Circle's Arc mainnet shipped agent wallet controls. Verifiable identity is still on the roadmap

Circle opened the public mainnet of Arc on 16 September 2026. Arc is an open, EVM-compatible Layer 1 where fees are paid in USDC, and its founding validator cohort is eleven institutions plus Circle, among them BlackRock, DTCC, Mastercard and Visa.¹² Circle reports more than 100 institutional and ecosystem builders live on day one, more than 1,200 projects built on Arc, and more than 700 million testnet transactions in under a year.¹

For agents, the launch adds Arc Portal, where a person funds an agent wallet, sets spend limits and delegates onchain tasks. It sits on top of the Circle Agent Stack, available since May: policy-controlled Agent Wallets, sub-cent Nanopayments through Circle Gateway, and an Agent Marketplace that Circle itself calls emerging.¹³

The same release files one agent item under the roadmap: an Agent Sector “for verifiable agent identity and auditable records.”¹ Identity on Arc is not absent, though. An agent can already register itself in an open registry. What Circle has not shipped is a way for a stranger to trust what that registration says, and that difference is the most useful thing to take from the launch.

What went live on 16 September

Gas is paid in USDC, so a fee is denominated in dollars and nobody has to hold a volatile network asset to send a payment.¹ Arc’s documentation describes a proof-of-authority validator set running Malachite, an implementation of Tendermint BFT, with Reth as the execution client and deterministic finality in under one second.⁴

The validator list reads as a statement of intent. BlackRock, DTCC, Galaxy, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation, Visa and Worldpay produce blocks alongside Circle.¹² Anyone can build and transact on the network; only the validator set is permissioned.

The agent controls are specific. An Agent Wallet runs on Circle’s user-controlled wallets with 2-of-2 MPC key management, so the agent never holds a key share. Its owner can cap USDC spending on outbound transfers and x402 payments, make those caps daily or monthly, and allowlist or blocklist wallet and contract addresses.⁵ Arc Portal puts funding, those limits and task delegation in one place for a person rather than a developer.¹

The scale numbers are Circle’s own and predate mainnet: projects from its developer community and transactions on a testnet Circle operates. Neither measures production activity.¹

Registered is not verified

Circle’s roadmap after mainnet centres on proof of stake, privacy and scalability. Its Network Sectors are a Privacy Sector for opt-in confidential transactions, a Payment Sector aimed at more than 100,000 transactions per second, and the Agent Sector. AgentVM is being designed so agents can work with sensitive data while the chain keeps an immutable record.¹ None of it is deployed.

Identity primitives already exist on Arc, and Circle says so. Its August direction paper lists ERC-8004 identity, an agent ID plus a URI pointing to the agent’s metadata, among the foundations that exist today on open standards. Arc’s own tutorial walks a developer through registering an agent in the ERC-8004 identity, reputation and validation registries on Arc Testnet.⁶⁷ Anyone writing that Arc has no agent identity is wrong. Anyone writing that Arc launched with verifiable agent identity is reading a roadmap as a changelog.

The gap between those statements is who stands behind the entry. An ERC-8004 registration is a claim the operator publishes about itself, and Circle’s paper describes reputation on top of it as a live registry with the signal still missing.⁶ An empirical study of ERC-8004 registrations found most did not resolve to a live service. A month earlier, Circle had named identity, delegation and recourse as the first unresolved piece of the agent economy.⁸

The ordering follows from what a chain can guarantee. Finality is a property of the chain, so Circle can promise that a payment settled in under a second. Which company an agent works for is a fact about the world outside the chain, and a registry can record the claim without being able to vouch for it.

A spending limit needs one party. Identity needs a voucher

A spending limit is a unilateral instrument. The owner decides that this agent may spend fifty dollars a day with five named addresses, and the decision is complete the moment it is made. No counterparty is consulted, and the system holding the money enforces it.

Identity is different because its value depends on someone other than the claimant. Where agent identity has shipped, it has shipped inside a party both sides already trust. Visa’s Trusted Agent Protocol lets a merchant check a signed request from an agent Visa recognises, and Circle counts it and Mastercard Agent Pay as early attempts at agent identity and delegation, neither yet an institutional standard.⁹⁸ Cloudflare has verified signed agents through Web Bot Auth since August 2025, and in August 2026 opened reservations for handles that link an agent to its owner’s Cloudflare account, with owner-capped Virtual Wallets promised for the coming months.¹⁰¹¹

Cloudflare shipped the name before the wallet, so the order is not a law. What holds is where the trust comes from: a card network or a CDN vouches, and a party outside that network is left with the operator’s own unverified claim. On 10 September, Ant International, Visa and Mastercard announced a Know Your Agent interoperability framework so that an agent registered with one need not register with the others. No specification, governance body or timeline has been published.¹² Coinbase fenced an agent inside an isolated portfolio, with trade-size and spend limits described at launch as coming later.¹³

The first three rows are complete on the owner’s side. The last three depend on somebody else, the last on a person who may never have heard of Arc.

What a spend cap cannot encode

Take the scenario Arc is built for. An agent with a funded wallet, a daily cap and a delegation finds a provider in the Agent Marketplace, a curated catalogue Circle wants to open into a ranked market. It calls an endpoint, pays a fraction of a cent and repeats that a few thousand times a day. Every payment is authorised, within budget and correctly recorded.

The cap encodes an amount and the allowlist encodes addresses. Neither encodes which company operates the service at the other end, or whether a human at either end should hear about the transaction. A sourcing agent that pays for contact data, a procurement agent that books a consultation: each settles cleanly, and neither establishes that the human at the far end agreed to be reached.

Nanopayments sharpen this. Circle built them for transfers as small as a millionth of a dollar, at a rate no person would review.³ Per-transaction approval stops being a design option at a few thousand calls a day. What remains is the rule set configured in advance, so questions a rule set cannot express become questions nobody asks.

So the Arc controls answer how much an agent may spend, where and on which tasks, and whether the payment settled. They leave open who the agent represents, who operates the counterparty, and whether a person agreed to the contact. Circle’s Agent Sector points at the first of those. The other two sit outside a payment network entirely, which is our reading of the architecture rather than a claim Circle makes.

How this connects to Tobira

Tobira works on the consent half. A Tobira @handle is a human-readable address for an agent representing a named person or company, backed by a W3C DID and an A2A-compatible Agent Card, so a stranger’s agent can find it. Identities and contact details are revealed only after both sides agree, so an introduction is something the receiving person opted into rather than something the paying side authorised for itself. That complements Arc rather than replacing it: an agent can hold an Arc wallet for settling a purchase and a readable identity for the moment a transaction turns into a conversation, the step covered in the consent layer for the agentic web.

What to remember

Live since 16 September 2026: the public Arc mainnet with USDC gas and eleven founding validators plus Circle, and Arc Portal for funding agent wallets, capping their spending and delegating tasks.

Available but unverified: self-registered agent identity through the open ERC-8004 registries.

Roadmap: verifiable agent identity and auditable records in a future Agent Sector, with AgentVM alongside it.

The distinction worth keeping is who has to act. An owner can configure a budget alone. Verified identity needs a voucher, and consent needs the person on the other side. Visa and Mastercard produce Arc’s blocks and vouch for agents on their own card rails. On Arc itself, the agent across the table still vouches for itself.

FAQ

Did Arc launch with verifiable agent identity?

No. Circle places verifiable agent identity and auditable records in a future Agent Sector. Agents can already register a self-declared identity in the open ERC-8004 registries, which Arc documents on its testnet, but nothing on Arc yet vouches for what that registration claims.¹⁷

What spending controls can an owner set on a Circle agent wallet?

USDC spending limits on outbound transfers and x402 payments, which can be daily or monthly, plus allowlists and blocklists of wallet and contract addresses. Keys use 2-of-2 MPC, so the agent never holds a key share. Arc Portal lets a person fund the wallet, set limits and delegate onchain tasks.⁵¹

How does the Circle Agent Stack relate to the Arc mainnet?

Circle launched the Agent Stack in May 2026 with Agent Wallets, Nanopayments through Circle Gateway, the Agent Marketplace and the Circle CLI. The September mainnet added a chain designed around those tools and Arc Portal for people who do not write code.³¹

Are the 1,200 projects and 700 million transactions production numbers?

No. Both figures are Circle’s own and predate the public mainnet: more than 1,200 projects built by its developer community, and more than 700 million transactions processed on testnet in under a year.¹

Does a spending limit tell a merchant who an agent represents?

No. The account owner sets it and the wallet enforces it, and it constrains the amount, the addresses and the permitted tasks. Establishing who operates a counterparty agent, and whether a human agreed to be contacted, needs a party both sides recognise and the consent of the person being reached.

Sources