It's the substrate AI agents have been waiting for.

Three asset transfer methods. One running, closed.

x402's V2 spec defines three ways to settle a payment, called asset transfer methods:

1. EIP-3009 — transferWithAuthorization. The dominant rail for USDC.

2. Permit2 — Uniswap's signature-permission standard. Works for any ERC-20.

3. ERC-7710 — settlement via MetaMask-style smart-account delegations.

The first two have hosted facilitators across the ecosystem. They're well-trodden.

The third has exactly one. MetaMask runs a developer-preview facilitator at tx-sentinel-base-mainnet.dev-api.cx.metamask.io/platform/v2/x402 for Base that implements erc7710. It is centrally operated by MetaMask. It settles via their internal tx-sentinel infrastructure.

Read the spec for ERC-7710 settlement:

Settlement is performed by calling redeemDelegations on the Delegation Manager. Unlike EIP-3009 and Permit2, ERC-7710 verification is performed entirely through simulation.

It's two sentences. The Coinbase reference implementation in github.com/coinbase/x402 has no erc7710.ts file. The MetaMask implementation is closed-source.

Conduit is building the open alternative.

Why the third method matters

The first two methods authorize transfers. Someone signs "you can take $0.01 USDC from me." That signature can be replayed; the spender has wide latitude to use it however they like (subject to amount caps).

ERC-7710 authorizes delegations. The user grants a smart account permission with caveats — "you can transfer up to $0.10 USDC per hour, only to these targets." Those caveats compose. A coordinator agent can take that permission and redelegate a slice of it to a specialist agent, attaching new caveats of its own. Every link in the chain enforces every other link's constraints.

This unlocks an architecture EIP-3009 and Permit2 cannot reach: AI agent workflows where the user's safety constraints (period caps, target allowlists) and the product's safety constraints (this payment is bound to this specific x402 request) are both enforced on-chain, simultaneously, with no trust in the agents involved.

That's the architecture Conduit is built on.

What Conduit is

Conduit is a receipt-bound payment layer for autonomous agents. It pairs:

• An open-source x402 facilitator that implements ERC-7710. Verify a paid request via simulation against the live MetaMask DelegationManager. Settle by submitting redeemDelegations on-chain.

• A custom caveat enforcer (X402ReceiptEnforcer) that binds each redeemed payment to a specific x402 request's intent hash. A redelegation carrying this caveat can only ever be redeemed for the exact payment the user authorized, even if the agent holding the redelegation is compromised.

• Settlement via 1Shot's Permissionless Relayer, which means users pay gas in stablecoins — never ETH. The whole flow can be funded with a single USDC balance.

What makes Conduit different from MetaMask's facilitator

MetaMask runs the only other erc7710 facilitator. Conduit is not duplicating their work; it's covering the cases they don't.

Both facilitators submit redeemDelegations against the same on-chain DelegationManager. Any caveat enforcer in the chain fires regardless of who submits. The differentiation isn't whether enforcers run — it's what tooling and documentation surrounds the agent-safety primitives. Conduit makes the pattern of "coordinator redelegates with a custom binding caveat to specialist" a documented, first-class story, not an emergent behavior.

Why now

Two things converged. First, MetaMask shipped the Advanced Permissions flow (ERC-7715), which lets dapps request granular permissions from users through the MetaMask UI — replacing the unbounded "approve" pattern that has hemorrhaged user funds for years. Second, x402's V2 spec recognized ERC-7710 as a first-class transfer method.

MetaMask runs their internal facilitator. Conduit runs the open one.

What's coming on this blog

Conduit is being built in the open. Every milestone gets a post. The next four are already drafted:

1. Spike 1's receipt — Conduit probed every hosted x402 facilitator and confirmed MetaMask's preview is the only one that implements erc7710. The Coinbase reference still has no erc7710.ts.

2. Spike 2's receipt — Conduit proved that 1Shot can carry the bytes[]/bytes32[]/bytes[] parameter shape that redeemDelegations requires, with full byte-for-byte fidelity. 1,500-byte payload sent, 1,500 bytes landed on-chain.

3. Spike 3's receipt — Conduit ran the architecture-defining experiment against the real DelegationManager on Base Sepolia. A custom caveat attached to a redelegation rooted in an ERC-7715-shaped grant does fire on every redemption. Architecture validated. Plus seven things the MetaMask delegation docs leave out.

4. The facilitator skeleton — Conduit's first piece of production code: an Express server that advertises ERC-7710, simulates redemptions for verification, and settles via 1Shot's Permissionless Relayer.

After that, the build. New posts as features land.

The recurring claim Conduit will keep making, because it is true:

The x402 spec defines three asset transfer methods. The third — the one that unlocks MetaMask as the payment authority — was spec-only until MetaMask shipped a closed developer preview. Conduit is shipping the open alternative.

— Conduit