tollgate-client

The instance-side runtime of Tollgate: the background tasks that keep a service's admission layer supplied and its usage accounted, all off the request path.

InstanceRuntime owns account discovery, lease slots, supervised lease managers, and the usage writer. Its cloneable RuntimeHandle provides staged admission, readiness, and reports.
LeaseManager keeps an account's lease slot stocked from a LeaseAllocator, refilling at a low-water mark and consolidating a drained tail lease into its replacement.
UsageWriter drains a bounded channel of usage events into a UsageSink in idempotent batches. When the channel is full, admission sheds before work is accepted, so committed work always has somewhere to be billed.
KeyManager refreshes customer credentials from a read-only KeySource, bounding cached evidence by feed freshness and key expiry.
PeriodRoller funds budget schedules and rolls due periods, for applications that talk to a store directly.

The request path only loads published state and reserves channel permits. Timestamps come from a Clock, so every behaviour is testable with a manual clock.

Topologies

Direct store: the runtime talks to a tollgate-store backend, such as tollgate-store-postgres.
Via server: with the http feature, HttpStore implements the store traits against a tollgate-server over authenticated TLS.

Shutdown

The runtime enforces one total shutdown deadline: it closes accounting admission, pauses refills, drains issued permits and guards, and releases account leases. Stop admitting, quiesce in-flight requests, then await the writer, so no committed usage is lost; undelivered events are counted rather than dropped silently.

Features

http: the HttpStore transport to a tollgate-server. Off by default; the direct-store topology needs none of it.

Getting started

docs/EMBEDDING.md gives the supported request order and shutdown sequence, and examples/pricing-api in the repository is a complete embedding. Credential distribution is in docs/CREDENTIAL_PROJECTION.md; the contract is INVARIANTS.md.

License