feat: add delegation capabilities to agents with allowed_agents field

src/crewai/agents/agent_builder/base_agent.py

@@ -2,7 +2,7 @@ import uuid
 from abc import ABC, abstractmethod
 from copy import copy as shallow_copy
 from hashlib import md5
-from typing import Any, Dict, List, Optional, TypeVar
+from typing import Any, Dict, List, Optional, TypeVar, Union
 
 from pydantic import (
     UUID4,
@@ -107,6 +107,10 @@ class BaseAgent(ABC, BaseModel):
         default=False,
         description="Enable agent to delegate and ask questions among each other.",
     )
+    allowed_agents: Optional[List[Union[str, 'BaseAgent']]] = Field(
+        default=None,
+        description="List of agent roles or agent instances that this agent can delegate tasks to",
+    )
     tools: Optional[List[Any]] = Field(
         default_factory=list, description="Tools at agents' disposal"
     )
@@ -236,6 +240,12 @@ class BaseAgent(ABC, BaseModel):
         """Set the task tools that init BaseAgenTools class."""
         pass
 
+    @field_validator('allowed_agents')
+    def validate_allowed_agents(cls, v):
+        if v is None:
+            return v
+        return [agent.role if isinstance(agent, BaseAgent) else agent for agent in v]
+    
     @abstractmethod
     def get_output_converter(
         self, llm: Any, text: str, model: type[BaseModel] | None, instructions: str

src/crewai/crew.py

@@ -860,8 +860,24 @@ class Crew(BaseModel):
         return self._merge_tools(tools, code_tools)
 
     def _add_delegation_tools(self, task: Task, tools: List[Tool]):
-        agents_for_delegation = [agent for agent in self.agents if agent != task.agent]
-        if len(self.agents) > 1 and len(agents_for_delegation) > 0 and task.agent:
+        # agents_for_delegation = [agent for agent in self.agents if agent != task.agent]
+        # if len(self.agents) > 1 and len(agents_for_delegation) > 0 and task.agent:
+        #     if not tools:
+        #         tools = []
+        #     tools = self._inject_delegation_tools(
+        #         tools, task.agent, agents_for_delegation
+        #     )
+        # return tools
+        if not task.agent or not task.agent.allow_delegation:
+            return tools
+        
+        agents_for_delegation = []
+        for agent in self.agents:
+            if agent == task.agent:
+                continue
+            if task.agent.allowed_agents is None or agent.role in task.agent.allowed_agents:
+                agents_for_delegation.append(agent)
+        if agents_for_delegation:
             if not tools:
                 tools = []
             tools = self._inject_delegation_tools(