OpenAI documents two different deadlines in its August 26, 2026 changelog entry: the Assistants API shut down that day, while four transcription models are scheduled to shut down on February 26, 2027. Those need different migration plans—not a blanket rewrite of every OpenAI integration.
The practical split is straightforward: find actual Assistants dependencies, then inventory transcription by the output your product needs. A model-name swap isn't enough if the replacement loses speaker labels, subtitle timing or translation.
This guide uses official documentation checked on October 7, 2026. No API calls, migration tests or audio comparisons were performed. The dates below are documented lifecycle dates, not observations of live API availability.
The August 26 changelog entry says: “The Assistants API shut down on August 26, 2026.” The migration guide independently describes it as sunset and no longer available, and directs integrations to Responses. Conversations is the documented replacement for Threads.
For transcription, the deprecations page lists February 26, 2027 as the shutdown date for each of these models:
whisper-1gpt-4o-transcribegpt-4o-mini-transcribegpt-4o-transcribe-diarizeTheir deprecation announcement is dated August 26, 2026. Deprecation and shutdown aren't interchangeable: the former starts the retirement process; the latter ends access, according to OpenAI's definitions. That doesn't prove a particular legacy request succeeds today, nor does it establish the response code an Assistants request would return.
The dated changelog entry also doesn't establish when it first became visible to readers. There's no retained basis here for claims about delayed surfacing, silent failures or whether particular customers received notice.
Make one inventory row per workflow. Record the owning service, its SDK or wrapper, endpoint family, configured model, stored state, tool dependencies, required output and migration owner. Include scheduled jobs and fallback paths—not just the main request handler. This is a recommended audit, not an audit performed for this article.
For Assistants, look for assistant and thread IDs, beta.assistants and beta.threads SDK usage, run polling, tool-output submission and persisted thread histories. Then trace who reads those IDs: a web handler may have moved while a worker or support tool still expects the old objects.
For transcription, search configuration as well as code for the four model identifiers. Record whether each job uploads a finished recording, consumes live audio or needs a transcript after an audio turn is committed. Add the requirements that a generic “speech to text” label hides: speaker attribution, word timing, subtitle files, English translation and downstream structured fields.
If a service uses only Chat Completions and none of these Assistants or transcription dependencies, this lifecycle notice alone doesn't require it to migrate. The Assistants guide is a migration guide for Assistants workflows, not evidence of a universal Chat Completions shutdown.
The migration guide maps Threads to Conversations, Runs to Responses and Run steps to Items. Conversations can hold messages, tool calls and tool outputs. The application now manages orchestration, including history pruning, tool loops and retries.
That means you need to preserve two contracts: what the assistant was configured to do, and how your application continues a user's work.
Recover the configuration you actually have. Inventory saved instructions, model selection and tool declarations. Don't assume an old assistant ID reconstructs that bundle in the new API. Keep a versioned copy of the configuration you can review and restore.
There's a watchpoint in the guide: it still describes creating reusable prompt objects from assistants, but explicitly warns that those objects are also being deprecated. The deprecations page dates that announcement to June 3, 2026, with shutdown of v1/prompts and reusable prompt objects scheduled for November 30, 2026. June 3 was not their shutdown date. OpenAI's stated migration direction is to move reusable prompt content into application code; don't build a long-lived replacement around a prompt ID without resolving that dependency.
Use stored history, not a dead export recipe. The guide says to preserve earlier conversations using messages already stored by your application. It labels the example that retrieves thread messages as a pre-sunset example: that Assistants retrieval call no longer works, according to the documentation. If you don't have the history locally, mark recovery as unresolved rather than promising that rerunning the example will retrieve it.
Before accepting a replacement, use this checklist:
These are recommended acceptance checks, not verified results. The guide's object mapping doesn't prove your integration passes them.
The current transcription guide makes three distinctions worth preserving in your migration plan:
gpt-transcribe. It can return a final transcript or stream text while processing the file.gpt-live-transcribe when you need text as speech arrives.gpt-transcribe with Realtime transcription.Streaming the output of a completed file is not the same thing as sending live audio. Don't move a file uploader to a persistent Realtime connection merely because its UI displays incremental text. Conversely, don't assume a file-transcription path preserves the interaction your live caller expects.
The specialized-capability table is the migration snag. It still directs readers to gpt-4o-transcribe-diarize for speaker-labeled file transcripts, and to whisper-1 for word timestamps, srt/vtt subtitles and translation of a completed recording into English. Those are among the models with the February 26 deadline.
The checked guide does not establish successor parity for those requirements. That isn't proof the successors can never support them; it's a gap you must resolve before cutover. Mark each required capability as accepted, explicitly out of scope or unresolved. A plain transcript isn't an acceptable substitute for speaker attribution in a meeting product or timed subtitles in a video pipeline unless the product owner accepts that change.
Use representative recordings you have permission to process. Include target languages and accents, code-switching, background noise, telephony audio, names, numbers, domain terms, long recordings and interrupted speech—the conditions OpenAI recommends testing.
Then check the contracts your downstream code consumes:
gpt-transcribe and gpt-live-transcribe use languages, rather than the singular language field used by some existing models. Review request construction instead of forwarding legacy options unchanged. keywords are hints, not words the model must insert.gpt-transcribe automatically uses earlier transcribed turns in Realtime input transcription and dedicated transcription sessions. Check whether that behavior fits your intended session boundaries.Don't treat acceptance as “the request returned text.” Accept the workflow only when its required outputs and failure handling work for your application. No such tests were executed for this guide.
For Assistants, don't plan rollback as routing traffic back to the sunset API. Keep a previous working version of the replacement's application code and configuration, and define a degraded mode if a required tool or recovered history isn't ready. Whether that fallback is acceptable is a product decision you need to test.
For transcription, a temporary legacy fallback before its documented deadline is only a recommendation where the endpoint and model are actually available and your requirements allow it. This article hasn't verified that availability. A fallback that depends on a retiring model isn't a plan for after February 26, 2027.
Before switching traffic, assign someone to own unresolved capabilities and a decision date before the relevant deadline. During rollout, watch missing outputs, invalid downstream formats, tool failures, retries and user/session mix-ups. Preserve authorized input fixtures and configuration versions so you can reproduce failures. Recheck the official timelines before release; neither a migration recommendation nor a successful test would guarantee future availability.
The useful outcome is a short list of real dependencies and explicit acceptance decisions. Move the affected Assistants workflows. For transcription, migrate the workflow and its output contract—not just the model string.
Official documentation checked from complete retained source captures retrieved on October 7, 2026. No live API availability, migration, transcription-quality or pricing tests were performed.
2026-08-31T14:08:00Z), by Mr. Technology. Original publication identity retained.