ADTK has an API that allows you to easily combine a large number of anomaly detection models ("detectors"), data transformers, and ensembling steps ("aggregators") into serial or parallel data flows ("pipelines" and "pipenets"). It can also be easily extended.
We've just recently released ADTK under an open source license (MPL). We'd love to have people try it out, make contributions, and ask any questions.
ADTK is pip installable and the documentation and examples are linked in the readme on Github.
Most of the credit goes to Tailai Wen, who led this effort.