DeepSeekReasoning Model

DeepSeek V4.1 Flash 1017

The October 2026 checkpoint of DeepSeek V4.1 Flash: the same 552B-parameter multimodal Mixture-of-Experts, with stronger reasoning, coding, agentic, and visual results and shorter outputs that finish tasks faster at lower cost. Image input, tool calling, and a controllable reasoning-effort dial.

import OpenAI from "openai";

const openai = new OpenAI({
  baseURL: "https://api.inference.net/v1",
  apiKey: "<YOUR_API_KEY>",
});

const completion = await openai.chat.completions.create({
  model: "deepseek-v4.1-flash-1017",
  messages: [
    {
      role: "user",
      content: "What is the meaning of life?"
    }
  ],
  stream: true,
});

for await (const chunk of completion) {
  process.stdout.write(chunk.choices[0]?.delta.content as string);
}

import OpenAI from "openai";

const openai = new OpenAI({
  baseURL: "https://api.inference.net/v1",
  apiKey: "<YOUR_API_KEY>",
});

const completion = await openai.chat.completions.create({
  model: "deepseek-v4.1-flash-1017",
  messages: [
    {
      role: "user",
      content: "What is the meaning of life?"
    }
  ],
  stream: true,
});

for await (const chunk of completion) {
  process.stdout.write(chunk.choices[0]?.delta.content as string);
}

Prompt caching

Keep the prompt prefix stable and byte-identical across calls.
Do not send prompt_cache_key. These routes do not support it and may reject the request.
Check usage.prompt_tokens_details.cached_tokens in the response to confirm cache reads.

Related models

Model

InputCache readOutput

Kimi K3

1024K input contextVisionToolsReasoning$3.00 / $15.002 variants

256K input contextTools$0.102 / $0.48

125K input context$0.05 / $0.23

$0.05

$0.23

Schematron V2 Turbo

125K input context$0.03 / $0.15

$0.03

$0.15

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