> ## Documentation Index > Fetch the complete documentation index at: https://docs.genova.gg/llms.txt > Use this file to discover all available pages before exploring further. # Intro to Character API > The Plug-n-Play API for AI NPCs / Assistants / Teammates in your Games & Apps ## Overview Our Character API allows you to build AI NPCs, assistants, or teammates that you can easily integrate with your games and apps. A Character is defined by its own system prompt as well as other core functions you could leverage: Actions and Voices (beta). You can explore the functionalities of our Characters using the [Genova Labs Playground](https://playground.genova.gg/). If you're looking for a quick setup, check out our [4-step Quickstart Guide](/quickstart-guide) to get started! ## How Characters Work Here's a simplified diagram of how components work together behind the Character APIs ### Important Terms **Character:** Purpose-built AI, powered by our models and systems, customized & tuned by you. **User:** Non-AI participant in the conversation, primarily represented by a string ID that maps to a distinct *User*. **Room:** A conversation session between *Character(s)* and *User(s)*. A *Room* stores *Messages* and automatically utilize truncation to keep content within into a model’s context length. **Message:** A message from a *User* or a *Character* in a conversation. *Messages* are stored as a list in the *Room*.