OpenAI and Anthropic ship GPT-6 Sol and Luna and Claude Opus 5.5 in the same week

OpenAI released GPT-6 Sol and Luna at API prices 50% below GPT-5.6 promotional pricing, and Anthropic released Claude Opus 5.5 the same day at 40% less than Opus 5.

The roundup also covers Claude Code cloud sessions reaching general availability, the Claude Marketplace launch, OpenAI's new misalignment disclosures after the Hugging Face incident, and DevDay on September 29.

The post is a relayed weekly digest, and it includes the author's closing promotion for AIPRM, which is not part of the reported news.