If it happens 10 times you have already accepted the same cost as the entire session fresh prefill.
People on HN are either too rich or wayyy too rich
Moreover it is mostly cached reads, so subagents with short context cost little, while long-context ones cost much more.
In my Claude Code sessions, it looks more like ~8% at most.
I'm on pro. Two days ago, 100% 5 hour was using 25% of my weekly. Today, 100% 5 hour is like 13% so something was fixed.
I am definitely getting frustrated with a lot of the changes they keep making in Claude Code. It's one thing to find settings have changed during your next interactive session, it's another when it changes how overnight unattended sessions behave. I really should be spending more time building my own harness again.
Also, the claim "15-20% of your tokens" seems unclear; of all tokens, or of tokens spent on background agents? Poorly edited AI writing strikes again!
Cache rules everything around me.
Similarly to “one language is best,” saying “one harness is best” is shortsighted in the best possible case.
That being said, Claude Code is bloatware.
Our DRIM system flagged the anomaly in CC's OTEL traces. Grouping requests by query_source showed that over one measured week agent_summary accounted for: 16.4% of total estimated spend (versus 15.7% for the main conversation), and 19.7% of all API requests with approximately 9,000 input tokens per output token.
Most requests reuse the prompt cache, but repeatedly reading a large cached transcript still has a cost. Longer contexts and more concurrent agents increase the overhead.
We couldn’t find a supported setting that disables only these summaries while preserving background agents and forks. Disabling those capabilities also stops the summaries, but changes the workflow we want to keep.
Our workaround is a small Bun preload that intercepts the summary timer without modifying the CC binary. It identifies the timer callback by source-text anchors and leaves other timers alone.
In controlled tests on Linux (from ver 2.1.257 to 2.1.312), the same workload produced five summary calls without the hook and zero with suppression enabled. On our current production setup, agent_summary calls remained at zero with the hook enabled. Background agents and forks continued running. The only visible change was that their generated status summaries stopped updating.
The workaround depends on implementation details. An update can break the callback matching and silently restore the requests. macOS and Windows are untested. If someone could help us with testing there, it would be much appreciated.
If you want to try it - the script, full technical explanation, test results, and installation instructions are on GitHub: https://gist.github.com/flamerix-ai/c3905705cc4205e5de3011fa...