include Base (with the highest adoption rate), Linea, Arbitrum, Oasis, Polygon, Worldcoin, Scroll, AltLayer, etc. Key levels and representative projects:

  • Frameworks: virtuals_io, khorusio, elizaOS. Virtuals leads with the G.A.M.E. framework and tokenized agency, having launched high-income practical agents like Otto and JoAI.

  • Infrastructure: PhalaNetwork (privacy computing), ekailabsxyz, LynethLabs, gizatechxyz, NEARProtocol, etc.

  • Agents Orchestration: ISEK_Official, ampersend_ai, hellomother_ai, karum_AI, questflow, etc.

  • AgentFi: Cod3xOrg, SilverbackDefi, kudo_archi, TheoriqAI, etc.

  • Identity & Reputation: ensdomains, ethos_network, etc.

  • Marketplaces & Discovery: autonolas (Olas), 8004_scan, DappRadar, etc.

  • Agents: wardenprotocol, OttoWallet, JoAIAgents, ZyfAI_, etc.

  • Storage & Data: pinatacloud, Filecoin, Unibase_AI, etc.

  • Developers Tooling: thirdweb, Ch40sChain, daydreamsagents, etc.

The ecology presents a vibrant, multi-framework coexistence pattern, with the Virtuals Protocol being the most integrated and viewed by the community as the closest leader to a complete closed loop.

$VIRTUAL : A recognized leader at the framework layer, directly built on the ERC-8004 + x402 closed loop, with a mature tokenized agent model, real revenue-driven buyback flywheel, making it the preferred target for the Ethereum ecological agency economy.

$KITE : As the native token of an independent L1 blockchain, it focuses on AI payments and execution layers, deeply integrating the x402 protocol, providing agents with exclusive instant micropayments, programmable authorizations, and verifiable execution. Although it does not directly belong to the ERC-8004 Ethereum ecology, it is highly complementary to the trust layer and is considered one of the most aggressive implementations of x402, backed by top institutions like PayPal Ventures and Coinbase.

$PIEVERSE : Positioned as 'The Agentic Neobank', focusing on gasless, auditable inter-agent payment infrastructure, deeply compatible with the x402 protocol, achieving seamless stablecoin trading and compliance records through the Universal Commerce Protocol (UCP) and pie-wrapped tokens. The project has a strong presence in the BNB chain ecology and is highly synergistic with the ERC-8004 trust layer, making it an important complement for the diversification of the payment layer.