Configuration

Worker, producer, store, API, and console configuration boundaries.

Worker configuration

Setting	Meaning
Queues	Queues this worker may serve
Capacity	Maximum concurrent handlers and admission capacity
Lease	Claim lifetime; heartbeat renews before expiry
Quantum	Per-admission fairness service quantum
Poll backoff	Empty-poll floor, ceiling, multiplier, and jitter
Shutdown timeout	Bounded graceful drain period
Memory limit	Optional drain-and-replace guard
Telemetry	Exporter-neutral adapter

Producer configuration

Authorization, circuit breaker, enqueue middleware, plugins, insert hooks, and the local event bus belong to the producer client. They do not change fleet admission policy.

Fleet configuration

Rate classes, queue pauses and weights, enqueue limits, concurrency ceilings, quarantine, and schedules live in the store and are writable through the control API.

Standalone API configuration

The Rust and Go control-API binaries select the same backend vocabulary:

Setting	Meaning
HG_STORE	pg, mysql, redis, or sqlite
HG_PG	PostgreSQL connection string when HG_STORE=pg
HG_MYSQL	MySQL URL when HG_STORE=mysql
HG_REDIS	Redis URL when HG_STORE=redis
HG_REDIS_PREFIX	Installation key prefix for Redis
HG_SQLITE	SQLite database path; defaults to headgate.db
HG_API_ADDR	Loopback listen address unless remote binding is explicitly allowed
HG_READ_ONLY	Set to 1 to enforce read-only API behavior
HG_API_ALLOW_REMOTE	Set to 1 only when an external authentication layer protects a non-loopback bind

SQLite and MySQL use the worker’s bounded polling path. PostgreSQL and Redis may also wake workers through their advertised notification capabilities.

Durations crossing public boundaries are milliseconds and must be at least one millisecond. Never silently round sub-millisecond values to zero.