Claude Platform

Coordinate multiple agents within a single session.

Claim the monthly Claude Platform credits included with Claude Max and Team plans, and learn what they cover.

Behavioral differences from Claude Opus 5 and the prompting and harness patterns that address them: effort calibration, thinking behavior in API integrations and chat, progress updates, unattended and multiagent tasks, safeguard refusals, frontend design, complex visual inputs, multi-app workflows, and pasted text in user messages.

Change system instructions or tool availability partway through a conversation without invalidating the cached prefix that came before them.

Overview of new features, breaking changes, and capability improvements in Claude Fable 5.1 and Claude Mythos 5.1.