API Security Scanner for OpenAPI and REST APIs

API security scanning explained

An API security scanner evaluates your endpoints for design and configuration weaknesses. APISAST performs static scanning against the OpenAPI contract, while also giving you guidance on when to pair results with dynamic checks. The outcome is a prioritized list of issues that developers can fix quickly, without staging data or live traffic.

Static vs dynamic API scanning

Features of the APISAST scanner

• 29 static analysis rules: declared authentication, sensitive data in URLs, pagination, error contracts, and documentation quality.
• API design signals: flags missing security requirements in a contract; runtime tests are still needed to verify object-level authorization and business logic.
• Problem-details checks: reviews documented error schemas for type, title, status, and detail fields.
• Automation ready: submit an OpenAPI file through the API from a pipeline and review the findings before merge.
• Report sharing: exportable summaries for security reviews and vendor assessments.

Need OpenAPI specifics? Visit the OpenAPI security scanner page.

How to perform a scan

1. Upload or paste the OpenAPI file, or provide a secure URL to the spec.
2. Select the rule profile (standard or comprehensive) to match your risk tolerance.
3. Run the scan and review findings grouped by severity with remediation steps.
4. Share a read-only report link with developers, product owners, or auditors.
5. Automate via CI to enforce the same checks on every pull request.

Improve the contract after a scan

Use findings as a starting point for design review. These guides show how to document and test common issues:

• API pagination best practices for bounded collection endpoints.
• OAuth2 and JWT authentication for security schemes and token checks.
• API rate limiting for quotas, 429 responses, and enforcement tests.

Use cases and industries

Looking for more technical depth? Read the SAST testing for APIs guide.

How to read a finding

A finding describes a rule, its severity, and the location in the submitted contract. For example, an operation without a declared security requirement can be intentional for a public catalogue or accidental for an account endpoint. Review the route owner, expected caller, and any global OpenAPI security default before changing the file. Add a requirement to the contract when it is missing, then test the live endpoint with no token and a token from another user. The static finding starts the investigation; it does not establish that the running service accepts unauthorised requests.

Treat an informational rule differently from an error. An undocumented rate-limit header asks whether the policy and response are described to clients. It does not prove the gateway has no limit. Confirm the runtime behaviour, update the OpenAPI response if appropriate, and scan again to verify the documentation change.

From report to a verified fix

Start with error-severity findings on sensitive write operations, then work through warnings and documentation issues. Keep the original report with the specification version so reviewers know what was analysed. Change the contract, run another scan, and compare the specific rule rather than only the overall score. If a finding is a false positive or an intentional design choice, record why and identify who accepted it.

Pair each contract change with an implementation test. A newly documented 429 should be exercised through the deployed gateway; a stronger security scheme should be tested with valid, missing, and wrong-tenant credentials. If the API behaviour differs from the specification, decide whether code or documentation is wrong before closing the issue. The testing methods guide helps choose the runtime check.

What a specification cannot reveal

APISAST reads OpenAPI and Swagger files; it does not send traffic to your API or inspect application source code. It cannot confirm object ownership, token validation, data returned by a resolver, or whether a quota is enforced under load. It also does not parse a native GraphQL schema. Use separate integration tests, dynamic probes, and monitoring for those questions. This boundary matters when a report is shared with an auditor: a clean contract is evidence of documented design, not proof that the running service has no vulnerabilities.

Uploaded specifications and reports are saved so you can reopen a result. Remove real credentials from examples before submitting a file. If your organisation has data-handling restrictions, review the deployment and storage policy before using a hosted scanner. The OpenAPI scanner guide shows the exact types of contract signal that a static scan can surface.

Start an API security scan

Upload your spec on the home page or connect CI to block risky changes automatically. If you want to compare static vs dynamic approaches, bookmark this page and cross-link to the API security SAST tools overview.