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Models · DeepSeek · 17 Oct 2026

DeepSeek upgraded V4.1 Flash to a 1017 version with shorter runs and opened a pay-per-request Search and Fetch API.

On 17 Oct 2026 DeepSeek updated its V4.1 Flash model to DeepSeek-V4.1-Flash-1017. It says tasks now run faster with shorter output, and that API pricing is unchanged. The same day it opened a Search and Fetch API at USD 0.75 per 1,000 successful requests, free in some tools until 1 Nov 2026.

What changed in the model

DeepSeek's update log for 17 Oct 2026 says its V4.1 Flash model has been upgraded to DeepSeek-V4.1-Flash-1017. People using the API do not need to change anything: the name deepseek-flash now points to the new version. The official web app and phone app models were updated too.

DeepSeek says the new version needs less task time and writes shorter outputs than the previous V4.1, so tasks should cost less and finish faster. The API calling method and prices are unchanged. The company also says it tuned the model for DeepSeek Harness, Tencent CodeBuddy and WorkBuddy, and recommends DeepSeek Harness 0.2.1-rc.1 or later.

The scores DeepSeek reports

The update log lists gains over the previous V4.1 on several benchmarks. It gives 42.6 on HLE without tools, 42.3 on Terminal-Bench 4.0 and 77.0 on DeepSWE v1.1. The part of the log we read does not give the earlier scores, so the size of the gain is not stated here.

These are DeepSeek's own figures. We did not find an independent test of the 1017 version yet, so treat the numbers as the maker's claims until a tester such as Artificial Analysis or LMArena publishes its own.

A new Search and Fetch API

The same day, DeepSeek made its Search and Fetch API available. The company says the search engine behind it is its own, indexes hundreds of billions of web pages, supports many languages and filters out SEO spam and low-quality AI-written pages.

Search takes a text query of up to 128 characters and returns between 1 and 50 results. Fetch takes a web address and returns the page as Markdown. Each costs USD 0.75 per 1,000 successful requests; failed calls, empty results and timeouts are not billed. Calls made through DeepSeek Harness, Claude Code or Codex are free for now. Billing for those starts at 00:00 Beijing time on 1 Nov 2026. Each account is limited to 5 requests a second on each API.

The model itself is not new. DeepSeek first released V4.1 Flash on 10 Sep 2026, according to TechNode, and said then that it beat V4 Pro on performance, cost, speed and total completion time. From 14 Sep, requests to V4 Pro were routed to V4.1 Flash at Flash prices.

How to try it

  1. Use the API model name deepseek-flash at https://api.deepseek.com. It works with OpenAI-style and Anthropic-style requests (the Anthropic base URL is https://api.deepseek.com/anthropic).
  2. You need a DeepSeek API key. The pages we read do not say how to get one.
  3. For search, send a POST request to /v1/tools/search with your query. To read one page, send a POST to /v1/tools/fetch with the web address.
  4. Or try the model in DeepSeek's official web app or phone app, which now run the new version.

How to get good results

Our practical advice, based on what the sources below say about it.

  1. Use the Harness DeepSeek namesDeepSeek says it tuned this version for DeepSeek Harness, Tencent CodeBuddy and WorkBuddy and recommends DeepSeek Harness 0.2.1-rc.1 or later. If you build coding agents, start there before trying other tools.
  2. Use the free window to test searchSearch and Fetch calls through DeepSeek Harness, Claude Code or Codex cost nothing until 1 Nov 2026. Count how many calls your agent makes now, so the USD 0.75 per 1,000 bill holds no surprise.
  3. Keep queries shortSearch accepts queries of 1 to 128 characters and supports operators such as site: and lang:. Short, specific queries with these filters should return cleaner results than long questions.
  4. Test it yourself before trusting the scoresThe benchmark numbers come from DeepSeek. Run a small set of your own tasks, including Tamil ones, on the old and new versions. Neither page we read states Tamil support.

Why it matters in Tamil Nadu

Students and developers in Tamil Nadu building agents or search-based apps get a model update and a web search API from DeepSeek, with published prices.

Where this comes from

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Cite this page

theTN.ai, "DeepSeek upgraded V4.1 Flash to a 1017 version with shorter runs and opened a pay-per-request Search and Fetch API.", 17 Oct 2026. https://thetn.ai/tech/2026-10-17-deepseek-v4-1-flash-1017-search-api/

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