Check NDJSON support for SwaggerUI

[fengelniederhammer]

swagger-api/swagger-ui#5342 (comment) claims that SwaggerUI now supports NDJSON. Check how that works and whether Spring Boot already provides the necessary versions.

[fengelniederhammer]

Disclaimer: Didn't check myself whether this is true.

AI analysis

Verdict: cannot implement yet.

• The linked comment (#issuecomment-4284664251) is misleading. swagger-ui 5.32.0 added only basic OpenAPI 3.2 recognition (QUERY method, info.summary, version badge).
• Streaming support via itemSchema (what actually renders application/x-ndjson in "Try it out") was explicitly deferred to a future PR — see swagger-ui#10721 "Enhanced Features (moved to future PR): itemSchema for streaming responses".
• The underlying bug remains unfixed: swagger-ui treats any content-type matching /json/i as parseable JSON, so NDJSON responses still fail with "can't parse JSON. Raw result:".
• Spring Boot / springdoc version is not the blocker. LAPIS already uses springdoc-openapi-starter-webmvc-ui:3.0.3, which bundles swagger-ui 5.32.2 (latest). Overriding org.webjars:swagger-ui independently is possible but pointless — no released swagger-ui version implements NDJSON Try-it-out yet.

Minimum version needed: unknown — not released in any swagger-ui version.

Action: none now. Leave open and watch for the follow-up PR to swagger-ui#10721 that implements itemSchema streaming.

[fhennig]

Ok, I also had a look, and can confirm. I think the keyword is "itemSchema for streaming responses"

BLOCKED - Unfortunately there is no other PR or issue we can track, except for the already linked 5342.