OpenAPITools/openapi-generator · error · RuntimeException

Invalid HTTP library {library}. Only {supportedLibraries} ar

Error message

Invalid HTTP library {library}. Only {supportedLibraries} are supported.

What it means

Error "Invalid HTTP library {library}. Only {supportedLibraries} are supported." thrown in OpenAPITools/openapi-generator.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java:799

                    needsCustomHttpMethod = true;
                },
                HTTPCLIENT, () -> {
                    setLibrary(HTTPCLIENT);
                    additionalProperties.put("useHttpClient", true);
                    needsUriBuilder = true;
                },
                UNITY_WEB_REQUEST, () -> {
                    setLibrary(UNITY_WEB_REQUEST);
                    additionalProperties.put("useUnityWebRequest", true);
                    needsUriBuilder = true;
                }
        );
        final Runnable action = libraryActions.get(library);
        if (action != null) {
            action.run();
        } else {
            String supportedLibraries = String.join(", ", libraryActions.keySet());
            throw new RuntimeException("Invalid HTTP library " + library + ". Only " + supportedLibraries + " are supported.");
        }

        final String inputFramework = (String) additionalProperties.getOrDefault(CodegenConstants.DOTNET_FRAMEWORK, latestFramework.name);
        final String[] frameworks;
        final List<FrameworkStrategy> strategies = new ArrayList<>();

        if (inputFramework.contains(";")) {
            // multiple target framework
            frameworks = inputFramework.split(";");
            additionalProperties.put("multiTarget", true);
        } else {
            // just a single value
            frameworks = new String[]{inputFramework};
        }

        for (String framework : frameworks) {
            boolean strategyMatched = false;
            for (FrameworkStrategy frameworkStrategy : frameworkStrategies) {

View on GitHub (pinned to fcec517be3)

Solutions

1. Set the 'library' option to one of the supported libraries listed in the message.

When it happens

Trigger: Thrown when the 'library' option for the C# client generator names an HTTP library that is not supported; the message lists the supported libraries. Choose one of the listed libraries.

Common situations: See trigger scenarios.

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/c68cf129954bbc68. Report an issue: GitHub.