LAST CALL · OCTOBER 23, 2026

The Oct 23 OpenAI Shutdown: Last-Call Migration Checklist — AI Agents 2026

This AI agents 2026 migration checklist is a last-call guide to the October 23, 2026 OpenAI model shutdown. Seven models stop working with no graceful fallback — this AI agents 2026 page lists what dies, replacements, and the five migration traps.

What is the AI agents 2026 OpenAI shutdown migration check?

The shutdown migration check is a last-call guide for the October 23, 2026 retirement of seven OpenAI models, when API requests to them start returning HTTP 404. It lists what dies, the vendor-recommended replacements with pricing context, and five migration traps — like hardcoded model names — that break apps silently.

Reviewed October 18, 2026

On October 23, 2026, OpenAI retires seven models. Requests to them stop working — HTTP 404, no graceful fallback. If your chatbot, classifier, or automation was built on any of them, this page is your 30-second triage: what's dying, what replaces it, and the five traps that break apps silently.

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Countdown to October 23, 2026 (UTC). Deadlines follow OpenAI's published deprecations page — verify there before you migrate.

☠️ What's dying on Oct 23

Model	Suggested replacement	Note
`gpt-4-0613`	`GPT-5.6 Sol`	The original pinned GPT-4 snapshot — the most common buried dependency.
`gpt-4-turbo`	`GPT-5.6 Sol`	Flagship-workload class; test prompts on the replacement, outputs differ.
`o1`	`GPT-5.6 Sol`	First-gen reasoning model; migrate reasoning-heavy chains carefully.
`o3-mini`	`GPT-6.1 Sol`	Cost-efficient reasoning — GPT-6.1 Sol preserves the cost profile.
`o4-mini`	`GPT-6.1 Sol`	Same reasoning class; re-run evals after switching.
`gpt-image-1`	`check deprecations page`	Image pipelines need a migration target from OpenAI's current docs.
`ft-*`	`rebuild or prompt-tune`	ALL fine-tunes of these families die. Fine-tuning is also winding down — confirm current status on OpenAI's deprecations page.

Replacements are suggested starting points, not official guidance. GPT-5.6 Sol is the replacement — it is not being retired. Always verify against OpenAI's deprecations page.

💰 Pricing context: replacement cost per 1M tokens

GPT-5.6 Sol
$4 input / $20 output

Flagship-class replacement for GPT-4 / GPT-4-turbo / o1 workloads.

GPT-6.1 Sol
$2 input / $10 output

Cost-efficient replacement for o3-mini / o4-mini reasoning workloads.

Pricing context per OpenAI's published API pricing at the time of writing — confirm current rates before budgeting. Cost shock is trap #4 below.

🪤 The 5 migration traps (check them off — your progress saves in this browser)

0 of 12 complete

1 · Pinned model strings in code

The dying model ID is buried in code, config files, environment variables, prompt templates, and no-code automation tools. Search for every ID — including short names like o4-mini — before you touch anything else.

2 · Fine-tune rebuilds

ft-* models die with their base models. If you rely on a fine-tuned model, you must rebuild or re-engineer it on a supported base — and OpenAI is winding down fine-tuning overall, so check you can still train a replacement.

3 · Eval drift on the new model

The replacement answers differently: tone, format, refusal behavior, and reasoning depth all shift. Run the same prompts through the suggested model and compare answers, speed, and cost on real work before switching traffic.

4 · Cost shock

GPT-5.6 Sol at $4/$20 per 1M tokens is a different price class than the mini models you're leaving. Multiply your current monthly token volume by the new rates — surprise bills are the second most common migration complaint.

5 · Queue & cron silent breakage

Scheduled jobs, queue workers, and background automations hit the same HTTP 404 — but silently, at 3am. After migration, verify every cron and queue still produces output, and add alerting on model_not_found errors.

Bonus · Supplier-built tools

If you pay for a tool built on OpenAI (agency chatbot, plugin, SaaS integration), ask the supplier which model it uses and whether they are switching before Oct 23. Their migration is your uptime.

FROM INGENIOUS AI

ModelMinder watches model retirements so you never find out from a 404 — deprecation radar for every model your stack depends on, with migration windows before the shutdown hits.

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Frequently asked questions

What happens when an OpenAI model is deprecated?

It keeps working until its published shutdown date. After that date, API requests return HTTP 404 with a model_not_found error and your app stops getting answers — it does not degrade gracefully. Switch before the deadline.

When is GPT-4 being shut down?

October 23, 2026. On the same date OpenAI also retires gpt-4-turbo, o1, o3-mini, o4-mini, gpt-image-1, and all ft-* fine-tunes of those model families. GPT-5.6 Sol is the replacement — not a retiree.

Does the Oct 23, 2026 OpenAI shutdown affect ChatGPT?

No. The shutdown applies to the OpenAI API (usage-billed developer access). OpenAI swaps ChatGPT's models on its own timetable, and Microsoft Azure has its own model retirement schedule — Azure users should check the Azure retirements page.

Can a retired OpenAI model be recovered?

No. Closed models' weights never leave OpenAI, so once a model is retired there is no way to call it again. The only recovery is migration: point your code at a supported replacement and re-test your workloads.

How do I find every place a dying model is named?

Search your code, config files, environment variables, prompt templates, and any no-code/automation tools for each model ID — including short names like o4-mini and gpt-4-turbo. Check scheduled jobs and queues too: cron jobs fail silently on the 404.