Question 1

What can Polytomic write into Klaviyo?

Accepted Answer

Profiles, and profile membership in an existing list. Profile writes are a create or update upsert, and you can match on Klaviyo profile ID, email address, phone number, or your own external ID, which makes it easy to key off whatever identifier your data warehouse already uses. Lists themselves, segments, events, metrics, campaigns, flows, and templates are read only. There is no profile delete mode, and catalogs are not supported at all, so product feed syncing is out of scope for this connector.

Question 2

Can a Klaviyo list stay exactly in sync with a data warehouse segment?

Accepted Answer

Yes, using mirror mode. A standard create or update sync only ever adds profiles to the list, which means people who stop qualifying stay in it. Mirror mode also removes profiles that are no longer present in the source, so the list ends up an exact reflection of your query. This is the reverse ETL pattern most teams want for things like active trial users or win back audiences, where membership needs to shrink as well as grow without anyone maintaining it manually.

Question 3

Can Polytomic manage subscription and consent status in Klaviyo?

Accepted Answer

No, and this is an important boundary. Consent and subscription data for email, SMS, push, and WhatsApp is readable on profiles, so you can bring it into your data warehouse for reporting and suppression logic. But those fields are not writable, so Polytomic cannot subscribe or unsubscribe anyone. List membership management and consent management are different things in Klaviyo, and this connector does the former. Consent changes should continue to flow through Klaviyo's own subscribe and unsubscribe mechanisms.

Question 4

How do incremental reads work for Klaviyo?

Accepted Answer

Most objects filter on their updated timestamp, so each ETL run pulls only what changed. Profiles, lists, segments, flows, and templates use their updated field, events use their datetime, and list and segment memberships use the joined timestamp. Campaigns are tracked with a separate cursor per channel, and segment profiles with a cursor per segment. Accounts, metrics, and campaign messages are full reads each time. One thing to plan for: membership incrementals detect joins and updates but not removals, so if you need to observe someone leaving a segment you will want a periodic full reconciliation.

Question 5

Will syncing hit Klaviyo's rate limits?

Accepted Answer

Polytomic throttles itself per object based on what each Klaviyo endpoint tolerates, running events considerably faster than the general read endpoints and pacing profile writes in between. On top of that, rate limited responses are retried with exponential backoff. Because profile writes go through the standard endpoint rather than a bulk one, large audience syncs are paced rather than instant, which is a deliberate trade to avoid exhausting the API allowance that your Klaviyo flows also depend on.

Klaviyo

Perfect pairings

Read and write Klaviyo

Mirror mode for lists

Flexible identity matching

Example workflows

What you can sync

From Klaviyo

To Klaviyo

How it works

How to set up

Frequently asked questions

Why teams choose Polytomic

No engineering required

Flexible data modeling

Handles scale automatically

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