Claude Opus 5 (Fast) API
About
Build advanced reasoning agents with Claude Opus 5 (Fast), a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers cost-effective pricing at $10.00/1M input and $50.00/1M output tokens, native tool calling support. Access Claude Opus 5 (Fast) via the OpenRouter API with up to 128K output tokens.
Capabilities
Input Modalities
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Output Modalities
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Limits
Context Window
1.0M
Tokens
Input Limit
1.0M
Tokens
Max Output
128K
Tokens
Pricing
Standard (per 1M tokens)
Input
$10.00
Output
$50.00
Caching (per 1M tokens)
Read
$1.00
Write
$12.50
Frequently Asked Questions
Claude Opus 5 (Fast) by OpenRouter costs $10.00 per 1M input tokens and $50.00 per 1M output tokens. Cached reads cost $1.00 per 1M tokens. Cache writes cost $12.50 per 1M tokens.
Model Details
ID
anthropic/claude-opus-5-fast
Provider
OpenRouterFamily
claude-opus
Release Date
Jul 24, 2026
Knowledge Cutoff
May 1, 2026
API Integration
NPM Package
@openrouter/ai-sdk-provider
Environment Variables
OPENROUTER_API_KEY
API Base URL
https://openrouter.ai/api/v1