Supported Specs

UIGen supports the two most widely used API specification formats.

OpenAPI 3.x

OpenAPI 3.0 and 3.1 are the primary supported formats. All features are available:

• Full $ref resolution including circular references
• components/schemas, components/securitySchemes, components/parameters
• servers array for environment switching
• requestBody with content type negotiation
• allOf, oneOf, anyOf schema composition (flattened to a single SchemaNode)
• All standard security scheme types: http (bearer, basic), apiKey, oauth2

Swagger 2.0

Swagger 2.0 (formerly OpenAPI 2.0) is fully supported. The adapter normalises Swagger 2.0 constructs to the same IR:

• definitions → schema resolution
• basePath + host + schemes → server URL
• securityDefinitions → auth schemes
• produces / consumes → content type handling
• formData parameters → request body schema

Format detection

UIGen auto-detects the spec format from the document's root keys:

• openapi: "3.x.x" → OpenAPI 3.x adapter
• swagger: "2.0" → Swagger 2.0 adapter

Both YAML and JSON are accepted.

Planned support

• OpenAPI 3.1: full support is in progress. Most 3.1 documents work today; edge cases around JSON Schema vocabulary differences are being addressed.
• GraphQL: planned for a future release.

Compatibility notes

UIGen aims to work with real-world specs, which are often imperfect. If your spec has issues, check ir.parsingErrors for details. See Adapters for how UIGen handles malformed or incomplete specs.