AI与科技 / Reported update
The cost choices behind context and cache defaults
On October 10, Tibo explained that Codex’s 300k context default reflects a cost trade-off. The team can also run 1M context, he said, but it costs more to use. This explains a product default; it is not a new model-limit announcement or benchmark.
Separately, Boris Cherny answered why cache time-to-live is not uniformly one hour. For typical Agent SDK workloads on the API, an hour costs more on average, so the default remains five minutes. Interactive use defaults to an hour because it is generally cheaper there; configuration remains possible.
The mechanisms differ: context determines how much information is handled at once, while cache lifetime affects reuse. Both replies explain workload-dependent defaults. We have not independently measured customer bills.
Sources and further reading
Edited
Selected through a verified followed account: @thsottiaux.