Offline: the page notices when the connection drops. Live lookup and link reading pause on their own and resume when it returns; your settings are not changed. A model that has been loaded once runs without the network.
A session file holds the transcript with each turn's evidence and timing, everything the tab indexed (memory, files, lookups), the attachments and the spider web. It is written to your device; nothing is uploaded. Opening one adds it to this tab and re-indexes its passages, so memory and the spider continue from it. In the console: bw.export(), bw.import(obj).
In this tab's console: await bw.ask("..."), bw.search("..."), bw.settings. From a page that embeds or opened this one: postMessage({bw:"ask", id, text}), replies as {bw:"reply", id, reply, ...}. From anything on this machine: run bw_relay.py (python3, no dependencies) and curl -s localhost:8770/v1/chat/completions -d '{"messages":[{"role":"user","content":"..."}]}'. The tab polls the relay; nothing else leaves it.
A chat model on this device's GPU, with a live memory. Everything the tab reads is embedded the moment it arrives: your files and links, what it looks up, what it has already said. That memory is the ground for the next answer, and the spider reads it back through time. Nothing leaves the tab.
Works offline once a model has loaded. Turn the network off and the page says so in the header; lookup and link reading pause and resume on their own.