Cloudflare cuts the average cost of its internal AI code review 68%, from $2.43 to $0.77
A post-mortem with real bills: how a multi-reviewer code review agent cut both cost and time while its token use tripled.
// Key points
- Average cost per review fell from $2.43 to $0.77; median time fell from 4m 09s to 1m 32s, and p99 from 15m 20s to 4m 41s.
- The biggest single change moved the prompt-cache breakpoint so repositories share one prefix: first-request cache reads rose from 14–26% to 91–99.5%.
- Tokens per review rose from 0.91M to 2.99M while cost still fell; about 40% of savings came from reviewer code changes, the rest from model and effort experiments.
- At the same per-token price, Sonnet 5.5 was 47–62% cheaper per run than Sonnet 5, depending on the reviewer.
Builder's takeAnyone building agents should read this line by line: the first cost cut isn't a cheaper model, it's moving the parts of the prompt that change to after the cache breakpoint. I'll run the same check on PandaClaws' generation chain and look at first-request cache hit rate; as I worked out in What Does It Cost to Keep Three AI Products Online Every Month?, structural mistakes are what inflate model bills.
// Background · from #Coding agents
Full timeline →- Oct 20 GitHub opens a Copilot model policy REST API at enterprise, team, app and organization level, generally available
- Oct 20 Copilot retires six models including GPT-5.5 and GPT-5.4 on October 19, pointing users to GPT-6.1 Sol and GPT-6 Luna
- Oct 20 GitHub: during unusual traffic, some anonymous HTTPS clones of public repositories may temporarily require authentication