DeepSeek · Open weights
DeepSeek V3.1 Terminus (Thinking)
Thinking-enabled DeepSeek-V3.1-Terminus with improved language consistency, upgraded Code/Search Agents, and stronger stability and reliability versus V3.1. FP8.
- Tools
- Structured output
- Input
- Text
- Output
- Text
- Discovery tier
- Open weights
Pricing
USD per 1M tokens- Input
- $0.25
- Output
- $0.70
Reference prices as published by the model provider. API example
Specifications
- Context window
- 128K
- Max output
- 65.5K
- Average output (7 days)
- 362 tokens
- Longer than 37% of 465 models
Side by side
Compare models
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Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
Intelligence Index
14.8
Better than 37% of 326 scored models
Indexes
Coding Index
43.5Composite of the coding evaluations
Better than 36% of 168 scored models
Math Index
89.7Composite of the math evaluations
Better than 87% of 118 scored models
Agentic work
AutomationBench-AA
2.7%Workflow automation, penalized for guardrail violations
Better than 17% of 173 scored models
AutomationBench-AA tasks completed
0.2%Workflows finished end to end without a guardrail violation
Better than 13% of 173 scored models
AA-Briefcasev1.1
458 EloAgentic knowledge work, rated head to head
Better than 18% of 166 scored models
GDPval-AAv2.1
709 EloEconomically valuable occupational tasks, rated head to head
Better than 22% of 187 scored models
Document reasoning
GDP.pdf
5.4%Professional reasoning over PDF documents, all-pass rate
Better than 23% of 171 scored models
AA-LCRv1.1
69.3%Reasoning across long documents
Better than 48% of 309 scored models
Reasoning and knowledge
Humanity’s Last Exam
16.4%Expert-level questions across academic fields
Better than 43% of 323 scored models
GPQA Diamond
79.2%Graduate-level science questions
Better than 46% of 291 scored models
MMLU-Pro
85.1%Multi-subject knowledge and reasoning
Better than 87% of 132 scored models
IFBench
57.0%Following precise output instructions
Better than 57% of 215 scored models
Coding
Terminal-Benchv4.0
0.0%Practical software engineering in a terminal
Better than 0% of 171 scored models
SciCode
38.0%Scientific computing in Python
Better than 17% of 174 scored models
LiveCodeBench
79.8%Recent competitive programming problems
Better than 82% of 129 scored models
Math
AIME 2025
89.7%Competition mathematics, 2025 problems
Better than 87% of 118 scored models
Legacy evaluations
Terminal-Bench Hard
30.3%Earlier terminal task suite
Better than 56% of 212 scored models
τ²-Bench Telecom
37.1%Tool use in a customer-support simulation
Better than 31% of 214 scored models
AA-LCR (unversioned)
69.3%Long-context reasoning, earlier grading
Better than 48% of 309 scored models
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
Live routing data
Performance and reliability
Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.
- Throughput
- 22.3 tok/s
- Faster than 14% of 250 models
- Time to first token
- 8.0 s
- Quicker than 16% of 250 models
- Prompt cache hits
- 79.6%
- Request success (24h)
- 99.5%
- Reliable
Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.
- Healthy (98% or more)
- Degraded (90–98%)
- Down (under 90%)
- No requests
Developers
Use it through the API
Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.
curl https://www.noumen.xyz/api/v1/chat/completions \
-H "Authorization: Bearer $NOUMEN_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "deepseek-ai/DeepSeek-V3.1-Terminus:thinking",
"messages": [{ "role": "user", "content": "Explain this stack trace." }]
}'import os
from openai import OpenAI
client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
model="deepseek-ai/DeepSeek-V3.1-Terminus:thinking",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)DeepSeek
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