Does SimpleOpenAI support Virtual Threads? How to use it with structured concurrency in Java 21

[EduardoAzaldegui]

Hi maintainers,

I'm evaluating using SimpleOpenAI in a high-concurrency, low-latency application running on Java 21+, and I want to leverage Virtual Threads for better scalability and simpler code structure.

However, I noticed that all public methods return CompletableFuture<T> — which suggests an async/callback-based model. This works fine, but it doesn't automatically benefit from Virtual Threads, since CompletableFuture callbacks typically run on the common fork-join pool or a fixed executor, not on virtual threads.

My Questions:

1. Is there a synchronous API available?
   For example: String chatCompletion(String prompt) instead of CompletableFuture<String> chatCompletionAsync(...).
   → If yes, I can safely call it inside a Thread.startVirtualThread(...) or StructuredTaskScope.

2. If only async APIs exist:

   • Are the underlying HTTP calls (e.g., via HttpClient) configured to be compatible with Virtual Threads?
   • Can I safely .join() the CompletableFuture inside a Virtual Thread without blocking real threads?

3. Best practices for using this library with Virtual Threads:
   Could you provide an example of how to properly integrate SimpleOpenAI into a virtual-threaded workflow?

4. Future plans:
   Are there any plans to add native Virtual Thread support (e.g., sync methods, or integration with StructuredTaskScope)?

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Why this matters:

With Virtual Threads, we can write simple, blocking-style code while achieving massive concurrency. But if the library internally blocks carrier threads or uses non-VT-friendly executors, we lose those benefits.

Thanks for your time and for maintaining this great library!