Segment.com: Customer.io as a Source
By setting up Customer.io as a Segment Source, you can pipe email data out of Customer.io and into any one of Segment’s hundreds of Destination integrations. Data will be sent to Segment as a track()
call.
How to Enable
In order to enable the Customer.io data source, you will need both a Customer.io and Segment.com account. If you are creating a new Segment account, please write “Customer.io” in the “How Did You Hear About Us?” field.
Getting Started
1. Select Customer.io from the Cloud Apps catalog from your workspace’s /sources page (The link should look like https://app.segment.com/WORKSPACENAME/sources/catalog
)
2. Give the source a nickname and a schema name. The nickname will be used to designate the source in the Segment interface, and the schema name is the namespace you’ll be querying against in your warehouse. Both can be whatever you like, but we recommend sticking to something that reflects the source itself, like Customer.io for the name and customer_io for the schema name.
3. On the Overview page, click to copy your write key.
4. Head over to the Integrations section of the Customer.io workspace you want to send email event data from, select the Data Management category on the right, then select Segment Source. Paste the write key in the resulting page.




5. In Segment, turn on the destinations you want to sync or connect your warehouse.
Confirm the Source is working
You can confirm that the Customer.io Source is working by sending a test campaign to yourself and checking the debugger. Customer.io supports these events:
- Email Delivered
- Email Opened
- Email Link Clicked
- Email Marked as Spam
- Email Bounced
- Unsubscribed




If these events are flowing into your Segment debugger, you’ll know that the Source is properly enabled.


Need help?
- If you run into any issues enabling the Customer.io Source, finding your write-key, setting up a Segment workspace, or find that your data isn’t syncing, please contact Segment’s support team at mailto:friends@segment.com.
- Not seeing Customer.io email events in the Segment debugger? Please get in touch with support!
Use Cases
For use case ideas, head to Segment and our announcement post