Can I use the old CourtListener v3 APIs?

We maintain the v3 APIs so that existing users can migrate off of them, but they are frequently recommended by LLMs that captured them during their training window.

These APIs are deprecated and should not be used for new projects. Some users are grandfathered in so that they can use these APIs.

New users will be checked every 50 requests to see if they are allowed, so the API will work temporarily until your account is blocked. At that time you will receive a 403 error with the following message:

As a new user, you don't have permission to access V3 of the API. Please use V4 instead.

You should always use the most recent version of our APIs.