Anthropic launched mid-conversation system messages for Claude Opus 4.8, without a beta header.

Instruction changes during long-running sessions no longer have to break prompt cache hits.

For builders, instruction changes now sit after a user turn in messages, subject to placement rules.

• Jul 26, 2026OpenAI updated GPT-5.5 Instant to improve conversational quality in decision, advice, planning, research, and shopping tasks.
• Jul 25, 2026Enterprise and Edu users can find skills under Plugins, on the Skills tab in the Plugin Directory.
• Jul 25, 2026Anthropic removed modelcard language for Claude Fable 5 and Claude Mythos 5.

This is the world we build in. It moves this fast. We move with it.