Case Study: How TMForum Automated Their API Factory
A Technical Deep Dive into Real-World Contract Driven Development
Impact Snapshot: Hard Numbers and Real Results
100+ APIs standardized and automated
End-to-end validation of API specifications
Automated Conformance Tool Kit (CTK) and Virtual Service (VS) generation
Unified tooling across OpenAPI specs for REST and AsyncAPI specs for Kafka
The Mission: A Complete Overhaul to Consistently Deliver at Speed and Scale
Here’s something you don’t see every day: A complete overhaul of API management that actually delivered. TMForum wasn’t just dealing with a handful of APIs—we’re talking about an API Factory managing over 100 APIs in the telecommunications domain.
The Real Challenge
When you’re working at this scale, good enough isn’t good enough. TMForum needed to:
Ensure consistent implementation across multiple vendors
Validate conformance efficiently
Keep specifications, testing tools, and reference implementations in sync
10x the Developer Experience (make it developer-friendly)
But here’s the kicker: They needed to do this while improving adoption rates and reducing the time to release new APIs from months to days.
The Solution: Contract Driven Development in Action
TMForum implemented Contract Driven Development (CDD) using Specmatic, but they didn’t just stop at basic testing. They built what they call the “API Forge”—a unified, fully automated API Factory that handles:
The Methodology: A Systematic Playbook for Real-World Success
Let’s get into the nuts and bolts. TMForum’s implementation of Contract Driven Development wasn’t just about throwing tools at the problem. We built a systematic approach that actually works in the real world.
Contract Definition (The Foundation)
Automated generation of OpenAPI and AsyncAPI specs as the single source of truth
Examples generated and validated against the contract
No more “it works on my machine” syndrome
Automated validation before anything hits production
Automated Toolchain (The Engine)
CTK generation straight from the specs
Virtual Service spun up automatically
User guides and Postman collections are just a click away
End-to-end testing of the tooling using Teswiz including visual validation with Applitools Eyes
Interactive CLI for rapid development
Developer Experience (The Game Changer)
Local testing environment matches production
Immediate feedback on spec changes
Docker containers for consistent environments
GitHub Actions integration for CI/CD
Quality Assurance (The Proof)
Every request/response pair validated
Error scenarios tested automatically
Edge cases covered systematically
Automated testing of the tooling including visual regression
Real-World Impact: Success Criteria that Provethe Difference
Development Velocity
API release cycle: Months → Days
CTK creation: Manual process → Automated
Testing: Spotty coverage → Comprehensive validation
Quality Metrics
Spec compliance: Verified automatically
Error handling: Systematically tested
Edge cases: Identified and validated
Maintenance Efficiency
Single source of truth
Automated synchronization
Self-documenting processes
The Async Evolution: Extending to Event-Driven Architectures
But wait, there’s more (and this is actually important). TMForum didn’t stop at REST APIs. They extended the entire framework to handle AsyncAPIs, proving this approach scales across different architectural patterns.
The async implementation includes:
Event-driven architecture support
Kafka integration (with more protocols coming)
Both event and command pattern support
Automated testing for asynchronous flows
Achieving Real-World Impact with TMForum's API Factory
The async implementation includes:
Event-driven architecture support
Kafka integration (with more protocols coming)
Both event and command pattern support
Automated testing for asynchronous flows
Achieving Real-World Impact with TMForum's API Factory
Your Next Moves: Get Started Today
If you’re managing APIs at scale, here’s your action plan:
Start Small
Pick one API that’s giving you trouble
Download Specmatic (it’s open source)
Follow the quick start guide at specmatic.io
See results in your first day
Scale Smart
Use Docker containers for consistency
Integrate with your CI/CD pipeline
Implement visual testing for UI components
Automate everything that can be automated
The Bottom Line: TM Forum is revolutionising the Telco Industry with Specmatic's Contract Driven Development
TMForum proved something important here: You can automate API testing and development without sacrificing speed, quality or control. They’re handling 100+ APIs with this setup. You can start with just one.
Stop hoping your APIs work. With Specmatic make them work.
Start Free →This isn’t just another tool – it’s a proven approach to API lifecycle management that actually works in the real world. The code is open source for OpenAPI, the documentation is solid, and the community is there to help.
Your move.