Fastbin is a drop in replacement of pycasbin the python implementation of the great authorization management casbin.

Fastbin is designed to address the primary concern when working with large sets of rules; Performance.

The root cause of working with large rule sets is the following: casbin/core_enforcer.py#L238

Iterating over 10,000 rules to get a yes or no answer takes time, there really isn't a way around the fact. This limitation comes from the generalization that casbin attempts to support. Independent on the format of your request, or policy definition casbin if able to support your authorization mechanism.

Fastbin makes a minimal set of assumptions to allow efficient filtering of the model so that the number of rules you are iterating over to get a result is much smaller and performance can be maintained. Using Fastbin when working with rule sets of any size, it is possible to keep resolution of enforcement sub millisecond.