Configuration

All configuration is environment-driven and validated once at startup by Config.from_env; a missing required variable fails fast with its name.

Required

Variable	Meaning
`KEYS_TABLE`	DynamoDB table of API-key digests
`USAGE_TABLE`	DynamoDB table for the usage ledger and rollups
`CLOUDMAP_NAMESPACE`	Cloud Map namespace of GPU gateways (only when no local model)
`CLOUDMAP_SERVICE`	Cloud Map service GPU gateways register into (only when no local model)

Variable	Meaning
`RELATIVEDB_MODEL`	checkpoint URI; when set, `/v1/forward` and `/health` execute in-process on the GPU (requires `pip install 'relational-transformers-gateway[inference]'`) and Cloud Map becomes optional

Variable	Default	Meaning
`PORT`	`8080`	listen port for `rtg-serve`
`UPSTREAM_TIMEOUT_SECONDS`	`25`	per-attempt timeout for workers and the LLM provider
`MAX_BODY_BYTES`	`10485760`	request-body cap (413 above it)
`DISCOVERY_CACHE_SECONDS`	`5`	Cloud Map result cache
`AUTH_CACHE_SECONDS`	`30`	API-key lookup cache; `0` disables
`WORKER_ATTEMPTS`	`3`	workers tried per request on connection failure
`RATE_LIMIT_RPS`	`0`	per-customer token-bucket rate; `0` disables
`RATE_LIMIT_BURST`	`2 × rps`	token-bucket burst capacity
`OPENAI_API_KEY`	—	LLM provider credential; unset returns 503 on LLM paths
`OPENAI_BASE_URL`	`https://api.openai.com`	OpenAI-compatible provider base
`OPENAI_ALLOWED_MODELS`	`gpt-5.6-sol,gpt-5.6-terra,gpt-5.6-luna`	model allowlist
`USAGE_RETENTION_DAYS`	`90`	request-ledger TTL

Auth caching applies to both hits and misses, so a revoked key keeps working for at most AUTH_CACHE_SECONDS and an invalid key cannot hammer DynamoDB.
Retry policy: only connection-level failures move to the next worker. An HTTP error from a worker is authoritative and returned as-is, because re-running a scoring request elsewhere could duplicate work.
Rate limiting is per-customer and in-memory — one gateway machine enforces it exactly; horizontal replicas each carry their own bucket.
/v1/models responses are filtered to OPENAI_ALLOWED_MODELS so the provider’s full catalog is never exposed to customers.