OpenAI pulled GPT-5.2 Instant, GPT-5.2 Thinking, and GPT-5.2 Pro from ChatGPT on June 12, with existing conversations auto-migrating to GPT-5.5, according to OpenAI’s ChatGPT release notes. The retirement had been announced with the release of GPT-5.3 Instant, following OpenAI’s policy that models “will generally remain available in ChatGPT for 90 days after a successor is released.”

Separately, OpenAI deprecated six API model snapshots on June 11, all scheduled for shutdown on December 11, 2026, according to the API deprecations page.

What Gets Retired

The API deprecation wave covers the following snapshots, with recommended replacements:

  • gpt-5-2025-08-07 → gpt-5.5
  • gpt-5-mini-2025-08-07 → gpt-5.4-mini
  • gpt-5-nano-2025-08-07 → gpt-5.4-nano
  • gpt-5-pro-2025-10-06 → gpt-5.5-pro
  • o3-2025-04-16 → gpt-5.5
  • o3-pro-2025-06-10 → gpt-5.5-pro

These are all pinned snapshots. Production applications calling these specific model IDs will stop working on December 11, according to OpenAI.

Platform Tooling Sunset

The deprecation wave extends beyond models. OpenAI also announced on June 3 that three developer platform features will shut down:

Agent Builder is being deprecated, with ChatKit remaining available as an alternative. Reusable prompts (both dashboard and API) shut down November 30, with developers directed to migrate prompt content into application code. The Evals platform goes read-only October 31 and shuts down entirely November 30, with OpenAI pointing teams to Promptfoo as a migration path, according to OpenAI.

Migration Timelines for Production Agents

OpenAI’s deprecation policy gives generally available models at least six months of notice, specialized variants (chat, Codex, deep research) at least three months, and preview models as little as two weeks, according to OpenAI.

For teams running autonomous agents in production, this deprecation cycle creates a concrete migration deadline. Any agent stack pinned to the retiring GPT-5 or o3 snapshots needs to be tested against the recommended replacements before December. The o3 to gpt-5.5 migration is particularly notable since it crosses model families entirely, potentially changing behavior in reasoning-heavy agent workflows that were tuned for o3’s specific characteristics.

The broader pattern is clear: OpenAI is consolidating around the GPT-5.5 family and retiring anything older aggressively. Teams that pin to model snapshots for reproducibility now face a recurring migration cost every 6 to 12 months.