--- title: "OpenCode Zen in Visual Studio 2026 | iolys" description: "Use OpenCode Zen in Visual Studio 2026 with your API key. Choose curated coding models, use supported tools and reasoning, and see available cost estimates." url: "https://getiolys.com/providers/opencode-zen" language: "en" updated: "2026-10-04" --- # OpenCode Zen. Your models in Visual Studio. Bring curated coding models into your C# and .NET workspace with one OpenCode Zen API key. Choose supported reasoning, work with iolys tools, and follow available cost estimates beside your conversation. - Provider: OpenCode Zen - Connection type: Pay-as-you-go API key - Access: Your Zen account, billed per request - Who pays for the AI usage: Uses your own API key, billed by the provider as prepaid credits or pay-as-you-go. There is no subscription to reuse. - Where the model runs: The model runs in the provider's own cloud service. - Best for: Implementation, debugging, code review, and image-assisted tasks with supported coding models. - Official site: https://opencode.ai/docs/zen/ OpenCode Zen is a metered service, separate from the OpenCode Go subscription. iolys connects your account directly; model charges stay with OpenCode. ## How to connect OpenCode Zen in Visual Studio 2026 1. Sign in to the OpenCode Console, configure billing, and obtain an API key. 2. In Manage Models, add OpenCode Zen and enter the key. Test Connection loads the public catalog; the first message checks your key and model access. 3. Choose the models to show in chat, then select a model and any supported reasoning effort for your C# or .NET task. ## What you get - **Choose curated coding models** — Pin supported discovered models to your chat picker. Image inputs, tools, reasoning, and context limits depend on the selected model. - **Keep your development workflow** — Use permitted iolys and MCP tools, skills, and agent modes with visible tool activity and cancellation in Visual Studio. - **See available cost estimates** — Returned tokens and known Zen prices produce turn and session estimates. Totals may exclude calls with missing usage or required pricing. ## 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. ## OpenCode Zen questions ### How can I use OpenCode Zen in Visual Studio for C#? Install the iolys extension for Visual Studio 2026 and open your C# solution. Sign in to the OpenCode Console, configure billing, and obtain an API key. In Manage Models, add OpenCode Zen and enter the key. Test Connection loads the public catalog; the first message checks your key and model access. Choose the models to show in chat, then select a model and any supported reasoning effort for your C# or .NET task. You can then ask OpenCode Zen to help with your C# and .NET code from the iolys workspace. ### Is there a VSIX extension to use OpenCode Zen in Visual Studio? Yes. iolys is a VSIX extension for Visual Studio 2026, and OpenCode Zen is one of the provider connections it ships with. Install the iolys VSIX once from the Visual Studio Marketplace, then add OpenCode Zen from the Manage Providers panel; there is no separate VSIX per provider. ### Is OpenCode Zen the same as OpenCode Go? No. Zen bills requests through your OpenCode account; Go is a separate subscription service. iolys provides separate connections and model selections for both. ### Does Test Connection validate my Zen API key? It loads the public model catalog with a nonempty stored key. Configured does not mean the key, credits, or model access have been validated. Your first message checks those. ### Which models can I use? Choose supported conversational models discovered in the current Zen catalog. Free-tier models, including Big Pickle and variants ending in -free, are excluded because access is restricted to the OpenCode client. Unknown protocols and System One/Jev structured decision models are also excluded. Refresh the catalog and select a replacement if your saved model is unavailable. ### Can I use images, reasoning, and tools? Yes, when the selected model supports them. Verified reasoning choices appear beside your prompt. iolys tools, MCP, skills, and permissions work through the existing workflow. Zen does not automatically enable provider-native web tools. ### How are Zen costs calculated? iolys uses returned token usage and known prices for the exact Zen model, including applicable cache and context tiers. Turn and session totals sum available estimates; calls with missing usage or necessary rates are excluded. Fees, taxes, and billing adjustments are not included. The OpenCode Console remains authoritative. ### Can I see my Zen balance or quota in iolys? No account balance or quota view is provided for Zen. Per-call tokens and available cost estimates are separate. Manage credit and limits in the OpenCode Console. ### What is restored when I reopen a conversation? The existing text conversation and available persisted monetary totals are restored. Old images, tool executions, signatures, and encrypted reasoning are not restored or re-executed. ## 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) - [What is iolys? AI coding agent harness for Visual Studio | iolys](https://getiolys.com/what-is-iolys) - [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)