DeepSeek V3.1 Terminus API
About
Build advanced reasoning agents with DeepSeek V3.1 Terminus, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers cost-effective pricing at $1.20/1M input and $1.20/1M output tokens, native tool calling support. Access DeepSeek V3.1 Terminus via the Synthetic API with up to 128K output tokens.
Capabilities
Input Modalities
text
Output Modalities
text
Reasoning
Yes
Structured Output
No
Tool Use
Yes
WeightsClosed
Limits
Context Window
128K
Tokens
Input Limit
128K
Tokens
Max Output
128K
Tokens
Pricing
Standard (per 1M tokens)
Input
$1.20
Output
$1.20
Frequently Asked Questions
DeepSeek V3.1 Terminus by Synthetic costs $1.20 per 1M input tokens and $1.20 per 1M output tokens.
Model Details
ID
hf:deepseek-ai/DeepSeek-V3.1-Terminus
Provider
SyntheticFamily
deepseek
Release Date
Sep 22, 2025
Knowledge Cutoff
N/A
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
SYNTHETIC_API_KEY
API Base URL
https://api.synthetic.new/openai/v1