---
title: "Bring Your Own Model (BYOM) in Visual Studio 2026 | iolys"
description: "Compare BYOM, BYOK, and BYOS for Visual Studio 2026: bring a model deployment, provider API key, local endpoint, or eligible AI subscription."
url: "https://getiolys.com/byom"
language: "en"
updated: "2026-10-04"
---

# Bring Your Own Model, Key, and Subscription in Visual Studio 2026

Model choice and payment choice are different decisions. The practical distinction is what you bring to the tool and who controls access, usage, and billing.

| Route | What you bring | Usage ownership |
| --- | --- | --- |
| BYOS — Bring Your Own Subscription | A subscription you already pay for: an eligible AI plan through its provider CLI, OpenCode Go through its API key, or your organization's Databricks workspace | Included access, credits, or quotas subject to provider terms |
| BYOK — Bring Your Own Key | Provider API key, including subscription access, prepaid credits, or pay-as-you-go usage | Defined by the provider plan; a key authenticates access |
| BYOM — Bring Your Own Model | Model deployment or endpoint you control | Your infrastructure or provider account |

Bring Your Own Subscription (BYOS) means working from a subscription you already pay for instead of opening a new metered account. Seven of the eleven iolys routes qualify: Claude, Codex, Kiro, Kimi, and Gemini reuse an eligible personal plan by signing in through their supported CLI, OpenCode Go uses its subscription through an API key, and Databricks reuses the workspace subscription your organization already holds. Eligibility, credits, and limits remain defined by each provider. The remaining routes are prepaid-credit APIs, DeepSeek, OpenRouter, and OpenCode Zen, and local models through Ollama.

## 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 |

## BYOM, BYOK, and BYOS questions

### What does Bring Your Own Model (BYOM) mean?

BYOM means connecting a model deployment or endpoint that you or your organization controls to the development experience you already use.

### Does BYOM always mean pay-as-you-go billing?

No. A local or self-hosted model can avoid a metered cloud-model bill. When BYOM uses a cloud provider API key or hosted deployment, usage and billing usually remain with that provider or infrastructure account.

### What is the difference between BYOM, BYOK, and BYOS?

BYOM brings a model or deployment, BYOK brings a provider API key, and BYOS brings a subscription you already pay for. BYOS includes eligible plans through supported provider CLIs, OpenCode Go through its API key, and your organization's Databricks workspace. BYOK and BYOS can overlap: OpenCode Go uses an API key for subscription access.

### Do I need a separate API account to use AI in Visual Studio 2026?

Not always. With iolys, seven of the eleven routes reuse a subscription you already pay for, so no second pay-as-you-go API account is required for those. OpenCode Go uses an API key for its subscription, while DeepSeek, OpenRouter, and OpenCode Zen API keys use prepaid credits or pay-as-you-go. Ollama needs no account at all.

### Can I use an existing AI subscription with iolys?

Yes. Use an eligible plan through its supported provider CLI, connect your OpenCode Go subscription with its API key, or use your organization's Databricks workspace. Provider availability, credits, quotas, and usage limits remain governed by that provider.

### Can I use a local model instead?

Yes. iolys supports local Ollama endpoints, so you can use compatible models running on infrastructure you control.

### What do I install to bring my own model into Visual Studio?

One VSIX: iolys. The iolys VSIX for Visual Studio 2026 is the only install needed, and your BYOM, BYOK, or BYOS route is then configured inside the Manage Providers panel rather than through an extra extension.

### Does iolys include model usage?

No. All currently available iolys features are free for personal and commercial use. AI provider subscriptions, API usage, enterprise endpoints, and local infrastructure costs remain separate.

## Related pages

- [Bring Your Own AI Subscription to Visual Studio 2026 | iolys](https://getiolys.com/)
- [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)