How to migrate from OpenAI API: gpt-5.1, gpt-5.3-codex, gpt-5.4-nano to gpt-6-sol for gpt-5.1 and gpt-5.3-codex; gpt-6-luna for gpt-5.4-nano (OpenAI's stated replacements)

147 days until OpenAI API: gpt-5.1, gpt-5.3-codex, gpt-5.4-nano shuts down (2027-04-01). Do not wait.

1. Export your OpenAI API: gpt-5.1, gpt-5.3-codex, gpt-5.4-nano data now. See the export checklist. Grab the full archive, verify it opens.
2. Set up gpt-6-sol for gpt-5.1 and gpt-5.3-codex; gpt-6-luna for gpt-5.4-nano (OpenAI's stated replacements). https://developers.openai.com/api/docs/deprecations - create the account and map your core objects before importing.
3. Run both in parallel for one cycle to catch gaps before OpenAI API: gpt-5.1, gpt-5.3-codex, gpt-5.4-nano goes dark.
4. Cut over: update integrations, billing and runbooks; keep the OpenAI API: gpt-5.1, gpt-5.3-codex, gpt-5.4-nano export archived.

Full export checklist →

Cite this page

"Migrating from OpenAI API: gpt-5.1, gpt-5.3-codex, gpt-5.4-nano to gpt-6-sol for gpt-5.1 and gpt-5.3-codex; gpt-6-luna for gpt-5.4-nano (OpenAI's stated replacements)." Bikoosh Shutdown Watch, verified 2026-11-05. https://bikoosh.com/shutdowns/migrate/openai-gpt-5-1-5-3-codex-5-4-nano-api-models/to-gpt-6-sol-for-gpt-5-1-and-gpt-5-3-codex-gpt-6-luna-for-gpt-5-4-nano-openai-s-stated-replacements

gpt-6-sol for gpt-5.1 and gpt-5.3-codex; gpt-6-luna for gpt-5.4-nano (OpenAI's stated replacements) is a documented option, not an endorsement. Shutdown Watch tracks vendor announcements and public deadlines; it is monitoring assistance, not legal or migration advice.