# Agents

URL: https://docs.hanzo.ai/docs/chat/agents

> Create custom AI agents in Hanzo Chat with system prompts, model selection, and MCP tool access.

Agents are custom AI personas with specific system prompts, model preferences, and tool access. They appear as selectable options in the Chat UI.

## Creating Agents

### Via chat.yaml

Define agents in your `chat.yaml` configuration:

```yaml
agents:
  - name: "Code Reviewer"
    model: "zen5-coder"
    systemPrompt: |
      You are a senior code reviewer. Analyze code for:
      - Bugs and logic errors
      - Security vulnerabilities
      - Performance issues
      - Style and readability improvements
      Always explain your reasoning and suggest fixes.
    tools:
      - filesystem
      - web

  - name: "Research Assistant"
    model: "zen5-pro"
    systemPrompt: |
      You are a research assistant. Search the web, analyze
      documents, and provide comprehensive answers with citations.
      Always cite your sources.
    tools:
      - web

  - name: "Writing Editor"
    model: "zen5"
    systemPrompt: |
      You are a professional editor. Review writing for clarity,
      grammar, tone, and structure. Suggest specific improvements
      while preserving the author's voice.

  - name: "Data Analyst"
    model: "zen5-pro"
    systemPrompt: |
      You are a data analyst. Help users understand data, create
      visualizations, write SQL queries, and interpret results.
      Think step-by-step through complex analysis.
    tools:
      - filesystem
```

### Via UI

1. Open Chat settings
2. Go to **Agents** section
3. Click **Create Agent**
4. Configure name, model, system prompt, and tools
5. Save — the agent appears in the model selector

## Agent Configuration

| Field          | Description                                | Required |
| -------------- | ------------------------------------------ | -------- |
| `name`         | Display name in the UI                     | Yes      |
| `model`        | Default model for this agent               | Yes      |
| `systemPrompt` | Instructions prepended to every message    | Yes      |
| `tools`        | List of MCP tool servers the agent can use | No       |
| `description`  | Short description shown in the UI          | No       |
| `icon`         | Custom icon URL                            | No       |

## MCP Tools for Agents

Agents can use MCP (Model Context Protocol) tools for extended capabilities. First define the MCP servers, then reference them in agent configs:

```yaml
mcpServers:
  filesystem:
    command: npx
    args: ["@hanzo/mcp-filesystem"]
    env:
      ALLOWED_DIRS: "/data"

  web:
    command: npx
    args: ["@hanzo/mcp-web"]

  github:
    command: npx
    args: ["@hanzo/mcp-github"]
    env:
      GITHUB_TOKEN: "${GITHUB_TOKEN}"

agents:
  - name: "DevOps Agent"
    model: "zen5-coder"
    systemPrompt: "You are a DevOps engineer..."
    tools:
      - filesystem
      - github
```

See [MCP Tools](https://docs.hanzo.ai/docs/mcp) for the full list of 260+ available MCP tool servers.

## Agent Presets

Agents can also be saved as presets for quick switching:

1. Configure an agent in model settings
2. Adjust temperature, top\_p, and other parameters
3. Click **Save As Preset**
4. The preset preserves both the system prompt and parameters

## Built-in Agents

Hanzo Chat includes several pre-configured agents:

| Agent   | Model      | Purpose                         |
| ------- | ---------- | ------------------------------- |
| Default | zen5       | General-purpose chat            |
| Coder   | zen5-coder | Code generation and review      |
| Analyst | zen5-pro   | Deep analysis and reasoning     |
| Quick   | zen5-flash | Fast responses for simple tasks |