claude-thermos keeps your prompt cache warm and recovers ~20% of a long session's bill.

Posted to Show HN July 24 at 104 points, it targets a failure specific to multi-agent workflows: when a main agent waits on a subagent past the five-minute cache TTL, the next turn re-encodes the whole conversation at cache-write rates. It runs Claude Code behind a loopback reverse proxy via ANTHROPIC_BASE_URL and, on an interval under the TTL, replays the last real request with max_tokens: 1 and no streaming to refresh the identical prefix. uvx claude-thermos. Clever, and slightly horrifying that it's necessary.