Warm sessions

Claude keeps a conversation’s prompt in a cache that expires when you stop. Coming back after it expires means paying to write the whole prompt again. Warm sessions sends a tiny request now and then to keep the cache alive while you’re away, and stops when it’s no longer worth it.

Turn it on

• Opt in from Settings › Performance › Warm sessions. It’s off by default.
• Choose which tabs to keep warm: pick Keep warm in a tab’s menu, or let Xval decides choose.
• A small flame marks warm idle tabs.

What it costs

• A daily spend cap, $2 by default (you can set $0.50 to $10), and at most 12 pings per session per day.
• It pings only when the saving you can expect from coming back beats the cost of the ping.
• It never pings after the cache has already expired, because that would only pay for the rewrite.
• Only idle or finished Claude sessions with at least 30k cached tokens qualify. A sleeping session is pinged only if you chose it.

How each ping works

A ping is a one-turn request forked from your session. It’s never saved to the conversation and it uses no tools. It runs in the session’s own folder at background priority, with your own Claude sign-in, and replays the session’s own launch settings.

How savings are measured

• Saved counts only realized savings. It goes up when your next real message arrives after the cache would have expired and still reads at least 90% of the pinged prompt.
• Every ping checks itself. If the cache wasn’t read, that counts as a miss. After two misses in a row, XAgents stops warming that session until you send a new message or choose Keep warm again.
• Spend is each ping’s reported cost.
• Dollar figures are API list-price equivalents. On a subscription they measure value, not a bill.

In our tests with a 5-minute cache, a pinged session read all 34,799 cached tokens when we returned after the cache would have expired. The unpinged control read 13,713 and rewrote 21,556.