Skip to content

DeepSeek V3.1 Terminus

DeepSeek V3.1 Terminus is DeepSeek's September 22, 2025 refined iteration of V3.1. It delivers more stable outputs with improvements to multilingual consistency, Code Agent performance, and Search Agent capability.

ReasoningTool Use
index.ts
import { streamText } from 'ai'


const result = streamText({
  model: 'deepseek/deepseek-v3.1-terminus',
  prompt: 'Why is the sky blue?'
})
OverviewPlaygroundAboutProvidersThroughputLatencyUptimeStatusSimilarFAQ

Frequently Asked Questions

  • What does "Terminus" mean in the context of DeepSeek V3.1 Terminus?

    Terminus indicates a mature, production-hardened iteration within the V3.1 generation. It's a refined checkpoint that addresses real-world feedback before the model family advances to the next major version.

  • What specific output quality problems does DeepSeek V3.1 Terminus fix over V3.1?

    It fixes Chinese-English language-mixing errors and random character insertions reported after V3.1's initial deployment. Outputs are more predictable and consistent.

  • How does DeepSeek V3.1 Terminus compare to V3.1 on benchmarks?

    DeepSeek V3.1 Terminus delivers more stable outputs across benchmarks, with particular improvements in Code Agent and Search Agent task performance.

  • Are the model weights publicly available?

    Yes. Weights are published on Hugging Face at the official DeepSeek repository, alongside API access through AI Gateway.

  • Is DeepSeek V3.1 Terminus backward compatible with existing V3.1 integrations?

    Yes. Terminus shares the same API surface as V3.1, including the deepseek-chat and deepseek-reasoner endpoints for non-thinking and thinking modes respectively.

  • Was DeepSeek V3.1 Terminus launched across all DeepSeek surfaces simultaneously?

    Yes. It launched across the DeepSeek App, Web interface, and API on September 22, 2025.

  • Should I upgrade from V3.1 to Terminus or wait for V3.2?

    If multilingual consistency or Code/Search Agent reliability are pain points, upgrade to Terminus now. It's the designated fix for those issues. If you're planning a broader migration, V3.2 is the next major generation step.