# Automatic Model Selection

### Intelligent Model Routing **Overview**

FastRouter’s intelligent model routing mode lets you delegate model selection to us. Instead of picking a specific model, just set:

```bash
"model": "fastrouter/auto"
```

### **How It Works**

FastRouter will automatically select the most appropriate model based on:

* Complexity of the query
* Domain or topic of the request
* Cost-efficiency

This is the fastest way to get started — no manual tuning, no need to maintain model preference lists.

### Example

```bash
curl --location 'https://api.fastrouter.ai/api/v1/chat/completions' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer API-KEY' \
--data '{
  "model": "fastrouter/auto",
  "messages": [
    {
      "role": "user",
      "content": "What is 2+2?"
    }
  ]
}'
```

FastRouter will analyze the input and select the best model from the available pool.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.fastrouter.ai/explore-features/automatic-model-selection.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.