Concepts
Region mode
Three sovereignty profiles — default, eu-strict, oss-only — and exactly which hops they affect.
Region mode is a per-workspace setting that controls where your code and its derived embeddings travel. Three modes ship today:
| Mode | Storage | Indexer worker | Embeddings | Status |
|---|---|---|---|---|
default | EU Frankfurt | EU Frankfurt | Managed proxy (US-routed) | GA |
eu-strict | EU Frankfurt | EU Frankfurt | EU (operated by us) | Phase 3 GA |
oss-only | EU Frankfurt | EU Frankfurt | EU, open-source models only | Phase 3 GA |
default
The out-of-the-box configuration. Code clones happen on the EU worker,
storage stays in Frankfurt, and only the embedding payload
(symbol-scoped code chunks) leaves your machine — sent to our
managed embedding proxy (api.prom.codes) under your
PROMETHEUS_API_KEY. The proxy routes to a provider in the US; which
model sits behind it is not exposed to the client. No identifying
metadata is sent — just the raw chunk text.
eu-strict
Swaps the default for an EU-hosted embedding endpoint we operate in Frankfurt. No code or embedding text leaves the EU. Trade-off: higher embed latency and a higher embedding cost per token, because we operate the endpoint ourselves rather than amortising over a multi-tenant cloud.
oss-only
Restricts embeddings to open-source models prom.codes runs itself, so
no code or embedding text reaches a third-party model provider. Use
this when your policy requires that no external provider sits in the
path at all. Like eu-strict, the embedding hop stays on
infrastructure we operate in the EU.
How to set it
Today: per-workspace, server-side, by us at provisioning time.
Self-service: arrives with the dashboard (Phase 2.9). The MCP server
respects a PROMETHEUS_REGION_MODE environment override for local
testing, but the authoritative setting lives on the workspace
record and the worker rejects index runs whose declared mode diverges
from the workspace's configured mode.
What does not change with region mode
- Storage is always EU Frankfurt for prom.codes tenants. We do not offer US or APAC storage.
- The MCP server transport (
stdio) runs entirely on your machine regardless of region mode. - The web surface (
prom.codes) is served from an EU Frankfurt edge region for every visitor.
If you need a region profile we do not list here (e.g. CH-only, on-prem), tell us — the architecture supports it, we just have not built the deploy automation yet.