import json
from typing import Dict, Optional, Union
from letta.agents.letta_agent import LettaAgent
from letta.interface import AgentInterface
from letta.orm.group import Group
from letta.orm.user import User
from letta.schemas.agent import AgentState
from letta.schemas.group import ManagerType
from letta.schemas.letta_message_content import ImageContent, ReasoningContent, TextContent
from letta.schemas.message import Message
from letta.services.mcp.base_client import AsyncBaseMCPClient
def load_multi_agent(
group: Group,
agent_state: Optional[AgentState],
actor: User,
interface: Union[AgentInterface, None] = None,
mcp_clients: Optional[Dict[str, AsyncBaseMCPClient]] = None,
) -> LettaAgent:
if len(group.agent_ids) == 0:
raise ValueError("Empty group: group must have at least one agent")
if not agent_state:
raise ValueError("Empty manager agent state: manager agent state must be provided")
match group.manager_type:
case ManagerType.round_robin:
from letta.groups.round_robin_multi_agent import RoundRobinMultiAgent
return RoundRobinMultiAgent(
agent_state=agent_state,
interface=interface,
user=actor,
group_id=group.id,
agent_ids=group.agent_ids,
description=group.description,
max_turns=group.max_turns,
)
case ManagerType.dynamic:
from letta.groups.dynamic_multi_agent import DynamicMultiAgent
return DynamicMultiAgent(
agent_state=agent_state,
interface=interface,
user=actor,
group_id=group.id,
agent_ids=group.agent_ids,
description=group.description,
max_turns=group.max_turns,
termination_token=group.termination_token,
)
case ManagerType.supervisor:
from letta.groups.supervisor_multi_agent import SupervisorMultiAgent
return SupervisorMultiAgent(
agent_state=agent_state,
interface=interface,
user=actor,
group_id=group.id,
agent_ids=group.agent_ids,
description=group.description,
)
case ManagerType.sleeptime:
if not agent_state.enable_sleeptime:
return LettaAgent(
agent_state=agent_state,
interface=interface,
user=actor,
mcp_clients=mcp_clients,
)
from letta.groups.sleeptime_multi_agent import SleeptimeMultiAgent
return SleeptimeMultiAgent(
agent_state=agent_state,
interface=interface,
user=actor,
group_id=group.id,
agent_ids=group.agent_ids,
description=group.description,
sleeptime_agent_frequency=group.sleeptime_agent_frequency,
)
case _:
raise ValueError(f"Type {group.manager_type} is not supported.")
def stringify_message(message: Message, use_assistant_name: bool = False) -> str | None:
assistant_name = message.name or "assistant" if use_assistant_name else "assistant"
if message.role == "user":
try:
messages = []
for content in message.content:
if isinstance(content, TextContent):
messages.append(f"{message.name or 'user'}: {content.text}")
elif isinstance(content, ImageContent):
messages.append(f"{message.name or 'user'}: [Image Here]")
return "\n".join(messages)
except Exception:
if message.content and len(message.content) > 0:
return f"{message.name or 'user'}: {message.content[0].text}"
return None
elif message.role == "assistant":
messages = []
if message.content:
for content in message.content:
if isinstance(content, TextContent):
messages.append(f"{assistant_name}: {content.text}")
elif isinstance(content, ReasoningContent):
messages.append(f"{assistant_name}: {content.reasoning}")
if message.tool_calls:
for tool_call in message.tool_calls:
if tool_call.function.name == "send_message":
messages.append(f"{assistant_name}: {json.loads(tool_call.function.arguments)['message']}")
else:
messages.append(f"{assistant_name}: Calling tool {tool_call.function.name}")
return "\n".join(messages) if messages else None
elif message.role == "approval":
# role == "approval" has two cases:
# 1. Approval REQUEST: has tool_calls (assistant calling tool that needs HITL)
# 2. Approval RESPONSE: no tool_calls, has approve field (user's decision)
# Check if this is an approval request (has tool_calls)
if hasattr(message, "tool_calls") and message.tool_calls:
# Treat like assistant message calling a tool
messages = []
if message.content:
for content in message.content:
if isinstance(content, TextContent):
messages.append(f"{assistant_name}: {content.text}")
elif isinstance(content, ReasoningContent):
messages.append(f"{assistant_name}: {content.reasoning}")
for tool_call in message.tool_calls:
if tool_call.function.name == "send_message":
messages.append(f"{assistant_name}: {json.loads(tool_call.function.arguments)['message']}")
else:
messages.append(f"{assistant_name}: Calling tool {tool_call.function.name}")
return "\n".join(messages) if messages else None
else:
# Approval response - user approved/rejected
if hasattr(message, "approve") and message.approve is not None:
status = "approved" if message.approve else "rejected"
reason = f": {message.denial_reason}" if hasattr(message, "denial_reason") and message.denial_reason else ""
return f"[User {status}{reason}]"
return None
elif message.role == "tool":
if message.content:
content = json.loads(message.content[0].text)
if str(content["message"]) != "None":
return f"{assistant_name}: Tool call returned {content['message']}"
return None
elif message.role == "system":
return None
else:
if message.content and len(message.content) > 0:
# Handle different content types
content_item = message.content[0]
if isinstance(content_item, TextContent):
return f"{message.name or 'user'}: {content_item.text}"
elif isinstance(content_item, ReasoningContent):
return f"{message.name or 'user'}: {content_item.reasoning}"
elif isinstance(content_item, ImageContent):
return f"{message.name or 'user'}: [Image Here]"
return None