feat: support workflow agents

Author: yaozheng-fang

veadk/agent.py

@@ -60,7 +60,6 @@ class Agent(LlmAgent):
     instruction: str = DEFAULT_INSTRUCTION
     """The instruction for the agent, such as principles of function calling."""
 
-    # factory
     model_name: str = getenv("MODEL_AGENT_NAME", DEFAULT_MODEL_AGENT_NAME)
     """The name of the model for agent running."""
 
@@ -122,7 +121,7 @@ def model_post_init(self, __context: Any) -> None:
                 self.after_model_callback.append(tracer.tracer_hook_after_model)
                 self.after_tool_callback.append(tracer.tracer_hook_after_tool)
 
-        logger.info(f"Agent `{self.name}` init done.")
+        logger.info(f"{self.__class__.__name__} `{self.name}` init done.")
         logger.debug(
             f"Agent: {self.model_dump(include={'name', 'model_name', 'model_api_base', 'tools', 'serve_url'})}"
         )

veadk/agents/loop_agent.py

@@ -0,0 +1,65 @@
+# Copyright (c) 2025 Beijing Volcano Engine Technology Co., Ltd. and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from google.adk.agents import LoopAgent as GoogleADKLoopAgent
+from google.adk.agents.base_agent import BaseAgent
+from pydantic import ConfigDict, Field
+from typing_extensions import Any
+
+from veadk.prompts.agent_default_prompt import DEFAULT_DESCRIPTION, DEFAULT_INSTRUCTION
+from veadk.tracing.base_tracer import BaseTracer
+from veadk.utils.logger import get_logger
+from veadk.utils.patches import patch_asyncio
+
+patch_asyncio()
+logger = get_logger(__name__)
+
+
+class LoopAgent(GoogleADKLoopAgent):
+    """LLM-based Agent with Volcengine capabilities."""
+
+    model_config = ConfigDict(arbitrary_types_allowed=True, extra="allow")
+    """The model config"""
+
+    name: str = "veLoopAgent"
+    """The name of the agent."""
+
+    description: str = DEFAULT_DESCRIPTION
+    """The description of the agent. This will be helpful in A2A scenario."""
+
+    instruction: str = DEFAULT_INSTRUCTION
+    """The instruction for the agent, such as principles of function calling."""
+
+    sub_agents: list[BaseAgent] = Field(default_factory=list, exclude=True)
+    """The sub agents provided to agent."""
+
+    tracers: list[BaseTracer] = []
+    """The tracers provided to agent."""
+
+    def model_post_init(self, __context: Any) -> None:
+        super().model_post_init(None)  # for sub_agents init
+
+        if self.tracers:
+            for tracer in self.tracers:
+                for sub_agent in self.sub_agents:
+                    try:
+                        tracer.do_hooks(sub_agent)
+                    except Exception as e:
+                        logger.warning(
+                            f"Failed to add hooks for sub_agent `{sub_agent.name}`: {e}"
+                        )
+
+        logger.info(f"{self.__class__.__name__} `{self.name}` init done.")

veadk/agents/parallel_agent.py

@@ -0,0 +1,65 @@
+# Copyright (c) 2025 Beijing Volcano Engine Technology Co., Ltd. and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from google.adk.agents import ParallelAgent as GoogleADKParallelAgent
+from google.adk.agents.base_agent import BaseAgent
+from pydantic import ConfigDict, Field
+from typing_extensions import Any
+
+from veadk.prompts.agent_default_prompt import DEFAULT_DESCRIPTION, DEFAULT_INSTRUCTION
+from veadk.tracing.base_tracer import BaseTracer
+from veadk.utils.logger import get_logger
+from veadk.utils.patches import patch_asyncio
+
+patch_asyncio()
+logger = get_logger(__name__)
+
+
+class ParallelAgent(GoogleADKParallelAgent):
+    """LLM-based Agent with Volcengine capabilities."""
+
+    model_config = ConfigDict(arbitrary_types_allowed=True, extra="allow")
+    """The model config"""
+
+    name: str = "veParallelAgent"
+    """The name of the agent."""
+
+    description: str = DEFAULT_DESCRIPTION
+    """The description of the agent. This will be helpful in A2A scenario."""
+
+    instruction: str = DEFAULT_INSTRUCTION
+    """The instruction for the agent, such as principles of function calling."""
+
+    sub_agents: list[BaseAgent] = Field(default_factory=list, exclude=True)
+    """The sub agents provided to agent."""
+
+    tracers: list[BaseTracer] = []
+    """The tracers provided to agent."""
+
+    def model_post_init(self, __context: Any) -> None:
+        super().model_post_init(None)  # for sub_agents init
+
+        if self.tracers:
+            for tracer in self.tracers:
+                for sub_agent in self.sub_agents:
+                    try:
+                        tracer.do_hooks(sub_agent)
+                    except Exception as e:
+                        logger.warning(
+                            f"Failed to add hooks for sub_agent `{sub_agent.name}`: {e}"
+                        )
+
+        logger.info(f"{self.__class__.__name__} `{self.name}` init done.")

veadk/agents/sequential_agent.py

@@ -0,0 +1,65 @@
+# Copyright (c) 2025 Beijing Volcano Engine Technology Co., Ltd. and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from google.adk.agents import SequentialAgent as GoogleADKSequentialAgent
+from google.adk.agents.base_agent import BaseAgent
+from pydantic import ConfigDict, Field
+from typing_extensions import Any
+
+from veadk.prompts.agent_default_prompt import DEFAULT_DESCRIPTION, DEFAULT_INSTRUCTION
+from veadk.tracing.base_tracer import BaseTracer
+from veadk.utils.logger import get_logger
+from veadk.utils.patches import patch_asyncio
+
+patch_asyncio()
+logger = get_logger(__name__)
+
+
+class SequentialAgent(GoogleADKSequentialAgent):
+    """LLM-based Agent with Volcengine capabilities."""
+
+    model_config = ConfigDict(arbitrary_types_allowed=True, extra="allow")
+    """The model config"""
+
+    name: str = "veSequentialAgent"
+    """The name of the agent."""
+
+    description: str = DEFAULT_DESCRIPTION
+    """The description of the agent. This will be helpful in A2A scenario."""
+
+    instruction: str = DEFAULT_INSTRUCTION
+    """The instruction for the agent, such as principles of function calling."""
+
+    sub_agents: list[BaseAgent] = Field(default_factory=list, exclude=True)
+    """The sub agents provided to agent."""
+
+    tracers: list[BaseTracer] = []
+    """The tracers provided to agent."""
+
+    def model_post_init(self, __context: Any) -> None:
+        super().model_post_init(None)  # for sub_agents init
+
+        if self.tracers:
+            for tracer in self.tracers:
+                for sub_agent in self.sub_agents:
+                    try:
+                        tracer.do_hooks(sub_agent)
+                    except Exception as e:
+                        logger.warning(
+                            f"Failed to add hooks for sub_agent `{sub_agent.name}`: {e}"
+                        )
+
+        logger.info(f"{self.__class__.__name__} `{self.name}` init done.")

veadk/runner.py

@@ -21,6 +21,9 @@
 
 from veadk.a2a.remote_ve_agent import RemoteVeAgent
 from veadk.agent import Agent
+from veadk.agents.loop_agent import LoopAgent
+from veadk.agents.parallel_agent import ParallelAgent
+from veadk.agents.sequential_agent import SequentialAgent
 from veadk.evaluation import EvalSetRecorder
 from veadk.memory.short_term_memory import ShortTermMemory
 from veadk.types import MediaMessage
@@ -38,11 +41,13 @@
     list[MediaMessage | str],  # multiple turn prompt with media and text-based prompt
 ]
 
+VeAgent = Union[Agent, RemoteVeAgent, SequentialAgent, ParallelAgent, LoopAgent]
+
 
 class Runner:
     def __init__(
         self,
-        agent: Agent | RemoteVeAgent,
+        agent: VeAgent,
         short_term_memory: ShortTermMemory,
         app_name: str = "veadk_default_app",
         user_id: str = "veadk_default_user",
@@ -166,10 +171,12 @@ async def run(
         return final_output
 
     def save_tracing_file(self, session_id: str) -> str:
-        if not isinstance(self.agent, Agent):
+        if not isinstance(
+            self.agent, (Agent, SequentialAgent, ParallelAgent, LoopAgent)
+        ):
             logger.warning(
                 (
-                    "The agent is not an instance of VeADK Agent, cannot save tracing file."
+                    "The agent is not an instance of Agent, SequentialAgent, ParallelAgent or LoopAgent, cannot save tracing file."
                 )
             )
             return ""

veadk/types.py

@@ -15,6 +15,9 @@
 from pydantic import BaseModel, Field
 
 from veadk.agent import Agent
+from veadk.agents.loop_agent import LoopAgent
+from veadk.agents.parallel_agent import ParallelAgent
+from veadk.agents.sequential_agent import SequentialAgent
 from veadk.memory.short_term_memory import ShortTermMemory
 
 
@@ -35,7 +38,9 @@ class AgentRunConfig(BaseModel):
         default="veadk_vefaas_app", description="The name of the application"
     )
 
-    agent: Agent = Field(..., description="The root agent instance")
+    agent: Agent | SequentialAgent | ParallelAgent | LoopAgent = Field(
+        ..., description="The root agent instance"
+    )
 
     short_term_memory: ShortTermMemory = Field(
         default_factory=ShortTermMemory, description="The short-term memory instance"