Introduction
APIs now sit at the center of digital business. They power mobile apps, partner integrations, payments, cloud platforms, and AI driven workflows. As the number of APIs grows, so does the attack surface. Recent studies show that 84 % of organizations experienced an API security incident in the past year, and only 27 % believe they have an accurate inventory of the APIs that return sensitive data. Analysts have estimated that insecure APIs and automated API abuse could contribute to more than 186 billion dollars in annual business losses worldwide.
Security and engineering leaders face an increasingly complex environment. Developers ship changes weekly or even daily. Security teams must validate authentication, authorization, and data handling across hundreds of fast moving interfaces. Compliance teams are expected to produce audit ready evidence with accuracy and speed, even when API behavior changes faster than documentation can keep up. Without reliable standards and consistent security protocols, organizations struggle to secure APIs at scale.
Platforms like Levo offer a much needed solution for this reality. By exposing runtime security intelligence through a governed, structured API interface, Levo helps organizations shrink both delivery cycles and risk exposure. With 84 % of firms reporting API incidents and nearly two thirds acknowledging blind spots in API inventory, solutions that provide real time visibility and enforceable controls are essential.
Levo delivers that visibility, enforces policy driven security, and embeds security across the API lifecycle. For engineering teams, this means faster, more confident releases.
What are API Security Standards
API security standards are a collection of rules and practices that define how APIs should authenticate clients, validate input, protect data, and enforce permissions. They ensure that every API across an organization follows consistent and predictable security behavior, which is critical as API ecosystems grow more distributed and complex.
API security standards work across three layers:
1. Design and Specification
APIs must be built with clear rules for authentication, authorization, input validation, and data exposure. Secure design standards define how resources are accessed, how errors are handled, and how much data an API is permitted to return. Strong design reduces common issues such as excessive data exposure, broken access control, and inconsistent authentication flows.
2. Implementation and Testing
Standards guide how developers implement and validate API behavior. This includes schema validation for REST and SOAP payloads, strict input handling, rate limiting, secure token management, and automated testing for authentication and authorization weaknesses. Consistent testing ensures that APIs adhere to their intended contract and do not introduce business logic or access-control flaws.
3. Monitoring and Governance
Security standards extend into runtime environments. APIs must produce reliable logs, expose telemetry, and support continuous verification. Organizations need a straightforward way to confirm that authentication rules are enforced, sensitive data is protected, and unusual behavior is detected across all environments. This makes standards an essential foundation for compliance and continuous security assurance.
Why API Security Standards Matter
Without well defined standards, API security becomes fragmented. Each team implements controls differently, documentation becomes inconsistent, and security gaps emerge across environments. Standards provide the structure needed to secure APIs at scale, support compliance requirements, and enable both developers and security teams to work efficiently with confidence.
Types of API Security
REST
What It Is
REST APIs use resource based endpoints with JSON payloads. They are easy to build and maintain, which is why they make up the majority of modern API traffic.
Why It Matters
REST maps closely to business objects. A single weak permission check or overly broad response can expose sensitive data. Since REST APIs ship updates frequently, security issues can slip into production unnoticed if standards are not enforced.
How It Is Implemented Securely
Secure REST implementations rely on:
- strict access control at object and function levels
- input validation for every parameter
- token based authentication validated on each request
- schema validation for payloads
- rate limits, quotas, and pagination
- restricting response fields to prevent data exposure
- continuous testing and runtime monitoring to catch drift
Common Risks
- broken object level and function level authorization
- excessive data exposure
- insecure token handling
- lack of rate limiting or throttling
- missing schema validation
SOAP (Interlink SOAP Article once published)
What It Is
SOAP is a protocol designed for systems that require strong contracts, strict schemas, and high assurance messaging. It uses XML payloads and WS Security standards for message integrity and confidentiality.
Why It Matters
SOAP is common in financial, telecom, banking, insurance, and enterprise integrations where reliability and security are mandatory. Weak XML handling or broken signature validation can lead to serious compromise.
How It Is Implemented Securely
Strong SOAP security requires:
- enforced XML schema validation for both requests and responses
- WS Security controls such as digital signatures, encrypted elements, and timestamps
- replay attack prevention
- strict SOAPAction header validation
- strong token validation and proper key management
- rejecting any message that deviates from the signed schema or structure
Common Risks
- XML External Entity (XXE) attacks
- signature stripping or rewriting
- SOAPAction spoofing
- schema bypassing
- incorrect or incomplete WS Security enforcement
Pro Tip : Levo.ai now automatically discovers SOAP APIs, click this link for more
GraphQL
What It Is
GraphQL exposes a single endpoint that allows clients to query exactly the data they need, using a flexible schema with nested relationships.
Why It Matters
This flexibility increases the attack surface. Deep queries, nested relationships, and resolver-level logic make it easy to expose more data than intended if controls are not strictly applied.
How It Is Implemented Securely
Secure GraphQL practices include:
- limiting query depth and complexity
- enforcing authorization checks at the field and resolver level
- validating and sanitizing user defined queries
- restricting introspection in production
- applying rate limits and cost analysis
- monitoring query patterns for anomalies
Common Risks
- overly permissive schemas exposing sensitive relationships
- excessive or recursive query patterns
- insufficient authorization at resolver level
- inference attacks via schema introspection
Why are API Security Standards Important?
API security standards matter because APIs now carry the majority of business logic, data flows, and customer interactions. Without consistent standards, modern enterprises face blind spots, unpredictable behavior, and escalating compliance and security risks.
1. Standards Reduce Risk Across Rapidly Changing API Ecosystems
What it means:
APIs change weekly or even daily in most organizations. According to industry data, more than 60% of enterprises update APIs monthly or weekly, and over 55% manage at least 500 APIs. Fast change without standards leads to drift, undocumented behavior, and exposed data paths.
Example:
A development team ships a small update to a payment API. A missing authorization check exposes transaction data for multiple users. Without enforced standards, this goes unnoticed until an incident occurs.
Levo provides automated discovery, documentation, and continuous testing so every API change is validated and governed. This prevents drift and ensures standards remain enforced across a growing ecosystem.
2. Standards Ensure Consistent Authentication and Authorization
What it means:
Different teams often implement authentication differently. Some rely on headers, some on cookies, and others on hand-rolled token logic. Without standards, object level and function level authorization weaknesses appear, which are among the most exploited API vulnerabilities.
Example:
A resource API checks authentication but not object ownership. An attacker manipulates an ID in a REST call and retrieves another user’s data.
Levo validates authentication and authorization behavior during discovery and testing. Because it sees real runtime traces, it identifies missing auth checks automatically and proves whether standards are enforced.
3. Standards Support Compliance and Audit Requirements
What it means:
Regulations like PCI DSS, DPDP, RBI Cyber Resilience, NIST SP 800-228, and industry-specific mandates now require organizations to demonstrate API security controls. This includes proving data handling, logging, encryption, and access enforcement.
Example:
A fintech must show how its APIs handle cardholder data and authenticate every request. Without consistent standards, producing evidence becomes slow, manual, and error prone.
Levo automatically maps sensitive data flows, generates audit-ready evidence, and provides continuous compliance checks drawn from real API behavior. This replaces months of manual documentation work.
4. Standards Reduce Developer Friction and Improve Velocity
What it means:
Developers spend 70% more time on debugging and manual testing than they believe they should, according to industry data. Poor documentation and lack of standard patterns slow down integration, cause rework, and reduce productivity.
Example:
A partner integration fails because the API documentation is outdated. Developers debug for days, slowing customer onboarding and impacting revenue.
Levo auto-generates accurate, multi-parameter API documentation and keeps it continuously updated. This helps developers integrate, debug, and build faster with confidence.
5. Standards Prevent Misconfigurations Created by AI-Generated Code
What it means:
AI now contributes up to 30 to 40% of code in modern applications, but 40% of AI-generated code contains security flaws such as missing input validation or insecure crypto. Standards help teams ensure that generated code follows secure patterns.
Example:
An AI assistant generates a new handler for a GraphQL resolver but omits authorization checks, creating a silent data disclosure risk.
Levo tests API behavior continuously and catches insecure AI-generated logic by validating runtime traces, input-output flows, and auth patterns.
6. Standards Create Predictability for Monitoring and Incident Response
What it means:
APIs often lack consistent logging. Without standards, security teams cannot perform root cause analysis or detect behavioral anomalies.
Example:
An incident occurs on a mission-critical financial API, but incomplete logs make it impossible to trace what happened.
Levo captures real runtime behavior at the trace level, giving security teams reliable visibility into what the API did, what data moved, and whether standards were met.
7. Standards Directly Protect Revenue and Customer Trust
What it means:
APIs drive a large share of enterprise revenue. Reports highlight that for many companies, APIs power more than 75% of revenue. A single breach or integration failure can slow product launches and damage trust.
Example:
A retail platform delays a major release for weeks due to unresolved API security issues. The delay impacts seasonal revenue targets.
Levo automates API security early and continuously, helping teams ship faster without compromising safety or customer trust.
API Security Standards and Compliances you should know
- NIST SP 800-228: Guidelines for API Protection
What it is
NIST SP 800-228 is a guideline for API protection in cloud native systems. It defines how organizations should discover APIs, classify data flows, enforce authentication and authorization, and apply security controls across the API lifecycle. It aligns API security with broader frameworks such as the NIST Cybersecurity Framework and modern zero trust principles.
Why it is important
For CISOs, SP 800-228 provides a concrete blueprint for turning API security from ad hoc efforts into a structured program. It helps standardize how APIs are inventoried, how risk is assessed, and how controls are applied from design to runtime. Following it also sends a strong signal to boards, regulators, and customers that API security is not an afterthought.
Example
A cloud native enterprise with hundreds of microservices wants a single view of which APIs expose sensitive data and which controls protect them. Mapping its environment to NIST SP 800-228 gives it a clear checklist: inventory APIs, classify data, validate schemas, enforce authorization, and monitor runtime behavior. Levo supports this approach by auto discovering APIs, validating schema and auth behavior, and providing continuous runtime evidence that aligns with the guideline.
What it is
The NPCI UPI API Security Guidelines define how banks and payment service providers in the UPI ecosystem must secure their APIs. The guidelines move from point in time checks to continuous security, with expectations around strong authentication, encryption, transaction integrity, anomaly detection, and ongoing testing for UPI related APIs.
Why it is important
UPI is real time and high value. Any weakness in API security can result in fraud, financial loss, and regulatory penalties. NPCI’s guidelines make API security an operational requirement, not just a compliance checkbox. They demand that participants treat API security as part of everyday operations.
Example
A bank exposes multiple UPI APIs for payment initiation, status checks, and dispute flows. NPCI expects the bank to continuously validate that these APIs enforce authentication, enforce consent, and resist automated abuse. Levo helps by monitoring live traffic, detecting anomalies in payment flows, and providing trace level evidence that the bank is enforcing the required controls.
- DSCI API Security Recommendations
What it is
The Data Security Council of India (DSCI) has issued API security recommendations that form a practical roadmap for resilient API programs. They focus on areas such as secure API design, contract first development, schema enforcement, authentication and authorization, monitoring, and governance.
Why it is important
These recommendations give Indian enterprises a clear set of expectations that go beyond generic “secure coding” advice. They help teams design APIs securely from the start, reduce business logic flaws, and align engineering practices with industry best practices.
Example
A SaaS provider serving Indian enterprises wants to assure its customers that its APIs follow DSCI aligned practices. It adopts contract first design with OpenAPI, enforces schemas, and builds automated security tests into CI. Levo complements this by validating that production behavior actually matches the contracts and by detecting drift, shadow endpoints, or unauthorized data exposure.
- RBI Master Directions on Cyber Resilience for PSOs
What it is
The Reserve Bank of India’s Master Directions on Cyber Resilience and Digital Payment Security Controls set mandatory requirements for non bank payment system operators. These directions cover governance, technology risk, incident response, and security controls for payment APIs and related infrastructure.
Why it is important
For payment system operators, these directions are not optional. They define how resilient payment services must be, how incidents should be handled, and how security controls must be embedded into daily operations. APIs are at the heart of payment flows, so API security is central to compliance with these directions.
Example
A payment switch provider must prove that it monitors its APIs for abuse, enforces strong authentication, and can detect and respond to suspicious patterns. Levo helps by continuously monitoring API traffic, highlighting high risk routes and abnormal usage, and providing evidence that can be used in internal reviews and regulatory audits.
- DPDP Act: Data Protection and API Behavior
What it is
India’s Digital Personal Data Protection (DPDP) Act sets rules for how organizations handle personal data. It requires clear consent, limited and lawful processing, data minimization, purpose limitation, breach notification, and accountability. For modern systems, much of this processing happens through APIs.
Why it is important
DPDP shifts data protection from a legal formality to a continuous technical obligation. CISOs must ensure that APIs respect consent, avoid over collection, protect personal data in transit and at rest, and provide evidence that these behaviors are being enforced.
Example
An online marketplace exposes APIs that return user profiles, orders, and payment information. To align with DPDP, it must ensure that these APIs only return the minimum required personal data and that access is logged and justified. Levo maps data flows across APIs, identifies where personal data appears in requests and responses, and provides the continuous monitoring needed to support DPDP compliance.
What it is
The OWASP API Security Top 10 is a list of the most critical API security risks, including broken object level authorization, broken authentication, excessive data exposure, unrestricted resource consumption, and security misconfiguration. It provides a widely accepted reference for the types of failures that most often lead to serious incidents.
Why it is important
For CISOs and engineering leaders, the OWASP list offers a simple way to focus efforts where they matter most. It also serves as a shared language between security and development teams, and as a baseline for designing tests, controls, and monitoring.
Example
A company discovers that many of its APIs lack object level authorization checks, which maps directly to API1 in the OWASP list. It prioritizes fixes for these endpoints and builds new test cases to prevent regressions. Levo supports this by detecting missing authorization in production behavior, validating that fixes are effective, and tracking coverage against OWASP aligned checks.
Different API Security Protocols Explained
API security relies on a set of core protocols that control how clients authenticate, authorize, and communicate with services. CISOs need a clear understanding of these protocols because choosing the right one determines how securely your organization protects user sessions, API tokens, and sensitive data.
Below are the essential protocols every modern API program must understand.
1. OAuth 2.0
What it is
OAuth 2.0 is an authorization framework that allows clients to access resources on behalf of a user without handling their credentials. It issues scoped access tokens that define exactly what a client is allowed to do.
Why it is important
Most mobile apps, SaaS platforms, and enterprise integrations rely on OAuth 2.0. Poorly implemented OAuth flows can allow attackers to steal tokens, bypass consent screens, or escalate privileges.
Example
A fintech app lets third party services access account balances. Using OAuth 2.0, the app issues a token with only read permissions. Without proper scoping, the token could allow fund transfers or access to personal data beyond what was intended.
2. OpenID Connect (OIDC)
What it is
OIDC is an identity layer built on OAuth 2.0. It verifies the user’s identity and provides standardized ID tokens for authentication.
Why it is important
OIDC makes single sign-on safer and more interoperable across modern apps and cloud services. It prevents systems from relying on custom session logic or weak identity assertions.
Example
A B2B SaaS platform allows customers to log in using corporate SSO. OIDC ensures that the identity information is trustworthy and cryptographically signed, reducing impersonation risks.
3. JSON Web Tokens (JWT)
What it is
JWTs are compact, signed tokens used for authentication and authorization. They can carry claims such as user ID, permissions, or expiration.
Why it is important
JWTs are widely used with OAuth and microservices. Weak signing algorithms, long lifetimes, or unvalidated claims often lead to privilege escalation.
Example
A microservice receives a JWT and assumes the user is an administrator because the token says so. Without verifying the signature or checking token expiry, the service grants unauthorized access.
4. mTLS (Mutual TLS)
What it is
Mutual TLS authenticates both the client and the server using certificates. It is commonly used for internal service-to-service communication and high assurance environments.
Why it is important
mTLS prevents man-in-the-middle attacks and ensures that only trusted services communicate with each other. It is critical for payment systems, banking APIs, and zero trust architectures.
Example
A payment gateway only accepts requests from partner banks that present valid client certificates. An attacker cannot impersonate a bank because they cannot produce the certificate.
5. HMAC (Hash-based Message Authentication Code)
What it is
HMAC is a method for signing API requests using a shared secret. The server verifies the signature to confirm integrity and authenticity.
Why it is important
HMAC makes it much harder for attackers to tamper with requests or replay old messages. Many financial APIs and webhook systems rely on HMAC.
Example
A trading API signs each request with an HMAC. If an attacker modifies the order amount, the signature becomes invalid and the API rejects the request.
6. API Keys
What it is
API keys are simple identifiers used to authenticate clients. They do not carry claims or permissions by themselves.
Why it is important
API keys are easy to implement but also easy to misuse. Keys stored in client-side code, mobile apps, or GitHub repos can be stolen and used by attackers.
Example
A weather service exposes an API key in client-side JavaScript. An attacker extracts it and uses it to generate large volumes of traffic, causing service disruption.
7. TLS/HTTPS
What it is
TLS encrypts data in transit between clients and servers, ensuring confidentiality and integrity.
Why it is important
Without TLS, attackers can intercept and modify API requests. TLS is the baseline requirement for all modern APIs.
Example
An IoT device sends authentication requests over plain HTTP. A network attacker captures the credentials and reuses them to impersonate the device.
8. SAML 2.0
What it is
SAML is an XML-based authentication protocol used for enterprise SSO, especially in older or legacy ecosystems.
Why it is important
Even though OIDC is now more common, many enterprises still use SAML in combination with API gateways and B2B integrations.
Example
A legacy HR system uses SAML to authenticate employees, who then access APIs through a gateway. Incorrect signature validation leads to a spoofed assertion and unauthorized access.
9. Webhooks Security (Signing and Verification)
What it is
Webhook security protocols ensure that inbound event notifications are authentic, often by using HMAC signatures and replay protection.
Why it is important
Webhooks are increasingly used in payments, e-commerce, and SaaS integration flows. Unverified webhooks allow attackers to trigger false events or bypass workflows.
Example
An attacker sends a fake “payment completed” webhook to an e-commerce system. Without signature verification, the order is marked as paid without any transaction occurring.
10. Rate Limiting and Throttling Protocols
What it is
These protocols define how many requests a client can make in a given time. They protect APIs from brute force attacks, scraping, and denial of service.
Why it is important
Most API attacks are automated. Rate limiting is one of the simplest and most effective ways to stop them.
Example
An attacker tries thousands of credential guesses per minute. Without rate limiting, the API is overwhelmed. With it, the API blocks the activity after a small number of attempts.
Shift Left API Security is the need of the hour
APIs are changing faster than most security programs can keep up with. Development teams release updates weekly or sometimes daily, and new APIs appear across environments without documentation or proper review. Traditional security testing, which happens late in the SDLC or only in production, cannot detect authorization gaps, data exposure, or business logic flaws early enough to prevent risk.
Shift Left API security moves security controls into the earliest stages of development. It gives teams visibility into API behavior during design, coding, and testing rather than after deployment. This prevents issues like broken object level authorization, excessive data exposure, insecure defaults, and unvalidated schemas from reaching production.
For example, a new microservice exposes a REST endpoint that returns customer data. Without Shift Left controls, the endpoint passes functional tests but returns more fields than intended, creating a privacy risk. With Shift Left security, the schema, authorization checks, and data flow are validated before the service ever reaches production.
Levo enables practical Shift Left adoption by automatically discovering APIs, generating accurate documentation, validating authentication and authorization behavior, and identifying unintended data exposure. It gives developers feedback based on real runtime intelligence, not guesses or manual reviews. This removes friction, reduces rework, and helps teams fix issues early while costs are still low.
Key API Security Best Practices to follow
CISOs need clear, actionable best practices that can be applied across teams and environments. The following practices create consistent, defensible API security programs.
1. Enforce Strong Authentication and Authorization
Every API should validate identity and permissions on every request. Avoid custom auth logic and rely on proven standards like OAuth 2.0, OIDC, and mTLS.
Example
A customer profile API checks that a token is valid but does not verify ownership of the resource. Object level authorization must be enforced, not assumed.
2. Validate All Input and Payloads
REST, SOAP, and GraphQL all require strict schema validation. Weak or missing validation enables tampering, injection attacks, and data leaks.
Example
A SOAP service accepts XML that deviates slightly from the schema. Without strict validation, the service becomes vulnerable to XXE or signature manipulation.
3. Minimize Data Exposure
APIs should return only the data required for each client or use case. Excessive fields or verbose responses increase the likelihood of privacy incidents.
Example
A GraphQL query returns deeply nested fields because the resolver does not enforce field level authorization.
4. Implement Rate Limiting and Abuse Protection
Most API attacks are automated. Rate limiting, quotas, and anomaly detection stop brute force, scraping, and resource abuse.
5. Use Secure Communication Channels
All traffic should use TLS and, where appropriate, mutual TLS. Avoid sending credentials, tokens, or sensitive data in query strings.
6. Maintain Accurate API Documentation
Documentation must reflect actual runtime behavior. Outdated docs cause integration failures, security gaps, and compliance issues.
7. Monitor Runtime Behavior Continuously
APIs evolve constantly. Monitoring must detect anomalies, log important events, and validate that security controls remain in place.
Why Levo is everything about API Security
Levo was designed for the reality of modern API ecosystems. APIs have become too numerous, too dynamic, and too business critical to secure manually. Traditional tools miss issues because they rely on static tests, incomplete discovery, and partial visibility into runtime behavior.
Levo approaches API security differently. It captures real runtime traces, maps data flows, identifies vulnerabilities from actual behavior, and validates authentication and authorization patterns across all environments. It creates a versioned, continuously updated security graph that reflects how APIs truly operate, not how they were designed on paper.
What this means for CISOs
- Security coverage improves because Levo sees every API, every parameter, and every behavior.
- Developer friction drops because Levo auto generates accurate documentation and provides actionable feedback.
- Compliance becomes easier because Levo produces evidence of data flows, access rules, and control enforcement.
- Risk is reduced earlier in the lifecycle because issues are caught during development, staging, and runtime.
Levo does not replace existing tools. It makes them smarter by giving them the context they never had. It makes developers faster, makes security continuous, and makes compliance repeatable.
The Way Ahead: Implement API Standards, Compliances and Beyond with Levo
API ecosystems will continue to grow. Regulations will become stricter. Attackers will get more automated. Organizations cannot rely on manual processes or periodic reviews to secure APIs at scale. Implementing strong standards and compliance frameworks is essential, but they only work when enforced consistently across every environment.
This is where Levo helps enterprises move beyond documentation and policy into continuous security. Levo discovers every API, maps its behavior, validates its controls, and produces audit ready evidence. It gives CISOs a single source of truth for how APIs work, what they expose, and whether they meet required standards.
With Levo, teams can adopt industry standards such as NIST SP 800-228, NPCI UPI guidelines, DSCI recommendations, RBI cyber resilience directives, DPDP requirements, and the OWASP API Security Top 10 with confidence. They can prove compliance, detect violations, and reduce risk while enabling developers to work at modern speed.
The future of API security is automated, continuous, and rooted in real runtime intelligence. Levo is the platform that makes this possible.
Book a demo through this link to see this live in action!
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