Reserve resources.
Prevent conflicts.
Ship faster.

A hosted HTTP API that lets any application reserve named resources — preventing race conditions, double-booking, and concurrent conflicts.

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What can you build with it?

Any application that needs to prevent two things from happening at the same time.

Job queue coordination
Two workers racing to claim the same job — the loser gets ALREADY_HELD and moves on.
worker-1 → JOB-42 ← worker-2
✓ ACQUIRED | ✗ ALREADY_HELD
Appointment & booking
Reserve a timeslot and reject double-booking — no database transaction needed.
MON
TUE
WED
THU
Printer & device pools
Capacity-based reservation: register Printer with capacity 3 and it auto-expands to Printer_0/1/2 — first available slot claimed.
🖨
🖨
🖨
| job-4 ⏳
Microservice mutex
Service A acquires a named lock before a critical section; Service B gets ALREADY_HELD and retries or backs off.
svc-a 🔓 svc-b
Traffic light coordination
Cars reserve the intersection before entering — only one vehicle holds the green light at a time. No queue logic to write.
H 🔴
V 🔴
🚗 🚗 🚗 🚗
Storage slot manager
Containers reserve named storage slots before moving in — slot releases on retrieval so the next container can claim the space.
🏪 A
🏪 B
🏪 C
| 📦 arriving

How it works

Three HTTP calls. No infrastructure to run.

1

Sign up

Google OAuth — takes 30 seconds. Your API key is on the dashboard the moment you sign in.

2

Reserve

POST /api/v1/Reservation/reserve from any language, any stack. No SDK required — just HTTP.

3

Release

POST /api/v1/Reservation/unreserve when done, or set a ttlSeconds and it auto-expires.

Pricing

Start free. Upgrade when you need more. No credit card required to get started.

Tier Price Ops / min Ops / day Concurrent locks API keys Event history Webhooks
Free Free forever $0 / mo 200 10k 500 1 24 h —
Starter Most popular $19 / mo 1,000 50k 10,000 10 7 days —
Pro $79 / mo 5,000 Unlimited 100,000 100 90 days ✓
Enterprise Custom 20,000 Unlimited 1,000,000 Unlimited Custom ✓

† Ops/min counts each Reserve and Unreserve call as one operation — a typical reserve-then-release cycle uses two ops. Read operations (GET status checks) have a separate limit at 5× the write limit shown above (e.g. Pro = 25,000 reads/min).

Start for free