ModelClock
Available in the API since Mar 17, 2026
OpenAI announced API availability for this model on 2026-03-17.
This date applies to API availability. Rollouts in consumer products or other hosting routes can happen on different dates.
- Hosting route
- First-party API
- Affected scope
- Not stated in the notice
- Announced
- Mar 17, 2026
- First seen by ModelClock
- Oct 8, 2026
What the provider published
learn.chatgpt.com ↗Introducing GPT-5.4 mini in Codex
GPT-5.4 mini is now available in Codex as a fast, efficient model for lighter coding tasks and subagents.
It improves over GPT-5 mini across coding, reasoning, image understanding, and tool use while running more than 2x faster. In Codex, GPT-5.4 mini uses 30% as much of your included limits as GPT-5.4, so comparable tasks can last about 3.3x longer before you hit those limits.
GPT-5.4 mini is available in the Codex app, the CLI, the IDE extension, and Codex on the web. GPT-5.4 mini is also available in the API.
Use GPT-5.4 mini for codebase exploration, large-file review, processing supporting documents, and other less reasoning-intensive subagent work. For more complex planning, coordination, and final judgment, start with GPT-5.4.
To switch to GPT-5.4 mini:
- In the CLI, start a new thread with:
codex --model gpt-5.4-mini
Read from the provider's text; the quote is the provider's exact lines.
