> ## Content Index > Fetch the complete content index at: https://stablecoininsider.org/llms.txt > Use this file to discover other available public pages before exploring further. # ERC-8004: Agent IDs for Stablecoin Payments, Explained - URL: https://stablecoininsider.org/erc-8004/ - Published: 2026-10-24T12:31:59.000Z - Updated: 2026-10-24T12:32:01.000Z - Description: ERC-8004 gives every AI agent an NFT identity, a public feedback trail and a verified wallet for stablecoin payments. Registrations jumped past 1.3 million in October 2026. Stablecoin Insider explains the three registries, what the surge really shows and how to use it before paying an agent. - Author: Alexandra - Tags: AI, Stablecoins, AI Agents, x402, Ethereum, Know Your Agent On 22 October 2026, 263,164 new AI agents got an on-chain identity in a single day. On 1 October the figure was 695 ([agenteconomy.to](https://agenteconomy.to/stats/erc-8004-agents)). Every one of them was minted under ERC-8004, the Ethereum standard that gives an agent a name, a public track record and a verified wallet for getting paid. That last part is why ERC-8004 matters to anyone moving stablecoins. Before your agent sends USDC to another agent, it needs to know who is on the other side and which address is really theirs. This explainer covers how ERC-8004's three registries work, what the October surge does and doesn't prove, how the standard fits next to x402 payments, and a checklist for using it before you pay an agent. ### Key Takeaways - ERC-8004 defines three registries for agents: Identity, Reputation and Validation ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). - Each agent is an ERC-721 token with a verified agentWallet for incoming payments ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). - 1,333,878 agents were registered across 24 chains as of 23 October 2026 ([agenteconomy.to](https://agenteconomy.to/stats/erc-8004-agents)). - At least 98.7% of one week's 208,589 Base registrations came from one platform ([Agentic Finance Graph](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). - Only 3.9% of wallets paying x402 sellers on Base were bound to a registered agent ([Agentic Finance Graph](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). ## What ERC-8004 is, and who wrote it ERC-8004, titled "Trustless Agents", is a draft Ethereum standard created on 13 August 2025\. Its authors are Marco De Rossi of MetaMask, Davide Crapis of the Ethereum Foundation, Jordan Ellis of Google and Erik Reppel of Coinbase ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). The problem it targets is simple. MCP and A2A let agents talk to tools and to each other, but they don't tell an agent which stranger to trust. ERC-8004 adds that missing layer with on-chain registries anyone can read ([EIP-8004 motivation](https://eips.ethereum.org/EIPS/eip-8004)). The standard went live on Ethereum mainnet on 28 January 2026\. During three months on testnet, builders registered 10,000+ agents and exchanged 20,000+ feedback entries, and Cyfrin, Nethermind and the Ethereum Foundation Security Team audited the contracts ([8004.org launch post](https://www.8004.org/blog/welcome-to-8004)). One line in the spec matters most for this site: "Payments are orthogonal to this protocol." ERC-8004 doesn't move money. It tells you who you're about to pay. ## The three ERC-8004 registries, in plain terms ### Identity Registry: an NFT that points to an agent card Registering mints an ERC-721 token. The token ID becomes the agentId, and the token URI points to a registration file listing the agent's name, description, endpoints (web, A2A, MCP, ENS, DID, email) and supported trust models ([EIP-8004 Identity Registry](https://eips.ethereum.org/EIPS/eip-8004)). The key field for payments is agentWallet. It's the address where the agent receives funds, and changing it requires an EIP-712 signature from an EOA or ERC-1271 approval from a smart wallet. When the NFT is transferred, agentWallet is cleared and the new owner must verify a wallet again ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). ### Reputation Registry: public, permanent feedback Any client address can post feedback on an agent as a signed value with 0 to 18 decimals, plus optional tags such as uptime or successRate. The agent's owner can't rate itself, and feedback can be revoked by its author but not deleted ([EIP-8004 Reputation Registry](https://eips.ethereum.org/EIPS/eip-8004)). The optional off-chain feedback file even has a proofOfPayment block with fromAddress, toAddress, chainId and txHash, which the spec says "can be used for x402 proof of payment" ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). That's the bridge between a stablecoin transfer and a rating. ### Validation Registry: third-party checks For high-stakes jobs, an agent can ask a validator contract to check its work. Validators answer with a score from 0 to 100, and the method can be stake-secured re-execution, zkML proofs or TEE attestations ([EIP-8004 Validation Registry](https://eips.ethereum.org/EIPS/eip-8004)). Status is mixed. QuickNode's explorer lists the Validation Registry as deployed on every mainnet it indexes ([QuickNode ERC-8004 contracts](https://erc-8004.quicknode.com/docs/contracts)), while the 8004.org FAQ still says that section is undergoing technical due diligence and "is not yet available" ([8004.org Learn](https://www.8004.org/learn)). Treat validation as early until the spec section is final. | Registry | What it answers before a payment | Main limit | Stablecoin Insider's usage rule | | ---------- | ---------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- | | Identity | Who is this agent, where is it reachable, which wallet gets paid | agentWallet is reset on NFT transfer ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)) | Pay agentWallet only after re-reading it on-chain | | Reputation | How past clients rated it, by tag | Sybil reviews are possible; summaries need a reviewer list ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)) | Filter feedback to reviewers you already trust | | Validation | Whether a named validator checked a job, scored 0 to 100 | Spec section not final per [8004.org](https://www.8004.org/learn) | Require it only for high-value tasks | ## Where ERC-8004 is deployed, including stablecoin chains The registries use CREATE2, so the addresses are identical on every mainnet: the Identity Registry sits at 0x8004A169FB4a3325136EB29fA0ceB6D2e539a432 and the Reputation Registry at 0x8004BAa17C55a88189AE136b182e5fdA19dE9b63 ([QuickNode](https://erc-8004.quicknode.com/docs/contracts)). QuickNode lists 18 mainnets, including Ethereum, Base, BNB Chain, Arbitrum, Polygon and Celo. Two are worth noting for payments: Arc, Circle's stablecoin chain, and Tempo, Stripe's payments chain ([QuickNode ERC-8004 contracts, updated 17 September 2026](https://erc-8004.quicknode.com/docs/contracts)). An agent registered on one chain can still transact on others, per the spec. ## The October 2026 registration surge, read carefully Here's the headline number. As of 23 October 2026, 1,333,878 agents were registered across 24 tracked chains. Base held 795,681, BNB Chain 374,823 and Ethereum 73,015 ([agenteconomy.to](https://agenteconomy.to/stats/erc-8004-agents)). Stablecoin Insider's math on those figures: Base is 59.7% of all registrations, BNB Chain 28.1% and Ethereum 5.5%, so three chains hold 93.2% ([agenteconomy.to data](https://agenteconomy.to/stats/erc-8004-agents)). The three days from 20 to 22 October added 483,715 agents, or 36.3% of the all-time total. Daily registrations averaged about 2,231 in September and 1,745 from 1 to 11 October, before jumping to 104,284 on 20 October and 263,164 on 22 October ([agenteconomy.to daily series](https://agenteconomy.to/stats/erc-8004-agents)). That's roughly 379x the 1 October level. So who's behind it? Mostly one platform. Between 13 and 20 October, 208,589 new identities were registered on Base, taking that chain from 111,902 to 320,491\. In a random sample of 300 IDs, every readable agent file pointed to centralcity.ai, so at least 98.7% of the week came from Central City ([Agentic Finance Graph, 20 October 2026](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). 📊 Count caution: trackers disagree because they count different chains and define an agent differently, and some include testnets. A registration is one cheap transaction. It says nothing about whether the agent is funded, active or real, so treat any headline total as an upper bound on agents, not a measure of activity. How wide is the spread? On 24 October, 8004scan showed 1,531,897 mainnet agents with a registration file and 1,856,631 including testnets, against 1,333,878 at agenteconomy.to ([Sato Hub tracker comparison, read 24 October 2026](https://satohub.ai/numbers/erc-8004-registered-agents)). Sato Hub reads each chain's registry counter, never adds chains together, and showed Base up 155.9% week over week to 19 October. ## Registered is not the same as paying in stablecoins This is the gap that matters for stablecoin volume. On 20 October, Agentic Finance Graph counted 9,593 registered agents on Base that had paid money leaving their own control. Against 320,491 Base registrations that day, that's about 3.0%, by Stablecoin Insider's division ([Agentic Finance Graph](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). The x402 side shows the same pattern from the other direction. Only 3.9% of wallets that paid x402 sellers on Base in the prior 7 days were bound to a registered agent, and sellers in the x402 Bazaar took $27.3K in 24 hours from 1,258 paying wallets ([Agentic Finance Graph](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). Central City is the exception that proves the measurement problem. Its agents paid through the platform's own fee routers instead of a standard x402 facilitator: 148,033 fee events worth $77.8K, with exactly 10% going to the platform treasury ([Agentic Finance Graph](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). That works out to about $0.53 per service payment. Why did trackers miss it? Because ERC-8004 clears agentWallet when a registration moves, and these payers were the minting accounts, not the wallet holding the NFT. It's a design feature that also hides spending from anyone counting by agentWallet alone. For scale, the whole stablecoin market is measured in hundreds of billions of dollars ([DefiLlama stablecoins](https://defillama.com/stablecoins)). Agent-to-agent spending tied to ERC-8004 identities is still a rounding error inside it. The identity layer is running ahead of the payment layer. ## How ERC-8004 fits with x402 and stablecoin payments Think of the agent payment stack as three questions. Who is this agent? ERC-8004\. How does it ask for money? [x402](https://www.x402.org/), which uses the HTTP 402 status code to request a stablecoin payment. Who does it act for? Credential protocols such as [Proof's x401](https://stablecoininsider.org/x401-protocol/). For a side-by-side of the payment protocols themselves, see [x402 vs AP2 vs ACK-Pay](https://stablecoininsider.org/x402-vs-ap2-vs-ack-pay/). Card networks are building their own version too: [Mastercard Agent Pay for Machines](https://stablecoininsider.org/mastercard-agent-pay-for-machines/) builds on x402 with budgets and permissions set by the business. [x401 Protocol: How AI Agents Prove Identity Before They PayStablecoin Insider on Proof's x401 identity protocol and how it pairs with x402 USDC payments.![](https://stablecoininsider.org/favicon.ico)Stablecoin Insider](https://stablecoininsider.org/x401-protocol/) One named deal this week wires ERC-8004 into a planned consumer stablecoin product. On 23 October, KOSDAQ-listed Squaretech said it signed an MOU with GOAT Network to explore AI agent payments in dollar stablecoins for foreign tourists, with each agent given an ERC-8004 on-chain identity, spending limits and user approval steps ([The Herald Business, 23 October 2026](https://biz.heraldcorp.com/article/10913112)). It's an MOU, not a launch, and it depends on Korean regulatory review. | Layer | Standard or tool | What it does for a stablecoin payment | | ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------ | | Identity of the agent | ERC-8004 Identity Registry ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)) | Confirms the agentId and its verified agentWallet | | Payment request | x402 over HTTP 402 ([x402.org](https://www.x402.org/)) | States price, token and chain, then settles in USDC or similar | | Who the agent acts for | x401 credentials ([Stablecoin Insider on x401](https://stablecoininsider.org/x401-protocol/)) | Proves a person or business approved the spend | | Track record | ERC-8004 Reputation Registry ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)) | Feedback can carry an x402 proofOfPayment | | Spend controls | Agent wallet policies ([custodial vs non-custodial agent wallets](https://stablecoininsider.org/custodial-vs-non-custodial-agent-wallets/)) | Caps, allowlists and approvals sit in the wallet, not the registry | ## Checklist: using ERC-8004 before your agent pays another agent If you run an agent that spends USDC, this is the order Stablecoin Insider would check things in: - **Resolve the agentId on the right chain.** Match the full agentRegistry string, chain ID plus registry address, not just the number ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). - **Read agentWallet live, every time.** It resets on transfer, so a cached address can be stale. - **Check domain verification.** A verified endpoint publishes /.well-known/agent-registration.json with a matching registration ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). - **Filter reputation by reviewer.** The spec requires a client address list for getSummary because unfiltered results are open to Sybil attacks. - **Cap the first payment.** A new counterparty gets a small test amount; Agentic Finance Graph found 456 agent wallets targeted by address poisoning in 7 days ([Agentic Finance Graph](https://dev.to/agenticfinancegraph/208589-new-ai-agents-on-base-in-one-week-where-the-money-went-and-two-things-we-were-counting-h0p)). - **Write feedback after settling.** Attach the txHash as proofOfPayment so your rating is tied to a real transfer. Who shouldn't bother yet? If your agent only pays two or three known APIs, an allowlist in the wallet does the job. ERC-8004 earns its keep when your agent picks counterparties it has never met. 💡 Stablecoin Insider's take: ERC-8004 is the most useful missing piece in agent payments because it separates who gets paid from who owns the agent. But the October surge is a platform campaign, not proof of an agent economy. Judge the standard by paying agents, not registered ones, and by how many x402 payers carry an identity. Today that's a small minority of payers on Base. If it becomes the majority in 2027, identity-gated stablecoin payments become the default. If it doesn't, ERC-8004 stays a directory. [How to accept x402 USDC payments from AI agents](https://stablecoininsider.org/how-to-accept-x402-usdc-payments-from-ai-agents/) --- ## FAQ #### What is ERC-8004 in simple terms? It's an Ethereum standard that gives AI agents an on-chain identity, a public reputation record and optional third-party validation. Each agent is an ERC-721 token pointing to a registration file ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). #### Does ERC-8004 handle stablecoin payments? No. The spec says payments are out of scope. It does store a verified agentWallet for receiving funds and lets feedback carry an x402 proof of payment ([EIP-8004](https://eips.ethereum.org/EIPS/eip-8004)). #### How many ERC-8004 agents are registered? About 1.33 million across 24 chains as of 23 October 2026, per agenteconomy.to. Other trackers count differently and show up to 1.86 million including testnets ([Sato Hub](https://satohub.ai/numbers/erc-8004-registered-agents)). #### Which chains support ERC-8004? The registries are live on 18 mainnets listed by QuickNode, including Ethereum, Base, BNB Chain, Arbitrum, Arc and Tempo, at the same addresses on each ([QuickNode](https://erc-8004.quicknode.com/docs/contracts)). #### Is ERC-8004 the same as x402? No. x402 is how an agent asks for and makes a payment over HTTP. ERC-8004 is how you find and vet the agent you're paying. They're designed to work together. #### Who created ERC-8004? Marco De Rossi (MetaMask), Davide Crapis (Ethereum Foundation), Jordan Ellis (Google) and Erik Reppel (Coinbase), with feedback from more than 80 teams ([8004.org](https://www.8004.org/blog/welcome-to-8004)). ## What to watch next Three signals will show whether ERC-8004 becomes payment infrastructure. First, the final Validation Registry spec. Second, whether daily registrations settle above the September run rate once the Central City campaign ends. Third, the share of x402 payers bound to a registered agent. If you build agents that spend stablecoins, the Monday move is small: register one production agent, verify its agentWallet and domain, and add an agentWallet lookup before every payment to a new counterparty. It costs one transaction and closes the most common stale-address mistake. This content is provided for informational and educational purposes only and does not constitute financial, investment, legal or tax advice. ERC-8004 is a draft standard and registry counts come from independent trackers, not from the standard's authors. No material herein should be interpreted as a recommendation, endorsement, or solicitation to buy or sell.