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

# Core concepts

> The public terms used across AXTL Docs.

# Core concepts

## Agent

An agent is the main AXTL resource. It represents a generated backend and its related configuration, versions, deployments, API keys, and usage.

## Requirements

Requirements are the plain-English instructions you give AXTL. They describe the API behavior you want.

## Spec

A spec is the structured plan AXTL may create from your requirements before generation. Some workspaces may expose extra review or approval steps during the beta.

## Generation

Generation is the process that turns requirements or an approved spec into a backend artifact.

## Artifact

An artifact is the generated backend package. It can be downloaded or deployed when it passes the required checks.

## Deployment

A deployment publishes a generated backend and creates an endpoint URL.

## Endpoint

An endpoint is a URL you call from your application. AXTL has control API endpoints, and your deployed backend has its own runtime endpoints.

## API key

An API key authorizes access. AXTL distinguishes platform bearer authentication for control API calls from agent-scoped API keys for invoking a deployed backend.

Agent API keys use:

```text theme={null}
Authorization: Bearer {AXTL_AGENT_KEY}
```

Agent keys are scoped to one agent. A key created for one agent cannot invoke another agent slug.

## Usage

Usage includes generation jobs, deployments, test calls, and quota consumption. Limits may vary by workspace during the beta.