Customize BitRouter with explicit model, provider, and tool capabilities without changing the request interface your applications use.

Customization adds or replaces a capability behind BitRouter's stable request surface. Use it when your team needs its own model, provider connection, or router-owned tool.

BitRouter does not treat every customization as one universal plugin type. Each surface keeps the contract and permissions appropriate to what it can do:

Models and providers add inference capacity behind the router.
Server tools let BitRouter execute a declared tool-calling loop.
Advisor, Sub-agent, and Fusion compose additional model calls for a specific routing strategy.
Web Search and Web Fetch add bounded external information capabilities.

Models & providers

Add models and provider connections that are not built in.

Tool calling

Add governed server-side tools and execution patterns.

Defining a capability does not enable it for every request. Keep activation explicit in deployment configuration and in each request. Use Configuration for routing behavior, and Usage when the task is operating BitRouter from an existing agent, protocol, or runtime rather than changing BitRouter's own behavior.