OpenAI Evals go read-only on 2026-10-31: the migration checklist before the 2026-11-30 shutdown

The read-only milestone for OpenAI's Evals platform lands on 2026-10-31: the official deprecation page marks the date as Existing evals become read-only — existing evaluations on the platform enter a read-only stage from that day, ahead of the full dashboard and API shutdown on 2026-11-30. Based on the deprecation page as fetched on 2026-10-31, this article turns the batch — Evals, v1/prompts, and Agent Builder — into a checklist you can act on: the timeline, the boundaries, and the migration paths OpenAI actually names.

1. Which row takes effect today

The Evals section of the deprecation page (2026-06-03: Evals platform) is a three-row timeline:

• June 3, 2026: Deprecation announced for the Evals platform.
• Oct 31, 2026: Existing evals become read-only.
• Nov 30, 2026: The Evals dashboard and API are scheduled to shut down.

Two boundary sentences right after the table define the scope of this batch: Graders documented for eval workflows are part of this transition — graders documented for eval workflows move with it; and Fine-tuning-related timelines remain covered in the self-serve fine-tuning section below — fine-tuning timelines do not follow this section and stay in the deprecation page's self-serve fine-tuning part.

An honest caveat: GPTMap holds no OpenAI API key, so on 2026-10-31 we could not verify item-by-item whether read-only mode is actually enforced inside the platform; on the day, the page still presented the row as a timeline entry. Treat the platform UI and official follow-ups as the source of truth for actual operability.

2. The timeline: 150 days and 30 days

The three rows, converted into intervals (calendar-command computed, not estimated):

Those 30 days between read-only and shutdown are the migration window: beyond the three timeline rows, the page lists no additional buffer measures or exemptions — right after the table come the two boundary sentences (graders in transition, fine-tuning handled separately) and one migration pointer, and nothing else.

3. The other two rows on 2026-11-30: v1/prompts and Agent Builder

The same 2026-06-03 batch announced two more products with the same shutdown date:

v1/prompts and reusable prompt objects. Two timeline rows: June 3, 2026, Deprecation announced and prompt creation de-emphasized in the platform; November 30, 2026, The v1/prompts API and reusable prompt objects are scheduled to shut down. The official migration sentence: To migrate, move reusable prompt content into your application code — the guide page is Migrate from prompt objects.

Agent Builder. Two timeline rows: June 3, 2026, Deprecation announced for Agent Builder; November 30, 2026, Agent Builder is scheduled to shut down. One easily missed sentence in this section: ChatKit remains available — Agent Builder shutting down does not mean ChatKit shuts down. The official migration pointer is Migrate from Agent Builder, with the destinations being the Agents SDK or ChatGPT Workspace Agents.

Three products, two dates, one announcement — if any of them is in your dependency list, the migration window is the same one: through 2026-11-30.

4. Evals to Promptfoo: the officially named path

The Evals section's migration guidance is a single sentence: See Moving from OpenAI Evals to Promptfoo for a migration path. That is the destination OpenAI names for this batch — the cookbook guide Moving from OpenAI Evals to Promptfoo on developers.openai.com (the authors verified the page loads on 2026-10-31).

This article does not restate the guide's step-by-step instructions — for the actual migration procedure, follow the cookbook page. What this article confirms for you: the path is the one the deprecation page itself names, the page loads today, and it closes the loop with this batch's timeline (read-only 10-31, shutdown 11-30) inside the same section.

5. A checklist for the last 30 days

Based on the page's three timeline rows and two migration guides, worth confirming one by one before 11-30:

1. Evals: do your workflows still read evaluation configs from the Evals platform? If so, follow Moving from OpenAI Evals to Promptfoo; graders used by those workflows are inside this transition too — do not migrate the evals and leave the graders behind.
2. v1/prompts: any remaining v1/prompts calls or reusable prompt object references in your code? The official path is moving the content into application code (Migrate from prompt objects).
3. Agent Builder: any agent flows still built in Agent Builder? The official destinations are the Agents SDK or ChatGPT Workspace Agents (Migrate from Agent Builder). If your chain only uses ChatKit, note the page verbatim — ChatKit remains available — so first clarify whether you depend on the Builder or the Kit.
4. Fine-tuning: if your Evals usage ties into fine-tuning evaluation, remember the page states fine-tuning timelines live in the self-serve fine-tuning section — a separate set of dates; do not apply this article's 11-30 to fine-tuning assets.

Every item above anchors to the deprecation page text; where the page is silent (export formats, transitional API behavior), this article does not guess.

6. Where this sits in the larger shutdown calendar

This batch is not an isolated event. From the same deprecation page, verified 2026-10-31, the surrounding rows are:

• 2026-12-01: the older GPT Image models row (announced 2026-06-02) — gpt-image-1-mini and siblings, replaced by gpt-image-2.5-sunburst or the flare variant.
• 2026-12-11: the GPT-5 and o3 snapshots row (announced 2026-06-11) — gpt-5-2025-08-07 and siblings, replaced by gpt-5.6-sol and matching tiers.
• 2027-01-14: the GPT-4 series rows (announced 2026-10-14) — gpt-4o-2024-08-06, gpt-4o-2024-11-20, and siblings, replaced by gpt-6-luna.

For quarterly migration planning, 11-30 (these three products) and 12-11 (GPT-5/o3 snapshots) are the next two hard dates; the row-by-row official replacement table lives in the shutdown-day article linked below.

7. Boundaries and common misreadings

• Read-only is not shutdown: 10-31 changes writability only; no row on the page says evaluations are deleted on 10-31. The deletion window is the 11-30 dashboard and API shutdown.
• ChatKit does not go down with Agent Builder: that is page verbatim (ChatKit remains available), not this article's inference.
• Graders are in scope, fine-tuning is not: both sentences come from the Evals section text; folding fine-tuning timelines into this batch is a common misreading.
• Verification boundary: the official page was fetched on 2026-10-31; whether read-only is enforced item-by-item in the platform, and how well third-party tooling supports the Promptfoo migration, are beyond the page text and this article makes no claims there.

8. Next steps

• For the row-by-row deprecation policy, notice-period floors, and the full shutdown calendar, see OpenAI Deprecation Lifecycle Guide: Notice Periods, Shutdown Calendar, Migration Checklist.
• For the shutdown day that just landed and its official replacement table, see The 2026-10-23 legacy snapshot shutdown day: 17 model rows go offline, with the official replacement table.
• For the migrations themselves, follow the official guides: Moving from OpenAI Evals to Promptfoo, Migrate from prompt objects, and Migrate from Agent Builder (links in the officialReferences above).