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

# Slash Commands

> Advertise available slash commands to clients

Agents can advertise a set of slash commands that users can invoke. These commands provide quick access to specific agent capabilities and workflows. Commands are run as part of regular [prompt](/protocol/v2/draft/prompt-lifecycle) requests where the Client includes the command text in the prompt.

## Advertising commands

After creating a session, the Agent **MAY** send a list of available commands via the `available_commands_update` session notification:

```json theme={null}
{
  "jsonrpc": "2.0",
  "method": "session/update",
  "params": {
    "sessionId": "sess_abc123def456",
    "update": {
      "sessionUpdate": "available_commands_update",
      "availableCommands": [
        {
          "name": "web",
          "description": "Search the web for information",
          "input": {
            "type": "text",
            "hint": "query to search for"
          }
        },
        {
          "name": "test",
          "description": "Run tests for the current project"
        },
        {
          "name": "plan",
          "description": "Create a detailed implementation plan",
          "input": {
            "type": "text",
            "hint": "description of what to plan"
          }
        }
      ]
    }
  }
}
```

<ResponseField name="availableCommands" type="AvailableCommand[]">
  The list of commands available in this session
</ResponseField>

### AvailableCommand

<ResponseField name="name" type="string" required>
  The command name (e.g., "web", "test", "plan")
</ResponseField>

<ResponseField name="description" type="string" required>
  Human-readable description of what the command does
</ResponseField>

<ResponseField name="input" type="AvailableCommandInput">
  Optional input specification for the command
</ResponseField>

### AvailableCommandInput

Currently supports text input with `type: "text"`:

<ResponseField name="hint" type="string" required>
  A hint to display when the input hasn't been provided yet
</ResponseField>

Command input specifications can add custom or future `type` values. Custom input types **MUST** begin with `_`; unknown non-underscore input types are reserved for future ACP variants. Clients that cannot render an input specification should preserve it when storing, replaying, proxying, or forwarding command metadata, and otherwise display the command without structured input.

## Dynamic updates

The Agent can update the list of available commands at any time during a session by sending another `available_commands_update` notification. This allows commands to be added based on context, removed when no longer relevant, or modified with updated descriptions.

## Running commands

Commands are included as regular user messages in prompt requests:

```json theme={null}
{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "session/prompt",
  "params": {
    "sessionId": "sess_abc123def456",
    "prompt": [
      {
        "type": "text",
        "text": "/web agent client protocol"
      }
    ]
  }
}
```

The Agent recognizes the command prefix and processes it accordingly. Commands may be accompanied by any other user message content types (images, audio, etc.) in the same prompt array.