Discover the Best API Discovery Tools in 2025

Selecting the right API discovery tools plays a massive role in API integration, API management, and many other areas where understanding your entire API portfolio is critical. These tools can help ensure that every API connected to your organization is discovered and cataloged, which is a major part of ensuring that APIs are secure. Without a thorough understanding of your organization’s APIs, it’s challenging to maintain their compliance, security, and effective utilization.

Enterprises’ API landscapes are evolving significantly with the rise of AI-powered development tools. Recent research confirms that AI-driven development is accelerating API creation, with AI agents automating everything from bug fixes to code optimization, often without proper documentation or oversight. This makes having a comprehensive API discovery tool more critical than before.

This guide will examine how API discovery can streamline many parts of your workflow. We’ll compare the top API discovery tools available in 2025, discover their advantages and use cases, and provide the information you need to choose the right solution for discovering APIs within your ecosystem.

What is API Discovery and Why Does It Matter?

API discovery involves understanding and mapping out APIs across applications and determining their capabilities and functionalities. Having automated, continuous API discovery  can help accelerate app development by understanding their capabilities. From a security perspective, API discovery helps in a variety of ways.

The Growing Challenge of Shadow APIs

Shadow APIs represent one of the most significant security challenges facing modern organizations. These are APIs that exist within your infrastructure but operate outside of official oversight, API documentation, and security controls. Research from Cequence Security analyzing 20 billion API transactions found that roughly 31%, or 5 billion of the 16.7 billion malicious transactions targeted unknown, unmanaged, and unprotected APIs, commonly referred to as shadow APIs.

The rise of AI-powered development tools has exacerbated the shadow API problem by enabling developers to rapidly create APIs without adhering to traditional governance processes. These quickly generated endpoints often bypass standard approval workflows, making them particularly difficult to track and secure.

According to Gartner research, “Most organizations grossly underestimate the number of shadow IT applications already in use.” This visibility gap makes shadow APIs one of the most challenging aspects of modern API security.

Three particular types of APIs can degrade an organization’s security posture: 

1. Shadow APIs (undocumented and unmanaged)
2. Zombie APIs (deprecated but still active)
3. Rogue APIs (maliciously created)

Modern API discovery tools are essential for identifying these hidden threats before attackers can exploit them. From there, prioritizing based on factors like sensitivity and exposure helps AppSec teams zero in on the APIs that matter most, balancing security with the speed of modern development.

Understanding API Discovery Methods

When evaluating API discovery tools, it’s important to understand the fundamental approaches they use, as each method has distinct advantages and limitations that can significantly impact your organization’s visibility into its API landscape.

Source Code-Based Discovery

Source code-based discovery is the most comprehensive approach to API identification. This method analyzes your actual codebase to identify APIs at the source, providing unparalleled visibility into your complete API portfolio. Unlike other approaches, source code analysis can identify APIs regardless of whether they’re currently active, receiving traffic, or even deployed to production environments.

This approach excels at discovering dormant APIs that may have been developed but never activated, development endpoints that exist in staging environments, APIs that are only occasionally used during specific business processes, and endpoints that may be commented out in code but could potentially be reactivated. Source code-based discovery also provides valuable context about API functionality, parameters, and intended usage patterns by analyzing the surrounding code structure.

The primary advantage of this method is its completeness since it reveals your entire API attack surface, not just the portions that are currently active. This is particularly valuable for security teams who need to understand all potential entry points into their systems, regardless of current usage patterns.

Traffic-Based Discovery

Traffic-based discovery monitors network traffic to identify APIs based on actual usage patterns and real-time data flows. This method observes HTTP requests and responses flowing through your network infrastructure, analyzing patterns to identify API endpoints, understand usage frequency, and map data flows between systems.

This approach is particularly effective for understanding how APIs are actually being used in production environments. It can provide insights into API performance, identify frequently accessed endpoints that may need additional security attention, reveal unauthorized API usage patterns, and help teams understand the operational characteristics of their API ecosystem.

Traffic-based discovery excels at providing real-time operational insights and can be valuable for performance optimization and capacity planning. However, it has inherent limitations since it can only see APIs that are actively receiving traffic during the monitoring period, may miss APIs that are used infrequently or during specific time windows, and cannot identify APIs that exist but aren’t currently accessible from the monitored network segments.

Hybrid and Specialized Approaches

Some modern API discovery tools combine multiple discovery methods to provide broader coverage and more comprehensive insights. These hybrid approaches might integrate source code analysis with traffic monitoring, combine static analysis with dynamic testing capabilities, or incorporate external scanning techniques to identify publicly accessible APIs.

Specialized approaches include external attack surface management tools that scan from outside your network perimeter, integration-based discovery that leverages API gateway logs and management platforms, and documentation-driven discovery that analyzes existing API specifications and documentation repositories.

The Evolution of API Discovery: Meeting AI Development Challenges

The world of API discovery has undergone a remarkable transformation, driven largely by the changing nature of software development itself. Modern trends toward AI-assisted discovery are enabling tools to understand not just what APIs exist, but how they’re intended to be used and how they interact with other system components.

The Impact of AI-Accelerated Development

With the proliferation of AI coding assistants, the need for comprehensive API catalogs has become even more important. AI agents can create technical documentation directly from source code, including docstrings, API specs, README files, and endpoint explanations, but they need accurate discovery data to work effectively.

The challenge is that AI-powered development tools are creating APIs faster than traditional discovery methods can catalog them. When APIs were fewer in number, manual API discovery was sufficient for the most part. However, developers using tools like GitHub Copilot, ChatGPT, or other coding assistants can rapidly generate new endpoints, modify existing APIs, or create entirely new services without following traditional API documentation and registration processes. This has amplified the shadow API problem, as functional endpoints are developed and deployed without proper oversight or security review.

Modern Discovery Requirements

Today’s API discovery tools must be capable of keeping pace with rapid development cycles while providing comprehensive coverage across diverse technology stacks. They need to understand modern development patterns, including microservices architectures, serverless functions, containerized applications, and cloud-native deployments.

The most effective modern discovery approaches combine automated scanning capabilities with intelligent analysis that can understand code context, identify potential security risks, and provide actionable insights for both development and security teams.

Key Selection Criteria for API Discovery Tools

Choosing the right API discovery tool requires careful consideration of multiple factors that will impact both the effectiveness of your discovery efforts and the integration with your existing development and security workflows.

Discovery Coverage and Accuracy

The most fundamental consideration is how comprehensively and accurately a tool can identify APIs in your environment. Evaluate whether the tool can discover APIs across all the technologies and frameworks your organization uses. Consider whether it can identify APIs in development environments, staging systems, and production deployments. Assess the tool’s ability to distinguish between different types of endpoints and its accuracy in identifying true APIs versus other HTTP endpoints.

Look for tools that can provide detailed information about discovered APIs, including parameter structures, authentication requirements, data types, and usage patterns. The tool should also be able to identify relationships between APIs and understand how they fit into larger application architectures.

Integration Capabilities and Workflow Compatibility

Modern development environments are complex ecosystems involving multiple tools, platforms, and processes. Your API discovery tool should integrate seamlessly with your existing technology stack, including source code management systems, CI/CD pipelines, API gateways, security tools, and monitoring platforms.

Consider how the tool fits into your development workflow. Does it require developers to change their coding practices or add additional steps to their deployment processes? Can it automatically update API inventories as code changes, or does it require manual intervention? The best tools enhance developer productivity rather than creating additional overhead.

Evaluate the tool’s reporting and visualization capabilities. Can it generate reports that are useful for different stakeholders, from developers who need technical details to executives who need high-level risk assessments? Does it provide APIs or integrations that allow you to incorporate discovery data into other tools and dashboards?

Security Features and Risk Assessment

API discovery should be viewed as a security enabler, not just an inventory tool. Evaluate the tool’s ability to identify security-relevant characteristics of discovered APIs, such as authentication requirements, data sensitivity, exposure levels, and potential vulnerabilities.

Look for features that help prioritize security efforts by identifying high-risk APIs, such as those that handle sensitive data, are publicly accessible, or have known security issues. The tool should integrate with your security testing tools and processes, enabling the automatic security scans and assessments of discovered APIs.

Consider the tool’s ability to detect shadow APIs, zombie APIs, and other potentially risky endpoints that may not be properly managed or secured. The tool should provide clear visibility into which APIs are properly documented and managed versus those that may have been created outside of standard processes.

Scalability and Performance Considerations

As your organization grows and your API portfolio expands, your discovery tool needs to scale accordingly. Evaluate the tool’s performance characteristics, including how quickly it can scan large codebases, how efficiently it processes network traffic, and how well it handles high-volume environments.

Consider the tool’s impact on your development and production systems. Does it require significant computational resources? Will it affect application performance or developer productivity? The best tools provide comprehensive discovery capabilities while maintaining minimal overhead on your systems.

Assess the tool’s ability to handle diverse and distributed environments, including multi-cloud deployments, hybrid architectures, and complex organizational structures. Can it provide unified visibility across different environments while respecting security boundaries and access controls?

Securing APIs in an AI-Accelerated World

As organizations adopt AI-powered development, the security challenges surrounding API discovery become increasingly complex. Developers using AI coding tools can rapidly generate new endpoints, creating APIs faster than traditional discovery and security processes can track them.

The key to maintaining security in this rapidly evolving landscape is comprehensive visibility combined with automated security processes. Organizations need discovery tools that can keep pace with accelerated development cycles while providing immediate security validation of discovered endpoints.

This requires a shift from periodic discovery efforts to continuous monitoring and assessment. Security teams need real-time visibility into new APIs as they’re created, along with automated processes for evaluating their security posture and ensuring they meet organizational standards.

The most effective approach combines proactive discovery with integrated security testing, ensuring that APIs are not only found but also secured adequately from the moment they’re identified.

Top 7 API Discovery Tools in 2025

Now, it’s time to look at the tools that can help with automated API discovery and API cataloging. Although many automated API discovery tools exist, these are the top tools covering various aspects and types of API discovery. Let’s take a look!

1. StackHawk

StackHawk provides comprehensive API discovery through source code analysis, offering the most complete view of your API landscape by examining your actual codebase rather than just network traffic.

API Discovery Features:

• Source code-based discovery that identifies ALL APIs, including dormant and infrequently accessed endpoints
• AI-powered framework detection supporting C#, Go, Java, JavaScript, Kotlin, TypeScript, Python, Rust, Scala, and PHP
• Sensitive data discovery for PII, PCI, and PHI identification across repositories
• Repository integrations with GitHub, GitLab, Azure Repos, and Bitbucket
• Developer collaboration features that identify who last touched each discovered asset

At StackHawk, we believe that Source Code is the Source of Truth. Unlike traffic-based tools that can only see active APIs, StackHawk’s AI-powered discovery examines your actual codebase to provide complete API visibility. This inside-out approach reveals your entire attack surface, including shadow APIs that traffic analysis simply cannot detect.

Modern software development is inherently complex, making it challenging for security teams to pinpoint all the “things” they need to test. StackHawk’s API Discovery and API security testing platform takes an inside-out approach, empowering developers and AppSec teams to achieve security and speed:

• Effortless Integration: Connect your code repositories through seamless SCM integrations
• Attack Surface Coverage: Monitor your progress toward achieving complete API coverage through visualization dashboards
• Continuous Monitoring: StackHawk’s discovery tracks code deployment frequency and compares it to your testing frequency
• Policy Alignment: Identify discrepancies between your security policies and actual testing coverage

Discover and Test, in one place

StackHawk goes beyond traditional API discovery tools by pairing discovery with powerful, API-focused DAST capabilities. This means newfound security doesn’t just stay on paper; you can immediately test those discoveries, ensuring your organization’s security posture is truly strengthened.

StackHawk’s API Discovery maintains read-only access to repositories, never sends code to third parties, and provides transparency about AI involvement. Organizations can disable AI processing to align with compliance requirements.

2. Salt Security

Salt Security’s API discovery focuses on identifying APIs through traffic analysis and behavioral patterns across enterprise environments.

API Discovery Features:

• Continuous, automated discovery of internal, external, and third-party APIs through traffic monitoring
• Behavioral analysis to identify API endpoints based on usage patterns and data flows
• Shadow API detection by analyzing unknown or undocumented endpoints in network traffic
• Real-time discovery that identifies new APIs as soon as they begin receiving traffic
• Risk scoring for discovered APIs based on data sensitivity and exposure levels

3. Akamai API Security (formerly Noname Security)

Akamai’s API discovery platform uses traffic-based analysis to identify APIs across complex, distributed cloud environments.

API Discovery Features:

• Automated discovery through network traffic analysis across multiple cloud platforms
• Protocol support for discovering HTTP, RESTful, GraphQL, SOAP, XML-RPC, and JSON-RPC APIs
• Shadow API identification by comparing discovered endpoints against documented API inventories
• Sensitive data classification for discovered APIs handling PII, financial data, and intellectual property
• Integration with Akamai’s CDN infrastructure for comprehensive traffic visibility

4. Wallarm

Wallarm’s API discovery builds comprehensive API inventories through real-time traffic analysis and behavioral monitoring.

API Discovery Features:

• Continuous API inventory building based on actual production traffic analysis
• Real-time discovery that identifies new API endpoints within 30 seconds of first use
• Shadow, orphan, and zombie API detection through traffic pattern analysis
• Automatic OpenAPI specification generation from observed API behavior
• Local traffic analysis with cloud-based aggregation for privacy-focused discovery

5. APIsec

APIsec’s discovery platform focuses on identifying APIs through external scanning and security-oriented analysis.

API Discovery Features:

• External API discovery through automated scanning of public-facing endpoints
• Shadow API detection by crawling and enumerating potential API paths
• Integration-based discovery through AWS API Gateway and other platform connectors
• Security-focused analysis that prioritizes the discovery of vulnerable or exposed APIs
• Automated API specification inference from discovered endpoint behavior

6. AWS API Gateway Discovery

AWS provides built-in discovery capabilities for APIs managed through their native gateway infrastructure.

API Discovery Features:

• Native discovery of APIs deployed through AWS API Gateway services
• CloudTrail integration for comprehensive API usage and access pattern analysis
• Automatic inventory generation for all APIs within AWS infrastructure
• Cost and performance analytics for discovered API endpoints
• Integration with AWS security services for discovered API protection

7. Kong API Management Platform

Kong’s discovery capabilities focus on APIs managed through their gateway infrastructure and service mesh.

API Discovery Features:

• Gateway-based API discovery for endpoints routed through Kong infrastructure
• Service mesh integration for discovering APIs in microservices architectures
• Plugin-based discovery extensions that can identify APIs through various methods
• Developer portal integration that maintains discoverable API catalogs
• Analytics-driven discovery that identifies API usage patterns and endpoint relationships

Conclusion

APIs are one of the most critical components of modern software, but their vast numbers and the rapid pace of AI-accelerated development make it difficult to know what you have and keep it all secure. The most effective approach to API discovery combines comprehensive visibility with immediate security action.

When choosing an API discovery tool, prioritize solutions that provide complete coverage of your API landscape and integrate security testing directly into your development workflow. The goal isn’t just to find APIs; it’s to ensure they’re secure from the moment they’re discovered.

For organizations serious about API security, source code-based discovery offers the most comprehensive visibility, while integrated security testing ensures that discovery leads directly to protection.

Want to see comprehensive API discovery in action? Schedule a demo to learn how source code-based discovery can illuminate your complete API landscape and help with continuous API discovery and testing.