Mongo Streams has support for all aggregation framework operations that are supported by mongodb.
Please take look into following examples to see more:

These are simple operations to return count of elements or distinct values. For more please look

.

Mongo Streams allows you to create mongo's mapreduce javascript aggregation operations. For syntax and examples look

.

Mongo Streams has limitted support for aggregation pipeline commands. All the aggregation pipeline commands are now
supported, but only basic expressions are supported now for $project operation. For list and exmaples of supported
functionality, please look

.