Claude Opus 5 has officially landed in Claude Code, and the update comes with a feature developers have been asking for: Fast Mode. According to reports from July 24, 2026, users can now invoke Anthropic's latest flagship model directly through the CLI by appending --model opus-5 to their commands. The headline claim is bold—2.5x faster performance at Opus 4.8 pricing, which translates to roughly 50% savings on token costs compared to standard Opus rates.

What Exactly Is Fast Mode?

Fast Mode isn't just a marketing buzzword—it represents architectural optimizations in how Claude processes and generates responses through the CLI interface. The mode prioritizes inference speed without sacrificing the quality that makes Opus 5 capable of handling complex, multi-step development tasks. For developers who rely on Claude Code for code generation, debugging, or refactoring workflows, this means less waiting and more coding.

How to Enable Fast Mode

Getting started is refreshingly simple. Developers need only run: claude code --model opus-5 from their terminal. No additional configuration files, no environment variable juggling—just one flag and you're off. The pricing automatically adjusts to Opus 4.8 rates, so there's no need to manually adjust billing settings or contact support.

Performance Implications for Your Workflow

The 2.5x speed claim deserves context. In practical terms, this means tasks that previously took several seconds—generating boilerplate code, explaining unfamiliar libraries, or walking through complex debugging scenarios—should complete noticeably faster. The improvement compounds across a full development session, potentially saving minutes or even hours depending on how heavily you lean on Claude Code.

Understanding the Pricing Change

The token cost reduction is the real story here for many developers. Running at Opus 4.8 pricing while using Opus 5's capabilities effectively creates a discount tier that wasn't previously available. Teams and individual developers watching their API spend will appreciate this change immediately, especially those running Claude Code in CI/CD pipelines or automated scripts.

Key Takeaways

  • Enable Fast Mode with claude code --model opus-5—no extra setup required
  • Expect approximately 2.5x faster response times compared to previous configurations
  • Token costs remain at Opus 4.8 rates, delivering roughly 50% savings versus standard Opus pricing
  • No quality trade-off—Fast Mode maintains full Opus 5 capabilities

The Bottom Line

This is exactly the kind of meaningful improvement that makes developers stick with a tool long-term. Anthropic has essentially handed Claude Code users premium performance at a discount, and the one-flag activation removes any friction from adoption. If you've been on the fence about upgrading your Claude Code setup, this release removes all excuses—run the command and start saving today.