We’ve added “field” and “field_message” to the Batch Subscribe error response. You’ll see data in these fields when a merge field error is encountered.

Previously, when you encountered a merge field error during a Batch Subscribe operation, you didn’t see any details about the field in the error. This can cause headaches when you’re troubleshooting a remedy.

These additional fields, when present, should provide more insight into how to resolve an issue.

We've added various endpoints to pull reports for a survey. You can start by viewing all surveys or export high-level results from the Survey Questions. You can also pull individual Survey Responses to get more detail.

Many of you have asked for a way to pull survey results via the Mailchimp Marketing API, and now there are various endpoints to help you do this.

When Transactional Demo users go over their inbound quota, we now return a 500 status code along with the message “Your inbound message quota has been exceeded. Please try again later.”

Previously, we were returning a 200 message and not processing the webhook. Now that an error is returned, the API response is more clear.

We’ve added a delivered webhook event that will trigger when we receive a successful SMTP response from the receiving server. 

You receive a send event when the message reaches our system, a deferral event if the message is deferred by the receiving server, and a bounce event if it eventually bounces. Now, we’ve added delivered as confirmation that the receiving server has responded successfully.

When syncing members in bulk via the Lists endpoint, tags are now properly added to existing members. If you would like to completely replace the tags of a member with the tags being passed in the request, we have added a new boolean param sync_tags, which will cause the call to replace any tags on the existing member. This will only work when making the call with updated_existing set to true.

Previously, when updating members in bulk via the Lists or Members endpoints, tags would not be added to an existing member. There was also no way to overwrite the tags completely.

We now allow a user to submit up to 500 pending API batches. For each completed batch, we send those results to each batch webhook that has been created. A user will not be able to create more API batches if there are 500 outstanding batch webhooks that have yet to complete. A 429 status code will be returned in this instance.

Previously, we did not have a limit on how many batch webhooks could be instantiated for a given user. This unbounded nature can have an impact on the performance of the API, which this new limit will help mitigate.

In the past, our implementation of Handlebars did not support camelCase, so all variables had to be written using all lowercase letters or using snake_case. Using camelCase for variable names is now supported.

A large portion of developers using the Handlebars templating engine are used to the JavaScript convention of writing variables in camelCase.