SSDF

Rails · 2026-09-09

Same SKU. Extra door. One treasury.

Agents on other chains want to pay. SSDF still settles into Coinbase Business. We do not become the bridge, the CCTP executor, or an ERC-8001-XCHAIN agent. A merchant catalog is not an agent.

The Medium piece on cross-chain agent payments is ERC-8001-XCHAIN / Trails. It is not x402. It does not mention Solana or Algorand. An agent may use that executor before it hits this store. We will not implement it.

Doors

Base USDC (canonical)

Live

eip155:8453

GET /api/x402/{sku} → 402 → PAYMENT-SIGNATURE → CDP verify/settle to SSDF_PAY_TO. Bazaar indexes this path.

Live. Humans use hosted Coinbase checkout of the same SKU. Hosted checkout does not list Bazaar.

Solana USDC

Gated

solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp

Same resource URL. Second accept. payTo = Business Solana USDC address (SSDF_PAY_TO_SOLANA). CDP settles SPL USDC into that deposit. Business credits the same USDC balance.

CDP already lists Solana. Coinbase Business Payments API already lists USDC on solana. The door stays gated until the Business Solana deposit address is set. Do not reuse the Base 0x payTo. Do not self-settle.

Algorand USDC

Mapped, not wired

algorand:wGHE2Pwdvd7S1UKDWQdhrjjw3md-vsSh1dBIUo9URQ

An Algorand agent must convert native USDC (ASA 31566704) onto a Coinbase-supported network, then pay the live 402. That conversion is the agent's. SSDF does not run it.

CDP facilitator does not list Algorand. Circle CCTP does not list Algorand. Coinbase Business deposit destinations list Aptos, Base, Ethereum, Optimism, Polygon, Solana, Sui — not Algorand. Retail Coinbase USDC-Algorand (2024) is not this treasury product. Wiring GoPlausible would move settlement off Coinbase.

Clerks

x402 (HTTP 402)

The payment protocol this store speaks.

A 402 lists accepts. An accept is scheme + network + asset + payTo. Multi-network is extra accepts on the same resource, not a second SKU.

Coinbase CDP facilitator

Verify + settle. Networks: Base, Polygon, Arbitrum, World, Solana.

SSDF already calls this for Base exact. Solana exact is the same clerk, different CAIP-2.

Coinbase Business

Custodial treasury. Deposit destinations per network.

USDC on Solana is a supported Business deposit network. Algorand is not on the Payments API table. Hosted checkout stays Base.

Circle CCTP

Burn-and-mint USDC across CCTP domains. Solana is domain 5. Base is domain 6.

Algorand is not a CCTP domain. An agent may use CCTP before paying SSDF. SSDF does not call CCTP and does not take a bridge fee.

ERC-8001-XCHAIN / Trails

Intent + executor for EVM cross-chain actions (EIP-712).

Kwame Bryan / Sequence Trails, 2026. Example path is Arbitrum → Base via CCTP. Solana and Algorand are not in that module. SSDF is not an IERC8001CrossChainExecutor. A merchant catalog is not an agent.

GoPlausible x402 facilitator

Third-party AVM facilitator (Algorand, plus Base/Solana on their endpoint).

Mapped, not wired. Same class as PayAI. Pointing 402 accepts here leaves Coinbase Treasury.

Paths

Agent converts, SSDF stays Base

live

An agent holding USDC on Solana can CCTP to Base, then pay the live 402. An agent holding USDC on Algorand must use its own off-ramp, Circle Mint (if qualified), or an exchange — CCTP will not take Algorand. SSDF never sees the origin chain. This path is already live. Do not build it.

Second accept: Solana exact into Business

gated

Advertise a second exact accept on the same /api/x402/{sku}. network solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp. asset EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v. payTo = Coinbase Business Solana USDC deposit. CDP settles. Business credits the same USDC ledger. Humans still check out on hosted Coinbase. Bazaar seed stays Base.

Algorand waits on Coinbase

mapped

Do not wire until CDP lists Algorand and Business exposes an Algorand USDC deposit destination. Until then the honest letter to an Algorand agent is: convert, then pay Base (or Solana once gated-open). Do not self-bridge. Do not become the transmitter.

Hard rules

  • Same SKU. Extra accept. Not a Solana catalog and not an Algorand catalog.
  • Treasury is Coinbase Business. A second deposit network is still that treasury.
  • CDP facilitator stays the settler. Do not point 402 accepts at GoPlausible, PayAI, Trails, or a self-hosted AVM facilitator.
  • SSDF does not bridge, burn, or mint USDC. CCTP and ERC-8001-XCHAIN are the agent's executor, not this store.
  • Do not self-settle Solana from treasury to force a screenshot. Listing a door is not demand.
  • Coinbase Bazaar seed stays Base exact. A Solana settle is a sale. It is not the Bazaar index path.

Machine index: /api/cross-chain. Live 402: /machine. Payment surfaces: /facilitators.