开源模型应用落地-FastAPI-助力模型交互-WebSocket篇（五）

import uvicorn
import os

from typing import annotated
from fastapi import (
    depends,
    fastapi,
    websocket,
    websocketexception,
    websocketdisconnect,
    status,
)
from langchain.agents import create_structured_chat_agent, agentexecutor
from langchain_community.utilities import serpapiwrapper

from langchain_core.prompts import chatprompttemplate, systemmessageprompttemplate, humanmessageprompttemplate
from langchain_core.tools import tool
from langchain_openai import chatopenai

os.environ["openai_api_key"] = 'sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'    #你的open ai key
os.environ["serpapi_api_key"] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"


class connectionmanager:
    def __init__(self):
        self.active_connections: list[websocket] = []

    async def connect(self, websocket: websocket):
        await websocket.accept()
        self.active_connections.append(websocket)

    def disconnect(self, websocket: websocket):
        self.active_connections.remove(websocket)

    async def send_personal_message(self, message: str, websocket: websocket):
        await websocket.send_text(message)

    async def broadcast(self, message: str):
        for connection in self.active_connections:
            await connection.send_text(message)

manager = connectionmanager()

app = fastapi()

async def authenticate(
    websocket: websocket,
    userid: str,
    secret: str,
):
    if userid is none or secret is none:
        raise websocketexception(code=status.ws_1008_policy_violation)

    print(f'userid: {userid},secret: {secret}')
    if '12345' == userid and 'xxxxxxxxxxxxxxxxxxxxxxxxxx' == secret:
        return 'pass'
    else:
        return 'fail'

@tool
def search(query:str):
    """只有需要了解实时信息或不知道的事情的时候才会使用这个工具，需要传入要搜索的内容。"""
    serp = serpapiwrapper()
    result = serp.run(query)
    print("实时搜索结果:", result)
    return result


def get_prompt():
    template='''
    respond to the human as helpfully and accurately as possible. you have access to the following tools:
    
    {tools}
    
    use a json blob to specify a tool by providing an action key (tool name) and an action_input key (tool input).
    
    valid "action" values: "final answer" or {tool_names}
    
    provide only one action per $json_blob, as shown:
    
    ```
    
    {{
    
      "action": $tool_name,
    
      "action_input": $input
    
    }}
    
    ```
    
    follow this format:
    
    question: input question to answer
    
    thought: consider previous and subsequent steps
    
    action:
    
    ```
    
    $json_blob
    
    ```
    
    observation: action result
    
    ... (repeat thought/action/observation n times)
    
    thought: i know what to respond
    
    action:
    
    ```
    
    {{
    
      "action": "final answer",
    
      "action_input": "final response to human"
    
    }}
    
    begin! reminder to always respond with a valid json blob of a single action. use tools if necessary. respond directly if appropriate. format is action:```$json_blob```then observation
    '''
    system_message_prompt = systemmessageprompttemplate.from_template(template)
    human_template='''
    {input}
    
    {agent_scratchpad}
    
     (reminder to respond in a json blob no matter what)
    '''
    human_message_prompt = humanmessageprompttemplate.from_template(human_template)
    prompt = chatprompttemplate.from_messages([system_message_prompt, human_message_prompt])

    return prompt

async def chat(query):
    global llm,tools
    agent = create_structured_chat_agent(
        llm, tools, get_prompt()
    )

    agent_executor = agentexecutor(agent=agent, tools=tools, verbose=true, handle_parsing_errors=true)

    result = agent_executor.invoke({"input": query})
    print(result['output'])
    yield result['output']

@app.websocket("/ws")
async def websocket_endpoint(*,websocket: websocket,userid: str,permission: annotated[str, depends(authenticate)],):
    await manager.connect(websocket)
    try:
        while true:
            text = await websocket.receive_text()

            if 'fail' == permission:
                await manager.send_personal_message(
                    f"authentication failed", websocket
                )
            else:
                if text is not none and len(text) > 0:
                    async for msg in chat(text):
                        await manager.send_personal_message(msg, websocket)

    except websocketdisconnect:
        manager.disconnect(websocket)
        print(f"client #{userid} left the chat")
        await manager.broadcast(f"client #{userid} left the chat")

if __name__ == '__main__':
    tools = [search]
    llm = chatopenai(model="gpt-3.5-turbo", temperature=0, max_tokens=512)
    uvicorn.run(app, host='0.0.0.0',port=7777)

<!doctype html>
<html>
    <head>
        <title>chat</title>
    </head>
    <body>
        <h1>websocket chat</h1>
        <form action="" onsubmit="sendmessage(event)">
            <label>userid: <input type="text" id="userid" autocomplete="off" value="12345"/></label>
            <label>secret: <input type="text" id="secret" autocomplete="off" value="xxxxxxxxxxxxxxxxxxxxxxxxxx"/></label>
            <br/>
            <button onclick="connect(event)">connect</button>
            <hr>
            <label>message: <input type="text" id="messagetext" autocomplete="off"/></label>
            <button>send</button>
        </form>
        <ul id='messages'>
        </ul>
        <script>
            var ws = null;
            function connect(event) {
                var userid = document.getelementbyid("userid")
                var secret = document.getelementbyid("secret")
                ws = new websocket("ws://localhost:7777/ws?userid="+userid.value+"&secret=" + secret.value);
                ws.onmessage = function(event) {
                    var messages = document.getelementbyid('messages')
                    var message = document.createelement('li')
                    var content = document.createtextnode(event.data)
                    message.appendchild(content)
                    messages.appendchild(message)
                };
                event.preventdefault()
            }
            function sendmessage(event) {
                var input = document.getelementbyid("messagetext")
                ws.send(input.value)
                input.value = ''
                event.preventdefault()
            }
        </script>
    </body>
</html>