Chroma's open-source under an Apache 2.0 License: https://github.com/chroma-core/chroma

Single-node Chroma is very easy to self-host for free: https://docs.trychroma.com/guides/deploy/docker

Typical FOSS model to offer a super useful core then charge for ancillary services and consulting to pay for development of the core.

It's a great model for people who want to have grasp beyond the typical software reach.

“Free as in freedom, not as in beer.”

https://en.m.wikipedia.org/wiki/Gratis_versus_libre