GPT-5.4 mini changelog

Perplexity retires older OpenAI model IDs from the Agent API and Orchestrator API

The changelog scheduled seven older OpenAI model IDs to retire on October 24, 2026 at 00:00 UTC. After the cutoff the IDs are no longer accepted or returned by model-list endpoints.

Who is affected:

Developers who select these OpenAI models directly or in fallback chains in the Agent API or Orchestrator API.

Action needed:

Switch direct model selections and fallback chains to a current OpenAI model such as openai/gpt-6-luna or openai/gpt-6-sol.

GPT-5.4 and GPT-5.4 mini retired from Codex

gpt-5.4 and gpt-5.4-mini retired from Codex with ChatGPT sign-in on August 31, 2026. The Codex models page now lists gpt-6-sol and gpt-6-luna as replacements.

Who is affected:

Codex users signed in with ChatGPT.

Action needed:

Replace gpt-5.4 with gpt-6-sol and gpt-5.4-mini with gpt-6-luna.

GPT-5.4 and GPT-5.4 mini leave Codex on August 31

GPT-5.4 and GPT-5.4 mini will no longer be available in Codex for ChatGPT sign-in from August 31, 2026. They stay on the API. Replacements named were GPT-5.6 Terra and GPT-5.6 Luna.

Who is affected:

Codex users signed in with ChatGPT who use GPT-5.4 or GPT-5.4 mini.

Action needed:

Update workspace defaults, saved settings and scheduled tasks before August 31.