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Claude Opus 4.5

Claude Opus 4.5 adds an effort parameter for token-usage control and excels at difficult coding, agentic workflows with computer use and tool use, frontend coding, and real-world web app development, with improvements in general intelligence and vision over previous Opus iterations.

Tool UseReasoningVision (Image)File InputExplicit Caching
index.ts
import { streamText } from 'ai'


const result = streamText({
  model: 'anthropic/claude-opus-4.5',
  prompt: 'Why is the sky blue?'
})
OverviewPlaygroundAboutProvidersThroughputLatencyUptimeStatusSimilarFAQ

What To Consider When Choosing a Provider

  • Configuration: The effort parameter (high by default) affects all token types for a request. Setting it in providerOptions.anthropic.effort lets you manage token usage per-request when running mixed workloads with varying complexity.
  • Zero Data Retention: AI Gateway supports Zero Data Retention for this model via direct gateway requests (BYOK is not included). To configure this, check the documentation.
  • Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.

When to Use Claude Opus 4.5

Best For

  • Agentic workflows combining computer use and tool use: Highlighted as a core strength for tasks requiring both capabilities in combination
  • Frontend coding and design for real-world web apps: Production-quality output on complex UI development tasks
  • Demanding reasoning and complex problem solving: The effort parameter (high by default) lets you apply maximum token usage per request for the hardest analytical work
  • External memory file handling: The model excels at managing context across long agentic sessions with memory file access
  • Tasks where effort-level control matters: Workloads mixing simple and complex requests that benefit from per-request token usage management

Consider Alternatives When

  • Fastest interactive response: Haiku 4.5 or Sonnet 4 variants are better suited for low-latency use
  • Sonnet-level depth suffices: A Sonnet model handles tasks that don't require Opus-level reasoning at lower cost
  • 1M token context window: Context size came to Opus models with version 4.6

Conclusion

Claude Opus 4.5 is built for the demanding intersection of agentic workflows: computer use, external tool calls, memory management, and frontend development, with the effort parameter giving teams explicit cost control on top of the model's capabilities. For organizations pushing on the complexity ceiling of what agents can handle autonomously, it's the right Opus checkpoint prior to 4.6.

Frequently Asked Questions

  • What is the effort parameter in Claude Opus 4.5 and how does it work?

    The effort parameter controls how much token usage the model applies when responding to a request. It defaults to high, affects all token types, and is set independently of the thinking budget via providerOptions.anthropic.effort in the AI SDK.

  • How do I configure the effort parameter through AI Gateway?

    Under providerOptions.anthropic in your AI SDK v5 call, pass an effort level of low, medium, or high alongside the model string anthropic/claude-opus-4.5.

  • What agentic capabilities does Opus 4.5 excel at specifically?

    Difficult coding tasks, agentic workflows combining computer use and tool use, and complex multi-step problem solving. The model handles tasks requiring sustained reasoning across long contexts and multi-turn interactions.

  • How does effort differ from the thinking budget?

    They are independent parameters. The effort parameter controls overall token usage across all token types; the thinking budget specifically controls extended reasoning tokens. You can set both separately to tune the cost-quality tradeoff.

  • What vision improvements does Opus 4.5 include?

    Opus 4.5 includes improvements in general intelligence and visual reasoning, handling image analysis, diagram interpretation, and document understanding with stronger accuracy than previous Opus versions.

  • Does Opus 4.5 support the 1M token context window?

    No. The 1M token context window came to Opus models with Claude Opus 4.6.

  • Is Claude Opus 4.5 suitable for frontend web development work?

    Yes, frontend coding and design for developing real-world web applications is specifically listed as an established strength of this model.