GPT-5.4 Retires from Codex: August 31 Deadline, How to Migrate
OpenAI is retiring GPT-5.4 and GPT-5.4-mini from Codex on August 31, 2026, with an official migration path to gpt-5.6-terra and gpt-5.6-luna. Here's exactly who's affected and how to switch.
The retirement only applies to Codex sessions signed in with a ChatGPT account. Users authenticating Codex with an API key, or calling the OpenAI API directly, aren't directly affected by this specific retirement -- but GPT-5.4 is no longer the frontier model, so sticking with it means giving up 5.6's capability and price advantages regardless. Worth planning the switch either way.
Last verified: 2026-08-08 (OpenAI official docs and 9to5Mac reporting).
Migration Mapping and Price Comparison
Official migration path: gpt-5.4 to gpt-5.6-terra, gpt-5.4-mini to gpt-5.6-luna. Prices verified against the LiteLLM authoritative pricing table.
| Old model to new model | Old price (in/out, per million tokens) | New price (in/out, per million tokens) | Change | Note |
|---|---|---|---|---|
| gpt-5.4-mini to gpt-5.6-luna | $0.75 / $4.50 | $0.20 / $1.20 | Cheaper and stronger | Luna got another 80% price cut on 7/30, now well below 5.4-mini's price |
| gpt-5.4 to gpt-5.6-terra | $2.50 / $15.00 | $2.00 / $12.00 | Cheaper and stronger | Terra got a 20% price cut on 7/30, with higher benchmark scores than 5.4 |
| (If you need more) gpt-5.6-sol | — | $5.00 / $30.00 | Flagship tier | OpenAI hasn't published a 5.4-to-sol migration mapping; sol is the strongest of the three tiers |
What to Know Before You Migrate
What exactly is being retired
It's the "ChatGPT-signed-in" Codex session -- the model list you see when signing into Codex CLI or the extension with a ChatGPT account (including Plus/Pro/Work). Whether gpt-5.4 keeps working after 8/31 for API-key-authenticated Codex or direct OpenAI API calls depends on OpenAI's real-time API documentation at the time -- this page doesn't make guarantees on OpenAI's behalf.
Why migrate even if you're not directly affected
GPT-5.6's three tiers have been fully available for over a month. Terra is now priced below the old 5.4 with better benchmark performance; Luna, after the 7/30 price cut, is both cheaper and stronger than 5.4-mini. There's no price or capability advantage left in sticking with the 5.4 family -- the only reason left is "I don't want to touch my config."
Saved configs, custom agents, scheduled tasks
OpenAI's official migration guidance explicitly says to replace gpt-5.4 with gpt-5.6-terra and gpt-5.4-mini with gpt-5.6-luna in saved configurations, custom agents, and scheduled tasks. If you haven't swapped these manually before 8/31, ChatGPT-signed-in tasks referencing the old models may fail or get auto-redirected after the cutoff -- exact behavior depends on OpenAI's announcement at the time.
Three Steps to Migrate
Worth doing all three regardless of how you authenticate.
1. Confirm how you authenticate
Figure out whether you're signed into Codex with a ChatGPT account or an API key first -- that determines whether 8/31 is a hard deadline for you or just a good-idea-anyway.
2. Swap models by task
Luna for heavy tool-calling, well-specified changes, and test-writing; terra as your everyday coding default; sol only for complex design work or hard debugging -- not every task needs the priciest tier.
3. Update saved configurations
Anywhere gpt-5.4 or gpt-5.4-mini appears -- custom agents, CI model IDs, scheduled tasks -- swap in gpt-5.6-terra or gpt-5.6-luna.
Timeline
Four key dates from 5.4's launch to its retirement.
GPT-5.4 and GPT-5.4 Pro launch
OpenAI releases the GPT-5.4 family at an official $2.50/$15.00 (per million tokens) input/output price.
GPT-5.6's three tiers (Sol/Terra/Luna) launch
The new generation arrives, with terra positioned as 5.4's successor and luna as 5.4-mini's.
Terra cut 20%, Luna cut 80%
Terra drops to $2.00/$12.00, Luna to $0.20/$1.20, widening the price gap with the 5.4 family further.
GPT-5.4 / GPT-5.4-mini retire from ChatGPT-signed-in Codex
Official migration path: gpt-5.4 to gpt-5.6-terra, gpt-5.4-mini to gpt-5.6-luna. API-key access isn't directly affected.
Primary Sources
9to5Mac reporting on the OpenAI Codex model retirement; OpenAI's official Release Notes and Codex Changelog; LiteLLM model_prices_and_context_window.json (openai key, verified 2026-08-08).
FAQ
Will my API key still work with gpt-5.4 after August 31?
The retirement announcement specifically targets ChatGPT-signed-in Codex sessions. Whether and how API-key-authenticated access is affected depends on OpenAI's API documentation at the time -- this page doesn't speak for OpenAI on that.
Is gpt-5.6-terra just gpt-5.4 renamed?
No, they're two different model generations -- OpenAI has simply designated terra as 5.4's migration target (comparable or better capability, lower price).
What happens if I do nothing?
If you're ChatGPT-signed-in: configs/agents/scheduled tasks referencing gpt-5.4 or gpt-5.4-mini will likely fail or need manual attention after 8/31, exact behavior per OpenAI's announcement at the time. If you're on API-key access: follow OpenAI's documentation at the time -- this page doesn't make promises on OpenAI's behalf.
Can I use terra and luna on QCode right now?
Yes, QCode has offered all three gpt-5.6 tiers (sol/terra/luna) since July 10, 2026, switchable with the same key.
Create a QCode account
Plans from ¥60 / $8.57. One key across Claude, GPT, and Gemini models.
Related Guides
Sol vs Terra vs Luna: How to Choose
Tier selection guidance for coding workloads
GPT-5.6 Pricing Guide
Full price table and cache pricing for all three tiers
AI Coding Models 2H 2026: How to Choose
The full landscape and a decision framework
This site is not affiliated with OpenAI. Retirement dates and migration paths follow OpenAI's official announcements; information on this page is current as of 2026-08-08 and may change.