Claude Sonnet 4 Reasoning API
About
Build advanced reasoning agents with Claude Sonnet 4 Reasoning, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers cost-effective pricing at $2.60/1M input and $13.00/1M output tokens, native tool calling support. Access Claude Sonnet 4 Reasoning via the Poe API with up to 64K output tokens.
Capabilities
Input Modalities
textimagepdf
Output Modalities
text
Reasoning
Yes
Structured Output
No
Tool Use
Yes
WeightsClosed
Temperature
Fixed
Attachment
Supported
Limits
Context Window
983K
Tokens
Input Limit
983K
Tokens
Max Output
64K
Tokens
Pricing
Standard (per 1M tokens)
Input
$2.60
Output
$13.00
Caching (per 1M tokens)
Read
$0.26
Write
$3.20
Frequently Asked Questions
Claude Sonnet 4 Reasoning by Poe costs $2.60 per 1M input tokens and $13.00 per 1M output tokens. Cached reads cost $0.26 per 1M tokens. Cache writes cost $3.20 per 1M tokens.
Model Details
ID
anthropic/claude-sonnet-4-reasoning
Provider
PoeFamily
claude-sonnet
Release Date
May 21, 2025
Knowledge Cutoff
N/A
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
POE_API_KEY
API Base URL
https://api.poe.com/v1