Connecting Non-SAP Systems with SAP BTP: APIs, Event Mesh & Integration Suite

[ChinmayTambe]

Connecting Non-SAP Systems with SAP BTP: APIs, Event Mesh & Integration Suite

Integration is one of the top priorities for SAP customers in 2025. As hybrid IT landscapes grow , combining SAP S/4HANA, legacy systems, and modern SaaS, the SAP Business Technology Platform (BTP) has become the central layer enabling these systems to talk to each other securely and in real time.

SAP’s Integration Suite, Event Mesh, and API Management together form the backbone of this connected ecosystem.

1. Why Integration Matters More Than Ever

Businesses rarely run fully on SAP alone. You might have Salesforce for CRM, Workday for HR, or custom-built logistics apps. These need to work seamlessly and tirelessly with SAP without faults, sharing customer data, triggering workflows, and ensuring real-time visibility across the value chain.

BTP helps unify all this through open connectors, APIs, and event-driven communication, without touching the core of SAP S/4HANA.

2. Integration Suite: The Foundation Layer

SAP Integration Suite offers a unified set of capabilities to design, manage, and monitor integrations between SAP and non-SAP systems.

Cloud Integration
For process-based, message-driven integration between SAP and non-SAP systems. It enables data flow through pre-built integration packages (for example, SAP → Salesforce → SAP), reducing development time.

API Management
Expose custom APIs from CAP-based apps or legacy systems, and consume REST APIs from third-party platforms. You can control access, apply rate limits, and ensure security via OAuth and API policies.

Integration Advisor
Suggests mappings and interface structures automatically, saving time and improving consistency during design.

Together, these tools simplify how business processes flow across a hybrid landscape.

3. Event Mesh: Making Systems Talk in Real Time

SAP Event Mesh introduces an event-driven architecture (EDA) , enabling systems to communicate through business events rather than constant API calls.

External systems can exchange data with SAP applications
When a customer creates an order in a non-SAP app, Event Mesh can instantly notify SAP S/4HANA or a CAP app to start fulfillment.

Processes stay synchronized in real time
Inventory changes, shipment updates, or status alerts are instantly propagated to every connected system , keeping everyone on the same page with standardized information and data.

You avoid modifying S/4HANA directly
By handling custom logic in BTP extensions and event subscribers, you reduce technical debt and simplify upgrades. The clean-core principle stays intact.

Event Mesh therefore acts as the “nervous system” of the landscape, transmitting business signals instantly across applications.

4. APIs + Events = The Future of Integration

Modern integration combines APIs for control and events for awareness.
APIs handle structured, request-driven interactions (“get order details”), while events handle spontaneous updates (“order created”).

Together, they enable loosely coupled architectures, where systems are connected, but not dependent.

5. Real-World Example: A Logistics Scenario

A German manufacturing company runs SAP S/4HANA for order processing, an on-premises warehouse management system (WMS), and a third-party shipping service that provides delivery tracking via REST APIs.

They use SAP BTP to integrate these three worlds, ensuring data consistency, real-time visibility, and a clean SAP core. Let’s see how the three pillars of integration make it work together.

Cloud Integration: The Process Connector

SAP Cloud Integration (part of Integration Suite) acts as the central traffic controller for data between S/4HANA and the warehouse system.

• Whenever a sales order is created in S/4HANA, Cloud Integration picks up the outbound IDoc or OData event (for example, “SalesOrder.Created”).
• It maps this order data into the format expected by the warehouse system, handling data transformations, enrichments, and protocol conversions (like IDoc → REST).
• The integration flow (iFlow) then securely transmits this data over HTTPS to the warehouse’s REST endpoint or message queue.
• At the end of the day, the same flow also synchronizes stock levels or order confirmations back into S/4HANA.

This ensures both systems always have the same view of orders and inventory, without manual file transfers or custom scripts.

Result:
Process-based data exchange between SAP and non-SAP systems, fully automated and monitored from BTP.

Event Mesh: The Real-Time Messenger

While Cloud Integration handles batch or process-oriented data, Event Mesh ensures real-time responsiveness across the landscape.

• When the warehouse system marks an order as “Delivered,” it publishes an event (for example, “DeliveryCreated”) to the SAP Event Mesh topic.
• Event Mesh then pushes this event to all subscribed systems, such as the customer portal and CAP-based tracking app on BTP.
• The subscriber apps instantly receive this update and can trigger follow-up actions, like sending a push notification or updating the customer’s order status on the web.

Unlike APIs that require constant polling, Event Mesh delivers updates asynchronously and only when needed, making the system more efficient and scalable.

Result:
Real-time synchronization without point-to-point dependencies, enabling instant reactions across systems.

API Management: The Secure Gateway

Now that multiple systems generate and consume data, API Management provides a unified and secure access layer for external consumption.

• The company creates a custom “Order Tracking” API that aggregates order and delivery data from both S/4HANA (via Cloud Integration) and the warehouse (via Event Mesh events).
• This API is managed through SAP’s API Management service, where policies handle:
• Security: OAuth 2.0, API keys, and JWT validation
• Traffic Control: Rate limits, quota management
• Monitoring: API usage analytics and latency reports
• The customer portal or mobile app consumes this API securely, allowing users to track their orders end-to-end from a single interface.

Result:
A governed, standardized entry point for all external consumers hence reducing complexity while protecting sensitive business data.

6. Key Takeaway

Connecting SAP and non-SAP systems doesn’t have to mean complex middleware landscapes anymore.
With SAP BTP, Integration Suite, APIs, and Event Mesh provide a unified, scalable, and governed way to achieve cross-system connectivity, without sacrificing your clean-core principles.

Start with one process, make it event-driven, and expand from there.
Integration is no longer a project phase, it’s an ongoing capability that defines how modern enterprises operate.

#SAPBTP #IntegrationSuite #EventMesh #APIManagement #SAPArchitecture #CleanCore #SAPIntegration #EnterpriseArchitecture #DigitalTransformation #SAPDevelopers

[tarunnagar]

Really insightful topic! Integrating non-SAP systems with SAP BTP can be a challenge, but using APIs, Event Mesh, and the Integration Suite makes it much smoother and more scalable. I’ve seen how this approach improves real-time data flow and reduces manual dependencies. Great read for anyone working on hybrid system architectures.