DeepSeek V4.1 Flash 1017 and Search / Fetch: already supported in iolys

DeepSeek released V4.1 Flash 1017 on October 17, 2026, alongside public Search and Fetch APIs. iolys already supports the updated model and both web tools, so you can use them in Visual Studio with your DeepSeek API key.

What changed in Flash 1017?

This is an update to V4.1 Flash. DeepSeek reports stronger benchmark results, shorter task completion times, and shorter outputs than the previous version. Its aim is to complete coding tasks with less waiting and less generated text. See the official October 17 announcement.

DeepSeek also describes improvements to building complete projects from a prompt, with examples involving games and 3D scenes. For C# and .NET work, try a bounded task such as implementing an ASP.NET Core endpoint with validation and tests, then review the changes and build results in your solution. The reported gains come from DeepSeek's evaluations; task time and cost still depend on your project and instructions.

Keep using deepseek-flash

You do not need to enter a new dated model ID. DeepSeek's API serves V4.1 Flash 1017 through deepseek-flash, so an existing iolys connection using that name reaches the updated model. DeepSeek also keeps its older Flash aliases compatible. See the current model details.

Flash retains vision and a 1M-token context window. You can keep attaching screenshots and relevant code while trying the new version; these capabilities were already part of V4.1 Flash.

Search for sources, then read the page

DeepSeek has opened two separate web APIs. Search returns relevant pages with links and summaries. Fetch reads a URL and returns its content as Markdown. Together, they let an agent find documentation and use the page itself as context. Search & Fetch documentation.

In iolys, both tools are available under DeepSeek Web Tools with the DeepSeek provider, on Flash and Pro, including in Plan mode. They use that connection's API key.

Try asking: "Find the official migration guide for this package, read the relevant page, and explain which changes apply to my solution."

This helps you check current documentation alongside your code. Page retrieval still depends on the website's availability and access rules.

What do the web tools cost?

Standard API rates, checked October 17, 2026:

These fees are separate from model tokens. Only successful requests with results or page content are billable; empty searches, errors, and timeouts are excluded. The number of search results does not change the request price. Billing rules.

iolys includes these web request fees in its turn and session cost estimates, helping you follow spending in the conversation. Your DeepSeek account remains the reference for actual charges.

Try it in Visual Studio

Open Manage Providers, add DeepSeek, enter your API key, and choose Test Connection. Select deepseek-flash in the chat. In Tools, enable deepseek_search and deepseek_fetch under DeepSeek Web Tools; include them in your tool selection if you use a custom agent.

Use your own DeepSeek API account and balance. See the October Update 3 release notes for the iolys changes.

Install iolys for Visual Studio to try Flash 1017 and bring web references into your C# and .NET conversations.

Share your DeepSeek experience

Tried Flash 1017 or the new web tools on your project? Join us on Discord to share your feedback, ask questions, or suggest improvements to the DeepSeek workflow in iolys.