generated: '2026-07-23'
method: searched
source: https://openbankinguk.github.io/read-write-api-site3/v3.1.11/profiles/read-write-data-api-profile.html
docs: https://developer.lloydsbanking.com/prod01/lbg/read-write
note: >-
  Cross-cutting request/response semantics. The Read/Write conventions are the
  OBIE UK Open Banking Read/Write standard as implemented by Halifax (a Lloyds
  Banking Group brand / CMA9 ASPSP). Open Data conventions are derived from the
  captured swagger.
authentication:
  style: fapi
  detail: OAuth2/OIDC over mutual-TLS with detached JWS request signing (Read/Write); none (Open Data).
  see: authentication/halifax-authentication.yml
idempotency:
  supported: true
  scope: Read/Write payment and consent POST operations (PIS)
  header: x-idempotency-key
  max_length: 40
  retention: >-
    ASPSP replays the original response for a repeated x-idempotency-key with an
    identical request body within the OBIE idempotency window (typically 24h).
  not_idempotent:
    - account-access-consent creation (per OBIE profile)
  detail: >-
    A unique x-idempotency-key must be sent on payment-order and consent
    submission requests so a retried request does not create a duplicate
    payment. Not applicable to the unauthenticated Open Data GETs.
pagination:
  style: cursor-hypermedia
  response_fields:
    links: [Links.Self, Links.First, Links.Prev, Links.Next, Links.Last]
    meta: [Meta.TotalPages, Meta.FirstAvailableDateTime, Meta.LastAvailableDateTime]
  request_params: [page]
  detail: >-
    Read/Write collection responses carry a Links block (hypermedia next/prev)
    and a Meta block with TotalPages. Open Data responses are returned as a
    single document keyed by a data payload plus meta.
request_tracing:
  header: x-fapi-interaction-id
  detail: >-
    RFC-style correlation id echoed on every Read/Write request and response
    for end-to-end tracing between TPP and ASPSP.
  related_headers: [x-fapi-auth-date, x-fapi-customer-ip-address, x-fapi-customer-last-logged-time]
versioning:
  style: uri-path
  detail: >-
    Version carried in the URL path (Open Data /open-banking/v2.2/...,
    Read/Write /open-banking/v3.1/...). See lifecycle/halifax-lifecycle.yml.
  see: lifecycle/halifax-lifecycle.yml
error_envelope:
  format: obie
  shape:
    Code: HTTP status code string
    Id: Unique reference for the error occurrence (correlates to x-fapi-interaction-id)
    Message: High-level error message
    Errors:
      - ErrorCode: UK.OBIE.* namespaced error code
        Message: Detailed message
        Path: JSON path to the offending field
        Url: URL to further information
  see: errors/halifax-problem-types.yml
content_negotiation:
  open_data_media_type: application/prs.openbanking.opendata.v1.3+json
  read_write_media_type: application/json
conditional_requests:
  headers: [If-Modified-Since, If-None-Match]
  response_headers: [ETag, Last-Modified]
  detail: Open Data GETs support conditional requests to avoid re-transferring unchanged reference data.
rate_limit_signaling:
  detail: >-
    Open Data responses can return 429 Too Many Requests; Read/Write applies
    per-TPP throttling governed by the OB Directory. No published quantitative
    headers captured.