Migrating off Assistants API — retirement date and replacement
OpenAI is retiring Assistants API on 2026-08-26 — in 27 days. The provider’s documented replacement is Responses API and Conversations API. This page is built from OpenAI’s official deprecation notice and is rechecked weekly; the source link is below.
When is Assistants API being deprecated?
| Model | Provider | Retires | Replacement |
|---|---|---|---|
| Assistants API | OpenAI | 2026-08-26 | Responses API and Conversations API |
Source: OpenAI deprecation notice · announced 2025-08-20
What should I migrate Assistants API to?
OpenAI documents Responses API and Conversations API as the successor. Migrating within the same provider keeps your endpoint, authentication and region behaviour unchanged — the measured latency below does not move when you switch models on the same host.
Measured latency of the OpenAI API host
| Region | p50 TTFB | p95 | Uptime | Probes |
|---|---|---|---|---|
| Asia (Tokyo) | 198 ms | 273 ms | 100% | 289 |
| Europe (Germany) | 292 ms | 402 ms | 99.7% | 290 |
| South America (São Paulo) | 230 ms | 402 ms | 100% | 288 |
| US (Central) | 127 ms | 203 ms | 100% | 289 |
Edge latency to the provider’s API host over the last 24 hours, measured from 4 regions. This measures the endpoint, not the model: swapping models on the same host does not change these figures, which is exactly why they are useful when deciding whether to stay with OpenAI or leave. Compare providers →
Other OpenAI models being retired
| Model | Provider | Retires | Replacement |
|---|---|---|---|
| gpt-5.2-chat-latest | OpenAI | 2026-08-10 | gpt-5.6-sol |
| gpt-5.3-chat-latest | OpenAI | 2026-08-10 | gpt-5.6-sol |
| Videos API | OpenAI | 2026-09-24 | — not named |
| sora-2 | OpenAI | 2026-09-24 | — not named |
| sora-2-2025-10-06 | OpenAI | 2026-09-24 | — not named |
| sora-2-2025-12-08 | OpenAI | 2026-09-24 | — not named |
| sora-2-pro | OpenAI | 2026-09-24 | — not named |
| sora-2-pro-2025-10-06 | OpenAI | 2026-09-24 | — not named |
How is this calendar maintained?
Entries are pulled from provider documentation by an automated weekly job and every one carries a link to its source. Nothing is inferred from blog posts or social media. When a provider changes a date, the change appears here after the next run and is visible in the changelog. The full calendar across all providers is on the deprecations page, and this provider’s own list is at OpenAI deprecations.