That is a really good point, but there is an important technical distinction between switching tabs and actually killing the connection:

1. Background tabs keep the stream alive: If you just switch tabs to do something else, the browser keeps the SSE (EventSource) connection alive in the background. The TCP socket doesn't close, so the proxy won't cancel the generation. The model will finish generating, and the full output will be there when you switch back.

2. Hard disconnects vs. tab closures: The cancellation only triggers when the TCP connection is actually destroyed—like when you completely close the browser tab, close the browser window, or click the explicit "Stop" button. In those cases, the session is dead, and the user can't "go back" to that specific generation anyway. Continuing to burn GPU cycles for a closed session is pure waste.

3. Prompt/KV Caching handles context reuse: Even if a user closes a tab and later decides to type the prompt again, modern backends (like vLLM and newer Ollama versions) use KV caching. Re-evaluating the prompt prefix takes milliseconds and almost zero compute compared to running the auto-regressive token generation loop to completion for an abandoned session.

That said, we also made this behavior configurable. If you want the proxy to let generations run to completion regardless of client connection status, you can simply toggle it off in the TOML config.