critical impact

OpenAI Assistants API shuts down on August 26, 2026

OpenAI is removing the Assistants API and directs developers to the Responses API and Conversations API.

Provider: OpenAI
Surface: OpenAI API
Change type: api sunset
Shutdown: August 26, 2026
Announced: August 26, 2025
Last verified: July 26, 2026

What breaks

Applications that create assistants, threads, messages, or runs through the Assistants API must migrate before the removal date.

Assistants API integrations will stop working after the API is removed.

Affected identifiers and fields

Search your code, environment variables, gateway configuration, and stored request templates for these exact values.

Assistants API
/v1/assistants
/v1/threads
client.beta.assistants
client.beta.threads

assistant
thread
run
client.beta
Assistants API v2

Migration target

Use the official Assistants-to-Conversations migration guide to move state and execution to Responses and Conversations.

Responses API
Conversations API
/v1/responses
/v1/conversations

What to do

Inventory Assistants and Threads SDK usage, map it to Responses and Conversations, migrate stored state, and run end-to-end tool and conversation tests before August 26.

Official source receipts

These provider pages support the dates, identifiers, symptoms, and migration direction recorded above.

Official source 1 · verified July 26, 2026OpenAI API deprecations — Assistants API ↗

OpenAI · Official documentation

Official source 2 · verified July 26, 2026Assistants to Conversations migration guide ↗

OpenAI · Official documentation