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DeepSeek V3.1 Terminus

DeepSeekReleased Sep 22, 2025

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...

Try in playground
Context window
164K tokens
Max output
33K tokens
Input
text
Output
text
Tokenizer
DeepSeek
Knowledge cutoff
Mar 31, 2025
Released
Sep 22, 2025
Reasoning
optional

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$0.270$0.0081$0.278
Output$0.950$0.028$0.978
Cache read$0.130$0.0039$0.134

Benchmarks

Design Arena

CategoryEloWin rateRank
3Dmodels121856%#37
Codemodels122556%#38
Data vizmodels120753%#45
Game devmodels119652.5%#52
SVGmodels112350.1%#48
UI componentsmodels123759.3%#34
Websitesmodels122956.4%#41

Head-to-head preference voting. How we filter and rank

Supported parameters

  • frequency_penalty
  • include_reasoning
  • logit_bias
  • max_tokens
  • min_p
  • presence_penalty
  • reasoning
  • repetition_penalty
  • response_format
  • seed
  • stop
  • structured_outputs
  • temperature
  • tool_choice
  • tools
  • top_k
  • top_p

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model deepseek/deepseek-v3.1-terminus.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek/deepseek-v3.1-terminus",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="deepseek/deepseek-v3.1-terminus",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "deepseek/deepseek-v3.1-terminus",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does DeepSeek V3.1 Terminus cost via API?
Through OpenKey, DeepSeek V3.1 Terminus costs $0.278 per 1M input tokens and $0.978 per 1M output tokens. That is the provider price ($0.270 / $0.950) plus a flat 3% fee — nothing else.
What is DeepSeek V3.1 Terminus's context window?
DeepSeek V3.1 Terminus accepts up to 164K tokens of context and returns up to 33K tokens per request.
Is DeepSeek V3.1 Terminus OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "deepseek/deepseek-v3.1-terminus" using any OpenAI SDK — only the base URL and API key change.
What inputs does DeepSeek V3.1 Terminus support?
DeepSeek V3.1 Terminus accepts text input and produces text output. Its knowledge cutoff is Mar 31, 2025.

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