1. Home
  2. Docs
  3. Simple API
  4. Simple API Reference
  5. Setting Tags and Custom Fields

Setting Tags and Custom Fields

You can set tags and custom fields as part of the subscription process. However, it can also be useful to apply tags, or add information about a visitor, at other times.

This API entry point lets you add or update a custom field in the account for any given subscriber. Note that custom field names are global to the account, not to any one list or subscriber, and a global field’s value is global to a subscriber within any account.

If the field doesn’t exist in the account, it is created. If the field value already exists, it is updated with the value you pass in. If the email address specified isn’t in a list managed by the account, nothing happens.

For example, if you create a field name “foo” then the field“foo” will be available to be set for all of the subscribers in the account. If you set the value of “foo” to be “bar” for “phil@example.com” then “bar” will be the value of “foo” associated with that address throughout that account.

You can use this API to tag a subscriber as they interact with your product or service, independently of their subscription activities.



You can add fields by adding one or more additional parameters, either in the URL (if you GET it), or as form parameters if you POST it.  Similarly, you can add tags via a comma separated list; tags are treated as custom fields with a value of 1.


Here are some examples, assuming the API key for the FeedBlitz account is “Abc123”, to help show how to use this API:


Adds / updates the tag “Widgets” to phil@example.com


Adds / updates three tags to phil@example.com: Widgets, Boxes and Stuff.


Assigns the value “Phil Hollows” to the custom field called “Name”


Adds a tag to phil@example.com, and also creates / updates FirstName and LastName