What did OpenAI's DevDay launch for developers?
DevDay 2026 shipped an Agents API, a Decisions API, Codex fully in the cloud, 'Sign in with ChatGPT' — and cached input at just $0.10 per million tokens.
Beyond the consumer headlines, OpenAI's DevDay 2026 shipped a serious toolkit for people who build with the API. The Agents API gives developers a managed harness for building agents without assembling the scaffolding themselves; the Decisions API promises sub-second structured answers for fast judgments; Codex coding is moving fully into the cloud so a coding task can follow you across devices; and ‘Sign in with ChatGPT’ lets a user's own ChatGPT subscription pay for the OpenAI usage inside your app, starting with 16 partners — a clever twist on who foots the compute bill. The quiet price revolution: cached input now costs just $0.10 per million tokens.
For anyone designing agent workflows, the implication is direct: reuse context, cache aggressively, and let draft-quality output be cheap while reserving premium models for the hardest steps.
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