x402 payment architecture

developer

Providers, lanes, and the vault-chain vs payment-chain separation: Bankr on Base, Meridian on Robinhood Chain, self-hosted disabled.

HISS tracks the vault chain and the x402 payment chain as separate facts. Vaults live on Robinhood Chain (4663) with USDG as the base asset — that never changes. Which chain a paid service call settles on depends on the provider lane the payment takes.

Architecture object

Served by GET /api/x402/schema and embedded in vault schemas:

json

{
  "vaultChain": "robinhood_chain",
  "vaultChainId": 4663,
  "baseAsset": "USDG",
  "baseAssetAddress": "0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168",
  "x402Providers": {
    "bankrCloud": {
      "status": "live_or_configured",
      "paymentChain": "base",
      "label": "Bankr x402 Cloud on Base where configured"
    },
    "meridian": {
      "status": "configured_or_live_or_blocked",
      "paymentChain": "robinhood_chain",
      "chainId": 4663,
      "asset": "USDG",
      "facilitator": "0x8E7769D440b3460b92159Dd9C6D17302b036e2d6",
      "label": "Meridian x402 facilitator on Robinhood Chain"
    }
  },
  "robinhoodMcpUsedForVaultExecution": false,
  "hissStoresRobinhoodCredentials": false,
  "hissPlacesOrders": false
}

Provider lanes

Provider	Payment chain	Asset	Status	Used for
Bankr x402 Cloud	Base	USDC	live (11 endpoints)	Phase 5 CoilOps + Phase 6 autonomy services; vault-service scaffolds
Meridian facilitator	Robinhood Chain (4663)	USDG	configured or blocked by env; mainnet-only	Vault x402 services when enabled and verified
Self-hosted	—	—	disabled research candidate	Historical notes only

Lane selection

Vault services prefer the Meridian lane when MERIDIAN_ENABLED=true and the server-only key is configured.
Otherwise the Bankr Base lane applies — always labeled with provider, chain, and reason; never a silent downgrade.
Preview the selection per service at GET /api/x402/providers.

$HISS is independent research software in pre-execution readiness checks — not investment advice, and not affiliated with Robinhood, Bankr, or Chainlink.