What is SAST?
Static Application Security Testing inspects code or interface contracts without executing them. APISAST reads OpenAPI or Swagger contracts to flag missing security declarations, risky URL parameters, and weak error documentation before an endpoint receives traffic. Dynamic tests are still needed to check the running service.
Traditional SAST engines inspect source code. APISAST focuses on the API contract: security schemes and requirements, response shapes, pagination, and versioning. That gives teams a focused design review before staging environments are ready.
The report is most useful when the contract matches the deployed service and has an identified owner.
Why use SAST for API security?
API incidents often originate from design-level gaps: missing auth on a “read-only” endpoint, insufficient pagination controls that enable scraping, or verbose 500 errors that reveal stack traces. API SAST exposes these risks from the single source of truth—the specification—so teams can remediate before testers or attackers ever send a request.
- •Shift security left into design reviews and pull requests.
- •Zero-traffic testing keeps PII and regulated data safe.
- •Consistent rule coverage across every service and version.
- •Clear mapping to the OWASP API Security Top 10 for auditability.
APISAST approach to SAST
APISAST ingests JSON or YAML OpenAPI files and runs 29 rules across security, syntax, documentation, error handling, versioning, and performance. Findings are ordered by severity and include remediation guidance.
Security-first rules
Checks for missing security requirements, insecure server URLs, and sensitive data in URL parameters.
Quality + compliance
Checks documented error schemas, pagination parameters, versioning signals, and description completeness so contracts stay consistent.
Explore the OpenAPI security scanner for a deeper look at how specification parsing works.
SAST vs DAST vs Fuzzing
SAST
- • Runs on specs or code with no traffic
- • Great for early-stage design and CI
- • Finds missing auth, error handling, docs gaps
DAST
- • Exercises live endpoints
- • Good at runtime issues (CORS, rate limits)
- • Requires stable staging data
Fuzzing
- • Throws unexpected payloads at running APIs
- • Catches serialization and parsing flaws
- • Complements SAST; later in pipeline
Most teams run SAST on every pull request, DAST on staging, and fuzzing on pre-prod. APISAST focuses on the SAST layer and links out to dynamic checks when specs suggest risky runtime behavior.
Need a runtime view? The API security scanner page compares static and dynamic scanning in depth.
Getting started with APISAST SAST tools
- Upload or point to the OpenAPI file. We support JSON/YAML up to 10 MB and detect versioning automatically.
- Choose the rule profile (standard or comprehensive) depending on risk tolerance.
- Review findings ranked by severity with code-level remediation tips.
- Share or export the report. Each issue links back to the spec line for quick fixes.
- Automate in CI/CD using the same ruleset to block risky changes before merge.
A practical contract review
Take a collection endpoint such as GET /orders. In the OpenAPI file, inspect its security requirement, query parameters, success response, and documented errors. APISAST may flag missing authentication, a missing pagination parameter, or no documented error response. Ask the API owner whether the route is intentionally public, what page-size limit the service enforces, and what clients receive when a request fails. A static finding is a prompt for those decisions, not a verdict about live behaviour.
After updating the contract, run the scan again and inspect the same rule IDs. Then call the endpoint in a test environment with no token, a valid token, and a token from another tenant. Confirm the list is bounded and the errors match the documented response. This pair of reviews catches drift in both directions: an implementation may be safer than an outdated spec, or a spec may promise a control the service does not enforce.
Choose the right evidence for each risk
Static analysis is well suited to repeatable checks on declared design: security schemes, HTTPS server URLs, sensitive query parameters, response schemas, and versioning markers. Source-code SAST can inspect implementation patterns; APISAST does not read application code. Dynamic tests can verify the behaviour of a running service. Fuzzing explores unexpected inputs, while integration tests can exercise specific ownership rules. Select a tool by the question it can answer rather than expecting one scan to cover the whole API Security Top 10.
Record the version of the specification and the report ID when sharing findings. If a rule is intentionally not applicable, document the owner and reason. A warning about rate-limit headers, for example, may reflect missing documentation rather than a missing gateway policy. The OWASP guide maps contract signals to the runtime tests still needed.
Structured data & governance
APISAST outputs machine-readable reports for review. Each finding includes a rule ID, severity, category, and location in the specification. Map those results to your own risk framework with runtime evidence rather than treating them as a full OWASP assessment.
For architectural overviews, see the static API security scanner or dive into OpenAPI-specific scanning.