Revolut

The public C ABI exposes Revolut product credential setup, backend opening, OAuth setup, provider state cleanup, recipient operations, and payment-draft operations. Shared account, transaction, and transfer operations remain capability-probed through gln_check_backend_operation_support.

Provider/API references:

• Revolut Business API documentation
• RFC 7523: JWT Profile for OAuth 2.0 Client Authentication and Authorization Grants

Exposed Surface

Do not model Revolut as supporting shared account, balance, transaction, or transfer submission operations unless gln_check_backend_operation_support reports support for the opened backend. Revolut-specific recipient and payment-draft entrypoints return typed backend result envelopes and redacted provider status/error details.

Open a Backend

gln_revolut_config_t config = {0};
gln_default_revolut_config(&config);
config.product_credential_ref_or_null = "revolut/product/default";
config.product_credential_root_or_null = "C:/ProgramData/Galanthus/RevolutProductCredentials";
config.environment_or_null = "sandbox";
config.storage_root_or_null = "C:/ProgramData/Galanthus/Revolut";
config.profile_name_or_null = "company-profile";

gln_backend_t* backend = NULL;
gln_error_t error = {0};
gln_default_error(&error);
gln_status_t status = gln_open_revolut_backend(
    &config,
    state_store,
    &backend,
    &error);

The state store must outlive the backend handle using it.

Product Credential Setup

Use gln_revolut_prepare_product_credentials before Revolut has issued a ClientID. Prepare creates or reuses a CurrentUser CNG-backed non-exportable signing certificate, validates reused certificate/key security, writes the prepared profile, exports public certificate material for Revolut registration, creates the product token root, and returns setup-safe JSON.

Use gln_revolut_finalize_product_credentials after registering the public certificate and redirect URI with Revolut. Finalize stores the ClientID for the existing prepared profile and validates profile/SID/ACL/key/token-root readiness so gln_revolut_product_credentials_preflight and gln_open_revolut_backend consume the same profile format.

Setup JSON reports public/setup status only: profile reference, environment, redirect URI, public certificate material/paths, certificate reuse, ClientID presence, token-root readiness, and preflight readiness. It does not expose private keys, private PEM, JWT/client assertions, authorization codes, access tokens, refresh tokens, raw token endpoint bodies, raw security descriptors, or the normal UI token-root path.

Token Persistence

Revolut token persistence is owned by Galanthus. storage_root_or_null provides the product-scoped root used by the resolver-backed implementation.

OAuth Setup

Revolut OAuth operations use the opened backend and persist token state through Galanthus-owned token storage. Public result JSON and typed status fields never include access tokens, refresh tokens, or authorization URLs.

Use gln_revolut_oauth_authorize_url to prepare an authorization URL for a caller-managed browser flow, gln_revolut_oauth_exchange_code to validate state and exchange the authorization code, gln_revolut_oauth_refresh to refresh persisted token state, gln_revolut_oauth_status to inspect redacted state, and gln_revolut_delete_token to clear persisted token state.

Provider State Cleanup

Use gln_revolut_delete_transfer_idempotency_state to clear the local Revolut transfer idempotency cache owned by the opened backend profile. This operation does not remove OAuth token state; use gln_revolut_delete_token for token cleanup.

Recipients and Payment Drafts

Recipient list/create/delete and payment-draft list/show/create/delete operations are exposed as Revolut-specific backend operations. Use the matching gln_get_backend_result_revolut_* projection for successful envelopes and release the top-level envelope with gln_destroy_backend_result when finished.

Runtime Checks

int can_list_recipients =
    gln_check_backend_operation_support(backend, GLN_BACKEND_OPERATION_REVOLUT_LIST_RECIPIENTS);
int can_create_payment_draft =
    gln_check_backend_operation_support(backend, GLN_BACKEND_OPERATION_REVOLUT_CREATE_PAYMENT_DRAFT);
int can_submit_shared_transfer =
    gln_check_backend_operation_support(backend, GLN_BACKEND_OPERATION_SUBMIT_TRANSFER);

Probe each operation independently before enabling it for an arbitrary backend handle.