[WIP] Langchain demo (#374)

# Motivation

<!-- Why is this change necessary? -->

# Content

<!-- Please include a summary of the change -->

# Testing

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# Please check the following before marking your PR as ready for review

- [ ] I have added tests for my changes
- [ ] I have updated the documentation or added new documentation as
needed

---------

Co-authored-by: jayhack <[email protected]>

Author: jayhack

pyproject.toml

@@ -62,6 +62,9 @@ dependencies = [
   "tomlkit>=0.13.2",
   "python-semantic-release",
   "uvicorn[standard]>=0.30.0",
+  "langchain[openai]",
+  "langchain_core",
+  "langchain_openai",
 ]
 
 license = { text = "Apache-2.0" }
@@ -146,6 +149,7 @@ dev-dependencies = [
   "pytest-asyncio<1.0.0,>=0.21.1",
   "loguru>=0.7.3",
   "httpx<0.28.2,>=0.28.1",
+  "jupyterlab>=4.3.5",
 ]
 
 

src/codegen/extensions/__init__.py

@@ -0,0 +1,54 @@
+"""Langchain tools for workspace operations."""
+
+from langchain.tools import BaseTool
+
+from codegen import Codebase
+
+from .tools import (
+    CommitTool,
+    CreateFileTool,
+    DeleteFileTool,
+    EditFileTool,
+    ListDirectoryTool,
+    RevealSymbolTool,
+    SearchTool,
+    SemanticEditTool,
+    ViewFileTool,
+)
+
+__all__ = [
+    # Tool classes
+    "CommitTool",
+    "CreateFileTool",
+    "DeleteFileTool",
+    "EditFileTool",
+    "ListDirectoryTool",
+    "RevealSymbolTool",
+    "SearchTool",
+    "SemanticEditTool",
+    "ViewFileTool",
+    # Helper functions
+    "get_workspace_tools",
+]
+
+
+def get_workspace_tools(codebase: Codebase) -> list[BaseTool]:
+    """Get all workspace tools initialized with a codebase.
+
+    Args:
+        codebase: The codebase to operate on
+
+    Returns:
+        List of initialized Langchain tools
+    """
+    return [
+        ViewFileTool(codebase),
+        ListDirectoryTool(codebase),
+        SearchTool(codebase),
+        EditFileTool(codebase),
+        CreateFileTool(codebase),
+        DeleteFileTool(codebase),
+        CommitTool(codebase),
+        RevealSymbolTool(codebase),
+        SemanticEditTool(codebase),
+    ]

src/codegen/extensions/langchain/__init__.py

@@ -0,0 +1,109 @@
+"""Demo implementation of an agent with Codegen tools."""
+
+from langchain import hub
+from langchain.agents import AgentExecutor
+from langchain.agents.openai_functions_agent.base import OpenAIFunctionsAgent
+from langchain_core.chat_history import ChatMessageHistory
+from langchain_core.runnables.history import RunnableWithMessageHistory
+from langchain_openai import ChatOpenAI
+
+from codegen import Codebase
+from codegen.sdk.enums import ProgrammingLanguage
+
+from .tools import (
+    CommitTool,
+    CreateFileTool,
+    DeleteFileTool,
+    EditFileTool,
+    ListDirectoryTool,
+    MoveSymbolTool,
+    RenameFileTool,
+    RevealSymbolTool,
+    SearchTool,
+    SemanticEditTool,
+    ViewFileTool,
+)
+
+
+def create_codebase_agent(
+    codebase: Codebase,
+    model_name: str = "gpt-4",
+    temperature: float = 0,
+    verbose: bool = True,
+) -> RunnableWithMessageHistory:
+    """Create an agent with all codebase tools.
+
+    Args:
+        codebase: The codebase to operate on
+        model_name: Name of the model to use (default: gpt-4)
+        temperature: Model temperature (default: 0)
+        verbose: Whether to print agent's thought process (default: True)
+
+    Returns:
+        Initialized agent with message history
+    """
+    # Initialize language model
+    llm = ChatOpenAI(
+        model_name=model_name,
+        temperature=temperature,
+    )
+
+    # Get all codebase tools
+    tools = [
+        ViewFileTool(codebase),
+        ListDirectoryTool(codebase),
+        SearchTool(codebase),
+        EditFileTool(codebase),
+        CreateFileTool(codebase),
+        DeleteFileTool(codebase),
+        RenameFileTool(codebase),
+        MoveSymbolTool(codebase),
+        RevealSymbolTool(codebase),
+        SemanticEditTool(codebase),
+        CommitTool(codebase),
+    ]
+
+    # Get the prompt to use
+    prompt = hub.pull("hwchase17/openai-functions-agent")
+
+    # Create the agent
+    agent = OpenAIFunctionsAgent(
+        llm=llm,
+        tools=tools,
+        prompt=prompt,
+    )
+
+    # Create the agent executor
+    agent_executor = AgentExecutor(
+        agent=agent,
+        tools=tools,
+        verbose=verbose,
+    )
+
+    # Create message history handler
+    message_history = ChatMessageHistory()
+
+    # Wrap with message history
+    return RunnableWithMessageHistory(
+        agent_executor,
+        lambda session_id: message_history,
+        input_messages_key="input",
+        history_messages_key="chat_history",
+    )
+
+
+if __name__ == "__main__":
+    # Initialize codebase
+    print("Initializing codebase...")
+    codebase = Codebase.from_repo("fastapi/fastapi", programming_language=ProgrammingLanguage.PYTHON)
+
+    # Create agent with history
+    print("Creating agent...")
+    agent = create_codebase_agent(codebase)
+
+    print("\nAsking agent to analyze symbol relationships...")
+    result = agent.invoke(
+        {"input": "What are the dependencies of the reveal_symbol function?"},
+        config={"configurable": {"session_id": "demo"}},
+    )
+    print("Messages:", result["messages"])