generated: '2026-07-23'
method: derived
source: openapi/uk-open-banking-account-info-api-openapi.yaml, openapi/uk-open-banking-payment-initiation-api-openapi.yaml, openapi/uk-open-banking-confirmation-of-funds-api-openapi.yaml
note: >-
  Cross-cutting request/response semantics of the shared OBIE UK Open Banking
  Read/Write standard captured in this repo. UNVERIFIED for GB Bank - these are the
  conventions an FCA-authorised ASPSP conforming to OBIE FAPI would implement, not
  observed GB Bank behaviour.
authentication:
  style: FAPI-grade OAuth2 / OpenID Connect with mutual-TLS client authentication
  flows: [authorizationCode, clientCredentials]
  sca: PSD2 Strong Customer Authentication (PSU consent + re-authentication)
  message_signing: detached JWS via x-jws-signature header
  ref: authentication/gb-bank-authentication.yml
idempotency:
  supported: true
  header: x-idempotency-key
  scope: payment-initiation write operations (POST domestic/international/file payments and consents)
  max_length: 40
  retention: ASPSP-defined; replay of the same key with an identical body returns the original result
  conflict_status: 409
  evidence: 18 x-idempotency-key parameter references in the payment-initiation standard spec
pagination:
  style: link-based
  response_fields: [Links, Meta]
  links: [Self, First, Prev, Next, Last]
  meta: [TotalPages, FirstAvailableDateTime, LastAvailableDateTime]
request_tracing:
  header: x-fapi-interaction-id
  description: TPP-supplied correlation id echoed by the ASPSP; also surfaced as the error envelope Id.
  related_headers: [x-fapi-auth-date, x-fapi-customer-ip-address, x-customer-user-agent]
versioning:
  scheme: uri-path
  read_write_version: v4.0.1
  open_data_version: v1.3
  pattern: /open-banking/v{major}.{minor}/{resource}
error_envelope:
  schema: OBErrorResponse1
  fields: [Id, Code, Message, Errors]
  ref: errors/gb-bank-problem-types.yml
media_types:
  request: application/json
  open_data: application/prs.openbanking.opendata.v1.3+json
rate_limiting:
  signaled_via: HTTP 429 responses (ASPSP-defined limits; no standard header set mandated in-spec)
  ref: errors/gb-bank-problem-types.yml