Run every location from one place.
PurrOS is an open-source, self-hosted operations platform (ERP) for businesses with 20–500 people: people, scheduling, time, cash, inventory, ordering, sales, checklists and reporting. Every feature is optional, and everything connects through a REST API.
/api/v1/sales/transactions:batch{ "source": "pos:store-101", "transactions": [{ "externalId": "txn-88213", "occurredAt": "2026-09-27T12:41:07Z", "lines": [{ "itemSku": "LATTE-12", "quantity": "2" }], "total": "12.97" }] }
{ "created": 1, "updated": 0, "rejected": 0 }Find your way in
Four sections, each written for the person who needs it.
Install PurrOS on your own server, configure email and storage, and manage roles, features, backups and upgrades.
How each feature works day to day, from timesheets and schedules to cash counts, stock and purchase orders.
A REST API for everything the product does: authentication, conventions, ingestion, webhooks and every endpoint.
Connect your POS, online store, timeclock, HR, payroll and accounting systems with small programs you control.
Feature guides
Switch on only what your business uses.
Bring your data in, send changes out
Batch ingestion is idempotent on source and external ID, so re-sending is always safe. Signed webhooks tell your other systems about new hires, locked pay periods, low stock and more, with retries and replay.