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

# AI agents

> Configure the assistant personas that power Railmail's chat.

**Agents** are configurable assistant personas used across Railmail, the same assistant you meet in the campaign, automation and segment builders. An agent defines *how* the assistant behaves; it is not an autonomous sending bot.

## What an agent controls

Open an agent to configure it across a few sections:

**Identity**

* **Agent name** and **display name** (shown in the assistant dropdown)
* **Description**: what this agent is for
* **System prompt**: the core instructions (required)

**Personality**

* **Tone**: Professional, Casual, Friendly, Formal, Playful or Direct
* **Creativity** and **Verbosity** (Concise, Balanced or Detailed)

**Knowledge & limits**

* **Knowledge base**: brand guidelines, tone and facts the agent should know
* **Constraints**: what the agent should *not* do

**Contexts & examples**

* **Available contexts** the agent can use
* **Example outputs**: input → output pairs that steer its responses

## Test in chat

The agent editor has a **Chat** tab to test the persona live. The assistant streams responses in real time. If you see *"Connection to chat server lost"*, use **Retry**. If you run out of AI credits, top up your [AI credits](/en/guide/ai-credits).

## Types and status

Agents are **Custom** (created by you) or **System** (built in), and each is **Active** or **Archived**. You can **Create**, **Edit**, **Duplicate** or **Delete** an agent.