What Klaviyo changed, 1 May 2026 to 31 October 2026
308 operations became 436. None were removed, 0 were newly deprecated, 128 were added, and 0 request fields became required.
Read from klaviyo/openapi at 3e40fc3 and 3e76f54 (version 2026-10-15). Generated 31 October 2026 by the specification parser the APIBreak Action uses, applied to Klaviyo's published specification.
Klaviyo publishes its API description in klaviyo/openapi, with stable and beta files. This page reads openapi/stable.json. Every operation in that file takes a revision header naming a dated API revision; this page compares the stable file over time rather than one revision against another. Version policy and shutdown dates are not in the specification, so this page does not state them; it reads the deprecated flag on each operation.
Removed from the specification
Nothing was removed in this window. That is a real result, not a gap in the check.
Newly deprecated in this window
A deprecation is the notice period. It is the cheapest moment to act and the easiest one to miss. This list compares operations present at the baseline.
No compared operation (one paired with a baseline operation) gained the deprecated flag in this window.
Deprecated as of the current specification (0)
Everything the vendor currently marks deprecated, whether or not it changed recently. The vendor has flagged each of these for possible removal, with or without a date attached.
No operation is currently marked deprecated.
Request fields removed from the specification
The current specification no longer lists these request fields, which the baseline did. A caller that still sends one is sending a parameter the new version does not define; whether Klaviyo rejects or ignores it at runtime is not something a specification diff can show, and what it means for an integration depends on how Klaviyo versions — see the note at the top of this page.
- PATCH /api/campaign-messages/{id} no longer lists data.relationships (application/vnd.api+json)
- PATCH /api/campaigns/{id} no longer lists data.attributes.audiences (application/vnd.api+json)
- PATCH /api/campaigns/{id} no longer lists data.attributes.name (application/vnd.api+json)
- PATCH /api/campaigns/{id} no longer lists data.attributes.send_options (application/vnd.api+json)
- PATCH /api/campaigns/{id} no longer lists data.attributes.send_strategy (application/vnd.api+json)
- PATCH /api/campaigns/{id} no longer lists data.attributes.tracking_options (application/vnd.api+json)
- POST /api/campaign-clone no longer lists data.attributes.new_name (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.audiences.excluded (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.audiences.included (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.campaign-messages (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.name (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.send_options (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.send_strategy (application/vnd.api+json)
- POST /api/campaigns no longer lists data.attributes.tracking_options (application/vnd.api+json)
- POST /api/events no longer lists data.attributes.profile.data.attributes.meta (application/vnd.api+json)
- POST /api/push-tokens no longer lists data.attributes.profile.data.attributes.meta (application/vnd.api+json)
- POST /client/events no longer lists data.attributes.profile.data.attributes.meta (application/vnd.api+json)
- POST /client/push-tokens no longer lists data.attributes.profile.data.attributes.meta (application/vnd.api+json)
- POST /client/subscriptions no longer lists data.attributes.profile.data.attributes.meta (application/vnd.api+json)
Klaviyo API questions
Every answer below is computed from the snapshot above, and each links to the Klaviyo specification it was read from.
- Which Klaviyo API endpoints were removed recently?
- None between 1 May 2026 and 31 October 2026, in openapi/stable.json in klaviyo/openapi. It went from 308 to 436 operations in that window, and every operation present at the start was still there at the end, at the same URL.
- Source: klaviyo/openapi, the two commits compared
- Which Klaviyo API endpoints are deprecated?
- No operation in openapi/stable.json in klaviyo/openapi, as of 31 October 2026, carries the deprecated flag. A specification can only show a deprecation the vendor marks in it, so Klaviyo's own changelog may still announce one.
- Source: klaviyo/openapi, the two commits compared
- Did any Klaviyo API request fields become required?
- None between 1 May 2026 and 31 October 2026, among the JSON request bodies in openapi/stable.json in klaviyo/openapi the comparison could read. A field inside a union (anyOf or oneOf) is not compared, so it is not counted either way.
- Source: klaviyo/openapi, the two commits compared
- Where is the Klaviyo OpenAPI specification?
- In the klaviyo/openapi repository on GitHub. This page reads openapi/stable.json at commit 3e76f54 (version 2026-10-15), dated 31 October 2026.
- Source: klaviyo/openapi on GitHub
The Action does not check Klaviyo yet
It checks GitHub REST and Stripe. If you want your CI to check the Klaviyo endpoints you call, say so in an issue, because requests like that decide which vendor the Action should support next.