Stoplight

Stoplight is an API design platform, acquired by SmartBear, that provides a complete design-first workflow for building high-quality APIs at scale. The platform centers on the principle that APIs should be designed before they are coded, reducing expensive rework and ensuring consistency across an entire API portfolio. The visual OpenAPI editor enables API designers to construct specifications using a form-based interface that generates valid OpenAPI 3.1 and 3.0 documents without requiring deep knowledge of the specification syntax. Reusable components and models promote a DRY approach: schemas, parameters, responses, and examples defined once can be referenced across multiple APIs, ensuring consistency and reducing duplication. Style guides enforce organizational API standards through automated linting with custom rules covering naming conventions, error response formats, pagination patterns, and security requirements. Mock servers generate responses from specifications, enabling frontend teams to develop against APIs before backend implementation begins. Contract testing validates that implementations match their design specifications, catching breaking changes in continuous integration. The platform provides API catalog visibility, giving architects and product managers a portfolio-wide view of all APIs, their owners, lifecycle status, and dependencies. Governance dashboards track API quality metrics including adherence to standards, documentation completeness, and security posture. Customers include Calendly, Schneider Electric, wefox, Transact, Fiserv, Arkema, Highmark Health, PagerDuty, and Sendcloud. A free tier is available with paid plans for teams and enterprise.