A collection of 8 posts
OpenAI shuts down GPT-4o, GPT-4o mini, GPT-4.1 and GPT-4.1 mini snapshots on Jan 14, 2027, fine-tunes included; new fine-tuning jobs stop Jan 6. The replacement, gpt-6-luna ($0.10/$0.50 per 1M), reasons by default and can't be fine-tuned.
GPT-6 Luna costs $0.10/1M input, $0.01 cached and $0.50 output with a 1.05M-token context. It is the only model behind the Decisions API (GA Oct 22, 400 questions/request), is rolling out to ChatGPT Free and Go, and replaces GPT-4o/4.1 snapshots retiring Jan 14, 2027.
GPT-6.1 Sol costs $2/$0.10/$10 per 1M tokens. Ultrafast went live Oct 8 at $12/$0.60/$60, 12h cache writes cost $5 per 1M, it is the Codex CLI default since 0.161.0, and it is in Google Cloud private preview. Benchmarks, Codex multipliers, cost math.
GPT-6 Sol ($2/$10) and GPT-6 Luna ($0.10/$0.50) launched 22 Sept 2026 at half the price of GPT-5.6. Specs, model IDs, pricing, OpenAI vs independent benchmarks, availability, API code, and Sol vs Astra.
OpenAI classified GPT-6 Astra as the first model to meet the Critical cybersecurity threshold under its Preparedness Framework. What the system card actually documents, what safeguards shipped, and what the June 2026 executive order really says.
GPT-6 Astra lists at exactly twice Claude Opus 5. On the one independent same-harness index that has run both, Opus 5 scores higher. Here is the full cost and benchmark breakdown.
OpenAI released GPT-6 Astra on 3 September 2026. Verified specification table, OpenAI-reported vs independently measured benchmarks, the 272K pricing cliff, staged rollout, and the API migration gotchas.
GPT-6 Astra costs $10/1M input and $50/1M output, but crossing 272K tokens reprices the entire request. Verified rates, the long-context cliff, and worked monthly costs.