Claude-Sonnet-4.5 API
About
Build advanced reasoning agents with Claude-Sonnet-4.5, 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-4.5 via the Poe API with up to 33K 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
33K
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-4.5 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-4.5
Provider
PoeFamily
claude-sonnet
Release Date
Sep 26, 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