generated: '2026-08-13'
method: searched
source: https://loops.so/docs/api-reference/changelog
docs:
  api: https://loops.so/docs/api-reference/changelog
  product: https://loops.so/changelog
scheme: dated-entries
versioning: >-
  The changelog is dated, not versioned. The OpenAPI document carries its own
  semantic version in info.version (1.21.6 as of 2026-08-13) and the changelog
  header describes itself as covering "new endpoints, fields, breaking changes,
  and deprecations across OpenAPI versions", but individual entries are not
  stamped with the OpenAPI version they landed in, so a consumer cannot map a
  dated entry to a spec version without diffing.
current_spec_version: 1.21.6
window: 2026-02-13 to 2026-07-23 (recent entries; the published log runs back to 2023-10-12)
entries:
  - date: '2026-07-23'
    breaking: false
    additions:
      - Create audience segment endpoint.
      - Endpoints for creating and editing workflows and workflow nodes.
      - Endpoints for reading event patterns.
    changes:
      - Removed `queuedContactLimitReached` from workflow node delete and mailing list change responses.
  - date: '2026-07-16'
    breaking: false
    changes:
      - '`rootNodeId` is now always a non-null string in workflow responses.'
  - date: '2026-07-08'
    breaking: false
    additions:
      - Endpoints for creating and updating themes and components.
  - date: '2026-07-02'
    breaking: false
    additions:
      - Guardian endpoint for validating email message content via the API.
  - date: '2026-07-01'
    breaking: false
    additions:
      - '`transactionalName` field in the transactional.email.sent webhook event.'
  - date: '2026-06-22'
    breaking: false
    additions:
      - Endpoints for viewing workflows and workflow nodes (open alpha).
  - date: '2026-06-19'
    breaking: false
    additions:
      - Endpoints for campaign groups, transactional groups, audience segments and email message previews.
    changes:
      - Campaign endpoints support audience targeting (mailing list, segment or filter), groups and scheduling.
      - Email message endpoints support CC/BCC, language, email format and property fallbacks.
      - Transactional email endpoints support groups.
  - date: '2026-06-05'
    breaking: false
    additions:
      - Endpoints for creating and editing transactional emails (open alpha).
  - date: '2026-05-20'
    breaking: false
    additions:
      - Upload endpoints for uploading images to use in emails.
  - date: '2026-04-24'
    breaking: false
    additions:
      - Endpoints for creating and editing campaigns (open alpha).
  - date: '2026-03-25'
    breaking: false
    additions:
      - Endpoints to check and remove suppression for contacts.
  - date: '2026-02-13'
    breaking: false
    additions:
      - '`campaignName` field in the campaign.email.sent webhook event.'
notable_older:
  - date: '2025-09-29'
    highlight: Webhooks became generally available to all users.
  - date: '2025-09-11'
    breaking: false
    deprecation: true
    highlight: >-
      All endpoints now return `success` and `message` in error response bodies.
      The top-level `error` and `path` keys were deprecated the same day, "but
      will continue to be supported for some time for backward compatibility" —
      no removal date was given. Both fields are still marked
      `deprecated: true` in OpenAPI 1.21.6, roughly eleven months later.
  - date: '2025-04-29'
    highlight: '`Idempotency-Key` header added to the Send event endpoint.'
  - date: '2025-03-28'
    highlight: '`Idempotency-Key` header added to the Send transactional email endpoint.'
  - date: '2025-01-14'
    deprecation: true
    highlight: >-
      List custom fields endpoint deprecated in favour of List contact
      properties. The deprecated endpoint is no longer present in OpenAPI
      1.21.6, so it has since been removed.
observations:
  - >-
    Cadence is high and the log is genuinely maintained — twelve dated entries
    in the six months to 2026-07-23, and the OpenAPI moved from 1.8.0 to 1.21.6
    over the same period.
  - >-
    Deprecations are announced with a rationale but never with a sunset date,
    and Loops publishes no Deprecation/Sunset response headers (RFC 8594). A
    client cannot detect a deprecation at runtime; it has to read this page.
  - >-
    Several endpoint families shipped as "open alpha" (campaigns 2026-04-24,
    transactional emails 2026-06-05, workflows 2026-06-22) with no published
    stability policy for what alpha means or when it ends.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com