DeepSeek

DeepSeek V3.1 Terminus

deepseek/deepseek-v3.1-terminus
Model weightsReleased Sep 22, 2025Open Weights
ThinkingToolsopen weights

DeepSeek-V3.1 Terminus is an update to [DeepSeek V3.1](/deepseek/deepseek-chat-v3.1) that maintains the model's original capabilities while addressing issues reported by users, including language consistency and agent capabilities, further optimizing the model's...

Cost / 1M tokens

Low usage

$0.27

input

—

cached input

$1.00

output

Context Window

164K

Up to 147K max output

Modalities

text → text

DeepSeek tokenizer

Quickstart & API

deepseek/deepseek-v3.1-terminus
Open the model picker in ChatOSS Desktop (Code, Kanban, or Chat) and select or paste this model ID.

Best for & Strengths

Key Strengths

Open weightsExtended reasoningTool & agent calling

Recommended Workloads in ChatOSS

  • Coding agents
  • Complex reasoning & debugging
  • Open-source AI workflows
Available in ChatOSS Code, Kanban Orchestrate, and Chat modes via Plus, Max, or BYOK.

Verified Evaluations

Benchmarks & Frontier Comparison

How DeepSeek V3.1 Terminus compares against leading open-weight and proprietary frontier models across independent agentic coding and reasoning suites.

View full Top 40 Leaderboard →
Benchmark (Metric)DeepSeek V3.1 TerminusDeepSeek V4.1 FlashGLM 5.3Kimi K3.1 ProClaude Opus 5.5
Agentic & Software Engineering
ChatOSS Agentic Coding Index (%)—63.2%58.3%65%74.1%
SWE-Bench Verified (%)—91.5%95.4%94.8%97%
DeepSWE v1.1 (Pass@1 %)—77%69%73.5%74.2%
Vibe Code Bench v1.1 (%)—87.7%78.1%88.4%90.3%
Terminal-Bench 4.0 (%)—42.3%42%46.2%65.2%
Code Migration (%)—45.6%44.2%52%66.7%
Intelligence & Token Economics
Artificial Analysis Intelligence Index (0–100)14.839.544.855.157.6
Input Price (/ 1M tokens)$0.27$0.15$1.40$2.00$4.00
Output Price (/ 1M tokens)$1.00$0.60$4.40$10.00$20.00

Artificial Analysis Intelligence Index

Artificial Analysis

14.8

Design Arena: 3D

Design Arena · Rank #72 (56% win)

1138 Elo

Design Arena: Code Generation

Design Arena · Rank #73 (56% win)

1173 Elo

Design Arena: Data Visualization

Design Arena · Rank #73 (53.4% win)

1168 Elo

Design Arena: Game Dev

Design Arena · Rank #89 (52.5% win)

1129 Elo

Active Provider Endpoints (2)

Upstream inference providers serving DeepSeek V3.1 Terminus, with per-provider pricing, context limits, quantization, and 24-hour uptime.

ProviderInput / 1MOutput / 1MCache Read / 1MContextMax OutputQuantizationUptime (24h)
SiliconFlow
siliconflow/fp8
$0.27$1.00—164K147Kfp897.3%
StreamLake
streamlake
$0.343$1.03—128K32K—99.9%

Supported API Parameters

Parameters accepted by this model when called through ChatOSS or OpenRouter.

frequency_penaltyinclude_reasoningmax_tokensreasoningresponse_formatstopstructured_outputstemperaturetool_choicetoolstop_ktop_p

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