Claude Opus 4.8 API
About
Build advanced reasoning agents with Claude Opus 4.8, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers available completely free of charge, native tool calling support. Access Claude Opus 4.8 via the AgentRouter API with up to 128K output tokens.
Capabilities
Input Modalities
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Output Modalities
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Reasoning
Yes
Structured Output
No
Tool Use
Yes
WeightsClosed
Temperature
Fixed
Attachment
Supported
Limits
Context Window
1.0M
Tokens
Input Limit
1.0M
Tokens
Max Output
128K
Tokens
Pricing
Standard (per 1M tokens)
Input
Free
Output
Free
Frequently Asked Questions
Claude Opus 4.8 by AgentRouter costs Free per 1M input tokens and Free per 1M output tokens.
Model Details
ID
claude-opus-4-8
Provider
AgentRouterFamily
claude-opus
Release Date
May 28, 2026
Knowledge Cutoff
Jan 1, 2026
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
AGENTROUTER_API_KEY
API Base URL
https://agentrouter.org/v1