generated: '2026-07-19'
method: searched
source: https://docs.extend.com/docs/getting-started-with-extends-api
docs:
- https://docs.extend.com/docs/getting-started-with-extends-api
- https://docs.extend.com/reference/authentication
- https://docs.extend.com/docs/integrating-with-extends-order-api
authentication:
  style: oauth2-client-credentials
  token_header: X-Extend-Access-Token
  detail: authentication/extend-authentication.yml
idempotency:
  supported: true
  header: X-Idempotency-Key
  scope: per logical create/update operation (e.g. creating orders)
  value: unique key per operation (UUID example published)
  behavior: >-
    Prevents duplicate processing when a request is retried. Required by Extend on idempotent
    create/update calls such as order creation.
  source: https://docs.extend.com/docs/getting-started-with-extends-api
pagination:
  style: page-based
  default_page_size: 25
  detail: >-
    List/search endpoints (e.g. Get Lead Offers, Search Line Items) return paginated results with
    a default page size of 25.
versioning:
  style: header-based-date
  header: Accept
  format: application/json;version=YYYY-MM-DD
  current: '2022-02-01'
  legacy: ['2021-04-01']
  note: >-
    The API version is negotiated via the Accept header. Some legacy endpoints (e.g. Products)
    still require version 2021-04-01; the required version is shown per endpoint in the API
    Reference.
  detail: lifecycle/extend-lifecycle.yml
required_headers:
- name: Accept
  example: application/json;version=2022-02-01
- name: Content-Type
  example: application/json
- name: X-Extend-Access-Token
  example: YOUR_ACCESS_TOKEN
- name: X-Idempotency-Key
  example: 550e8400-e29b-41d4-a716-446655440000
  applies_to: idempotent create/update calls
transport:
  https_required: true
error_semantics:
  detail: >-
    Endpoints use standard HTTP status codes (e.g. 200 with empty arrays for no-content cases,
    403 Forbidden for cross-merchant access). See errors/ if/when an error reference is captured.
webhooks:
  supported: true
  detail: asyncapi/extend-webhooks.yml