--- title: "What is iolys? AI coding agent harness for Visual Studio | iolys" description: "iolys is a multi-provider AI coding agent harness for Visual Studio 2026, letting C# and .NET developers use the AI provider of their choice." url: "https://getiolys.com/what-is-iolys" language: "en" updated: "2026-10-02" --- # What is iolys? iolys is a multi-provider AI coding agent harness for Microsoft Visual Studio 2026. It lets C# and .NET developers use AI providers including Claude, Codex, Kiro, Ollama, DeepSeek, Kimi, OpenRouter, OpenCode Go, OpenCode Zen, Databricks Unity Catalog, and Gemini without leaving Visual Studio. ## Who is iolys for? iolys is for C# and .NET developers using Microsoft Visual Studio 2026 on 64-bit Windows. ## What does an AI coding agent harness do? An agent harness connects AI coding agents to a development environment. iolys provides solution context, tools, task workspaces, visible tool activity, and permission controls inside Visual Studio. ## Which AI providers does iolys support? iolys supports Claude, Codex, Kiro, Ollama, DeepSeek, Kimi, OpenRouter, OpenCode Go, OpenCode Zen, Databricks Unity Catalog, and Gemini. Connection methods include supported provider CLIs, APIs, enterprise endpoints, and local models. ## Does iolys support Claude? Yes. iolys supports Claude for C# and .NET in Microsoft Visual Studio 2026. Connection type: Provider CLI. Who pays for the AI usage: Your AI subscription. Where the model runs: Provider cloud. ## Does iolys support Codex? Yes. iolys supports Codex for C# and .NET in Microsoft Visual Studio 2026. Connection type: Provider CLI. Who pays for the AI usage: Your AI subscription. Where the model runs: Provider cloud. ## Does iolys support Kiro? Yes. iolys supports Kiro for C# and .NET in Microsoft Visual Studio 2026. Connection type: Provider CLI. Who pays for the AI usage: Your AI subscription. Where the model runs: Provider cloud. ## Does iolys support Ollama? Yes. iolys supports Ollama for C# and .NET in Microsoft Visual Studio 2026. Connection type: Local endpoint. Who pays for the AI usage: No provider bill. Where the model runs: Your machine or network. ## Does iolys support DeepSeek? Yes. iolys supports DeepSeek for C# and .NET in Microsoft Visual Studio 2026. Connection type: Provider API. Who pays for the AI usage: Prepaid credits or pay-as-you-go. Where the model runs: Provider cloud. ## Does iolys support Kimi? Yes. iolys supports Kimi for C# and .NET in Microsoft Visual Studio 2026. Connection type: Provider CLI. Who pays for the AI usage: Your AI subscription. Where the model runs: Provider cloud. ## Does iolys support OpenRouter? Yes. iolys supports OpenRouter for C# and .NET in Microsoft Visual Studio 2026. Connection type: OpenAI-compatible API. Who pays for the AI usage: Prepaid credits or pay-as-you-go. Where the model runs: Provider cloud. ## Does iolys support OpenCode Go? Yes. iolys supports OpenCode Go for C# and .NET in Microsoft Visual Studio 2026. Connection type: Subscription API key. Who pays for the AI usage: Your AI subscription. Where the model runs: Provider cloud. ## Does iolys support OpenCode Zen? Yes. iolys supports OpenCode Zen for C# and .NET in Microsoft Visual Studio 2026. Connection type: Pay-as-you-go API key. Who pays for the AI usage: Prepaid credits or pay-as-you-go. Where the model runs: Provider cloud. ## Does iolys support Databricks Unity Catalog? Yes. iolys supports Databricks Unity Catalog for C# and .NET in Microsoft Visual Studio 2026. Connection type: Unity Catalog / Model Serving. Who pays for the AI usage: Your organization's subscription. Where the model runs: Your organization's infrastructure. ## Does iolys support Gemini? Yes. iolys supports Gemini for C# and .NET in Microsoft Visual Studio 2026. Connection type: Provider CLI. Who pays for the AI usage: Your AI subscription. Where the model runs: Provider cloud. ## Is iolys a Visual Studio Code extension? No. iolys targets Microsoft Visual Studio 2026 on Windows. Visual Studio Code is a separate editor. ## Does iolys replace GitHub Copilot? iolys is a separate AI coding assistant and can be considered as an alternative for C# and .NET work. It connects directly to your configured AI providers without requiring a GitHub Copilot subscription. It does not promise feature parity with GitHub Copilot. ## Can iolys use existing AI subscriptions? Yes. Bring Your Own Subscription (BYOS) reuses an eligible personal AI plan through its supported provider CLI, an OpenCode Go subscription through its API key, or the Databricks workspace your organization already holds. Provider eligibility, quotas, and usage limits still apply. ## Is iolys an AI provider? No. iolys is a provider-independent integration layer for AI coding agents and models. AI access comes from the provider account, enterprise endpoint, or local model you connect. ## Is iolys free? Yes. All currently available iolys features are free for personal and commercial use. AI provider subscriptions, API usage, and infrastructure costs remain separate. ## Is iolys a VSIX? Yes. iolys is packaged and distributed as a VSIX extension for Microsoft Visual Studio 2026 on 64-bit Windows. It is not a standalone application, a web service, or a Visual Studio Code extension. ## How do I install iolys? Install the iolys extension from the Visual Studio Marketplace, open your solution in Visual Studio 2026, and configure a supported AI provider or local Ollama endpoint. ## Requirements iolys targets the Visual Studio 2026 IDE on 64-bit Windows. It requires access to a supported AI provider or a local Ollama instance. Git is required for isolated parallel workspaces. Visual Studio Code is a separate editor; iolys is an extension for the Visual Studio IDE. ## Price All currently available iolys features are free for personal and commercial use. AI provider subscriptions, API usage, and infrastructure costs remain separate. iolys does not include a bundled model allowance. ## Provider connection matrix Verified 19 September 2026. | Provider | Connection type | Access route | Who pays for the AI usage | Where the model runs | Best for | Guide | | --- | --- | --- | --- | --- | --- | --- | | Claude | Provider CLI | BYOS: bring your Claude subscription | Your AI subscription | Provider cloud | C# and .NET implementation, debugging, code review, refactoring, and tasks that combine solution context with web research and reusable skills. | https://getiolys.com/providers/claude | | Codex | Provider CLI | BYOS: use eligible ChatGPT subscription access | Your AI subscription | Provider cloud | Agentic refactors, repository-wide changes, code review, debugging, and implementation work across .NET solutions. | https://getiolys.com/providers/codex | | Kiro | Provider CLI | BYOS: keep your Kiro account and plan | Your AI subscription | Provider cloud | Structured implementation, specification-led work, multi-file changes, and long-running engineering tasks in C# solutions. | https://getiolys.com/providers/kiro | | Ollama | Local endpoint | No mandatory per-token cloud bill | No provider bill | Your machine or network | Private codebases, offline-capable workflows, experimentation with open models, and teams that want infrastructure control. | https://getiolys.com/providers/ollama | | DeepSeek | Provider API | Keep the provider relationship direct | Prepaid credits or pay-as-you-go | Provider cloud | C# generation, debugging, code explanation, refactoring, and cost-conscious model selection for .NET work. | https://getiolys.com/providers/deepseek | | Kimi | Provider CLI | BYOS: use the access attached to Kimi Code | Your AI subscription | Provider cloud | Repository exploration, multi-step implementation, debugging, and code changes across established .NET projects. | https://getiolys.com/providers/kimi | | OpenRouter | OpenAI-compatible API | Use your OpenRouter account directly | Prepaid credits or pay-as-you-go | Provider cloud | Choosing coding models across vendors, reviewing screenshots, researching documentation, and tracking API spending from Visual Studio. | https://getiolys.com/providers/openrouter | | OpenCode Go | Subscription API key | BYOS: bring your OpenCode Go subscription | Your AI subscription | Provider cloud | Using several coding model families under one subscription for implementation, code review, and debugging in C# and .NET. | https://getiolys.com/providers/opencode-go | | OpenCode Zen | Pay-as-you-go API key | Your Zen account, billed per request | Prepaid credits or pay-as-you-go | Provider cloud | Implementation, debugging, code review, and image-assisted tasks with supported coding models. | https://getiolys.com/providers/opencode-zen | | Databricks Unity Catalog | Unity Catalog / Model Serving | Keep enterprise AI governed in Databricks | Your organization's subscription | Your organization's infrastructure | Enterprise .NET teams that govern model access with Databricks Unity Catalog and expose approved chat models through Model Serving endpoints. | https://getiolys.com/providers/databricks | | Gemini | Provider CLI | BYOS: reuse Gemini CLI authentication and quota | Your AI subscription | Provider cloud | Code generation, explanation, debugging, large-context exploration, and everyday C# development. | https://getiolys.com/providers/gemini | ## Related pages - [Bring Your Own AI Subscription to Visual Studio 2026 | iolys](https://getiolys.com/) - [Bring Your Own Model (BYOM) in Visual Studio 2026 | iolys](https://getiolys.com/byom) - [AI coding agent capabilities for Visual Studio | iolys](https://getiolys.com/capabilities) - [Visual Studio integrations for C# and .NET | iolys](https://getiolys.com/integrations) - [GitHub Copilot alternative for Visual Studio and C# | iolys](https://getiolys.com/copilot-alternative-visual-studio) - [AI providers and BYOS for Visual Studio 2026 | iolys](https://getiolys.com/providers) - [The story behind iolys | From iolite to AI in Visual Studio](https://getiolys.com/our-story) - [Install iolys from the Visual Studio Marketplace](https://marketplace.visualstudio.com/items?itemName=iolys.iolys-visual-studio) - [iolys blog](https://getiolys.com/blog)