generated: '2026-08-13'
method: searched
source: https://developers.klaviyo.com/en/docs/changelog_
also: https://github.com/klaviyo/openapi/blob/main/CHANGELOG.md

scheme: dated-revision
format: ISO 8601 date (the revision release date), passed in the `revision` request header
current_version: '2026-07-15'
current_version_in_repo: '2026-04-15'
window: recent — the live changelog is the source of truth for full history

note: >-
  Two changelogs exist and they are NOT the same. The developer-portal changelog
  (developers.klaviyo.com/en/docs/changelog_) is current through 2026-07-15. The
  CHANGELOG.md in github.com/klaviyo/openapi has not been updated past 2023-02-22 and
  should not be read as current.

entries:
  - version: '2026-07-15'
    date: '2026-07-15'
    status: GA
    breaking: false
    type: addition
    highlight: Custom Objects metadata and record APIs are generally available — object types, schemas and relationships.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: GA
    breaking: false
    type: addition
    highlight: Events API gains a `backfill` flag to record historical events without triggering flows (migrations and replays).
  - version: '2026-07-15'
    date: '2026-07-15'
    status: GA
    breaking: true
    type: breaking-change
    highlight: >-
      Profile conversations moved from singular to plural across channels — responses
      now return a list with one conversation per channel (SMS, WhatsApp, Instagram).
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Customer Agent API — programmatic configuration and observation of Klaviyo's AI agent (skills, tools, knowledge).
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Brand APIs — create/read/update/delete brand logos, colors, buttons and social groups.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Sending Domains API — automate domain registration and DKIM setup, with separate verification and activation steps.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Template Preview Send API — send test emails via a Create Template Preview Send Job endpoint, capped at 100 requests/day.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Billing Usage API — current-period metered usage against plan caps, account-level.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Bulk Export APIs — large-scale export of events by metric and profiles by audience, job-based with polling and download.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Applications API — list published applications in Klaviyo's integrations marketplace, with filtering and cursor pagination.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: Text Messaging API — provision SMS senders and manage carrier registration.
  - version: '2026-07-15'
    date: '2026-07-15'
    status: Beta
    breaking: false
    type: addition
    highlight: API Keys API — get, list and update private keys programmatically (XS rate-limit tier).

x-evidence:
  - {fetched: '2026-08-13', url: 'https://developers.klaviyo.com/en/docs/changelog_', http_status: 200}
  - {fetched: '2026-08-13', url: 'https://raw.githubusercontent.com/klaviyo/openapi/main/CHANGELOG.md', http_status: 200, note: stale — last entry 2023-02-22}