How to Add Cost-Aware Model Selection to Your AI Agent

How to Add Cost-Aware Model Selection to Your AI Agent Every AI agent picks a model. Most pick the same one every time — usually the most expensive one. That is a fine default when you are prototyping, but in production it means you are overpaying for simple tasks and underpowering complex ones. This tutorial shows how to add dynamic, cost-aware model selection to any AI agent using WhichModel, an open MCP server that tracks pricing and capabilities across 100+ LLM models. The Problem LLM pricing changes constantly. New models launch weekly. Picking the right model for each task requires knowing current prices across providers, which models support the capabilities you need, and how model quality maps to task complexity. Maintaining this yourself means building a pricing database, keeping it updated, and writing routing logic. Or you can let your agent ask WhichModel. Setup: 30 Seconds Add WhichModel to your MCP client config: { "mcpServers" : { "whichmodel" : { "url" : "https://whichm