ERC-8004 Goes Multi-Chain: The Race for AI Agent Identity Infrastructure

ERC-8004 is no longer just an Ethereum standard. In the past week, Polygon announced official adoption (POL surged 12% on the news), BNB Chain published a formal proposal to bring the AI agent registry to BSC, and Taiko confirmed deployment plans. The race to become the home chain for AI agents has gone multi-chain—and with it, the question of how to Know Your Agent across different networks becomes urgent.

The multi-chain moment

When ERC-8004 launched on Ethereum mainnet on January 29, 2026, it brought over 22,000 agents on-chain with a standardized identity registry. That was significant. What’s happening now is bigger: the standard is spreading to Layer 2s and competing chains, each positioning themselves as infrastructure for the AI agent economy.

The stakes are clear. The World Economic Forum projects the AI agent economy at $236 billion by 2034—if trust infrastructure exists. Visa reports 4,700% growth in AI-driven traffic to retail sites. Every major chain wants to be where that activity settles.

On February 3, Polygon announced ERC-8004 adoption, describing it as making “identity and reputation portable across L2s.” The market responded—POL jumped 12% on the news. The same day, the ERC-8004 team designated February 2026 as “Genesis Month” for multi-chain expansion.

BNB Chain’s formal proposal

BNB Chain isn’t far behind. On December 5, 2025, BEP-620: Trustless Agents on BNB Chain was published—a formal proposal to deploy the same three-registry architecture (Identity, Reputation, Validation) on BSC and opBNB.

The proposal makes an explicit case for BSC’s advantages: 2,000 transactions per second and approximately $0.001 per transaction. For agent-intensive applications where thousands of identity lookups and reputation updates happen daily, these economics matter.

BNB Chain’s ecosystem has already built supporting infrastructure. The BNB Attestation Service (BAS) has forked the official ERC-8004 contracts repository and maintains a Python SDK for developers. A test environment exists at dev.8004.bnbattest.io. Most notably, BNB Chain’s official account has announced BASCAN.io—the first ERC-8004 Public Agent Registry Scanner for BNB Chain, designed to let anyone see “who an agent is, how it behaves, and what has been executed onchain.”

Third-party integrations are already live. Unibase deployed ERC-8004 identity infrastructure on BNB Chain in late October 2025, becoming the first x402 payment protocol facilitator on the network. Their BitAgent platform actively uses this infrastructure for agent identity.

However, it’s important to note: despite all this ecosystem activity, no official ERC-8004 contracts have been deployed to BNB Chain mainnet or testnet yet. The infrastructure is being built; official deployment awaits BEP-620 finalization.

The Ethereum Foundation’s AI push

The ERC-8004 standard didn’t emerge in a vacuum. It was designed by engineers from MetaMask, Google, Coinbase, and the Ethereum Foundation—serious institutional backing that gives chains confidence in adoption.

Davide Crapis, one of the ERC-8004 co-authors, now leads the Ethereum Foundation’s new dAI Team (Decentralized AI Team), launched in September 2025. The team’s mission: “make Ethereum the preferred settlement and coordination layer for AIs and the machine economy.” They’re focused on two areas: giving AI agents ways to transact and own assets on Ethereum, and using AI to improve Ethereum itself.

Marco De Rossi (MetaMask) has been explicit about multi-chain ambitions: “We’re pushing the standard toward multi-asset, multi-chain flows so agents can pay and get paid in whatever currency and network the use case demands.”

MetaMask has published detailed thinking on self-custody in the era of AI agents, exploring how wallet infrastructure needs to evolve for autonomous systems. The challenge: agents need to hold keys and sign transactions, but the security model designed for humans doesn’t map cleanly to software that runs 24/7.

Current deployment status

Here’s where things actually stand as of February 4, 2026:

Deployed on mainnet: Ethereum (IdentityRegistry at 0x8004A169FB4a3325136EB29fA0ceB6D2e539a432, ReputationRegistry at 0x8004BAa17C55a88189AE136b182e5fdA19dE9b63)

Deployed on testnets: Ethereum Sepolia, Base Sepolia, Linea Sepolia, Optimism Sepolia, Mode Testnet, 0G Testnet, Hedera Testnet. The official contracts repository tracks all deployments.

Announced/in progress: Polygon (just announced), Taiko (endorsed October 2025), BNB Chain (BEP-620 proposal stage)

Ecosystem integrations: Phala Network has built a TEE (Trusted Execution Environment) extension for ERC-8004, enabling hardware-attested agent identity. This addresses validation scenarios where you need cryptographic proof that an agent is running specific code in a secure enclave.

The ValidationRegistry—the third component of ERC-8004 designed for third-party attestations—remains under active development. The specification is being finalized with input from the TEE community, which explains why Phala’s implementation is an extension rather than using a deployed ValidationRegistry contract.

How cross-chain identity works (and doesn’t)

The ERC-8004 specification addresses multi-chain scenarios through CAIP-10 alignment—the Chain Agnostic Improvement Proposal that provides a standard way to identify accounts across different blockchains. The global identifier format is: {namespace}:{chainId}:{identityRegistry}:{agentId}.

In theory, this lets an agent registered on Ethereum be recognized on Polygon or BNB Chain. The agent’s identity includes its home chain in the identifier, so systems querying the agent know where to look for authoritative registration data.

In practice, the hard questions remain unanswered:

If an agent registers on Ethereum and later deploys on Polygon, which reputation history matters? The ERC-8004 registries are chain-specific by design—each chain maintains its own Identity, Reputation, and Validation registries. An agent’s feedback score on Ethereum doesn’t automatically transfer to its Polygon presence.

If an agent behaves badly on BSC but has a clean record on Ethereum mainnet, how do you Know Your Agent across the full picture? Cross-chain reputation aggregation isn’t built into the standard—it’s explicitly left as an exercise for the ecosystem.

As CCN’s analysis notes, the standard brings AI agents on-chain but introduces new risk vectors: “The same properties that make blockchain useful—immutability, permissionlessness—also mean that malicious agents can register just as easily as legitimate ones.”

The trust layer gap

ERC-8004 is often described as “a trustless extension of Google’s A2A protocol”—and that framing is precise. The standard provides discovery and reputation infrastructure, but “trustless” means something specific in crypto: you don’t need to trust intermediaries because verification happens on-chain. It doesn’t mean the agents themselves are trustworthy.

The current generation of ERC-8004 explorers—8004scan.io, Agentscan.info, and others—index what’s on-chain: registration data, feedback scores, validation status. They’re valuable tools for discovery.

What they don’t show: whether an agent’s identity has transferred between owners, how old the addresses giving feedback actually are, whether vouchers cluster suspiciously, or how an agent’s reputation on one chain compares to another.

As ERC-8004 goes multi-chain, these gaps compound. A bad actor could register fresh identities on each chain, accumulating reputation in parallel without any cross-chain signal that it’s the same entity behaving badly across networks. The registry gives you discovery. It doesn’t give you trust.

This is where transparent verification becomes essential. Knowing that Agent #12345 exists on Polygon is step one. Knowing that the wallet controlling it was created yesterday, has received feedback only from brand-new addresses, and shares funding patterns with known scam clusters—that’s the information that actually matters for trust decisions.

What other chains might adopt

The specification is compatible with all EVM chains, which opens a long list of potential adopters: Arbitrum, Avalanche, Fantom, zkSync, Scroll, and others. The barrier isn’t technical compatibility—it’s ecosystem coordination and prioritization.

Non-EVM chains present a different challenge. Solana has its own thriving agent ecosystem, but ERC-8004 is an Ethereum standard. A fragmented identity landscape across EVM and non-EVM chains would complicate the “portable agent identity” vision. Whether equivalent standards emerge for Solana, or whether bridges can connect different identity systems, remains an open question.

Backpack Exchange’s analysis positions ERC-8004 as potentially foundational: “Just as ERC-20 standardized tokens and ERC-721 standardized NFTs, ERC-8004 could become the standard way AI agents exist on-chain.” That’s an optimistic framing, but it captures the ambition.

What to watch

February 2026 is shaping up as the month ERC-8004 goes from “Ethereum standard” to “industry standard.” The dominoes are falling: Polygon announced, BNB Chain is preparing, Taiko is deploying, and the ERC-8004 team is actively coordinating “Genesis Month” expansion.

The questions to track:

When does BNB Chain officially deploy? BEP-620 is in proposal stage. The infrastructure (BAS, BASCAN, Unibase integration) is ready. Official contract deployment would bring BSC’s massive user base into the ERC-8004 ecosystem.

How will cross-chain reputation work? No standard exists yet. Someone will build it—either the ERC-8004 team, third-party indexers like The Graph, or trust layer projects that aggregate across chains.

Will the ValidationRegistry finalize? The third registry is still being specified. Phala’s TEE extension shows demand for hardware-attested validation. The final spec will shape what kinds of third-party verification become standard.

Will non-EVM chains adopt equivalent standards? Solana’s agent ecosystem is substantial. A unified identity layer would require either EVM bridges or native Solana standards.

The AI agent economy is going multi-chain. The infrastructure for Knowing Your Agent across all of it is still being built.