🪦 Dead
OpenAI Assistants API
Product killed · Replaced by Responses API · shut down August 26, 2026
- Born
- Died
- Lifespan
- 2y 9m
- Cause of death
- Replaced by Responses API
- Killed by
- OpenAI
- Type
- Service
OpenAI's first stab at agents-as-a-service: threads, runs, file search and code interpreter bundled behind one beta endpoint. Announced at DevDay on November 6, 2023, it never left beta, and on August 26, 2025 OpenAI gave it exactly one year to live. It died on the day — a hard cut, no read-only mode, no grace period — with the Responses API inheriting its best parts and developers inheriting a full rewrite. 1,024 days, every one of them labelled "beta".
Collateral damage: Every agent built on threads and runs had to be rewritten against the Responses API before the deadline; requests to the old endpoints now return errors.