Resolve issues pertaining to main module reloading mechanisms internal to Agno/agent-ui

Fixes #8

scripts/agno_agent.py

@@ -1,82 +1,21 @@
-import argparse
-import os
-from logging import Logger
-from pathlib import Path
-
-from agno.agent.agent import Agent
-from agno.memory.agent import AgentMemory
 from agno.models.anthropic.claude import Claude
 from agno.models.google.gemini import Gemini
 from agno.playground.playground import Playground
 from agno.playground.serve import serve_playground_app
-from agno.storage.sqlite import SqliteStorage
-from dotenv import load_dotenv
 from sensai.util import logging
 from sensai.util.helper import mark_used
 
-from serena.agent import SerenaAgent
-from serena.agno import SerenaAgnoToolkit
+from serena.agno import SerenaAgnoAgentProvider
 
 mark_used(Gemini, Claude)
 
-os.chdir(Path(__file__).parent)
-Logger.root.setLevel(logging.INFO)
+logging.configure(level=logging.INFO)
 
-load_dotenv()
-
-
-parser = argparse.ArgumentParser(description="Serena coding assistant")
-parser.add_argument("--project-file", required=True, help="Path to the project file, either absolute or relative to the root directory")
-args = parser.parse_args()
-
-project_file = Path(args.project_file).resolve()
-# If project file path is relative, make it absolute by joining with project root
-if not project_file.is_absolute():
-    # Get the project root directory (parent of scripts directory)
-    project_root = Path(__file__).parent.parent
-    project_file = project_root / args.project_file
-
-# Ensure the path is normalized and absolute
-project_file = project_file.resolve()
-
-
-serena_agent = SerenaAgent(str(project_file), start_language_server=True)
-
-# Even though we don't want to keep history between sessions,
-# for the agno ui to work as a conversation, we a persistent storage on disk
-# This storage should be deleted between sessions.
-# Note that this might collide with custom options for the agent, like adding vector-search based tools.
-# See here for an explanation: https://www.reddit.com/r/agno/comments/1jk6qea/regarding_the_built_in_memory/
-sql_db_path = Path("tmp") / "agent_storage.db"
-sql_db_path.parent.mkdir(exist_ok=True)
-# delete the db file if it exists
-if sql_db_path.exists():
-    sql_db_path.unlink()
-
-# model = Claude(id="claude-3-7-sonnet-20250219")
-# Or use any other model supported by agno, e.g. the newest Gemini:
-model = Gemini(id="gemini-2.5-pro-exp-03-25")
-
-agno_agent = Agent(
-    name="Serena",
-    model=model,
-    # See explanation above on why storage is needed
-    storage=SqliteStorage(table_name="serena_agent_sessions", db_file=str(sql_db_path)),
-    description="A fully-featured coding assistant",
-    tools=[SerenaAgnoToolkit(serena_agent)],  # type: ignore
-    # The tool calls will be shown in the UI anyway since whether to show them is configurable per tool
-    # To see detailed logs, you should use the serena logger (configure it in the project file path)
-    show_tool_calls=False,
-    markdown=True,
-    system_message=serena_agent.prompt_factory.create_system_prompt(),
-    telemetry=False,
-    memory=AgentMemory(),
-    add_history_to_messages=True,
-    num_history_responses=100,  # you might want to adjust this (expense vs. history awareness)
-)
-
-app = Playground(agents=[agno_agent]).get_app()
+# Define the model to use (see Agno documentation for supported models; these are just examples)
+model = Claude(id="claude-3-7-sonnet-20250219")
+# model = Gemini(id="gemini-2.5-pro-exp-03-25")
 
+app = Playground(agents=[SerenaAgnoAgentProvider.get_agent(model)]).get_app()
 
 if __name__ == "__main__":
     serve_playground_app("agno_agent:app", reload=False)

src/serena/__init__.py

@@ -1 +1,7 @@
 __version__ = "0.1.0-dev1"
+
+
+def serena_root_path() -> str:
+    from pathlib import Path
+
+    return str(Path(__file__).parent.parent.absolute())

src/serena/agno.py

@@ -1,9 +1,20 @@
+import argparse
 import logging
+import os
+import threading
+from pathlib import Path
 from typing import Any
 
+from agno.agent import Agent
+from agno.memory import AgentMemory
+from agno.models.base import Model
+from agno.storage.sqlite import SqliteStorage
 from agno.tools.function import Function
 from agno.tools.toolkit import Toolkit
+from dotenv import load_dotenv
+from sensai.util.logging import LogTime
 
+from serena import serena_root_path
 from serena.agent import SerenaAgent, Tool
 
 log = logging.getLogger(__name__)
@@ -89,3 +100,81 @@ class SerenaAgnoToolkit(Toolkit):
         function.entrypoint = entrypoint
         function.skip_entrypoint_processing = True
         return function
+
+
+class SerenaAgnoAgentProvider:
+    _agent: Agent | None = None
+    _lock = threading.Lock()
+
+    @classmethod
+    def get_agent(cls, model: Model) -> Agent:
+        """
+        Returns the singleton instance of the Serena agent or creates it with the given parameters if it doesn't exist.
+
+        NOTE: This is very ugly with poor separation of concerns, but the way in which the Agno UI works (reloading the
+            module that defines the `app` variable) essentially forces us to do something like this.
+
+        :param model: the large language model to use for the agent
+        :return: the agent instance
+        """
+        with cls._lock:
+            if cls._agent is not None:
+                return cls._agent
+
+            # change to Serena root
+            os.chdir(serena_root_path())
+
+            load_dotenv()
+
+            parser = argparse.ArgumentParser(description="Serena coding assistant")
+            parser.add_argument(
+                "--project-file", required=True, help="Path to the project file, either absolute or relative to the root directory"
+            )
+            args = parser.parse_args()
+
+            project_file = Path(args.project_file).resolve()
+            # If project file path is relative, make it absolute by joining with project root
+            if not project_file.is_absolute():
+                # Get the project root directory (parent of scripts directory)
+                project_root = Path(serena_root_path())
+                project_file = project_root / args.project_file
+
+            # Ensure the path is normalized and absolute
+            project_file = project_file.resolve()
+
+            with LogTime("Loading Serena agent"):
+                serena_agent = SerenaAgent(str(project_file), start_language_server=True)
+
+            # Even though we don't want to keep history between sessions,
+            # for agno-ui to work as a conversation, we use a persistent storage on disk.
+            # This storage should be deleted between sessions.
+            # Note that this might collide with custom options for the agent, like adding vector-search based tools.
+            # See here for an explanation: https://www.reddit.com/r/agno/comments/1jk6qea/regarding_the_built_in_memory/
+            sql_db_path = (Path("temp") / "agno_agent_storage.db").absolute()
+            sql_db_path.parent.mkdir(exist_ok=True)
+            # delete the db file if it exists
+            log.info(f"Deleting DB from PID {os.getpid()}")
+            if sql_db_path.exists():
+                sql_db_path.unlink()
+
+            agno_agent = Agent(
+                name="Serena",
+                model=model,
+                # See explanation above on why storage is needed
+                storage=SqliteStorage(table_name="serena_agent_sessions", db_file=str(sql_db_path)),
+                description="A fully-featured coding assistant",
+                tools=[SerenaAgnoToolkit(serena_agent)],
+                # The tool calls will be shown in the UI anyway since whether to show them is configurable per tool
+                # To see detailed logs, you should use the serena logger (configure it in the project file path)
+                show_tool_calls=False,
+                markdown=True,
+                system_message=serena_agent.prompt_factory.create_system_prompt(),
+                telemetry=False,
+                memory=AgentMemory(),
+                add_history_to_messages=True,
+                num_history_responses=100,  # you might want to adjust this (expense vs. history awareness)
+            )
+            cls._agent = agno_agent
+            log.info(f"Agent instantiated: {agno_agent}")
+
+        return agno_agent