Key Concepts

This page defines the terms you will encounter throughout the Movmint FX Services documentation. Each section is linkable — use it as a reference when building your integration.

Product

A Product is a directional currency pair you are approved to trade — for example, USDC-BSD, where USDC is the source currency and BSD (Bahamian Dollar) is the target currency. Direction matters: USDC-BSD and BSD-USDC are distinct Products.

Your Product subscription determines which from_currency / to_currency pairs, funding rails, and transaction limits are available to your API credentials. All operations — Quote, Capture, FlowLink, and Prefunded Accounts — validate against your active Product subscription. A request for a corridor you are not subscribed to is rejected.

Your approved Products are provisioned during Business Onboarding.

Participants

Every FX transaction carries one or more participants — the people or organizations sending and receiving funds. Participants are supplied in the participants array of the quote request and are used for compliance screening, travel-rule obligations, and delivery.

`participant_type`	Meaning
`ULTIMATE_ORIGINATOR`	The party on whose behalf funds originate (e.g. the end customer sending money).
`ORIGINATOR`	The sending party initiating the transaction.
`ULTIMATE_BENEFICIARY`	The party who ultimately receives the funds.
`BENEFICIARY`	The receiving party (intermediary or final recipient).

For required fields per participant type, see Quote — Participants.

Funding and delivery rails

Both the source (where funds come from) and the target (where converted funds go) are configured per transaction using a source_type. Four rail types are supported:

`source_type`	As source	As target
`BANK_ACCOUNT`	Pull via bank rails	Deliver via US ACH / FedNow / Local RTGS
`CARD`	Not supported	Push-to-card (debit cards only)
`DLT_WALLET`	On-chain transfer in	On-chain transfer out
`CLIENT_BALANCE`	Debit a prefunded balance instantly	Credit a prefunded balance instantly

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Note on field naming
Both source_configuration and target_configuration use a field named source_type to indicate the rail.

For rail-specific field requirements, see Quote — Source and destination funding.

Idempotency

Most write endpoints require an x-idempotency-key header containing a UUID you generate. Reusing the same key on a retry guarantees the operation is performed at most once — the server returns the original response instead of executing the request again. This is essential for safely retrying over unreliable networks without risk of duplicate transactions.

x-idempotency-key: 550e8400-e29b-41d4-a716-446655440000

Generate a fresh UUID per unique operation. Reuse it only when retrying the exact same request.

Quote expiry

A quote locks the FX rate for a short window — typically 30 seconds. The quote response includes:

expiry_seconds — how long the quote is valid from creation.
valid_until — the absolute UTC timestamp by which you must capture.

Capturing after valid_until returns 410 Gone. Request a new quote if the window lapses.