The more APIs you have, the more complex it becomes to manage them efficiently. This is where declarative API management comes in, bringing automation, consistency, and scalability to your API deployment, versioning, and overall lifecycle management. How does declarative API management work? Is it the same as API management as code? And does your business need it? Let us answer all your burning questions…
What is declarative API management?
Declarative API management (APIM) is a way of using a desired state model for your API management. It brings automation, consistent security, predictability, auditability and more to your API lifecycle, as well as supporting enhanced collaboration between teams.
Tyk serves as an example of this, allowing you to describe your entire API management system declaratively, from API definitions to policy-driven security.
With declarative APIM, you can store and version the canonical desired state of your API and API gateway configurations in Git, which serves as the single source of truth for your deployments. This makes auditing, as well as rolling out updates (and rolling back if need be) seamless, with teams easily able to collaborate and approve changes.
You can store your API security policy configurations alongside your application source code, for consistent, reliable security at scale. Using an operator helps you automate and synchronize. The operator monitors the desired state in your Git repository and compares it to the current state of your API platform. It then applies any required changes to ensure your deployment matches your desired state, easily rectifying any drift without the need for manual processes.
API industry thought leader Kelsey Hightower sums it all up succinctly:
“GitOps is the best thing since configuration as code. Git changed how we collaborate, but declarative configuration is the key to dealing with infrastructure at scale, and sets the scene for the next generation of management tools.”
Is declarative APIM the same as API management as code?
No, declarative APIM is not the same as API management as code (AMaC), though the two are closely related.
API management as code is a broad practice where you manage everything related to APIM (APIs, products, policies, gateways, configurations, environments, and so on) through source-controlled configuration files, automated pipelines, and CI/CD. The focus is on treating API management like infrastructure, which enables you to efficiently manage APIs at scale and apply consistency and security across your entire API estate with less burden on your developers.
Declarative API management is one form of AMaC. With a declarative approach, your teams focus on what the API configuration should be, rather than how to create it. You can use a range of tools to achieve this, with the tools figuring out how to make your desired state configurable.
API management as code can also be imperative (through the use of procedural scripts) or use a combination of declarative and imperative approaches.
Declarative vs imperative API management
Imperative API management requires developers to manage state transitions and updates step by step – their focus is on how to do things. With declarative API management, the focus is more on what needs to be achieved in terms of the desired state, rather than how to get there. Developers swap manual processes for simplification and automation.
What benefits does declarative API management provide?
Declarative API management delivers multiple manifest benefits, including:
- Automation: This not only levels up your efficiency by reducing manual process requirements but also irons out issues such as excessively verbose or buggy code.
- Faster release cycles: The greater efficiency and reduced manual burden of declarative APIM means you can ship products and updates faster, beating the competition to market and delighting your customers with your agility and pace.
- Consistency: From security policies to seamless version control, using Git to store your configurations supports greater consistency and predictability.
- Robust security: Being able to automate security as you enforce it across your API estate helps you stay at the forefront of defending against threats and keeping data safe.
- Seamless version control: Declarative APIM makes it easy for your teams to collaborate and roll out changes, with knock-on benefits to all those using your APIs.
- Auditability: With robust, version-controlled infrastructure in place, it’s easy to track changes and see who has done what and when, making declarative API management ideal for regulated organizations.
- Faster troubleshooting: Being able to monitor and observe clearly what has happened means you can troubleshoot swiftly when something goes awry.
- Scalability: Automation supports you to scale with confidence, growing to hundreds or thousands of APIs while knowing your lifecycle management remains consistent and secure.
- Reduced cognitive load: Enabling teams to focus on where you want to be (i.e. your desired state), rather than how to get there, is a win for all concerned.
How does declarative configuration differ from imperative API management?
Let’s dive into a bit more detail about the differences between API management where you declare the desired state (declarative) and where you have to define how to get there (imperative).
| Declarative APIM | Imperative APIM | |
| Approach | Define the desired end state then | Create step-by-step instructions |
| Focus | What you want the final configuration to be like | How you’re going to configure everything |
| Implementation | Use tools to turn your desired state declaration into reality | Use scripts/commands for sequential execution |
| Idempotency | Naturally idempotent, with the same result every runtime | Often non-idempotent unless manually enforced |
| Scalability | Highly scalable | Harder to scale due to more manual nature |
| Error handling | Operator handles drift and can reconcile and validate state automatically | Teams must handle errors, retries, and ordering |
| Complexity | Lower operational complexity with a higher degree of abstraction | Higher operational complexity with full control |
| Use cases | Standardized and regulated environments, large-scale API governance | One-off tasks, customer orchestration |
Which tools support declarative API management?
Typical tools that support a declarative API management approach include Terraform, GitOps, Kubernetes CRDs, and Tyk. Tools such as ArgoCD and Kustomize also work well with Tyk Operator, making it easy to manage your API configurations alongside your applications.
For practical insights into how you can deploy these tools, check out our practical guide to using Tyk Operator, ArgoCD, and Kustomize.
How does GitOps relate to declarative API management?
GitOps enables you to operationalize declarative API management. You declare your desired state, then provision GitOps to keep every environment in that state, automatically and reliably.
The benefits of this can be enormous. Check out this video presentation for insights into the advantages of GitOps-driven API management, along with practical details of how to handle multi-tenant deployments. The presentation also provides a real-world example of automated API provisioning in a cloud-native environment.
Is declarative API management suitable for large-scale microservices?
Declarative APIM is eminently suitable for large-scale microservices. It can deliver consistency across hundreds of services efficiently, enforcing standardization while minimizing reliance on manual steps. The predictable, repeatable, and highly extensible nature of such a framework makes this ideal for a microservices environment.
The fact that declarative definitions are such a strong fit for GitOps and automation, supporting continuous drift detection and reconciliation, also makes them well-suited to microservices, particularly as the number of services grows. Smooth CI/CD pipeline capabilities add to the attractions.
Idempotency also comes into play in large-scale microservices setups. Microservices deploy constantly, and a declarative approach makes your platform more resilient to repeated, partial, or failed deploys. This removes the burden of worrying about ordering or incremental changes, as your tooling computes the differences automatically.
For larger businesses with microservices architectures and a keen need to focus on compliance, declarative API management again fits the bill. Easier to audit and govern than imperative API management, it supports a more seamless compliance journey through robust version control, trackable and reviewable policy changes, and a complete environment history.
Of course, with any large-scale environment, there will always be challenges to look out for. In terms of large-scale microservices and declarative API management, you’ll need to structure your approach correctly to avoid unnecessary complexity. Modularization, templates, and overlays can all help with this, with tools such as Terraform and Kustomize really coming into their own at scale.
You’ll also need to think about how to balance governance with a practical workflow approach that supports developer creativity. A lightweight, flexible approach is essential if you don’t want your central API and microservices governance to negatively impact team autonomy.
How do I deploy APIs declaratively?
Deploy APIs declaratively by defining infrastructure, routes, and runtime settings in configuration files that tools like Kubernetes, Terraform, or Serverless Framework can read and execute. Declarative deployment removes manual steps, enforces consistency, and enables predictable rollouts across environments.
Ready to deploy APIs declaratively and begin reaping the rewards? This comprehensive walkthrough of GitOps enabled API management in Kubernetes is a great starting point.
Next, explore the role of Tyk Sync in enabling GitOps workflows by maintaining API configurations as code, which you can version and deploy through CI/CD pipelines. This means you can manage your API configurations declaratively using version-controlled files.
Then it’s time to get to know Tyk Operator, for declarative configuration with automatic drift detection and reconciliation.
Challenge the Tyk team to help
Naturally, the Tyk team is also on hand to chat about whatever you need. Whether your focus is on declarative API management, API-first innovation, AI adoption and governance, or anything else API-related, we’re here to help. Contact us today to find out more.