Announcing Tollgate: quota admission and usage accounting without per-request I/O

We’ve open-sourced Tollgate, a Rust library that checks whether a request may run, calculates its cost and records the charge for billing without I/O on the request path. I built it for an API where the work itself takes nanoseconds. Each instance spends a fenced lease of units allocated from an account’s central balance, using atomic counters and immutable policy snapshots. A background control plane handles lease refills, policy updates and usage ingestion. A few parts that may interest Rust...