WebContainer preview server concurrency and request handling

WebContainer HTTP Server Request Management

StackBlitz WebContainers allow Node.js HTTP servers to run directly within the browser, serving content via a preview port inside an iframe. Because these servers operate within the browser's JavaScript event loop, the mechanism for handling simultaneous incoming requests remains undocumented.

There is uncertainty regarding how the preview environment manages backpressure or request queueing when multiple concurrent HTTP requests are sent to the same local development port. It is unclear if the environment imposes a specific concurrency limit or if request processing is strictly bound by the single-threaded nature of the browser tab's event loop.

• Does the WebContainer preview server implement a request queue or a maximum concurrency limit for incoming HTTP traffic?
• Is request handling isolated per preview port, or do multiple ports share a unified resource pool within the WebContainer instance?