> ## Documentation Index
> Fetch the complete documentation index at: https://docs.memorylake.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Use API Key Overview

> Learn different ways to use your API key to interact with Model Router

## What is This Guide?

This guide shows you three main ways to use your API Key with Model Router:

1. **Direct API Requests**: Make HTTP requests directly using cURL or any HTTP client
2. **Minimal MVP Examples**: Simple, ready-to-run code examples in popular programming languages
3. **AI Application Integrations**: Connect Model Router to existing AI tools like Claude Code or Codex CLI

## Before You Start

<Info>
  Before making any API calls, make sure you know which models are available to your API key. Check the [List Available Models](/features/model-router/list-available-models) guide first.
</Info>

## Three Ways to Use Your API Key

### 1. Direct API Requests

If you want to make requests directly using HTTP tools like cURL, Postman, or any HTTP client, this is the simplest approach.

**Best for**: Quick testing, automation scripts, or when you need full control over the request

**Learn more**: [Direct API Requests](/features/model-router/getting-started/use-api-key/direct-api-requests)

### 2. Minimal MVP Examples

Ready-to-run code examples in Python, Node.js, and TypeScript that you can copy and use immediately.

**Best for**: Building your own application, learning how to integrate Model Router, or prototyping

**Learn more**: [Minimal MVP Examples](/features/model-router/getting-started/use-api-key/minimal-mvp-examples)

### 3. AI Application Integrations

Connect Model Router to existing AI development tools without writing code.

**Best for**: Using AI tools like Claude Code or Codex CLI with Model Router

**Learn more**: [AI Application Integrations](/features/model-router/getting-started/use-api-key/ai-app-integrations)

## Quick Start Checklist

1. ✅ [Create an API Key](/features/model-router/getting-started/create-api-key)
2. ✅ [Check Available Models](/features/model-router/list-available-models)
3. ✅ Choose one of the three methods above
4. ✅ Make your first API call
5. ✅ [View Your Usage](/features/model-router/view-usage-and-billing)

## Related Documentation

* [Create API Key](/features/model-router/getting-started/create-api-key)
* [List Available Models](/features/model-router/list-available-models)
* [View Usage and Billing](/features/model-router/view-usage-and-billing)
* [Direct API Requests](/features/model-router/getting-started/use-api-key/direct-api-requests)
* [Minimal MVP Examples](/features/model-router/getting-started/use-api-key/minimal-mvp-examples)
* [AI Application Integrations](/features/model-router/getting-started/use-api-key/ai-app-integrations)