API Versioning (Boot 4 / Framework 7)

Spring Framework 7 provides API versioning in the mapping layer. Prefer it over hand-rolled /v1 prefixes, custom HandlerMapping implementations, or version-sniffing filters.

Declare versions on mappings

@RestController
@RequestMapping("/api/orders")
class OrderController {

    @GetMapping(path = "/{id}", version = "1.0")
    OrderV1 getV1(@PathVariable UUID id) { ... }

    @GetMapping(path = "/{id}", version = "1.2")
    OrderV2 getV2(@PathVariable UUID id) { ... }
}

Use semantic version strings. A + suffix means the mapping handles that version and newer versions, for example version = "1.2+".

Configure one request resolution strategy

@Configuration
class WebConfig implements WebMvcConfigurer {
    @Override
    public void configureApiVersioning(ApiVersionConfigurer configurer) {
        configurer
            .useRequestHeader("API-Version")
            .setDefaultVersion("1.0")
            .addSupportedVersions("1.0", "1.2");
    }
}

Choose exactly one source: request header, query parameter, path segment, or media-type parameter. Keep the choice consistent across the application. WebFlux uses the corresponding WebFluxConfigurer hook.

Required behavior and deprecation

Versioning is required unless a default is configured or setVersionRequired(false) is used. Missing or unsupported versions should be covered by the API error contract. Use StandardApiVersionDeprecationHandler for Deprecation, Sunset, and Link response headers.

Boot properties can provide defaults under spring.mvc.apiversion.* or spring.webflux.apiversion.*, but keep the resolution strategy in Java configuration when its behavior must be explicit.

Gotchas

• Agent hand-rolls /api/v1 prefixes or a version filter - use the mapping version attribute.
• Agent writes version = 1 - the value is a semantic version String, such as "1.0".
• Agent uses useHeader or useQueryParameter - use useRequestHeader or useQueryParam.
• Agent enables versioning without a default or versionRequired(false) - un-versioned requests return 400.
• Agent mixes a path segment and a request header - choose one source of truth.
• Agent invents custom sunset headers - use StandardApiVersionDeprecationHandler.