Unsubscribe from Constant Contact

Audience: Low-code Engineers

Skill Prerequisites: Actions, Forms, Constant Contact account

Removes the email address from a form field from one Constant Contact list. The contact and its other lists are kept.

note

This action is part of the Constant Contact add-on (ActionForm.ConstantContact). The add-on is installed separately and is licensed with the CONSTANTC feature, but the action doesn't check the license when it runs. If you don't see the action in the Email group, the add-on isn't installed. See Constant Contact.

caution

In 1.28, this action always fails with The email address is invalid. It reads the address from the email field, then looks up a field named after that address, which doesn't exist. Until this is fixed, remove contacts from lists in Constant Contact, or call the Constant Contact API with Server Request.

caution

The action uses Constant Contact's old V2 API (api.constantcontact.com/v2). Constant Contact no longer issues V2 API keys and recommends the V3 API, which this action doesn't support. It stops working when Constant Contact turns off the V2 API.

Typical Use Cases

• Let visitors leave one newsletter list from an unsubscribe form

Don't use it to

• Unsubscribe someone from all your email. The action only removes one list from the contact. Constant Contact's own unsubscribe link in your emails does that.
• Delete a contact. The contact stays in Constant Contact.
• Unsubscribe someone from a workflow, an API endpoint or a scheduled job. The action reads the address from a form field.

Related Actions

Action Name	Description
Subscribe To Constant Contact	Adds an email address to a Constant Contact list.
Server Request	Calls the Constant Contact V3 API, which this action doesn't support.

Input Parameter Reference

Parameter	Description	Supports Tokens	Default	Required
API Key	The V2 API key of your Constant Contact developer account. Type the key itself. A token isn't replaced.	No	empty string	Yes
Token	The V2 access token for your Constant Contact account. It's sent as a bearer token. Type the token itself. A token isn't replaced.	No	empty string	Yes
List Name	The name of the list to remove the contact from, exactly as it appears in Constant Contact, including capitals.	No	empty string	Yes
Email Field	The email field on the form with the address to remove.	No	none selected	Yes

Output Parameters Reference

The action has no output parameters.

What it does

1. Finds the ID of the list with the name in List Name.
2. Finds the contact with the email address and the lists it's on.
3. Saves the contact again with all its lists except this one. The change is marked as done by the account owner (ACTION_BY_OWNER).

If the list was the contact's only list, the contact is left on no lists.

What happens when it fails

The action stops execution and the form shows one of these errors:

Message	When
This service is not configured properly	API Key, Token or List Name is empty.
The email address is invalid	The email field is empty. In 1.28 you also get it when the field has an address. See the caution above.
This list does not exist	No list has the name in List Name.
This email address is not subscribed to this list	The address isn't a contact, or isn't on the list.
Something went wrong during the registration	Constant Contact's answer to the contact lookup can't be read.
Error loading stream from ...	Constant Contact returned an error, for example for a wrong key or token, or the V2 API no longer answers. The message includes the request URL.

Considerations

• Error text shows the API key. The Error loading stream message includes the request URL, and the API key is part of the URL. If the form shows this error to a visitor, they can read the key. Because of the 1.28 email field problem, the action doesn't get this far today.
• Keys in plain text. The API key and token aren't tokenized, so you type them into the action and they're saved with the form. Anyone who can edit the form can read them.
• API key in the URL. The API key is sent in the query string of every request, so it can show up in proxy and web server logs.
• Anyone can unsubscribe any address. The action removes whatever address is in the field. A visitor can type someone else's address. If that matters, send a confirmation link by email first and run the action only from that link.

Examples

tip

To understand how to use the below examples, please see Running Examples.

1. Remove a visitor from the newsletter list

Add this action to the button of an unsubscribe form with an Email field. It removes the address in Email from the Newsletter list. Replace the API key and token with your own. In 1.28 it fails as described in the caution above.

{
    "Title": "Unsubscribe from Constant Contact",
    "ActionType": "UnsubscribeFromConstantContact",
    "Description": "Remove the visitor from the newsletter list",
    "Parameters": {
        "ApiKey": "your-v2-api-key",
        "Token": "your-v2-access-token",
        "ListName": "Newsletter",
        "EmailField": "Email"
    }
}

Revised 10/03/2026