MDB is the industry-standard protocol that runs vending machines, kiosks, and unattended devices around the world. MDB by Paying.co is the software that brings them into the cashless era — a single clean API in front of a messy serial bus. Skip the state machines, the reverse-engineering, and the 2am debugging. Drop our connector in, talk to your processor, take card.
MDB is a finicky little protocol. Master-slave polling, 9-bit serial, address mapping, level 1/2/3 negotiation, cashless device state machines. Our software handles every byte of that for you — so the only thing you write is the business logic for taking a payment.
We speak MDB to the machine and standard HTTPS to your code. Polling, ACKs, level negotiation, address mapping, state transitions — all hidden behind a clean API call.
Up to 32 devices on a single bus, all coordinated from a single controller. We handle device discovery, addressing, prioritization, and conflict resolution — you just send a charge request.
Card tap, chip insert, mobile wallet, QR — whatever payment your processor supports, we wire end-to-end into the MDB cashless device state machine. The machine vends only after the processor approves.
Bus timeouts, device disconnects, processor failures — the software self-heals. Auto-reconnect, retry policies, dead-letter callbacks, and full audit logs. You find out something went wrong via webhook, not a 2am support call.
Writing your own MDB stack is doable. It's also a quarter-long detour that pulls your best engineers away from the product they should be building. Here's what that detour looks like — and what licensing instead looks like.
mdb.charge() from your applicationWe exposed everything a normal application actually wants — charge, refund, status, webhooks. The protocol mess stays inside the connector. Your code stays readable.
mdb.charge() call. The connector handles polling, state, payment authorization, vend release, and confirmation — from card tap to product dispense.Same protocol underneath, same install pattern. Pick the connector that matches the processor you already work with.
The MDB bridge for Datacap-powered terminals. NETePay, dsiEMVUS, and the Datacap processing stack — bus-addressed and ready to vend. Includes webhook callbacks, configurable timeouts, and full audit logging.
The MDB bridge for PAX terminals running on BroadPOS or your processor of choice. Same plug-and-play install, same configurable behavior — with full support for PAX A-series and Aries hardware.
MDB isn't theoretical. It's the protocol behind a generation of unattended payment deployments — from snack machines in office breakrooms to access control at the parking gate. If it takes a card without a cashier, there's a bus underneath it.
Snack, beverage, coffee, and combo vending with seamless cashless payment integration. The original home of MDB — and still where it does the most work every day.
Learn moreOrder-ahead, ticketing, info display, customer check-in. Anywhere a customer expects to tap their card and get something back. MDB is the wire that makes it instant.
Learn moreCard readers and entry systems for buildings, parking facilities, secured areas, and gated lots. MDB carries both the credential check and the open-the-gate command.
Talk to usWe don't have ten tiers. We have one number per device per year. License the connector that matches your processor — the rest is software.
Pick your processor, license the connector, plug it in. You're taking card on any MDB device the same week. No firmware to write. No state machines to debug. No 2am calls.