| Organization | The legal entity that contracts with TBook and owns API keys. Every API resource is scoped to one organization; the API key is the identity. |
| Account | An investment principal under an organization. Types: individual, omnibus, treasury, business — see Account Models. |
| Asset | An RWA product (e.g. rcusdp, xaua), native on some chain, exposed through one or more vaults. |
| Rail | The path from the funding chain to the asset. TBook vaults use direct: the account's USDC and the vault live on the same chain. |
| Vault | An investable instance of an asset on a rail (rcusdp-sui, xaua-sui). |
| Settlement cycle | The recurring window in which deposits and redemptions are batched and settled (accepting → processing → settled). Exposed as settlementCycle numbers and vault.cycle.* events. |
| Transaction intent | The platform-side record of a money movement, created at build time (txi_…), tracked built → submitted → confirmed → settled (terminal alternatives: failed, expired). |
| Share | A unit of proportional ownership in a vault. Minted on deposit settlement, burned on redemption settlement. For XAUa, one unit corresponds to one gram of gold. |
| NAV / share price | Net asset value of the underlying portfolio per share/unit; the price in the catalog. |
| Claimable | USDC waiting in the vault for the account to claim after a redemption settles (or after a rollback refund on the gateway rail). Claims always pay the account's own wallet. |
| Custody attribute | Who controls the account's wallet: waas (wallet-as-a-service), self (the account holder, e.g. a multisig), org (the organization, e.g. an omnibus pool wallet). Descriptive — the signing mechanics are identical. |
| Attestation | The organization's confirmation that it performed KYC (individuals/pools) or KYB (business clients) on an account. TBook relies on the attestation; the organization owns the compliance relationship. |
| Whitelist (XAUa) | Issuer-maintained list of wallets allowed to transact the gold token. Required before any xaua-* transaction. |
| Idempotency key | Idempotency-Key header on money-movement POSTs that makes retries safe: replays with the same key and body return the original response for 24 hours (org-scoped); the same key with a different body returns 409 idempotency_conflict; a concurrent duplicate while the first request is still executing returns 409 idempotency_in_progress (retry with the same key). The Node SDK generates one automatically and echoes it back as idempotencyKey on results. |
| WaaS | Wallet-as-a-service (Crossmint, Privy, …) — provisions per-user wallets and signs the unsigned transactions returned by the API. |
| USDC | The quote and settlement currency for all v1 assets. |