feat: scaffold agent backend

* Update index.py

* add dotenv

* Update index.py

* Update index.py

* streaming

* cleanup

* cleanup

* update default prompt

* lint

* add .env.local

* Delete .env

agent-frontend/.env.local

@@ -0,0 +1,8 @@
+NEXT_PUBLIC_ONCHAINKIT_PROJECT_NAME=agent-frontend
+NEXT_PUBLIC_ONCHAINKIT_CDP_KEY=
+NEXT_PUBLIC_ONCHAINKIT_WALLET_CONFIG=smartWalletOnly
+CDP_API_KEY_NAME=
+CDP_API_KEY_PRIVATE_KEY=""
+OPENAI_API_KEY=
+NETWORK_ID=base-sepolia
+CDP_WALLET_DATA={}

agent-frontend/.gitignore

@@ -22,9 +22,6 @@ npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
 
-# local env files
-.env*.local
-
 # vercel
 .vercel
 

agent-frontend/api/index.py

@@ -1,9 +1,142 @@
-from flask import Flask
+from flask import Flask, request, Response, stream_with_context, jsonify
+from dotenv import load_dotenv
+import os
+import sys
+import time
+import json
+from typing import Iterator
+
+from langchain_core.messages import HumanMessage
+from langchain_openai import ChatOpenAI
+from langgraph.checkpoint.memory import MemorySaver
+from langgraph.prebuilt import create_react_agent
+
+# Import CDP Agentkit Langchain Extension.
+from cdp_langchain.agent_toolkits import CdpToolkit
+from cdp_langchain.utils import CdpAgentkitWrapper
+
+load_dotenv()
 app = Flask(__name__)
 
-@app.route("/api/python")
-def hello_world():
-    return "<p>Hello, World!</p>"
+class InputValidationError(Exception):
+    """Custom exception for input validation errors"""
+    pass
+
+# Event types
+EVENT_TYPE_AGENT = "agent"
+EVENT_TYPE_COMPLETED = "completed"
+EVENT_TYPE_TOOLS = "tools"
+EVENT_TYPE_ERROR = "error"
+
+# Environment variable name for wallet data
+WALLET_DATA_ENV_VAR = "CDP_WALLET_DATA"
+
+def format_sse(data: str, event: str = None) -> str:
+    """Format data as SSE"""
+    response = {
+        "event": event,
+        "data": data
+    }
+    return json.dumps(response) + "\n"
+
+def initialize_agent():
+    """Initialize the agent with CDP Agentkit."""
+    # Initialize LLM.
+    llm = ChatOpenAI(model="gpt-4o-mini")
+
+    # Read wallet data from environment variable
+    wallet_data = os.getenv(WALLET_DATA_ENV_VAR)
+
+    print("Initialized CDP Agentkit with wallet data:", wallet_data)
+
+    # Configure CDP Agentkit Langchain Extension.
+    values = {}
+    if wallet_data is not None:
+        # If there is a wallet configuration in environment variables, use it
+        values = {"cdp_wallet_data": wallet_data}
+
+    agentkit = CdpAgentkitWrapper(**values)
+
+    # Export and store the updated wallet data back to environment variable
+    # wallet_data = agentkit.export_wallet()
+    # print("Exporting wallet data:", wallet_data)
+    # os.environ[WALLET_DATA_ENV_VAR] = wallet_data
+
+    # Initialize CDP Agentkit Toolkit and get tools.
+    cdp_toolkit = CdpToolkit.from_cdp_agentkit_wrapper(agentkit)
+    tools = cdp_toolkit.get_tools()
+
+    # Store buffered conversation history in memory.
+    memory = MemorySaver()
+    config = {"configurable": {"thread_id": "CDP Agentkit Chatbot Example!"}}
+
+    # Create ReAct Agent using the LLM and CDP Agentkit tools.
+    return create_react_agent(
+        llm,
+        tools=tools,
+        checkpointer=memory,
+        state_modifier="You are a helpful agent that can interact onchain on the Base Layer 2 using the Coinbase Developer Platform Agentkit. You are empowered to interact onchain using your tools. If you ever need funds, you can request them from the faucet. You can also deploy your own ERC-20 tokens, NFTs, and interact with them. If someone asks you to do something you can't do, you can say so, and encourage them to implement it themselves using the CDP SDK + Agentkit, recommend they go to docs.cdp.coinbase.com for more informaton.",
+    ), config
+
+# Autonomous Mode
+def run_agent(input, agent_executor, config) -> Iterator[str]:
+    """Run the agent and yield formatted SSE messages"""
+    try:
+        for chunk in agent_executor.stream(
+            {"messages": [HumanMessage(content=input)]}, config
+        ):
+            if "agent" in chunk:
+                content = chunk["agent"]["messages"][0].content
+                if content:
+                    yield format_sse(content, EVENT_TYPE_AGENT)
+            elif "tools" in chunk:
+                content = chunk["tools"]["messages"][0].content
+                if content:
+                    yield format_sse(content, EVENT_TYPE_TOOLS)
+    except Exception as e:
+        yield format_sse(f"Error: {str(e)}", EVENT_TYPE_ERROR)
+
+def run_inference(input: str = "Be creative and do something interesting on the blockchain. Choose an action or set of actions and execute it in a way that highlights your abilities.") -> Iterator[str]:
+    """Initialize agent, run inference and yield SSE responses"""
+    start_time = time.time()
+    print("Running agent...", flush=True)
+
+    try:
+        agent_executor, config = initialize_agent()
+        print(f"Agent init time: {time.time() - start_time:.2f} seconds", flush=True)
+
+        for response in run_agent(input, agent_executor=agent_executor, config=config):
+            yield response
+    except Exception as e:
+        print(f"Error during inference: {str(e)}", flush=True)
+        yield format_sse(f"Error: {str(e)}", EVENT_TYPE_ERROR)
+    finally:
+        print("Agent finished running.", flush=True)
+        yield format_sse("Agent finished", EVENT_TYPE_COMPLETED)
+
+
+@app.route("/api/chat", methods=['POST'])
+def chat():
+    try:
+        data = request.get_json()
+        if not data or 'input' not in data:
+            raise InputValidationError('Input must be provided')
+
+        return Response(
+            stream_with_context(run_inference(data['input'])),
+            mimetype='text/event-stream',
+            headers={
+                'Cache-Control': 'no-cache',
+                'Content-Type': 'text/event-stream',
+                'Connection': 'keep-alive',
+                'X-Accel-Buffering': 'no'
+            }
+        )
+    except InputValidationError as e:
+        return jsonify({'error': 'Invalid request: Missing required input'}), 400
+    except Exception as e:
+        app.logger.error(f"Unexpected error in chat endpoint: {str(e)}")
+        return jsonify({'error': 'An unexpected error occurred'}), 500
 
 if __name__ == "__main__":
     app.run(port="5328")

agent-frontend/pyproject.toml

@@ -15,6 +15,7 @@ pydantic = "^2.9.2"
 cdp-sdk = "^0.10.0"
 cdp-agentkit-core = {path = "../cdp-agentkit-core"}
 cdp-langchain = {path = "../cdp-langchain"}
+python-dotenv = "^1.0.1"
 
 [build-system]
 requires = ["poetry-core"]