OpenAI's Codex lead Tibo says Day 12 brings more effective usage in Codex and Work through context reuse, longer caching and smarter routing
Day 12/ We’ve made improvements to Codex & Work that increase the effective usage you get. We achieved this by reusing context across subagents, keeping context cached longer, and improved request routing that allows us to increase cache hits.
Context
Usage limits are a top complaint from heavy Codex users, and getting more work from the same limits matters as much as a reset.
This is a first hand post from Tibo, who leads Codex at OpenAI, as part of a daily series he calls a 28 day push. Unlike Day 10, this update is an efficiency change rather than a reset of usage limits, and OpenAI gave no figure for how much usage increases.
Deep dive
On October 16, Tibo posted Day 12 of his series of daily Codex updates. He wrote that OpenAI has made improvements to Codex and Work that increase the effective usage people get.
He said this came from reusing context across subagents, keeping context cached longer, and improving request routing so more requests hit the cache. Cached context can be served without reprocessing, which uses less computing and so counts less against limits.
In replies to his own post, Tibo pointed to OpenAI's upgrade of GPT 6 Astra Pro for Pro users, covered earlier in this deck, and to a post from OpenAI designer Gavin Nelson showing dots on the iPhone Home Screen, telling people to update their app.
On Day 10, Tibo announced another global reset of Codex usage limits, as covered in the October 15 deck. Day 12 did not include a reset, and the post does not say how much more work users can expect from the same limits.
What to expect next
Watch whether Codex users report getting noticeably more done before hitting limits, and whether OpenAI shares numbers on the effect of the caching changes.
Also watch the remaining days of Tibo's 28 day push for further resets or limit changes, and whether rivals such as Anthropic respond with their own usage improvements for Claude Code. Any change to plan limits or pricing would be the next signal.