APIs are the backbone of interconnected applications, enabling organizations to innovate, integrate, and scale rapidly. However, as enterprises continue to expand their digital ecosystems, they often encounter a common and complex challenge: API sprawl. Unchecked, API sprawl can lead to increased security risks, inefficient resource utilization, and the frustrating experience of redundant or hard-to-locate services across teams. Postman details the explosive growth in APIs in their State of API report. Back in 2021, Gartner predicted that by 2025 less than 50% of APIs will be managed, meaning that the massive growth in APIs will be largely unmanaged. 

In this article, we’ll dive into the challenges posed by API sprawl and explore actionable best practices for discovering, managing, and securing APIs effectively. By adopting these strategies, businesses can streamline their API landscape, boost collaboration, and mitigate potential risks—ensuring their APIs remain assets, not liabilities, in their innovation journey. 

The Primary Drivers of API Sprawl

We can attribute the increasing problem of API sprawl to several factors inherent in most modern business environments. They include: 

Increased Integration of Applications

As organizations implement more and more applications across various business domains, the number of APIs needed to connect and interact with these components also grows. Each application or service often exposes an API for integration, resulting in an extensive network of interconnected APIs.

Cloud and Distributed Systems

The increased adoption of cloud computing and distributed architectures has further fueled API proliferation. Cloud services often require APIs for interaction with compute, storage, networking, and security services. Organizations adopting multi or hybrid cloud strategies inevitably end up with more APIs to manage, monitor, and secure.

Third-Party Components and Vendor Integrations

Many modern businesses rely heavily on third-party services and external APIs to reduce the need for in-house development. While these APIs often provide essential services like payment processing, they add another layer of complexity to API management.

Integration with Multiple Partners and Legacy Systems

When onboarding external partners and vendors, organizations must integrate their systems and APIs into their own workflows. Naturally, as the number of partners increases, so does the number of external APIs. To complicate matters further, each of these APIs will have its own security and operational requirements. Meanwhile, some partner organizations may have legacy systems that may be poorly documented and maintained.

The Impact of API Sprawl 

Excessive API sprawl can have profound implications for security and operational efficiency, resulting in sprawling attack surfaces and blind spots in software and API inventories. 

For example, organizations struggling with API sprawl typically have a variety of rogue APIs. Shadow APIs may exist in the environment without being documented. Orphan APIs are described in the documentation, but not found in production. Zombie APIs were supposed to be removed, but never actually decommissioned. These “rogue” APIs are unknown or unmaintained by the security and operational teams and can allow attackers to slip unnoticed into the organizational perimeter. 

API sprawl can cause operational issues by creating blind spots in a business's software and API inventories. For example, orphan and zombie APIs require maintenance and support from development and DevOps teams—despite being functionally useless—because it's difficult to determine whether they are safe to remove. 

Best Practices for Mitigating API Sprawl

Despite these concerns, modern organizations cannot afford to sacrifice the opportunities for rapid innovation that APIs provide. In many ways, API sprawl is a natural consequence of progress. This is why managing API sprawl is so important. 

So, how can organizations manage API sprawl? With the following best practices: 

API Discovery

API discovery is the first and most important stage of managing API sprawl. Visibility is everything in complex API environments, meaning organizations must implement policies that support clear and well-documented inventories of actual APIs, like OpenAPI Schemas. 

Unfortunately, this is often easier said than done. Organizations typically have enormously complex processes, teams distributed across the globe, and a huge number of vendors and subcontractors, which can seriously complicate the discovery process. 

Wallarm's API Discovery solution can help overcome this issue. It allows our customers to monitor existing traffic, automatically build a picture of their actual API usage (including an OpenAPI specification), discover unused and undocumented APIs, and control sensitive data flows. By automatically building the API schemas for our customers, we provide easier management and faster development without hassle or complexity.

API Governance

It's also critical to implement a comprehensive API governance strategy that: 

• Defines API Ownership and Responsibility: Each API (or set of APIs) should have a designated team or individual responsible for its maintenance, security, and performance.
• Establishes API Lifecycle Policies: Set clear policies for each stage of an API's "lifecycle," from initial development through updates and, eventually, to deprecation and removal. Lifecycle policies should align with business needs—if an API is no longer needed or is outdated, a process should be in place to safely retire it.
• Provides Clear Guidelines for Adding or Removing APIs: Teams should know how to create, update, or retire APIs. Clear guidelines ensure smooth transitions and help teams avoid issues like orphan or shadow APIs. 

Continuous Monitoring

Continuous monitoring is also a key component of any plan to mitigate API sprawl. Organizations should continuously monitor current API usage and periodically review unused APIs. 

The greater an organization's visibility over its systems, the better it will be able to implement the policies necessary to discontinue obsolete APIs and monitor the usage of new ones. 

Modern solutions, like Wallarm API Discovery, help provide this visibility, notifying organizations about all new and unused APIs in their systems. Moreover, our solution is fully customizable and can meet any business's unique needs, such as discover sensitive data and apply rules for sensitive endpoints and notify about changes in APIs to prevent API abuse and prevent the attacks mentioned in OWASP Top 10.

Encouraging Collaboration

As noted, poor collaboration between security, development, and operations teams can complicate API sprawl management. Wallarm's solutions help overcome this issue. 

Wallarm offers features to detect and block API attacks while exporting current API schemas in formats like OpenAPI or CSV. Security teams can share these schemas with developers, who can review them and provide expected API designs. Wallarm then compares the actual state of APIs to expected schemas, helping identify discrepancies. This exchange keeps all teams aligned, improves security, and ensures APIs are effectively managed across the organization.

Manage API Sprawl with Wallarm API Discovery

Wallarm's API Discovery tool provides runtime visibility for your entire API portfolio, allowing you to manage API sprawl. It helps you regain control over your API attack surface and reduce associated risk and inventory. It tracks and corrects issues based on actual user traffic and identifies and remediates risky APIs based on real-time traffic and OpenAPI specs. Learn more and book a demo at https://www.wallarm.com/product/api-discovery