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 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:
{
"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": {
"hint": "query to search for"
}
},
{
"name": "test",
"description": "Run tests for the current project"
},
{
"name": "plan",
"description": "Create a detailed implementation plan",
"input": {
"hint": "description of what to plan"
}
}
]
}
}
}
The list of commands available in this session
AvailableCommand
The command name (e.g., “web”, “test”, “plan”)
Human-readable description of what the command does
Optional input specification for the command
A hint to display when the input hasn’t been provided yet
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:
{
"jsonrpc": "2.0",
"id": 3,
"method": "session/prompt",
"params": {
"sessionId": "sess_abc123def456",
"prompt": [
{
"type": "text",
"text": "/web agent client protocol"
}
]
}
}
