Environment Flags

OpenProxyAI's core request path (auth, rate limiting, policy, cache, provider routing) always runs. A small set of environment variables toggle optional subsystems on top of it.

Flag	Effect
AIRGAP_MODE	When true, disables everything that calls out to a third party the proxy doesn't strictly need to function: Langfuse observability, ClickHouse analytics dual-write, hosted spend reports, and Stripe metered billing sync. Use this for on-prem / air-gapped deployments.
BATCH_SPEND_ENABLED	Enables batched request-log flushing instead of writing each request individually — reduces database write load at high volume.
PROMETHEUS_ENABLED	Mounts a /metrics endpoint for Prometheus scraping.
PROVIDER_HEALTH_CHECK_ENABLED	Enables periodic background polling of provider health, used by the router to avoid sending traffic to a degraded provider key.
ADAPTIVE_LB_ENABLED	Enables adaptive load-balancer sampling — the router adjusts weighted rotation based on observed latency instead of using only the static configured weights.

Sidecar behavior

ClickHouse (analytics), Langfuse (observability), Prometheus (metrics), and outbound webhook delivery are all treated as sidecars: if one of them is unreachable or errors, the request still succeeds. Core request handling (auth, rate limiting, policy, provider calls, and the primary audit log in Postgres) never depends on a sidecar being up.

Where these are set

Environment flags are set in backend/.env (or your deployment's equivalent — a Helm values.yaml override, a Kubernetes ConfigMap, etc.) and read once at process startup.