activeBackend property
What the embedder actually runs on, which is CPU whatever was asked — ON
NATIVE. The web shell builds this object too, and there it still holds
cpu while EmbeddingModel.activeBackend is null and the runtime may be
on WebGPU. That is harmless because this field is a cache KEY: it is a
constant, so it can never trigger a rebuild. Read the model's own
activeBackend for the answer; do not read this one.
Named for the answer, not the request — deliberately unlike the
preferredBackend on ActiveModelParams and RuntimeConfig, which do
hold the raw request. The shells build this object and a RuntimeConfig
from the same local a few lines apart, so two fields with one name and
opposite meanings is a trap; this one matches
EmbeddingModel.activeBackend, which is where the value surfaces.
Implementation
final PreferredBackend activeBackend;