Breaking the API Testing Bottleneck: AI-Powered OpenAPI Spec Generation

Picture this: Your organization finally achieves complete visibility into its attack surface. You can see 165 APIs sprawled across your infrastructure. 

But when you go to test those APIs for security vulnerabilities, you’re presented with a new challenge. Only a fraction of those APIs have the documentation that security testing tools require to understand endpoints, parameters, and data structures, leaving the majority untestable.

This isn’t hypothetical. Since launching source-based API Discovery in the StackHawk platform last year, we’ve learned that this is exactly what’s happening with many of our customers. Visibility across your API attack surface is extremely valuable, but being able to test it dynamically, in runtime, is no easy feat. According to a StackHawk customer survey, 85% of security teams cited missing API specifications as a primary barrier to API security testing.

Today, that changes with StackHawk’s AI-powered OpenAPI Spec Generation.

The API Testing Bottleneck That’s Blocking Security Teams

APIs are now the dominant attack surface in modern applications, yet our approach to API documentation remains stuck in manual, developer-dependent processes. The explosion of APIs in modern applications—accelerated by AI-powered code generation—has fundamentally outpaced our ability to document and secure them.

For AppSec teams, this creates a gap: they’re held accountable for API security coverage, but they depend entirely on developers to produce the OpenAPI specs needed for testing.

This leaves AppSec teams blocked from achieving coverage across enterprise environments:

• Legacy systems running in production have no remaining team members who understand the codebase. 
• Applications acquired through M&A arrive without specifications and little business incentive to invest in retroactive documentation.
• Shadow APIs emerge outside governance frameworks, created by teams focused on delivery rather than documentation.
• External development partners lack the access or motivation to maintain API specifications.

Manual spec creation is time-consuming, error-prone, and often deprioritized, leaving AppSec teams blocked by engineering resources that are stretched thin. 

StackHawk’s AI-Powered Automated OpenAPI Spec (OAS) Generation removes that bottleneck. 

How it Works: From Source Code to API Security Testing in the Blink of AI

StackHawk’s approach transforms source code analysis directly into comprehensive OpenAPI specifications—no manual intervention from engineers required.

Step 1: Source-Based API Discovery

As part of StackHawk’s API Attack Surface Discovery, we connect to your code repositories and perform deep structural analysis of your codebase, identifying API endpoints, routing patterns, data models, and authentication flows. 

Step 2: AI-Powered Spec Generation 

Leveraging our advanced LLMs, StackHawk transforms that code analysis into OpenAPI specifications that accurately reflect your API’s behavior and are tailored to your specific implementation. Framework-specific pattern recognition captures not only basic endpoints but also parameter validation rules, response schemas, authentication requirements, and error handling patterns.

Step 3: Immediate Testing Integration

The generated specs feed directly into StackHawk’s testing engine, enabling immediate security testing for authentication bypasses, data exposure vulnerabilities, and business logic flaws. The entire process, from source code to the first security scan, typically completes in under 15 minutes.

Secure, Privacy-First Processing

Throughout this process, StackHawk maintains enterprise-grade data protection. Because we analyze code structure and API patterns rather than processing raw source code content, we ensure your intellectual property remains secure while still generating specifications that are accurate enough for comprehensive security testing.

What Source-Based Spec Gen Unlocks for Security Teams

Network traffic-based API security tools require production infrastructure and extended observation periods, resulting in incomplete coverage. StackHawk’s approach leverages source code analysis to deliver comprehensive specifications immediately with no infrastructure overhead, delivering fast, accurate, and always-up-to-date specs.

Fast and Scalable Security Coverage

With StackHawk, AppSec’s old workflow—discover APIs, request specs from developers, wait weeks, maybe receive documentation, finally begin testing—collapses into a single automated step. Security teams can now answer “How do we test this API?” with immediate action rather than relying on developers. By eliminating the #1 barrier to API security testing, StackHawk shortens the path from discovery to covered from weeks to minutes.

Complete and Accurate Specs

Unlike traffic-based approaches that only capture actively used APIs, source code analysis reveals all endpoints—including unused paths, error handlers, authentication flows, and protected endpoints that never appear in production traffic monitoring. This eliminates blind spots across legacy systems, acquired applications, and shadow APIs. And unlike manual documentation that relies on imperfect developer recall and notes, StackHawk generates a comprehensive picture of how your APIs actually function—including edge cases and rarely-used endpoints that teams often miss.

Always Up-to-Date Documentation

Static documentation becomes outdated almost as soon as it’s created. With StackHawk, API changes are automatically detected, and specs are automatically regenerated to match your new implementation. This ensures your security testing always reflects your actual attack surface throughout the API lifecycle with every code update—not what your APIs looked like months ago when someone last updated the documentation. 

“It’s working phenomenally – better than expected. We’re getting more accurate results than our current specs, with zero false positives and faster scans. – Lake Setser, InfoSec Lead at Community America Credit Union

Transforming API Security Testing

OpenAPI specifications form the foundation of the entire API security lifecycle, powering risk assessment, threat modeling, runtime monitoring, and behavioral analysis. The challenge has always been creating and maintaining those specs at scale.

StackHawk’s automated OpenAPI Spec Generation removes that barrier. What once took weeks of developer effort and left gaps across complex enterprise API attack surfaces is now instant and continuous—making full-lifecycle API security achievable at modern engineering speed.

Join our upcoming Office Hours to learn how StackHawk’s AI-Powered OpenAPI Spec Generation can eliminate the documentation bottleneck in your API security program.