OpenAI deprecates Prompts API, Evals platform, and Agent Builder with November 30 shutdown

OpenAI announced on June 3, 2026 the deprecation of three developer-platform products — reusable prompt objects (the v1/prompts API), the Evals platform, and Agent Builder — with a coordinated shutdown timeline anchored on November 30, 2026. The announcement was posted to the OpenAI developer changelog and detailed on the platform's deprecations page. Taken together, the three sunsets signal a tightening of OpenAI's API surface as the company concentrates customers on the Agents SDK, ChatKit, and external evaluation tooling.

What's new

The consolidated changelog entry reads, verbatim: "Announced the deprecation of reusable prompt objects, the Evals platform, and Agent Builder." The deprecations page expands each item:

• Reusable Prompts API. "The v1/prompts API and reusable prompt objects are being deprecated." OpenAI's recommended migration is to "Move reusable prompt content into your application code." Shutdown date: November 30, 2026.
• Evals platform. Both the dashboard and the API are being retired. OpenAI flags October 31, 2026 as the read-only milestone — "Existing evals become read-only" — with full shutdown on November 30, 2026. The documentation references Promptfoo as an alternative evaluation tool.
• Agent Builder. Agent Builder is being discontinued on November 30, 2026; ChatKit remains available. OpenAI directs existing users to "Continue with the Agents SDK or ChatGPT Workspace Agents."

The three deadlines are aligned: a single November 30, 2026 cliff for all three products, with one earlier read-only milestone for stored eval runs.

Context

The three deprecated products were introduced separately as OpenAI experimented with multiple shapes for developer-facing scaffolding around model use — server-managed prompt templates (Prompts), in-platform model evaluation (Evals), and a low-code visual builder for agent workflows (Agent Builder). All three sat alongside more code-first primitives — the Responses API, the Agents SDK, and the Codex/ChatKit surfaces — and the parallel offerings have created overlap in the OpenAI developer story.

The November 30, 2026 cutoff puts customers on a roughly six-month migration window from the June 3 announcement, in line with the SDK-level migration cadence OpenAI used for the Assistants API sunset.

Why it matters

This is a coordinated trim, not a one-off sunset. By dating all three shutdowns to the same November 30 line, OpenAI is signalling a deliberate consolidation: server-managed prompt templates and in-platform evals become customer-owned (with Promptfoo as the suggested external option for evals), and the no-code Agent Builder gives way to the code-first Agents SDK plus the productized ChatGPT Workspace Agents. For teams building on OpenAI's platform, the practical work over the next six months is to (a) inline prompt content that currently lives behind v1/prompts, (b) move evals into Promptfoo or a comparable self-managed harness, and (c) re-platform any visual Agent Builder flows onto the Agents SDK. The broader signal — fewer overlapping surfaces, a sharper line between primitives the API owns and scaffolding customers own — is consistent with how OpenAI has tightened its product surface elsewhere in 2026, including the consolidation around the Responses API.