# Bring your own model (BYOM)
Bring your own model (BYOM) is the idea that an app, tool, or platform should let **you** decide which AI model it uses, instead of forcing its own model on you, on its own terms.
The app provides the interface and the workflow. You provide the brain: a frontier model through your own account, an open-weight model running on your machine, or anything in between.
## The problem it solves
Many products bundle AI the same way: one model (or a short list), chosen by the vendor, running on the vendor's servers, billed through the vendor, with usage limits set by the vendor. As a user, you inherit ALL of their decisions:
- **Quality**: you're stuck with whatever model they picked, even when a better one exists for your task
- **Privacy**: your data goes wherever their model runs, under their data policy
- **Cost**: you pay their markup, often hidden in a subscription with quotas
- **Continuity**: they can swap, degrade, or remove the model at any time. Your workflow changes without your consent
- **Lock-in**: the more your work depends on their AI, the harder it is to leave
That's a clear case of [[SaaS Misalignment with User Objectives]]. The vendor's incentives (margins, retention, data) aren't the same as yours.
## What BYOM looks like in practice
There are different levels of freedom:
1. **Model picker**: choose among the models the vendor supports. Better than nothing, but still their list
2. **Your own account**: plug in your own API key for a provider. That's [[Bring Your Own Key (BYOK)]]. You pick the provider, and billing and data go through your account
3. **Any compatible endpoint**: point the app to any OpenAI-compatible API, including routers like [[OpenRouter]]
4. **Local models**: run open-weight models on your own hardware with [[Ollama]] or [[LM Studio]]. Nothing leaves your computer
BYOK is a subset of BYOM. BYOK is about *whose account* pays. BYOM is about *which model* does the work, wherever it runs.
## Examples
- **Code editors and agents**: [[Cursor]] lets you use your own API keys, and tools like [[Cline]] and [[OpenCode]] work with many providers and local models
- **Obsidian plugins**: [[Copilot plugin for Obsidian]] and [[Smart Connections plugin for Obsidian]] support multiple providers, including local models (see [[Obsidian AI Plugins]])
- **Terminal tools**: [[Emeraldian]]'s assistant works with Anthropic, OpenAI, OpenRouter, Groq, Ollama, or LM Studio
- **My own product**: [[Knowii Voice AI]] runs speech-to-text models locally, and you choose which model to download and use: small and fast, or large and accurate
## Why I care about this
I strongly believe that BYOM is the AI version of the [[File over app principle]]. Your notes shouldn't be locked into an app, and your AI capabilities shouldn't be locked into a vendor either.
Models improve every few weeks. The best model today won't be the best one in six months. A tool that lets you swap the model keeps getting better over time. A tool that doesn't ages with its vendor's choices.
It also matters a lot for [[Data Ownership]]. Some content should never leave your machine (personal journals, customer data, health information). With BYOM, you can use a local model for sensitive work and a frontier model for the rest.
## Trade-offs
It's not free, though:
- **More setup**: accounts, API keys, endpoints, model downloads
- **Inconsistent results**: the app's prompts and features are usually tuned for specific models. A weaker model can make the whole product look bad
- **Hardware requirements** for local models
- **Support burden** for the vendor, which is why many of them avoid it
- **Your responsibility**: you manage the costs, rate limits, and security of your keys
When evaluating an AI tool, ask yourself: can I change the model? If the answer is no, you're renting the vendor's judgment along with the tool.
## References
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## Related
- [[Bring Your Own Key (BYOK)]]
- [[SaaS Misalignment with User Objectives]]
- [[File over app principle]]
- [[Data Ownership]]
- [[Local-first software]]
- [[Self-hosting]]
- [[Large Language Models (LLMs)]]
- [[Small Language Models (SLMs)]]
- [[Ollama]]
- [[LM Studio]]
- [[OpenRouter]]
- [[Obsidian AI Plugins]]
- [[Knowii Voice AI]]