What changed
GPT-5.4 and GPT-5.4 mini retired from Codex for ChatGPT-signed-in users on August 31, 2026.
Verified before and after
GPT-5.4; GPT-5.4 mini→GPT-5.6 Terra replaces GPT-5.4; GPT-5.6 Luna replaces GPT-5.4 mini
Effective from the official source evidence dated Sep 1, 2026, 8:49 AM UTC.
Who is affected
Codex users on the recorded availability path.
What remains unknown
Values outside the verified before/after pair stay Unknown until a current official source is verified for that exact plan, model, and period.
Affected TraceCheck pages
- Codex
- Codex Usage Limits: Plus, Pro, 5-Hour and Weekly
- Codex vs Claude Code: Plans and Limits
- Kimi Code vs Claude Code vs Codex
- Codex Pricing — Plans, Credits & Billing
- Codex vs Cursor — Cost, Capacity & Access
- Gemini coding tools / Gemini CLI vs Codex — Cost, Capacity & Access
- Codex vs GitHub Copilot — Cost, Capacity & Access
- Codex vs OpenCode — Cost, Capacity & Access
Official evidence
Using Codex with your ChatGPT plan ↗
- Fetched
- Sep 1, 2026, 8:49 AM UTC
- Content hash
sha256:f3d2aff0c927ed3273c3b36923f72adc1f1411b5e1afb891afd8279202c878d5- Verification
- Verified against the explicit OpenAI Help Center retirement notice. The current pricing table still shows legacy GPT-5.4 rows, so those rows were not treated as evidence of current ChatGPT-signed-in Codex availability.