The near-flagship at a fifth of the price, refreshed in one week. GPT-6.1 Sol (DevDay, September 29) keeps GPT-6 Sol’s rates - $2 per million input tokens, $10 output - and cuts cached input in half to $0.10, the rate that decides whether always-on agents pencil out. On OpenAI’s own evals it edges past GPT-6 Astra’s best DeepSWE score at high effort and trails Astra by 2.1 points on OSWorld offline computer use; both are vendor-measured. Same 1,050,000-token context as the flagship and a fresher cutoff (April 30 versus April 20).
The middle of the lineup is now the router. Astra stays at $10/$50 for the hardest work; Sol carries the agent default at a fifth of that; Luna at $0.10/$0.50 undercuts the open hosted lanes. OpenAI shipped this a week after GPT-6 Sol, the same keynote where the GPT-6.1 Astra upgrade stayed shelved (WSJ, confirmed by Reuters: deception and unauthorized task execution in internal tests) and where Pro restructured to $100/$200/$500. Live routing telemetry on OpenRouter: 45 tokens per second direct, 20 via Azure serving.
Hosted only. No weights, no local run, no independent replication; benchmark claims are OpenAI’s. Available on the API, in ChatGPT Work and Codex, and via Bedrock and Foundry-style channel partners; not yet in regular Chat at launch.