Anthropic drops Claude Opus 4.8 with fast mode, dynamic workflows

The introduction of dynamic workflows in Claude Code marks a significant shift from simple chat to true autonomous engineering capable of executing multi-file migrations independently. Fast mode makes Opus 4.8 three times cheaper and 2.5x faster, vastly improving the economics of long-running agentic loops. Dynamic workflows run hundreds of parallel subagents to plan, execute, and verify large-scale changes without constant human supervision. Claude Code can now handle long-running sessions across entire repositories, allowing developers to fully hand off feature builds or bug sweeps. API access to Fast mode requires joining a waitlist, but it is available immediately in Claude Code via the `/fast` flag.