The Assistants API saved us months of work — 5★
We were about to roll our own RAG stack. The Assistants API handled threading, tool calls, and vector stores out of the box. Production in three weeks.
Lead Engineer · B2B SaaS, Canada · 2026-04-02
4.6★ · 1840 reviews · San Francisco, USA
Frontier AI models powering ChatGPT, GPT-5, and the Assistants/Realtime API.
Research and deployment company behind GPT-5, ChatGPT, DALL·E, Sora, and the OpenAI API. The default starting point for most teams shipping AI products in production.
We were about to roll our own RAG stack. The Assistants API handled threading, tool calls, and vector stores out of the box. Production in three weeks.
Lead Engineer · B2B SaaS, Canada · 2026-04-02
GPT-5 has been a workhorse. Main gripe is that scaling tier upgrades can be slow during peak usage. Otherwise excellent.
Product Manager · Fintech, Germany · 2026-03-22
JSON-mode + function calling reliability is unmatched. We replaced a fragile regex pipeline and our error rate dropped from 12% to under 1%.
Engineering Lead · Data analytics, USA · 2026-02-14