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IBM i continues to run some of the most important applications inside modern businesses.

Orders, inventory, pricing, manufacturing, customer information, financial transactions, and decades of business logic may all depend on the platform.

But the environment surrounding IBM i has changed.

Organizations now need those applications to communicate with cloud platforms, mobile applications, customer portals, analytics tools, automation platforms, AI applications, and an expanding ecosystem of third-party services.

That makes IBM i integration architecture an increasingly important part of planning for 2027.

The goal isn’t to replace IBM i.

It’s to create an architecture that makes the platform easier to connect, extend, secure, and evolve as business requirements change.

What Is IBM i Integration Architecture?

IBM i integration architecture defines how IBM i applications communicate with the rest of an organization’s technology environment.

It establishes the methods, standards, and technologies used to move information between IBM i and other systems.

A modern architecture may include:

Instead of creating a new custom connection every time another application needs IBM i data, organizations can build reusable integration capabilities.

That distinction becomes increasingly important as the number of connected applications grows.

Why Point-to-Point Integration Becomes Difficult to Scale

Many integration environments grow organically.

A new application needs customer information, so a custom interface is created.

Another application needs inventory data, so another connection is built.

A third system needs order information, resulting in another integration.

Over time, organizations can end up with a complicated network of:

Each integration may work individually.

The challenge appears when something changes.

Updating one IBM i application can affect several downstream systems. Troubleshooting becomes more difficult because teams need to understand how every connection works.

A modern IBM i integration architecture reduces that complexity by creating consistent ways for applications to interact.

1. Put APIs at the Center of the Architecture

APIs provide a standardized interface between IBM i and modern applications.

Instead of giving external systems direct knowledge of IBM i programs or database structures, APIs can expose defined business capabilities.

Examples include:

The consuming application only needs to understand the API.

IBM i remains responsible for the underlying RPG logic and business rules.

This creates an important separation between how the business works and how another application accesses that capability.

2. Build Reusable Business APIs

One of the most important architectural shifts is moving away from application-specific integrations.

Imagine three applications need inventory availability:

A point-to-point approach might create three different integrations.

A reusable API approach creates one:

Get Inventory Availability

Each approved application can consume the same business service.

This can reduce duplicate development while making security, testing, documentation, and maintenance easier to manage.

As new applications are introduced, the integration capability already exists.

3. Keep Trusted RPG Business Logic Where It Belongs

Modern integration does not require moving business logic away from IBM i.

In many organizations, RPG applications contain years of tested rules around:

Recreating those rules somewhere else can introduce unnecessary risk.

A better architecture can allow RPG to continue performing trusted processing while APIs provide modern access to those capabilities.

For IBM i teams, this also means integration can become part of the existing RPG development environment rather than a completely separate technology stack.

4. Decide When Real-Time Integration Matters

Not every process needs to operate in real time.

Batch processing remains effective for many IBM i workloads.

But some business processes increasingly benefit from immediate connectivity.

Examples include:

Organizations should ask:

How quickly does another person or system actually need this information?

If the answer is “immediately,” APIs or event-driven integration may be more appropriate than scheduled file transfers.

The goal is not to eliminate batch processing.

It is to use the right integration pattern for the business requirement.

5. Add Event-Driven Integration Where It Creates Value

APIs usually respond when something requests information or initiates an action.

Events work differently.

They communicate that something has happened.

Examples include:

That event can trigger downstream workflows automatically.

For example:

OrderShipped

could trigger:

  1. A customer notification.
  2. A CRM update.
  3. A customer portal update.
  4. An analytics event.

IBM i continues handling the core transaction while the broader architecture responds immediately.

This combination of APIs and events can make IBM i environments considerably more responsive.

6. Design for Cloud and SaaS Connectivity

Most enterprise technology environments now extend beyond the data center.

Organizations increasingly rely on cloud-based:

IBM i integration architecture should assume that applications may exist across multiple environments.

APIs provide a consistent way to connect these systems without requiring the IBM i application itself to move.

This supports hybrid architectures where IBM i remains central to business operations while other capabilities operate in cloud environments.

7. Treat Security as an Architectural Requirement

More connectivity creates more responsibility.

API security should therefore be part of the architecture from the beginning.

Important controls include:

Applications should receive access only to the information and functionality they require.

For example, an application that retrieves order status should not automatically receive permission to change customer credit limits.

Integration architecture should make those boundaries clear.

8. Build Observability into Every Integration

Modern integration environments can include many moving parts.

An API request may travel through:

  1. A cloud application.
  2. An API endpoint.
  3. An RPG program.
  4. Db2 for i.
  5. Another external service.

When something fails, teams need to know where and why.

Monitoring should provide visibility into:

The most important question isn’t simply:

“Is the API online?”

It’s:

“Did the business process complete successfully?”

9. Design APIs for Automation

A strong integration architecture also creates the foundation for automation.

Once IBM i business functions are available through controlled APIs, automated workflows can use them.

For example:

A new eCommerce order could automatically:

  1. Validate the customer.
  2. Check inventory.
  3. Calculate pricing.
  4. Create the IBM i order.
  5. Trigger fulfillment.
  6. Return confirmation.
  7. Notify the customer.

Instead of employees moving information manually between applications, systems communicate directly.

This reduces repetitive work while allowing IBM i to remain responsible for the core business rules.

10. Prepare the Architecture for AI

AI is adding another type of consumer to enterprise integration environments.

AI assistants and agents increasingly need access to trusted business information.

For IBM i organizations, that might include:

Direct, unrestricted AI access to IBM i is rarely the right architectural approach.

APIs can provide a controlled bridge.

An AI assistant might request:

Get Order Status

The API authenticates the request.

IBM i retrieves the approved information.

The API returns only the required data.

The AI application interprets the result.

This preserves an important principle:

IBM i remains the trusted business system. AI becomes another controlled consumer of its capabilities.

11. Make Integration Easier for Developers

Architecture should not only improve system connectivity.

It should improve the developer experience.

Well-designed APIs should include:

Developers should not need extensive knowledge of the underlying RPG application to consume a business service.

This can also help address the IBM i skills gap.

A web developer may not understand RPG, Db2 for i, libraries, or IBM i program structures.

But they can understand a documented REST API.

12. Establish API Governance Before the Environment Grows

Once organizations see the value of APIs, the number of endpoints can grow quickly.

Without governance, API environments can eventually become as complicated as the point-to-point integrations they replaced.

Establish standards for:

Every production API should have a clear owner and business purpose.

Teams should also know which applications depend on it.

A Simple IBM i Integration Architecture

A modern architecture might look like this:

Experience Layer

↓

API & Integration Layer

↓

IBM i Business Logic

↓

Data Layer

This architecture allows each layer to evolve without forcing organizations to rewrite the entire system.

How to Start Improving Your IBM i Integration Architecture

Modernization does not need to begin with a large architecture project.

Start with one business process.

Step 1: Identify a Pain Point

Look for:

Step 2: Identify the Business Capability

Instead of thinking about tables or programs, define the business function.

For example:

Check Inventory

rather than:

Read inventory file ABC123.

Step 3: Create a Reusable API

Expose the business capability through a secure, documented interface.

Step 4: Connect One Application

Use the API to solve the immediate integration problem.

Step 5: Monitor the Results

Measure:

Step 6: Reuse the Capability

When another application needs the same information, reuse the existing API.

That is how an integration project begins becoming an integration architecture.

Looking Ahead: IBM TechXchange 2026

These conversations around integration architecture, AI, data, hybrid cloud, infrastructure, and security will continue throughout the IBM ecosystem this fall.

Kato Integrations intends to participate in IBM TechXchange 2026, taking place October 26–29 in Atlanta, Georgia.

The event brings together developers, engineers, architects, and technologists for hands-on sessions and technical discussions around many of the same technologies shaping modern IBM i environments.

We’ll share more about Kato’s plans as the event gets closer.

Learn more about IBM TechXchange:

https://www.ibm.com/events/techxchange

Frequently Asked Questions About IBM i Integration Architecture

What is IBM i integration architecture?

IBM i integration architecture defines how IBM i applications and data securely communicate with web, mobile, cloud, SaaS, analytics, automation, AI, and other enterprise systems.

Why are APIs important for IBM i integration?

APIs provide standardized, reusable interfaces to IBM i business logic and data without requiring external applications to understand underlying RPG programs or database structures.

Does modern IBM i integration require replacing RPG?

No. Existing RPG applications can continue performing trusted business logic while APIs provide modern access to those capabilities.

Should every IBM i integration operate in real time?

No. Batch processing remains appropriate for many workloads. Real-time APIs and event-driven integration are most valuable when customers, employees, or connected applications need information immediately.

How do APIs support IBM i cloud integration?

APIs allow cloud and SaaS applications to securely exchange information with IBM i regardless of whether the core IBM i environment remains on-premises, hosted, or part of a hybrid architecture.

Can IBM i integration architecture support AI?

Yes. Secure APIs can provide controlled access to approved IBM i business functions and data, allowing AI applications and agents to interact with IBM i without unrestricted access to underlying systems.

What is API governance?

API governance establishes standards for how APIs are designed, secured, documented, versioned, tested, monitored, and eventually retired.

Where should an IBM i integration modernization project begin?

Start with a high-value business process experiencing manual work, delayed information, duplicate data, or integration complexity. Build a reusable capability that solves that problem before expanding the architecture.

Final Thoughts

The future of IBM i is increasingly connected.

The platform no longer operates only inside the boundaries of traditional enterprise applications.

It is becoming part of a broader ecosystem of cloud platforms, mobile applications, analytics tools, automation, APIs, and AI.

A thoughtful IBM i integration architecture makes that evolution manageable.

Organizations do not need to replace trusted RPG applications to participate in modern technology environments.

They need secure, reusable ways to connect them.

Build the right APIs.

Use real-time integration where it creates value.

Introduce events where responsiveness matters.

Monitor everything.

Design for security.

And create an architecture that allows IBM i to continue doing what it does best while making its capabilities available to whatever comes next.

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