adding NON-BREAKING/BACKWARDS-COMPATIBLE support for LangChain's v1 astream events to the AgentRearrange & Agent classes PLUS added an example of how to use it

examples/rearrange_swarm_with_langchain_v1_astream_events/example.py

@@ -0,0 +1,83 @@
+import os
+import asyncio
+from dotenv import load_dotenv
+load_dotenv()
+
+from swarms.structs import Agent
+from swarms.models import Anthropic
+from swarms.structs.rearrange import AgentRearrange
+
+llm = Anthropic(anthropic_api_key=os.getenv("ANTHROPIC_API_KEY"), streaming=True)
+
+async def sequential():
+
+  agent1 = Agent(
+      agent_name="Blog generator",
+      system_prompt="Generate a blog post like stephen king",
+      llm=llm,
+      dashboard=False,
+      streaming_on=True
+  )
+
+  agent2 = Agent(
+      agent_name="Summarizer",
+      system_prompt="Summarize the blog post",
+      llm=llm,
+      dashboard=False,
+      streaming_on=True
+  )
+
+  flow = f"{agent1.name} -> {agent2.name}"
+
+  agent_rearrange = AgentRearrange(
+    [agent1, agent2], flow, verbose=False, logging=False
+  )
+
+  result = await agent_rearrange.astream(
+     "Generate a short blog post about Muhammad Ali."
+  )
+
+  # LEAVING THIS CALL BELOW FOR COMPARISON with "completion-style" .run() approach ;)
+  # await agent_rearrange.run(
+  #   "Generate a short blog post about Muhammad Ali."
+  # )
+
+async def parallel():
+
+  writer1 = Agent(
+      agent_name="Writer 1",
+      system_prompt="Generate a blog post in the style of J.K. Rowling about Muhammad Ali",
+      llm=llm,
+      dashboard=False,
+  )
+
+  writer2 = Agent(
+      agent_name="Writer 2",
+      system_prompt="Generate a blog post in the style of Stephen King about Muhammad Ali",
+      llm=llm,
+      dashboard=False
+  )
+
+  reviewer = Agent(
+      agent_name="Reviewer",
+      system_prompt="Select the writer that wrote the best story. There can only be one best story.",
+      llm=llm,
+      dashboard=False
+  )
+
+  flow = f"{writer1.name}, {writer2.name} -> {reviewer.name}"
+
+  agent_rearrange = AgentRearrange(
+    [writer1, writer2, reviewer], flow, verbose=False, logging=False
+  )
+
+  result = await agent_rearrange.astream("Generate a 1 sentence story about Michael Jordan.")
+  
+  # LEAVING THIS CALL BELOW FOR COMPARISON with "completion-style" .run() approach ;)
+  # result = agent_rearrange.run(
+  #   "Generate a short blog post about Michael Jordan."
+  # )
+
+# asyncio.run(sequential())
+asyncio.run(parallel())
+

swarms/structs/agent.py

@@ -713,7 +713,7 @@ class Agent:
 
                             # Print
                             if self.streaming_on is True:
-                                response = self.stream_response(response)
+                                self.stream_response(response)
                             else:
                                 print(response)
 
@@ -882,6 +882,15 @@ class Agent:
             )
             raise error
 
+    async def astream_events(
+        self, task: str = None, img: str = None, *args, **kwargs
+    ):
+        try:
+            async for evt in self.llm.astream_events(task, version="v1"):
+                yield evt
+        except Exception as e:
+            print(f"Error streaming events: {e}")
+
     def __call__(self, task: str = None, img: str = None, *args, **kwargs):
         """Call the agent
 

swarms/structs/rearrange.py

@@ -266,6 +266,140 @@ class AgentRearrange(BaseSwarm):
             logger.error(f"An error occurred: {e}")
             return e
 
+    async def astream(
+        self,
+        task: str = None,
+        img: str = None,
+        custom_tasks: Dict[str, str] = None,
+        *args,
+        **kwargs,
+    ):
+        """
+        Runs the swarm with LangChain's astream_events v1 API enabled.
+        NOTICE: Be sure to only call this method if you are using LangChain-based models in your swarm.
+        This is useful for enhancing user experience by providing real-time updates of how each agent
+        in the swarm is processing the current task.
+
+        Args:
+            task: The initial prompt (aka task) passed to the first agent(s) in the swarm.
+
+        Returns:
+            str: The final output generated.
+        """
+        try:
+            if not self.validate_flow():
+                return "Invalid flow configuration."
+
+            tasks = self.flow.split("->")
+            current_task = task
+
+            # If custom_tasks have the agents name and tasks then combine them
+            if custom_tasks is not None:
+                c_agent_name, c_task = next(iter(custom_tasks.items()))
+
+                # Find the position of the custom agent in the tasks list
+                position = tasks.index(c_agent_name)
+
+                # If there is a prebois agent merge its task with the custom tasks
+                if position > 0:
+                    tasks[position - 1] += "->" + c_task
+                else:
+                    # If there is no prevous agent just insert the custom tasks
+                    tasks.insert(position, c_task)
+
+            logger.info('TASK:', task)
+
+            # Set the loop counter
+            loop_count = 0
+            while loop_count < self.max_loops:
+                for task in tasks:
+                    agent_names = [
+                        name.strip() for name in task.split(",")
+                    ]
+                    if len(agent_names) > 1:
+                        # Parallel processing
+                        logger.info(
+                            f"Running agents in parallel: {agent_names}"
+                        )
+                        results = []
+                        for agent_name in agent_names:
+                            if agent_name == "H":
+                                # Human in the loop intervention
+                                if (
+                                    self.human_in_the_loop
+                                    and self.custom_human_in_the_loop
+                                ):
+                                    current_task = (
+                                        self.custom_human_in_the_loop(
+                                            current_task
+                                        )
+                                    )
+                                else:
+                                    current_task = input(
+                                        "Enter your response:"
+                                    )
+                            else:
+                                agent = self.agents[agent_name]
+                                result = None
+                                # As the current `swarms` package is using LangChain v0.1 we need to use the v0.1 version of the `astream_events` API 
+                                # Below is the link to the `astream_events` spec as outlined in the LangChain v0.1 docs
+                                # https://python.langchain.com/v0.1/docs/expression_language/streaming/#event-reference
+                                # Below is the link to the `astream_events` spec as outlined in the LangChain v0.2 docs
+                                # https://python.langchain.com/v0.2/docs/versions/v0_2/migrating_astream_events/
+                                async for evt in agent.astream_events(current_task, version="v1"):
+                                    # print(evt) # <- useful when building/debugging
+                                    if evt['event'] == "on_llm_end":
+                                        result = evt['data']['output']
+                                        print(agent.name, result)
+                                results.append(result)
+
+                        current_task = ""
+                        for index,res in enumerate(results):
+                            current_task += "# OUTPUT of " + agent_names[index] + "" + res + "\n\n"
+                    else:
+                        # Sequential processing
+                        logger.info(
+                            f"Running agents sequentially: {agent_names}"
+                        )
+
+                        agent_name = agent_names[0]
+                        if agent_name == "H":
+                            # Human-in-the-loop intervention
+                            if (
+                                self.human_in_the_loop
+                                and self.custom_human_in_the_loop
+                            ):
+                                current_task = (
+                                    self.custom_human_in_the_loop(
+                                        current_task
+                                    )
+                                )
+                            else:
+                                current_task = input(
+                                    "Enter the next task: "
+                                )
+                        else:
+                            agent = self.agents[agent_name]
+                            result = None
+                            # As the current `swarms` package is using LangChain v0.1 we need to use the v0.1 version of the `astream_events` API 
+                            # Below is the link to the `astream_events` spec as outlined in the LangChain v0.1 docs
+                            # https://python.langchain.com/v0.1/docs/expression_language/streaming/#event-reference
+                            # Below is the link to the `astream_events` spec as outlined in the LangChain v0.2 docs
+                            # https://python.langchain.com/v0.2/docs/versions/v0_2/migrating_astream_events/
+                            async for evt in agent.astream_events(f"SYSTEM: {agent.system_prompt}\nINPUT:{current_task}", version="v1"):
+                                # print(evt) # <- useful when building/debugging
+                                if evt['event'] == "on_llm_end":
+                                    result = evt['data']['output']
+                                    print(agent.name, 'result', result)
+                            current_task = result
+                            
+                loop_count += 1
+
+            return current_task
+        except Exception as e:
+            logger.error(f"An error occurred: {e}")
+            return e
+
     def process_agent_or_swarm(
         self, name: str, task: str, img: str, is_last, *args, **kwargs
     ):