Claude Opus 4.5 | Faster, Cheaper, Better for Developers

Your Claude Code sessions burn through tokens too fast and cost too much. Opus 4.5 fixes both problems while writing better code than any previous model.

Here's the headline: 67% cheaper pricing ($5/$25 per million tokens, down from $15/$75) with 76% fewer output tokens for the same work. Try it right now:

claude config set model claude-opus-4-5-20251101
claude

You're now running the most token-efficient coding model available.

The Token Efficiency Revolution

This isn't marketing fluff. GitHub reports Opus 4.5 "surpasses internal coding benchmarks while cutting token usage in half." Replit says it "beats Sonnet 4.5 and competition on our internal benchmarks, using fewer tokens to solve the same problems."

Here's what that looks like in practice:

Fewer tokens means faster responses, lower costs, and more headroom before hitting context limits.

Multi-Agent Mastery

Opus 4.5 writes better prompts for sub-agents than any other model. Anthropic explicitly trained it for delegation.

This matters when you're running parallel agents for testing, code generation, or task distribution. Your primary agent orchestrates sub-agents more effectively:

# Example: Running parallel browser tests
claude "Run 4 parallel test agents against staging -
test login flow, checkout, search, and user settings"

The model handles the coordination. Each sub-agent gets clear, specific instructions. Results synthesize back to you without the chaos of previous models.

The Effort Parameter

New API control for tuning speed vs thoroughness. Set it per-call without switching models:

const response = await anthropic.messages.create({
  model: "claude-opus-4-5-20251101",
  max_tokens: 8192,
  thinking: {
    type: "enabled",
    budget_tokens: 10000  // Low: 1024, Medium: 5000, High: 10000+
  },
  messages: [{ role: "user", content: prompt }]
});

Low effort for quick tasks. High effort for complex refactoring. You control the thinking budget.

Auto-Compaction for Infinite Context

Hit 95% of your 200K context window? Claude automatically compacts earlier messages while preserving your full chat history. Alex Albert calls it "effectively infinite context."

Manual control when you need it:

/compact

Best practice: compact at logical milestones rather than waiting for automatic triggers. Preserves more detail where it matters.

When Things Go Wrong

Error: "model not found"

Fix: Update your Claude Code installation:

npm update -g @anthropic-ai/claude-code

Error: "rate limit exceeded"

Fix: Opus 4.5 has separate limits from Sonnet. Check your plan tier or add a brief delay between requests.

Error: "context too long"

Fix: Use /compact manually or break your task into smaller chunks. See memory optimization for advanced patterns.

What This Means for Your Workflow

Opus 4.5 isn't just an upgrade - it's a different approach to AI-assisted development:

• Delegate more: Hand off complex coordination tasks you wouldn't trust to previous models
• Run longer sessions: Token efficiency means more work before compaction
• Pay less: 67% cost reduction at the same or better quality

The model scores 80.9% on SWE-bench Verified (new high) and leads across 7 of 8 programming languages. Your code works the first time, not the fifth.

Next Steps

• Configure your model selection strategy for when to use Opus vs Sonnet
• Learn sub-agent design patterns to maximize delegation
• Set up efficiency patterns for production workflows

The convergence of premium intelligence with practical affordability is here. Faster, cheaper, and better at orchestration. Start building.