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Migration FAQ: v1/v2 API retirement

Find answers to common migration questions for the legacy API retirement.


v1/v2 legacy APIs are scheduled to retire on June 30, 2024.

Users of Klaviyo's v1/v2 APIs have until June 30, 2024 to migrate to our new APIs. At this time, our v1/v2 APIs will officially be retired. To learn more about Klaviyo’s API lifecycle, check out our updated API versioning and deprecation policy.

Klaviyo users

If I’m not sure what integration I'm using, how do I determine the source of any v1/v2 API calls?

Export your API audit report and follow this guide to audit your API usage.

When I run the API usage report, how do I know which rows are related to v1/v2 APIs?

In the report, the boolean field Is v1/v2 Legacy Endpoint will tell you if the call is from a legacy endpoint.

In the API usage report, why do I see rows with API private keys but no key label?

Either the private key has been deleted or it was not named.

In the API usage report, why do I see some rows without an API private key?

Client-side API calls do not require a private key. For v1/v2, those calls correspond to any /track and /identify calls in your report.

My Track API calls don’t have a private API key, how do I determine the source?

Track API calls create events in your account. Go to the Metrics tab and input the API integration filter. Carefully review these metrics to determine what source created them. Note that in your report, if you see any rows for a POST method to /api/events or /client/events, at least some events have already been converted to the new APIs.

Do I need to update my API keys?

No, your API keys will work for v1/v2 and our new APIs.

I updated everything - why am I still seeing a banner that says I am not compliant?

The banner will show if there have been any v1/v2 calls in the last 14 days. After 14 days have elapsed, the banner will disappear.

Why don’t I see any v1/v2 calls on the API usage page?

The developer logs only show calls to our new APIs. Although the API usage page will display v1/v2 calls, the information is much more limited. We recommend using API audit report instead.

How do I know if I’m all set?

The banner on your developer tools page will no longer show up. Note that it monitors activity over the last 14 days, so if you resolved all instances of the legacy APIs yesterday, the banner will still show for another 13 days. This is because you might have some intermittent activity across 2 weeks.

How do I know what new API to use?

We suggest you use the API comparison chart to map v1/v2 endpoints to new equivalent functionality.

What technology partners did you contact?

We contacted all the partners listed on Klaviyo Connect. You may wish to reach out to them to ensure you don’t need to take any action, but it is not required.

Do I need to worry about the klaviyo object?

No, API calls via klaviyo object are being migrated under the hood and will continue to be supported in the future.

Do I need to worry about Shopify?

No updates to your Shopify integration are required. If you're using a self-hosted ecommerce integration, you'll need to upgrade to the proper version - see upgrade guidance for our self-hosted integrations here:

All other Klaviyo-built integrations do not require any updates on your end.

If you're using a third party integration (built by a Klaviyo technology partner), we recommend running the API usage report to determine impact. Per the FAQ above, we've also contacted all tech partners about the migration process.


What if I cannot meet the deprecation deadline?

API calls made to v1/v2 endpoints after June 30, 2024 fail automatically, and no data from the request is sent to Klaviyo. Any marketing automations reliant on v1/v2 API calls (segments, lists, flows, campaigns, reports, etc.) will no longer update.

What response can I expect if I call a v1/v2 API endpoint on July 1, 2024?

v1/v2 API calls made on July 1, 2024 will return a 410 GONE error code. The call’s response body contains a link to the correct new API equivalent. For more information on which new endpoints to use, check out the API comparison chart.

What will users of my integration experience if I am not able to complete the migration by the deadline?

Any remaining instances of v1/v2 APIs in your integration may cause parts or all of your integration to break.


If a 3rd party integration you're using fails to migrate to Klaviyo's new APIs prior to June 30, 2024, the integration is at risk and may no longer function properly. Any activities dependent on data coming from that integration will cease receiving new information. If your account is impacted by the deprecation, we recommend reaching out directly to the company who built the integration. This is the best course of action to get the integration up and running again. We are hard at work collaborating with our ecosystem to help them through the migration process, however, it is the responsibility of the integration owners to ensure compliance with the migration deadline.

Can you provide a list of accounts using my integration?

We are not able to provide this information.

How do I find what APIs are being called by my integration?

If you have a Klaviyo demo or staging account, you can go to the Developer tools dashboard, and click the Audit API Endpoints section to download an audit of all v1/v2 API usage. Check out this guide to read more about using the API audit tool. If you do not have a demo or staging Klaviyo account, you will need to search your integration’s codebase to identify calls.

Can you confirm that I have migrated all my API calls?

The best way to ensure you have fully migrated your API calls is to confirm your integration codebase does not include any calls to our v1/v2 APIs. If you are still unsure that your migration is complete, contact your partner manager.

How do I start the migration process?

We recommend reviewing the migration strategy documentation to begin the migration process.

Where can I see what new endpoints to use as I migrate?

To compare legacy APIs to their new API equivalents, please review the API comparison chart.

My integration only uses Track and Identify, how can I migrate?

The Track and Identify migration guide offers specific guidance for integrations using only these two legacy APIs.

Where can I go if I need additional help?