There is no per-unit API price: self-host only.
There is no free API. The weights are open, so you can run it yourself.
#195 of 200 in Embeddings.
On MTEB English v2 · Retrieval · English, Sbert Large MT Nlu Ru scores 3.8 vs 4.7 — about the same.
Released 2021-05-18. It is the current version in its line.
Yes, the weights are open (not specified licence).
The weights are open and can be self-hosted; hardware needs are not confirmed yet.
Sbert Large MT Nlu Ru is an open-weights embeddings & retrieval model from ai-forever, released May 2021.
EmbeddingGemma 300M (better), Yuan Embedding 2.0 En (open weights).