generated: '2026-07-17'
method: searched
source: https://developers.portone.io/api/backward-compatibility
notes: >-
  PortOne runs two concurrent API generations: V2 (api.portone.io, current) and
  V1 (api.iamport.kr, legacy Iamport, maintenance-only). Versioning is by host /
  URI generation, not per-request version headers. PortOne publishes an explicit
  backward-compatibility contract for both V1 and V2.
versioning:
  scheme: generation-host
  current: v2
  generations:
    - {version: v2, host: https://api.portone.io, status: current}
    - {version: v1, host: https://api.iamport.kr, status: legacy, note: Iamport; maintenance-only, new integrations directed to V2}
  docs: https://developers.portone.io/api/backward-compatibility
backward_compatibility:
  policy_url: https://developers.portone.io/api/backward-compatibility
  guarantees:
    - Required response fields are never removed or made optional within an existing use case.
    - Field types are only changed within the compatibility rules above.
  additive_allowed:
    - New fields, new enum values, and new oneOf cases may be added at any time.
    - Clients must tolerate unknown fields/values without crashing (forward-compatible parsing).
  v1_note: V1 additions are pre-announced via notice before rollout.
deprecation:
  policy_url: https://developers.portone.io/api/backward-compatibility
  unstable_apis: >-
    Operations marked UNSTABLE are exempt from the backward-compatibility policy
    and may change or be discontinued.
  advance_notice: true
  advance_notice_channel: email / developer notice
  examples:
    - 'V1 imp_success / success response fields are deprecated (use status/imp_uid semantics).'
    - "V2 'pg' request field is deprecated in favor of channelKey / pgProvider."
status_page:
  url: https://iamport.github.io/service-status/
  provider: Upptime (github.com/iamport/service-status)
  note: >-
    Open-source Upptime uptime monitor / status page maintained under the legacy
    Iamport org. No separate branded PortOne V2 statuspage.io was located.
webhook_ip:
  v2: 52.78.5.241
  note: PortOne emails customers in advance before adding/changing the webhook source IP.
sla:
  url: null
  note: No public numeric uptime SLA target was found on the developer center at review time.
deprecated_operations: []