sqlite-persistence

sqlite-persistence

The thing the other examples can't show: credits that survive a restart.

examples/express-api and examples/nextjs-ai-route both use InMemoryAdapter, so every reload starts from a full balance. This one stores balances and usage events in ./usage.db via @uselimit/storage-sqlite, so state carries across processes.

Run it

Build both packages first, then install:

pnpm --filter "@uselimit/*" build
cd examples/sqlite-persistence
pnpm install

Then run it more than once:

pnpm start   # Starting balance: 100 -> 85
pnpm start   # Starting balance:  85 -> 70
pnpm start   # Starting balance:  70 -> 55

Each run performs three metered operations at 5 credits each, following the check → operate → consume flow. The recorded usage-event count grows across runs too, since the events table is the same durable source of truth quotas are derived from.

pnpm reset   # delete usage.db (and its -wal / -shm sidecars) to start over

What to notice

• Seeding happens once. The tenant and its balance are created on the first run only; every later boot finds them already there. That's what your signup flow does in a real app.

• usage.db is a real file. Open it with any SQLite client and look at balances and usage_events.

• Consumption is atomic. Two processes running this at the same time can't double-spend the same credits — the deduction, the quota check, and the event insert share one transaction.

• Nothing resets. By the fourth run the summaries feature quota (50 credits per month) is spent and requests start coming back refused:

  ✗ second document: refused — Feature quota exceeded for 'summaries' (resets 2026-10-10T…)
  

  It stays that way even past that reset date. uselimit doesn't yet advance a tenant's periodStart or refill balances at resetAt, so the quota window never rolls over — pnpm reset, or refill from your own scheduler. This is the sharpest edge in the library today and it's next on the roadmap.

Requires Node >= 22.13 for node:sqlite. Node 22.x prints an ExperimentalWarning on first use; Node 24 doesn't.