Every vendor who integrates with restaurant POS systems will tell you they "integrate with all major systems." What they won't tell you is that each POS has a fundamentally different API surface, different data models, different authentication approaches, and different levels of documentation quality — and that "integration" can mean anything from a production-hardened bidirectional connection to a fragile screen-scraping workaround held together by hope.
We've built integrations with Aloha, PAR Brink, Oracle MICROS, Square, Toast, and Revel. This is what each of those actually looks like from the engineering side.
The Three Patterns POS Integrations Actually Use
Before getting into specific systems, it helps to understand that restaurant POS integrations fall into three architectural patterns, in order of how easy they are to build and maintain:
- Native REST/JSON API with OAuth — the POS vendor publishes a documented API, you register as a developer, get credentials, and make HTTP calls. Toast's Partner API and Square's Orders API fall here. Relatively clean. Documentation exists. Webhook support for order status events. This is what modern software integration looks like.
- Proprietary SDK or middleware layer — the POS vendor has an integration SDK or requires connecting through their approved middleware (PAR Brink's OpenPOS layer, for example). More complicated than a REST API, but still documented and supported. You're working within their integration ecosystem, which means you're dependent on their support and their release cycle.
- Legacy XML/SOAP or direct database — older systems like classic Aloha (NCR's original Aloha product, not Aloha Cloud) expose integration through COM objects on the local Windows machine, XML files written to a local directory, or direct SQL queries to a local database. Not joking. These integrations require a local agent running on the POS hardware, which means you're deploying and maintaining software on-premises at every location. This is a different operational model entirely.
Most voice ordering vendors will claim compatibility with a system without specifying which pattern they're using. The pattern determines your real operational exposure: remote updates, support complexity, failure modes when the POS vendor pushes an update, and what happens when the POS terminal goes offline.
Aloha (NCR/Shift4): The Legacy Reality
Aloha is one of the most widely deployed POS systems in the independent QSR and casual dining space, particularly in older installations. It comes in two distinct products: legacy Aloha (the on-premises Windows-based system that many operators have been running for 10+ years) and Aloha Cloud (NCR's SaaS-hosted version, now under Shift4 after the acquisition).
Legacy Aloha integration is painful. The primary integration path is the Aloha EDI interface, which uses a file-drop model: your system writes an order file in a specific format to a network share, and Aloha's local process picks it up. Latency is non-trivial — this is not a real-time API. For phone ordering, the lag is usually acceptable (1–3 seconds). For drive-thru where sub-second response is expected, it becomes a design constraint. You also need a local agent running on the Aloha machine or a local server, which means your software is now inside the restaurant's local network.
Aloha Cloud is better: it has a REST API and does not require local software. But many Aloha operators have not migrated to Cloud because the migration requires re-training staff and re-entering menu data. If you're integrating into an Aloha environment, the first question to ask the operator is: which version? The answer changes the integration approach entirely.
PAR Brink: More Modern, Still Has Quirks
PAR Brink is prevalent in the franchise QSR space — larger pizza chains and burger concepts that upgraded from older systems in the 2015–2020 window often landed here. The OpenPOS integration layer is PAR's documented third-party integration framework. It's REST-based and reasonably well documented by restaurant POS standards.
The menu data model in Brink is combo-centric, which maps well to QSR use cases but requires careful handling of modifier trees. A combo in Brink has a defined structure: a base item, eligible sides, eligible drinks, and modification groups per component. When you inject an order via the API, you need to populate the combo structure exactly as Brink defines it for that location's menu configuration. Menu configuration diverges between locations within the same franchise brand more than most people expect — a franchisee who added a regional item or modified a combo for local taste has a slightly different menu schema than the brand-standard configuration.
This means you can't build one integration and assume it works identically across 30 franchise locations. You need a menu sync process that pulls the current menu schema from each location and validates your order injection against it. This is operational overhead that most voice ordering vendors don't surface during the sales process.
Oracle MICROS: The Enterprise Tier
MICROS (now Oracle Hospitality) is the dominant POS in hotel food service and larger casual dining chains. For QSR specifically, MICROS Simphony is the relevant product. MICROS integrations use Oracle's Hospitality Integration Platform (OHIP) for cloud-based properties, or the legacy MICROS ISGRI interface for on-premises deployments.
Oracle's integration ecosystem is more formally governed than other restaurant POS vendors. To access OHIP, third-party developers go through Oracle's partner certification process, which takes time and requires Oracle to approve your application. This isn't a barrier to get into — Oracle has a financial incentive to have a healthy third-party ecosystem — but it's a 4–8 week process that some smaller vendors skip by finding workarounds, which creates unsupported integrations that break on Oracle update cycles.
If you're evaluating a vendor that claims MICROS integration, ask whether they have Oracle Partner certification for their OHIP integration. If the answer is vague, you're probably looking at an unofficial connection that may work fine until it doesn't.
Toast: The Easiest Integration Today
Toast has invested heavily in its partner ecosystem and it shows. The Toast Partner API uses standard OAuth 2.0, has good documentation, supports webhooks for order status events, and has a sandbox environment that actually reflects production behavior. For developers, it's the most pleasant POS API in the restaurant space.
The operational challenge with Toast isn't the API — it's menu sync and multi-location management. Toast's multi-location menu management has improved but still has edge cases where location-level menu overrides don't propagate predictably to the API. If you're deploying across multiple Toast locations within a franchise group, test explicitly with the locations that have local menu modifications, not just the locations running the brand-standard menu.
Toast also has an ongoing relationship with third-party apps through their Toast App Marketplace. Being a listed Marketplace partner confers some legitimacy signal to operators, but listing requirements don't validate the technical quality of the integration — they validate that the vendor exists and has agreed to usage terms. Do your own technical diligence regardless.
Square and Revel: Independent and Fast Casual Context
Square's Orders API is clean and modern. For independent restaurants (a single location or 2–4 locations running Square), the API surface is well-documented and the integration timeline is relatively short. The limitation is that Square's POS data model is less structured around restaurant-specific concepts — it handles items and modifiers well but doesn't have native combo/meal logic. For QSR voice ordering with complex combo handling, you need to implement that logic in your integration layer rather than relying on the POS to enforce it.
Revel is common in iPad-based fast casual and coffee shop deployments. The Revel API is documented but the documentation quality is uneven. Some endpoints work as described; others have undocumented behavior that you discover in production. Revel's support for third-party integrations is less proactive than Toast. Budget extra testing time for a Revel integration, especially for menu sync edge cases.
The Offline Problem Nobody Talks About
Every POS integration needs a defined behavior for when the POS is offline or unreachable — because POS systems go offline. Updates get applied at 2 AM that don't complete cleanly, hardware fails, internet connectivity drops at the restaurant level. A voice ordering system that silently discards orders during a POS outage is an operational disaster. One that queues orders locally and injects them when connectivity is restored is manageable, but requires careful handling of order timing (a queued order placed at 12:05 PM that gets injected at 12:47 PM is no longer a useful order to make).
The right behavior is: detect POS unreachability immediately, fall to a human-answered backup for the duration of the outage, alert the operator in real time, and don't queue orders for later injection without explicit operator acknowledgment. Simple to specify, non-trivial to implement correctly.
Ask any voice ordering vendor: what happens when the POS API is unreachable? The answer to that question tells you more about the maturity of the integration than any feature comparison chart.
What "Production Integration" Actually Means
There is a meaningful difference between a vendor who has done a proof-of-concept integration with a POS system and one who has that integration running in production across multiple locations with daily order volume. POC integrations find roughly 40–60% of the failure modes. Production integrations with 90 days of live volume find the rest: edge cases in modifier combinations, race conditions on concurrent orders, menu sync failures that cause items to appear available when they're 86'd, end-of-day reconciliation discrepancies.
Before committing to a vendor, ask: how many locations are currently running the integration with your specific POS in production, and for how long? A vendor who has been running 15 Brink locations for 18 months is in a different category than one who ran a 3-location pilot for 8 weeks. The failure modes you'll hit in a live deployment are not the same as the ones that show up in a demo.
None of this is to say that integrations with any of these systems are impossible or impractical. All of them work. The question is what level of engineering investment, ongoing maintenance, and operational monitoring they require — and whether the vendor you're evaluating has already paid that cost, or whether you'll be paying it during your deployment.