OpenAI API changes, October 2026: what changed
15 entries from OpenAI's public changelog, published 2026-09-05 to 2026-10-05, newest first. By type: deprecation: 3, new: 11, fix: 1.
The API changelog and the deprecations page are covered. The changelog entries have no separate headline, so each title here is the entry's lead sentence shortened.
Only the breaking changes and deprecations: OpenAI API breaking changes and deprecations, Sep 5 to Oct 5, 2026.
Read on 2026-10-05: https://developers.openai.com/api/docs/changelog and https://developers.openai.com/api/docs/deprecations
| Date | Type | Change |
|---|---|---|
| 2026-10-01 | deprecation | GPT-5.3-Codex, GPT-5.1, GPT-5.4-Nano gpt-5.3-codex, gpt-5.1 and gpt-5.4-nano are deprecated with a shutdown date of April 1, 2027; the listed replacements are gpt-6-sol for the first two and gpt-6-luna for gpt-5.4-nano. |
| 2026-10-01 | deprecation | Text-to-speech models tts-1, tts-1-hd and two dated gpt-4o-mini-tts snapshots are deprecated with a shutdown date of January 6, 2027; the listed replacement is gpt-realtime-2.1-mini. |
| 2026-09-29 | new | Added computer use to the Agents API The Agents API adds computer use with an OpenAI-hosted browser; your app handles website access approvals and sign-in. |
| 2026-09-29 | new | Released GPT-6.1 Sol GPT-6.1 Sol (gpt-6.1-sol) is available in the Responses and Chat Completions APIs. |
| 2026-09-29 | new | Added Ultrafast mode for GPT-6 Astra GPT-6 Astra supports an ultrafast service tier in the Responses API, subject to rate limits. |
| 2026-09-25 | fix | Fixed an image encoding bug in GPT-6 Sol and GPT-6 Luna An image encoding bug that degraded image understanding in GPT-6 Sol and GPT-6 Luna was fixed. |
| 2026-09-22 | new | Released GPT-6 Sol and GPT-6 Luna GPT-6 Sol and the lower-cost GPT-6 Luna were released in the API. |
| 2026-09-15 | new | Added API key creation governance controls Organizations and projects can restrict API key creation, for example to service-account keys only, or disable new key creation. |
| 2026-09-11 | deprecation | GPT-5.4-Cyber OpenAI announced that gpt-5.4-cyber shuts down on October 1, 2026, pointing users to the most capable cyber model available to them. |
| 2026-09-10 | new | Released the Agents API in public beta The Agents API is in public beta with durable sessions, streaming, and support for your own tools and MCP servers. |
| 2026-09-10 | new | GPT-Live 1 is generally available GPT-Live 1 (gpt-live-1), a full-duplex voice model, is generally available. |
| 2026-09-10 | new | Expiration dates for project API keys Administrators can set an expiration date when creating a project API key and can enforce a maximum key lifetime. |
| 2026-09-08 | new | Prompt Cache Diagnostics is generally available Prompt Cache Diagnostics is generally available in the Responses API for GPT-5.6 and later models. |
| 2026-09-08 | new | Released GPT Image 2.5 Sunburst and Flare The GPT Image 2.5 Sunburst and Flare image models were released, with new xhigh and max quality settings. |
| 2026-09-08 | new | GPT-Rosalind is generally available GPT-Rosalind, a model for life sciences research, is generally available through OpenAI's trusted-access program. |
What the paid brief adds
This page is the free list. The paid issue covers these 15 OpenAI entries and the other three vendors (142 entries in all) and adds:
- the action checklist: what to do for each entry, or a plain "none" when the change needs nothing from you;
- an "Act first" section: the 46 breaking changes and deprecations and nothing else, grouped by vendor, each with what to do;
- a source link for every entry;
- a CSV file with all entries, one row each, to filter or import.
Issue 1, a one-time $7 download: an HTML brief plus a CSV. A short README text file comes with them. The issue covers 2026-09-05 to 2026-10-05. You pay once for this one dated issue: nothing is billed again, and no later issue or update is included. The price and terms are shown on the Gumroad page before you pay.