OpenAI pulls GPT-5.5 from Codex on October 14, API spared

GPT-5.5 arrived in ChatGPT on April 23, 2026 and leaves it on October 14, 2026, a run of under six months in the products where most people met it. The notice came as a post from the @ChatGPT account on September 15, covered by Gizmochina, and it names the exits: ChatGPT, ChatGPT Work and Codex, on every plan.

At a glance

• OpenAI will pull GPT-5.5 from ChatGPT, ChatGPT Work and Codex on October 14, 2026, on every plan, and ordinary chat users will be moved to whatever model becomes the new default.
• Codex users signed in with a ChatGPT account are told to move to GPT-5.6 Sol or GPT-6 Astra, updating workspace defaults, custom agents, scheduled tasks and any script naming 5.5.
• Anything authenticated with an API key keeps working, and the announcement does not name the model that takes over as ChatGPT's new default.

If you have not tracked the numbering: Wikipedia records GPT-5.5, codename Spud, shipping on April 23, 2026 as the successor to GPT-5.4, with API access withheld at launch over what OpenAI called different safeguards and opened on April 24. GPT-5.5 Instant then reached free users on May 5, becoming ChatGPT's default for everyone, and OpenAI reported 82.7% on Terminal-Bench 2.0 and 35.4% on FrontierMath Tier 4.

The API keeps GPT-5.5, the ChatGPT surfaces do not

The retirement covers ChatGPT, ChatGPT Work and Codex on October 14, 2026, across all plans. For everyday chat use it should be invisible, since conversations move to whatever model OpenAI sets as the new default. Anything authenticated with an API key keeps running as before.

The wording from the @ChatGPT account was short:

On October 14, it's time to say farewell to GPT-5.5 in ChatGPT, ChatGPT Work, and Codex across all plans. If you use GPT-5.5 in Codex, switch to GPT-5.6 Sol or GPT-6 Astra.

The people who feel it are the ones who built something around 5.5, above all Codex users signed in with a ChatGPT account. OpenAI presents the change as part of keeping the lineup current.

Hardcoded model names are the part that breaks

Official guidance points Codex users to GPT-5.6 Sol, with GPT-6 Astra named in some references. Acting on that means workspace defaults, saved model settings, managed configurations, custom agents, scheduled tasks and any script that calls GPT-5.5 by name. Apps and automation tools with the model string written into them need the most edits. GPT-5.4 class models were pulled from Codex at the end of August 2026, about six weeks before this cutoff.

Wikipedia records one quirk of the model now being retired. A tendency to mention goblins, gremlins and similar creatures began with GPT-5.1 and became noticeable in GPT-5.5's Codex testing; OpenAI attributed it to reward signals used when training the Nerdy personality, which carried beyond that personality. The response was to retire Nerdy, remove the reward signal, filter training data and add a developer-prompt instruction for GPT-5.5 in Codex.

Why one model can leave Codex and still answer API calls

The split follows how you sign in. ChatGPT, ChatGPT Work and the Codex app authenticate through a ChatGPT account, and that is where the October 14 cutoff lands. Requests carrying an API key go through a separate surface with its own lifecycle, and those are unaffected.

Think of one kitchen with two doors: the dining room can close while the delivery window stays open, the same cooks behind both. In practice a team's production service calling GPT-5.5 with a key survives the date, while the same team's Codex sessions in the editor stop offering the model.

Does a retirement notice actually remove a model?

Not from the places where code already runs. According to Tech Insider, cloud security firm Orca found GPT-4o, pulled from the ChatGPT consumer app in February 2026, still present in 37.6% of AI-adopting cloud environments, more than any newer OpenAI release.

Tech Insider also lists the retirements that came before this one: GPT-4.5 left ChatGPT on June 27, 2026, and two days later four Azure chat-tuned snapshots, gpt-5-chat, gpt-5.1-chat, gpt-5.2-chat and gpt-5.3-chat, were folded into a single rolling alias, gpt-chat-latest. Deprecation notices on Azure, the same outlet writes, have followed a pattern described as six months, three months, two weeks.

The announcement leaves two things open. API access is described as continuing for now, with no end date attached, which makes «for now» the load-bearing phrase for anyone running GPT-5.5 in production. Oddly, the post hands Codex users two model names to migrate to and tells everyone else only that the default will change.

Under four weeks to switch

October 14 is under four weeks out. Until then the work is mechanical: change workspace defaults and managed configurations, repoint custom agents and scheduled tasks, and search your scripts for the string GPT-5.5. The thing worth watching is which target the guidance settles on, since it currently names both GPT-5.6 Sol and GPT-6 Astra, and no date has been given for GPT-5.5 leaving the API.