Glossary
Terms used in SSF-SPEC-004 and the wallet-gateway documentation. Terms carried forward from SSF-SPEC-001 are noted as such.
For the SSF-SPEC-001 glossary, see the SSF-SPEC-001 Glossary.
| Term | Definition |
|---|---|
| Wallet Client | A conformant client application that connects to the wallet-gateway on behalf of a payer. |
| Gateway Message | A JSON object transmitted over the WebSocket connection, conforming to the message envelope defined in SSF-SPEC-004, Section 5.2. |
| Caller Address | The EVM address that identifies the wallet in a given gateway message. Must match the address recovered from the message signature. |
| Domain Separator | A bytes32 EIP-712 domain separator hex string. Used as the primary identifier for a supported token throughout the wallet-gateway interface. Full token metadata (including contract address, name, decimals, version, and network identifier) is available from the Basic Data Service. (From SSF-SPEC-001) |
| Transfer History | The record of ERC-20 Transfer events for supported tokens associated with a given wallet address. Transfers of unsupported tokens and all other on-chain activity are excluded. (From SSF-SPEC-001) |
| Subscription | A per-connection registration to receive real-time push notifications for a specified set of tokens. Active only while the originating connection remains open and non-idle. |
| Idle Timeout | The gateway-configurable duration after which a connection with no inbound activity is closed. Recommended value: 5 minutes. |
| BrokenDownAmount | A response object returned by GET_FEES carrying two fields: fees (the total fee in token units) and remaining (the principal amount that will reach the beneficiary). |
| Submission Status | One of the ordered states a payment or registration submission passes through: ENQUEUING, PENDING, BROADCASTING, SUCCESS, FAILURE. |
| Terminal State | A submission status from which no further transitions occur. The terminal states are SUCCESS and FAILURE. |
| Permit Nonce | The per-owner counter maintained by an ERC-2612 token contract. Each successfully executed permit increments the nonce, invalidating all previously issued permits for that owner. The gateway provides nonce retrieval via GET_NONCE so wallets need not query the token contract directly. (From SSF-SPEC-001) |
| Payload ID | A client-generated identifier (UUID) included in a TransferRequest submission. Used by the gateway and broadcast-service to enforce idempotency and correlate status notifications back to the originating submission. (From SSF-SPEC-001) |
| Zero-UUID | The Acquirer ID consisting entirely of zero bytes (0x00000000000000000000000000000000). Passed as acquirerId in GET_FEES and in the payment payload when no acquirer is involved. (From SSF-SPEC-001) |
| WSS | WebSocket Secure — the WebSocket protocol carried over TLS. The wallet-gateway accepts WSS connections only. |
| Ping / Pong | WebSocket-level keepalive frames (RFC 6455). The gateway sends ping frames before closing idle connections. Clients SHOULD respond with pong to reset the idle timer. |
| Supersession | The event by which a new connection for a given wallet address displaces and terminates an existing connection for the same address. The previous connection is closed with code 4001 / "superseded". |