The Lil Regie API can be found in Advanced > API. When you get there, you'll find an API key generated for you:

It’s a simple API at this stage, but it will allow you to fetch some useful information about your event. We’re using REST as the transport and JSON as the data format.
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There are currently 2 operations available – pulling down data for “bookings” and “attendees”.

Note that each request will have an associated URL next to it.

With this url, you can use your booking or attendee data in the software of your choice, after translating it from JSON.

Our API is still in its early stages. We’d love to hear how you’re using it, and your suggestions and needs for how we can make it better!