First Leeward

Simulation

Simulate a fiat deposit

POSThttps://api.firstleeward.com/v0/simulation/fiat-deposits

Simulates a bank transfer credited to the project's master collateral account. The deposit is recorded as already settled, the master balance is credited, and FIAT_DEPOSIT_CREATED is delivered, matching what a reconciled transfer does in production. Only available to Program-Funded projects, which are the ones that have a master collateral account. currency must be one the project accepts top-ups in, which is the project's billing currency.

Authorizations

Authorizationstring · headerrequired

API key as Bearer token, e.g. Bearer YOUR_API_KEY

Headers

Leeward-Versionenum<string>required

API version (YYYY-MM-DD). Available option: 2026-09-18

Body

application/json

amountnumberrequired

Amount the sender transferred, credited to the master account

currencystringrequired

Currency the transfer was sent in, as an ISO 4217 alpha code (e.g. HKD). Must be a currency the project accepts top-ups in.

senderNamestring

Name of the sender. Randomly generated if omitted.

referencestring

Reference the sender attached to the transfer. Absent if omitted.

Response

200Response for status 200
idstring<uuid>required

Unique fiat deposit identifier

accountIdstring<uuid>required

Account credited by the deposit

transactionIdstringrequired

The bank's unique identifier for the incoming transfer. Use it to reconcile the deposit against a bank statement.

statusstringrequired

Current deposit status

Available options:SETTLED
amountnumberrequired

Amount credited to the account balance

currencystringrequired

Currency the credit was applied in

originalAmountnumberrequired

Amount of the incoming transfer, as received by the bank

originalCurrencystringrequired

Currency the transfer was sent in, as the bank reported it. A transfer must be sent in the billing currency of your card program.

senderNamestring | nullrequired

Name of the sender, when the bank reported one

referencestring | nullrequired

Reference the sender attached to the transfer, when present

occurredAtstringrequired

ISO 8601 timestamp of when the bank received the transfer

createdAtstringrequired

ISO 8601 timestamp of creation

updatedAtstringrequired

ISO 8601 timestamp of last update

400Response for status 400
Option 1 · SimulationInvalidStateError
errorobjectrequired
Show child attributes
codestringrequired
messagestringrequired
detailobject | nullrequired
Option 2 · SimulationUnsupportedCurrencyError
errorobjectrequired
Show child attributes
codestringrequired
messagestringrequired
detailobject | nullrequired