OpenAI releases GPT-6 Sol and GPT-6 Luna, with Luna at $0.10 per million input tokens

Sources: primary, discussion
Summary: The OpenAI API changelog entry dated 2026-09-22 names model ids gpt-6-sol and gpt-6-luna, both reasoning models accepting text and image input through the Responses and Chat Completions APIs. Standard pricing per million tokens for prompts up to 272K input tokens is $2 input, $0.20 cached input, and $10 output for Sol, and $0.10 input, $0.01 cached input, and $0.50 output for Luna. The openai.com announcement page returned HTTP 403 to this run, so the changelog is the primary source actually read and no capability claim is carried here.
Why it matters: Luna puts a reasoning model an order of magnitude below current frontier input pricing, which changes what is economical to run at fan-out scale, for example as subagents.
Follow-up: Independent benchmark results for both models, and whether the openai.com announcement carries capability claims the changelog omits.