What Is API Visibility: Examples, Tools & Best Practices

APIs now function as the operational core of modern enterprises, powering products, partner ecosystems, and data flows. Their growth trajectory is accelerating. Recent industry research shows that 30% of organizations experienced 51 to 100% growth in their API footprint within a year, and another 25% saw their API count more than double. More than 55% of enterprises now manage 500 or more APIs, yet nearly 40% admit they do not maintain an accurate inventory.

This visibility gap creates material security and operational risk. 99% of organizations reported API related security issues in the past 12 months, and 55% delayed application releases because of unresolved API risks. Over 60% of teams are not confident in the accuracy of their API inventories, and only 15% believe they have full coverage across all environments. Sensitive data exposure is rising, with 31% of enterprises reporting production level exposure, and 75% acknowledging they lack a complete API inventory.

For a CISO, this reality represents more than a security weakness. It directly affects resilience, uptime, and strategic risk management. Effective API visibility is no longer optional. It is the prerequisite for prevention, governance, and trust. Without a precise understanding of what APIs exist, what data they process, and how they behave, meaningful security becomes impossible.

What is API Visibility?

API Visibility is the unified ability to know what exists, what it does, and what it handles across your entire API ecosystem. It combines three foundational pillars: a complete API inventory (what APIs exist), accurate API documentation (what each API does), and deep sensitive data understanding (what information each endpoint processes or exposes). Together, these provide an authoritative, real time view of your API landscape, eliminating blind spots and enabling teams to operate with confidence instead of guesswork.

In large scale, distributed architectures, achieving visibility is both essential and difficult. Modern systems span hundreds or thousands of microservices, multi cloud environments, CI/CD pipelines, and third party integrations, each generating constantly shifting API surfaces. Without continuous discovery, documentation enrichment, and sensitive data classification, organizations lose track of shadow APIs, zombie endpoints, version sprawl, and high risk data flows. 

Effective API visibility seamlessly ingests traffic, correlates logs, maps dependencies, and analyzes payloads in real time. The result is a living, always current blueprint of how your APIs work, interact, and handle data, powering stronger security, faster engineering decisions, and sustainable governance at scale.

Pillars of API Visibility

API visibility is built on three core pillars: knowing what exists, understanding what it does and identifying what it handles. Together, these elements create a complete and continuously updated picture of your API surface, which is essential for both security and governance at scale.

1. API Inventory or Catalogue: Knowing What Exists.

This pillar focuses on continuously discovering every API in your ecosystem, including internal, external, partner, third party, shadow and zombie endpoints across development and production. Modern teams deploy new APIs faster than security teams can track them, and deprecated ones often remain online without authentication. A dynamic and accurate inventory eliminates these blind spots and ensures nothing is overlooked.

2. API Documentation: Understanding What It Does.

Documentation provides the behavioural blueprint of each API. It includes specifications such as OpenAPI or Swagger that define endpoints, methods, parameters, rate limits, authentication requirements and expected responses. Without clear documentation, security scanners cannot replicate real interactions or validate authentication paths. Many enterprises struggle here, with 66% reporting incomplete or missing API documentation.

3. Sensitive Data Discovery: Knowing What It Handles.

This pillar focuses on identifying which APIs process sensitive data such as personally identifiable information, payment information or health records. Field level detection is essential because even a single risky parameter can create a major exposure. Sensitive data issues remain one of the biggest challenges in API security, with 31% of enterprises reporting exposure in live APIs. Understanding these data flows ensures teams can prioritise protections where they matter most.

Why is API Visibility Important?

API visibility is the control point that keeps security, compliance and engineering aligned as API ecosystems scale. Without it, organisations operate in the dark, exposing critical systems and sensitive data to avoidable risk.

1. Preventing Breaches and Service Disruption

Unknown or undocumented APIs are prime targets because they fall outside baselines, logging and monitoring. Shadow and zombie APIs bypass governance and often remain misconfigured or unauthenticated. These blind spots open paths for data exfiltration, business logic abuse and denial of service attacks. If an API is invisible, it cannot be tested or monitored, leaving essential workflows exposed.

2. Reducing Sensitive Data Exposure and Compliance Risk

Regulatory frameworks such as PCI DSS, HIPAA, GDPR and India’s DPDP Act all require a complete inventory of systems that process sensitive data. Yet 75% of enterprises still lack a full API inventory, and 31% have already experienced sensitive data exposure in production environments. Fintech organisations, in particular, face mounting pressure with the March 2025 PCI DSS Phase 2 deadline. Manual discovery cannot keep up, making automated visibility essential to classify data flows and enforce encryption, RBAC and monitoring at scale.

3. Enabling Effective Security Testing

Security testing is only as comprehensive as the inventory it relies on. Missing endpoints create false confidence, as scanners test only a subset of the real surface. Spreadsheet-based inventories and quarterly audits fail to match weekly or daily deployment cycles, leading to API drift. Continuous visibility enables continuous testing and ensures that shift left and shift right controls accurately reflect what is running in production.

4. Accelerating DevOps and Reducing Friction

Limited visibility slows engineering teams, forcing developers to fill documentation gaps or manually map APIs before release. As a result, 59% of enterprises have delayed application rollouts due to API security concerns. Automated discovery and documentation remove this operational bottleneck, allowing DevOps teams to maintain velocity while security teams uphold governance.

Who Needs API Visibility?

• API visibility is not a security-only requirement. It is a cross-functional capability that supports every team responsible for building, operating and governing modern digital systems.
• Engineering Leaders
  Engineering organisations gain clarity on API reuse, duplication and performance. A continuous catalogue shows where teams are unintentionally rebuilding services, where consolidation is possible and how dependencies impact system behaviour at scale.
• Security Leaders
  CISO and security teams depend on visibility to understand the full attack surface, enforce policies and prioritise risk-based remediation. By exposing shadow and zombie APIs, visibility strengthens threat detection and eliminates blind spots that attackers routinely exploit.
• Compliance Teams
  Compliance functions require accurate, up-to-date records to satisfy audits for standards such as ISO 27001, SOC 2 and PCI DSS. Without visibility, they cannot demonstrate where sensitive data flows or validate controls applied to each API.
• Developers and Product Teams
  Developers rely on clear API documentation to understand behaviour, troubleshoot faster and iterate safely. Incomplete or outdated specifications slow delivery, introduce errors and impede business outcomes.
• Enterprises with Rapidly Expanding API Footprints: Many large enterprises report double digit API growth year over year, with some teams seeing their API estates expand by more than 80% due to microservices and partner integrations. In several sectors, it is now common for organisations to operate well over 800 to 1,200 APIs across environments. At this pace, manual mapping, spreadsheets and quarterly audits fail immediately. Continuous visibility becomes essential to maintain accuracy, security and operational control at scale.
  

Risks of Incomplete API Discovery & Visibility

Incomplete API discovery creates systemic blind spots that attackers, auditors and even internal teams can easily exploit. When organisations lack a unified, real time view of their API landscape, the risks compound across security, compliance and operations. Some of these risks are:

1. Blind Spots and New Attack Entry Points: Unknown APIs operate outside baselines and logging. Shadow and zombie endpoints bypass authentication, expose sensitive data and give attackers unguarded paths into critical systems. Any API that is invisible to defenders becomes a direct opportunity for exploitation.

2. Misconfiguration and Drift: APIs evolve constantly. Without continuous inventory, deprecated or unauthenticated endpoints stay exposed long after they should be retired. More than 60% of teams lack confidence in their API inventory, which leads to inconsistent policies, access issues and configuration drift that attackers can leverage.

3. Delayed Detection and Incident Response: You cannot monitor what you cannot see. Without full visibility, runtime detection and behavioural analytics fail to cover the actual attack surface. Nearly 95% of API attacks in a year originate from authenticated sources, which makes it essential to monitor every endpoint, not only public ones.

4. Compliance Violations and Third Party Risk: Regulatory frameworks such as PCI DSS, ISO 27001 and SEBI CSCRF require complete visibility into all systems processing sensitive data, including external and partner APIs. Manual inventories often miss third party integrations entirely, creating hidden compliance failures and ungoverned data flows.

5. Business Disruption and Slower Release Cycles: Lack of visibility forces developers to pause releases to map APIs or remediate undocumented behaviour. More than 55% of organisations delayed application rollouts due to API security concerns. When the API surface is unknown, engineering velocity and business continuity suffer.

Limitations of Legacy API Discovery Approaches

Traditional API discovery methods were built for slower, monolithic systems. In modern microservice and multi cloud environments, they fail almost immediately. Legacy approaches create gaps that compound risk and operational drag.

Legacy discovery creates the illusion of control while leaving critical blind spots untouched. Modern API ecosystems demand continuous, automated and context rich discovery to match their speed and complexity.

• Manual Cataloguing Does Not Scale: Relying on developers to list APIs or maintain spreadsheets collapses under enterprise scale. Many organisations now operate more than 500 APIs, with new ones introduced every sprint. Human driven inventories are always outdated, incomplete and inconsistent.
• Documentation Gaps Break Visibility: Developers optimize for delivery, not documentation. As a result, 66% of enterprises report missing or incomplete API documentation. Without accurate specs, security teams cannot generate tests, validate authentication paths or enforce consistent governance.
• Rapid CI/CD Creates Constant Drift: High velocity pipelines deploy new APIs and revisions in hours, not months. Older endpoints often remain exposed without authentication, while new ones appear instantly. Manual inventories cannot keep pace with the speed and frequency of change.
• Static Scanners Miss Runtime Reality: Traditional scanners focus on code repositories, hosts or predefined OpenAPI files. They cannot see APIs that surface only at runtime or classify internal, external and third party traffic flows. This leaves large parts of the attack surface unaccounted for.
• Sensitive Data Mapping Is Manual and Unmanageable: Tracing PII, PCI or PHI across distributed microservices requires deep, end to end observability. Yet 75% of enterprises lack a complete API inventory, making manual data flow mapping impossible at scale. Sensitive data exposure becomes a predictable outcome rather than an exception.

Key Steps to Build an Effective API Visibility Strategy

A robust API visibility strategy must be continuous, automated and deeply contextual. The goal is to eliminate blind spots, reduce operational friction and ensure that security, engineering and compliance teams operate from a single source of truth.

A modern visibility strategy connects discovery, documentation, data classification and governance into a unified operational framework that scales with the pace of API driven development.

1. Automate Discovery Across All Environments: Adopt agentless methods such as eBPF based sensors to detect APIs across development, QA, staging and production. Continuous traffic analysis surfaces active, dormant, shadow and zombie endpoints that traditional tools miss.

2. Generate and Maintain Documentation Automatically: Auto generate OpenAPI or Swagger specifications with version history, parameters, rate limits and authentication details. Automated documentation reduces drift, accelerates onboarding and enables comprehensive security testing.

3. Classify Sensitive Data at Field Level: Identify and tag PII, PHI and PCI data within request and response payloads. Field level classification helps teams prioritise high risk APIs and align controls with regulatory requirements.

4. Contextualise Every Endpoint: Capture metadata such as authentication status, rate limiting, version history and observed error patterns. Behavioural context transforms raw inventories into actionable insights and supports risk scoring.

5. Integrate Inventory with Testing and Monitoring: Ensure new endpoints automatically trigger both shift left and shift right workflows. Align dynamic testing, static analysis and runtime monitoring so that the complete API attack surface is continuously validated.

6. Assign Ownership and Manage the Lifecycle: Map APIs to accountable teams, decommission deprecated endpoints and maintain version lineage. Clear ownership reduces operational gaps and ensures secure API evolution.

7. Enforce Governance and Compliance: Use continuously updated inventories to generate audit ready reports for ISO 27001, PCI DSS, SOC 2 or DPDP. Validate third party API controls and ensure that sensitive data flows are fully documented and monitored.

KPIs to Measure API Visibility

Clear metrics are essential to validate the maturity of an API visibility program and ensure it keeps pace with rapid architectural change. The following KPIs help security, engineering and compliance leaders quantify progress and identify gaps. These KPIs provide a quantifiable framework for tracking visibility, reducing risk and demonstrating operational maturity across the entire API ecosystem.

• Inventory Coverage: Measure the percentage of APIs discovered compared to the estimated total. The benchmark is complete visibility across all environments with a goal of reaching 100 percent coverage.
• Shadow and Zombie APIs Identified: Track the number of undocumented, abandoned or inactive APIs surfaced and remediated. A declining trend indicates stronger governance and reduced attack exposure.
• Documentation Completeness: Evaluate the proportion of APIs with accurate and up to date specifications. Maintaining more than 90 percent completeness reduces drift and improves testing accuracy.
• Sensitive Data Exposure: Monitor how many APIs process PII, PCI or PHI without appropriate controls. Reducing this count demonstrates improved classification, enforcement and regulatory alignment.
• Time to Inventory Update (MTTI): Assess how quickly new or modified APIs appear in the inventory. The target is near real time reflection of changes to avoid blind spots during deployments.
• Mean Time to Detect and Respond (MTTD and MTTR): Measure the speed from exposure to detection and remediation. Comprehensive visibility should measurably lower both metrics as hidden endpoints and misconfigurations are eliminated.
• Compliance Readiness: Determine whether inventory and data classification provide audit ready evidence for standards such as ISO 27001, SOC 2 or PCI. Mature programs show consistent, automated compliance reporting with minimal manual intervention.

Best Practices for Effective API Visibility

Achieving mature API visibility requires more than an inventory. It demands continuous discovery, contextual intelligence and seamless integration across the software lifecycle. These best practices create a proactive visibility model that strengthens security, supports compliance and accelerates development across complex API driven architectures. 

• Continuous and Automated Discovery: Adopt continuous, automated discovery that monitors every environment. Modern development cycles move too quickly for periodic scans or manual updates to stay accurate.
• Behaviour Aware Inventory: Enrich each API with runtime context such as authentication schemes, rate limits, status codes and error patterns. Behaviour level insights enable precise risk scoring and prioritised remediation.
• Sensitive Data Discovery and Mapping: Automatically identify sensitive fields and track data flows across microservices. Field level mapping ensures compliance and focuses protection on APIs that handle critical information.
• Centralised Portal and Cross Team Collaboration: Provide a unified portal where developers, security and compliance teams access the same real time inventory. A single source of truth eliminates duplication, misalignment and version sprawl.
• Integration Across the SDLC: Embed visibility into CI and CD workflows as well as runtime environments. Every new or updated endpoint should automatically generate documentation, trigger testing and enable monitoring.
• Risk Based Prioritisation: Use contextual attributes such as authentication status, rate limiting and sensitive data exposure to prioritise the APIs that pose the greatest risk to the business.
• Shift Left and Shift Right Alignment: Combine design time governance with runtime monitoring to detect misconfigurations and attacks early. Alignment across the lifecycle ensures issues are caught before they become production incidents.

Challenges in Achieving API Visibility

Even with strong intent and modern tooling, achieving full API visibility remains difficult for large and fast growing organisations. The obstacles are structural, operational and increasingly shaped by emerging technologies. These challenges highlight why many enterprises still struggle to achieve comprehensive visibility. Overcoming them requires automation, unification of data sources and a strategy designed for complexity at scale.

• Scale and Complexity: Microservices, cloud native architectures and distributed systems generate thousands of dynamic endpoints. API estates are expanding at a pace that manual mapping and periodic audits cannot match. The average enterprise footprint grows faster than traditional processes can sustain.
• Fragmented Tools and Organisational Silos: API knowledge is often scattered across gateways, code repositories, developer teams and infrastructure tooling. Each system provides only a partial view, leaving critical gaps that prevent a unified inventory.
• Resource Constraints: Many organisations report budget limitations at 30 percent and staffing constraints at 22 percent, making it challenging to invest in continuous discovery, documentation automation and data classification. Visibility initiatives stall when teams cannot dedicate the required resources.
• Evolving Regulatory Pressures: Compliance frameworks such as PCI DSS Phase 2 and the India DPDP Act require continuous tracking of systems that process sensitive data. As regulations evolve, visibility programmes must constantly update inventory, documentation and reporting processes to remain audit ready.

Impact of AI and Autonomous Agents: AI driven and agentic workloads introduce new unpredictability. Machine generated API calls create nonlinear request patterns, invoke hidden dependencies and operate at machine scale. Visibility systems must adapt to identify, classify and monitor these interactions without manual intervention.

How to Choose the Right API Visibility Tools

Selecting an API visibility platform requires more than checking for basic discovery features. CISOs and engineering leaders need solutions that deliver deep context, automation and alignment across security, compliance and development. The right tool must operate at scale, integrate seamlessly and withstand the velocity of modern software delivery.

Choosing the right API visibility tool means selecting a platform built for continuous discovery, deep context and enterprise scale so teams can maintain control even as their API ecosystems grow.

• Comprehensive, Continuous Coverage: Prioritise platforms that discover every API type across internal, external, partner and third party services. Coverage should span REST, GraphQL, gRPC and SOAP to ensure no gaps in hybrid or multi cloud environments.
• Agentless, Low Overhead Instrumentation: Tools should use passive OS layer methods such as eBPF to analyse traffic without code changes or latency. This approach ensures accurate discovery while eliminating operational friction.
• Sensitive Data Awareness: Select tools that automatically detect APIs handling PII, PHI and PCI. Visibility must include data classification and authentication context to prioritise risk based on exposure levels.
• Real Time Risk Context: The platform should enrich every endpoint with live metadata including authentication, rate limits, response codes and behaviour patterns. This context is essential for filtering noise, scoring risk and accelerating remediation.
• Auto Update and Version Tracking: Continuous detection of new APIs, version changes and deprecations is critical to prevent drift. Tools must generate complete histories that reflect real time application behaviour.

• Flexible Integration Across the Stack: Choose solutions that integrate with CI/CD pipelines, code repositories, API gateways, SIEMs and ticketing systems. Visibility must flow across engineering, security and compliance workflows.
• Full Visibility Without Performance Impact: Ensure the platform delivers complete coverage without introducing latency or requiring architectural changes. Passive, out of path sensors enable deployment even in complex or air gapped environments.
• Actionable Insights for All Stakeholders: The tool should provide insights that support incident response, compliance reporting and developer productivity. Effective platforms help prioritise fixes, map dependencies and encourage API reuse.
• Proven Scalability: The solution must handle thousands of microservices and high volume traffic with minimal overhead. Scalability is essential for enterprises operating across distributed and rapidly evolving architectures.

Top API Visibility Tools for 2025

API visibility platforms are evolving from simple endpoint enumeration to full stack discovery, documentation and behaviour mapping. The best tools now combine runtime telemetry, code insights and sensitive data intelligence to deliver continuous, unified visibility across hybrid architectures.

Below are the leading API visibility tools of 2025, ranked based on depth, automation and ecosystem integration. While Levo.ai leads due to its comprehensive coverage, organisations should evaluate multiple options based on scale, maturity, and internal workflows.

1. Levo.ai
2. Traceable.ai
3. Rapid7
4. Akto
5. Inviciti
6. Qualys
7. Salt Security
8. StackHawk
9. Akamai Security
10. Orca Security

API Visibility platforms provide end to end insight into every API across development, staging, and production. They automatically discover shadow and third party APIs, classify sensitive data, and surface authentication, configuration, and behavioural gaps in real time. By maintaining an always current inventory and enriching each endpoint with deep runtime context, these tools enforce continuous governance, reduce security blind spots, and ensure operational, compliance, and architectural integrity at scale.

Read More: Top 10 API Discovery Tools in 2025

Why Levo.ai Is the Right API Visibility Platform for 2025

As enterprises scale into thousands of distributed APIs, partial visibility is no longer enough. Organisations need a platform that not only discovers every API but also understands its behaviour, data flows, risks and lifecycle context. This is where Levo.ai stands apart, delivering holistic, real time API visibility that unifies discovery, documentation, API security testing, governance and compliance into a single, automated engine.

What Makes Levo.ai the Clear Leader

1. 100% Discovery Across All API Types: Levo automatically discovers internal, external, partner, third party, shadow and zombie APIs using eBPF-powered runtime sensors and multiple agentless techniques. It maps APIs across dev, QA, staging and production, without code changes, traffic mirroring or configuration overhead.

2. Behaviour Aware Inventory: Every endpoint is enriched with deep runtime metadata such as authentication scheme, rate limits, error patterns, version history and traffic behaviour. This context enables risk based filtering, faster triage and smarter prioritisation.

3. Sensitive Data Discovery & Protection: Levo maps PII, PCI and PHI flows at field level and flags endpoints handling sensitive information. Misconfigurations or exposures are surfaced instantly, with real time detection and blocking to prevent data leakage.

4. Automated Documentation & Version Control: The platform auto generates OpenAPI/Swagger specs with 12+ parameters, including methods, URLs, request/response bodies, rate limits and status codes. Version tracking eliminates drift and ensures every change is captured and auditable.

5. Proactive Security Testing & Governance: Levo bridges shift left and shift right by connecting discovery to automated security tests, runtime threat detection and active blocking. It supports custom test cases, OWASP aligned checks and enterprise specific rules for continuous hardening.

6. Continuous Compliance Out of the Box: The platform automatically generates evidence and reports for ISO 27001, PCI DSS 4.0, GDPR and the DPDP Act. Automated inventory, classification and version history simplify audits and eliminate manual compliance effort.

How to Achieve Total API Visibility with Levo

Achieving complete API visibility requires more than dashboards or point in time scans, it demands continuous, automated intelligence that understands every API, its behaviour, its data, and its risks. Levo.ai delivers this through a unified methodology built to eliminate blind spots across modern, distributed architectures.

Levo’s Four-Pillar Methodology for Total Visibility

1. Know What APIs Exist—Without Asking Developers
Levo continuously discovers every API across dev, QA, staging and production using eBPF sensors and fully agentless techniques. It identifies internal, external, partner, third-party, shadow and zombie APIs automatically, ensuring no endpoint remains undocumented or hidden behind gateways, microservices or code repos.

2. See the Data Each Endpoint Handles
Through live traffic inspection, Levo classifies sensitive data at the field level—PII, PCI, PHI and more. This helps teams instantly understand which APIs carry regulatory, financial or privacy risk, and where corrective action is needed before exposure occurs.

3. Discover and Eliminate Hidden Entry Points
Levo detects APIs that appear only in traffic but not in code (shadow) and APIs present in code but unused in traffic (zombie). Both represent high-risk entry points for attackers. Levo surfaces these blind spots early, enabling teams to fix misconfigurations, deprecate unused endpoints and enforce Zero Trust API governance.

4. Maintain Continuous Compliance—With Zero Manual Overhead
By keeping an always-updated API inventory and mapping sensitive data flows, Levo generates audit-ready evidence for PCI DSS 4.0, ISO 27001, SOC 2, GDPR and India’s DPDP Act. Compliance becomes continuous and automated—no spreadsheets, no manual documentation, no last-minute fire drills.

Beyond these pillars, Levo’s technical architecture—eBPF for kernel-level visibility, agentless deployment with zero performance overhead, seamless CI/CD and cloud provider integrations—and its end-to-end security modules (governance monitoring, automated testing, runtime blocking) make it the most complete and future-ready API visibility platform in the industry today.

Conclusion: Implementing API Visibility for Complete API Protection

APIs are multiplying faster than organisations can track. With AI driven workloads, distributed microservices and tightening regulatory demands, visibility is no longer a luxury; it is the foundation of security and control. You can’t protect what you can’t see.

Manual inventories, static documentation and scan based tools simply cannot keep up. Today’s reality demands continuous, automated discovery enriched with behavioural insight and sensitive data awareness, embedded directly into the SDLC rather than added after deployment.

The numbers tell the story: API ecosystems are exploding, security incidents are rising, and most teams still lack a reliable inventory. At this scale, automated visibility isn’t just efficient; it is the only scalable path forward.

That is where Levo.ai reframes what visibility means. By turning real time discovery, documentation and data classification into an always on control plane, Levo enables proactive defence instead of reactive cleanup. Every API is identified, contextualised and governed, then connected to automated testing, monitoring and runtime protection.

Whether you are building new microservices, modernising legacy stacks or enabling AI agents, Levo gives you the clarity and confidence to move fast without exposing risk.

See everything. Understand everything. Secure everything.

That is the Levo.ai approach to next generation API visibility.

Get full visibility into your APIs in Real Time with Levo. Book your Demo today to implement API security seamlessly.