Cheaper Pro & Smart With Claude - Prompt Cache Rework

Short version: Pro with Claude now costs a lot less to run in real conversations. We noticed that follow-up messages weren't reusing the cached context from earlier messages the way they should have been, so each new turn was paying to re-process a bunch of the same tokens. We rebuilt how we hand context to the model and the cache now holds across turns, across chats, and during sub-agent runs.

Improvements

• Follow-up messages in Pro chats are ~10x cheaper - The second (and every later) message in a Claude Pro chat now hits the prompt cache instead of paying full price. In our tests a typical 17K-token follow-up dropped from ~1.2 credits to ~0.1 credits
• Starting a new chat is cheaper too - The system prompt is now cached across chats, so the first message of a fresh Claude chat reuses the cache from your previous conversation (within a 5-minute window) instead of paying full price for the system prompt every time
• Smart mode sub-agents benefit as well - When Smart mode delegates code work to an Opus sub-agent, that sub-agent now uses the same caching wins: system prompt shared across delegations, history cached within a run. No change for Gemini Flash (Google handles caching server-side, nothing for us to tune)

No action needed - it just works. If you're curious about the raw numbers, the credit counter in Usage History now shows the difference directly: first Claude message in a chat is typical, every follow-up is usually 10x smaller.