Connect Reverse ETL Source to Customer.io Audience

Configure a Reverse ETL source with your Customer.io Audience destination.

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This guide takes you through the steps to connect a Reverse ETL source to the Customer.io Audience destination. You can create a new segment or use an existing segment to sync the data.

The below steps assume that you have already set up a Reverse ETL source and configured the connection settings for the connected Customer.io Audience destination.

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You can connect multiple Reverse ETL sources to the Customer.io Audience destination.

Customer.io segment settings

SettingDescription
Choose whether to create a new Customer.io SegmentSpecify whether you want to sync data to a new or existing Customer.io segment.

  • If you select Create a new Customer.io Manual Segment, then specify the name and description (optional) for the new segment.
  • Select Use an existing Customer.io Manual Segment if you have an existing Customer.io segment. Then, choose the list automatically prepopulated by RudderStack based on your specified connection settings.
Sync modeChoose the sync mode to specify how RudderStack syncs the data to the segment.

Note: RudderStack supports only Mirror mode for this destination.

Mapping settings

warning

Make sure that the users exist in Customer.io before adding them to any segment. Otherwise, such records will be ignored.

See the Customer.io Troubleshooting guide for more information.

Use this section to map the identifier warehouse column (that RudderStack uses to identify your records) to specific Customer.io segment fields. Note that you can map this warehouse column to either of these Customer.io segment fields: ID, Email, or CIO_ID.

Schedule settings

RudderStack determines how and when to run a sync based on the sync schedule you set for your Reverse ETL connection.

Schedule typeDescription
BasicRun syncs at a given time interval and specified time (in UTC).
CRONRun syncs based on a specified CRON expression (in UTC).
ManualRun syncs manually.

Sync observability settings

SettingDescription
Retain sync logsThis setting is toggled on by default and instructs RudderStack to store the sync logs in your warehouse. You can also configure the below settings:

SettingDescription
Sync log retentionSpecify the retention period of the sync logs in your warehouse.

If you set it to 1, then RudderStack deletes any sync log older than a day (in UTC time).
Snapshot table retentionSpecify the number of snapshot tables to retain.
Retry failed recordsThis setting is toggled on by default and causes RudderStack to continually retry sending the failed records.
warning
Storing sync logs and snapshot tables may incur additional warehouse costs.

record event structure

The Customer.io Audience destination supports only record events.

A sample record event that RudderStack sends to Customer.io segments is shown:

{
  "action": "insert",
  "channel": "sources",
  "context": {
    "sources": {
      "job_id": "<2s4ZjYKSKztME0SmfBUB5t8KA3j>",
      "job_run_id": "cu9na4c7miqjfjeogkv0",
      "task_run_id": "cu9na4s7miqjfjeogkvg",
      "version": "local"
    }
  },
  "fields": {},
  "identifiers": {
    "id": “30”
  },
  "messageId": "57f32b79-f030-4bdc-8f24-4f573f4acf99",
  "receivedAt": "2025-01-24T11:10:58.799Z",
  "recordId": "4",
  "request_ip": "[::1]",
  "rudderId": "0afd110a-4d8a-42c5-a959-05d3ef3b4e87",
  "type": "record",
  "userId": "36b9732a-cd10-4aec-b03e-36969a9b14a2"
}

FAQ

Why can’t I add a Reverse ETL source from the destination page?

The Reverse ETL feature supports only source-driven pipeline configuration. It means that you must configure a Reverse ETL source in RudderStack and then connect it to a new or existing destination. Note that this destination should not be connected to any other source.

See Reverse ETL FAQ for more information.

Questions? Contact us by email or on Slack