Multiple providers, one workspace
Use Claude, Codex, Kiro, Kimi, Gemini, DeepSeek, OpenRouter, OpenCode Go, or OpenCode Zen. Choose a provider and model while keeping the same iolys interface, solution context, and permission flow.
For C# and .NET developers
A GitHub Copilot alternative
for Visual Studio.
iolys is a free Visual Studio 2026 extension that connects ten AI provider routes to your C# and .NET solution, and it is the alternative to choose when you want to reuse a subscription you already pay for: sign in through a supported Claude, Codex, Kiro, Kimi, or Gemini CLI, connect OpenCode Go with its API key, or use your organization's Databricks workspace, instead of buying a GitHub Copilot plan. GitHub Copilot remains the broader product across editors and GitHub itself; iolys is narrower on purpose, and does not promise feature parity with it.
Why consider iolys?
Choose your AI access inside your IDE.
If you are looking for a GitHub Copilot alternative for C#, iolys gives you a workspace that connects directly to the providers you configure. No GitHub Copilot subscription is required.
Bring a subscription or API key
Reuse eligible account access through supported provider CLIs, or connect with your own API credentials. Provider plans, quotas, and billing remain with the provider you choose.
Connect the infrastructure you control
Use compatible local models through Ollama or approved chat-capable Databricks Model Serving endpoints. Choose the route that fits your project and organization.
iolys vs GitHub Copilot
What actually differs, with sources.
Each GitHub Copilot statement below is taken from an official GitHub or Microsoft page and links to it. Rows we could not source are left out rather than guessed. GitHub Copilot information verified ; plans and features change often.
| Capability | iolys | GitHub Copilot |
|---|---|---|
| Price of the extension | 0 USD. Every currently available feature is free for personal and commercial use. | Free plan at 0 USD with 2,000 completions and 50 chat requests per month. Pro 10 USD, Pro+ 39 USD, and Max 100 USD per user per month. Business 19 USD and Enterprise 39 USD per user per month. GitHub Copilot plans and licenses ↗ |
| How AI usage is paid for | By the provider you connect: an eligible subscription, your own API key, an enterprise endpoint, or a local model. iolys meters nothing and adds no billing of its own. | With GitHub AI Credits, where 1 credit equals 0.01 USD. Chat, agent mode, code review, the cloud agent, Copilot CLI, and Copilot Apps consume credits. Code completions and next edit suggestions do not, and stay unlimited on every paid plan. GitHub AI Credits ↗ |
| Reusing a subscription you already pay for | Yes, for seven of the eleven routes. Claude, Codex, Kiro, Kimi, and Gemini reuse an eligible personal AI plan through their supported CLI, OpenCode Go uses its subscription through an API key, and Databricks reuses the workspace subscription your organization already holds. DeepSeek, OpenRouter, and OpenCode Zen use prepaid provider credits instead, and Ollama runs on your own hardware. | A GitHub Copilot plan is required. From Pro, third-party agents such as Claude Code and Codex can be used inside Copilot, with usage drawn from GitHub AI Credits rather than from a plan you hold with those providers. GitHub Copilot plans ↗ |
| Provider and model choice | Eleven connection routes, chosen per task: five subscription-backed CLIs, the OpenCode Go subscription API, a Databricks Unity Catalog workspace, DeepSeek, OpenRouter, and OpenCode Zen APIs, and local Ollama models. | A catalogue of GitHub-hosted models, with model selection from the Pro plan. Availability can vary by feature and by plan. Models in Copilot ↗ |
| Local models | Supported in the Visual Studio 2026 IDE through a compatible Ollama endpoint on your machine or network. | Documented for Copilot CLI, which can target OpenAI-compatible endpoints, Azure OpenAI, or Anthropic, including locally running models such as Ollama. Using your own LLM models in Copilot CLI ↗ |
| Enterprise-governed endpoint | Chat-capable Databricks Unity Catalog Model Serving endpoints selected by your organization. | Visual Studio Bring Your Own Model connects Microsoft Foundry deployments and keys from supported providers in Agent Mode. Bring Your Own Model in Visual Studio ↗ |
| Supported editors | Visual Studio 2026 only, on 64-bit Windows. This is a deliberate limit, not a roadmap gap. | GitHub, VS Code, Visual Studio, Xcode, JetBrains IDEs, Neovim, Eclipse, Raycast, SQL Server Management Studio, and Zed. Supported platforms ↗ |
Sources
- GitHub Copilot plans and pricing ↗
- GitHub Copilot licenses and per-seat prices ↗
- Bring your own LLM models in Copilot CLI ↗
- Bring Your Own Model in Visual Studio ↗
GitHub, GitHub Copilot, Microsoft, and Visual Studio are trademarks of their respective owners. iolys is not affiliated with or endorsed by GitHub or Microsoft.
The harness around your agent
Put your AI subscription to work across your .NET solution.
iolys connects the agent to your development workflow: independent tasks, reusable specialists, and a build-and-test loop you can inspect.
Explore all iolys capabilities →Run tasks in parallel
Work on a C# fix and an independent feature in separate Git worktrees and branches. Open each workspace in its own Visual Studio instance to keep files and build state separate.
Try a parallel workflow →Create custom agents
Define a C# reviewer or test writer with reusable instructions and selected tools. Share workspace agents through version-controlled .github/agents files.
Build, test, and review
Let the agent inspect compiler diagnostics, run builds and tests, and refine its changes. Review tool activity and file diffs, with permissions under your control.
Get started
Try iolys with your C# solution.
All currently available iolys features are free for personal and commercial use. AI access and infrastructure costs remain separate.
- 01
Install iolys from the Visual Studio Marketplace and open your solution in Visual Studio 2026 on 64-bit Windows.
- 02
Connect a supported provider using its setup guide. Choose eligible CLI account access, an API key, an enterprise endpoint, or a local model.
- 03
Select your provider and model, attach relevant files or a selection, and start a task. Follow tool activity and review permission requests in the conversation.
Find the right connection for your work.
iolys is a separate product with its own workflow and capabilities. Evaluate the features your team needs when choosing an AI coding assistant.
Claude Code in Visual Studio
Connect eligible Claude account access through the supported CLI.
Use Claude →Codex for C# and .NET
Bring eligible Codex account access into your solution workflow.
Use Codex →Ollama models
Connect a compatible model running on your own machine or network.
Use Ollama →BYOM, BYOK, and BYOS
Understand model deployments, API credentials, and subscription access.
Compare access routes →GitHub Copilot alternative FAQ
Choosing an AI assistant for Visual Studio.
What is an alternative to GitHub Copilot for Visual Studio?
iolys is an AI coding workspace for Visual Studio 2026 and an alternative to consider for C# and .NET development. It connects supported provider CLIs, APIs, enterprise endpoints, and local models in one extension, with solution context, visible tool activity, and permission controls.
Do I need a GitHub Copilot subscription to use iolys?
No. iolys connects to the AI providers you configure directly. You need eligible account access for a supported provider CLI, an API key, an enterprise endpoint, or a compatible local Ollama model. A GitHub Copilot subscription is not required.
Is iolys a free GitHub Copilot alternative?
Yes, iolys itself is free: all currently available features are free for personal and commercial use. AI provider subscriptions, API usage, and infrastructure costs remain separate, and iolys does not include a bundled model allowance.
How much does iolys cost compared to GitHub Copilot?
iolys costs 0 USD and you pay only the AI provider you connect. GitHub Copilot has a free tier limited to 2,000 completions and 50 chat requests per month, then Pro at 10 USD, Pro+ at 39 USD, and Max at 100 USD per user per month, with Business at 19 USD and Enterprise at 39 USD per user per month; its chat, agent, code review, CLI, and cloud agent usage draws GitHub AI Credits at 0.01 USD per credit. GitHub Copilot prices verified 18 September 2026 on the official GitHub plans page and can change.
Which AI models can I use instead of GitHub Copilot in Visual Studio?
iolys gives you eleven connection routes in Visual Studio 2026: Claude, Codex, Kiro, Kimi, and Gemini through supported provider CLIs, OpenCode Go through its subscription API, DeepSeek, OpenRouter, and OpenCode Zen through provider APIs, Databricks Unity Catalog endpoints, and local models served by Ollama. You choose the provider and model for each task.
Do I have to switch to VS Code to use AI coding agents?
No. iolys runs inside the Visual Studio 2026 IDE, so agent conversations, solution context, tool activity, and permission requests stay in the environment where your C# and .NET work already happens.
Can I use my existing AI subscription in Visual Studio?
Yes. iolys reuses eligible account access through Claude, Codex, Kiro, Kimi, and Gemini CLI connections, OpenCode Go subscription access through an API key, and the models your organization already pays for in its Databricks workspace. This is Bring Your Own Subscription (BYOS); provider eligibility, quotas, and usage limits still apply.
Can I use local models as a GitHub Copilot alternative for C#?
Yes. Connect a compatible Ollama model to iolys and work from your C# solution in Visual Studio 2026. The model runs on the machine or endpoint you configure, and its capabilities depend on the model and available hardware.
Which Visual Studio versions does iolys support?
iolys targets Visual Studio 2026 on 64-bit Windows for C# and .NET development. Visual Studio Code is a separate editor; this extension is built for the Visual Studio IDE.
Is there a VSIX alternative to the GitHub Copilot extension?
Yes. iolys is a VSIX extension for Visual Studio 2026 that you install from the Visual Studio Marketplace instead of, or alongside, the GitHub Copilot extension. The iolys VSIX brings its own provider connections, so it does not depend on a GitHub Copilot subscription.
Does iolys replace every GitHub Copilot feature?
No, iolys is a separate product and does not promise feature parity with GitHub Copilot. Evaluate it for the workflow you need: conversations with solution context, agent tasks, provider choice, tool activity, and permission controls inside Visual Studio 2026.
Bring your preferred AI to Visual Studio 2026.
Start with a provider you already use and a C# solution you know.
Install iolys