⚡ Live Playground: AI Dev Tool: Hono Cloudflare Workers D1

```python
# AI Dev Tool: FastAPI Pydantic v2 Micro-SaaS Starter
# ================================================
# A production-ready starter boilerplate for building micro-SaaS applications
# using FastAPI, Pydantic v2, and PostgreSQL Vector Search Extension.

from fastapi import FastAPI, Depends
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from pydantic import BaseModel
from typing import List
import psycopg2
from psycopg2 import Error
from psycopg2.extras import DictCursor
import uvicorn

# Initialize the FastAPI application
app = FastAPI()

# Define the security scheme for authentication
security = HTTPBearer()

# Define the Pydantic model for user authentication
class UserAuth(BaseModel):
    username: str
    password: str

# Define the Pydantic model for vector search query
class VectorSearchQuery(BaseModel):
    query: str
    limit: int = 10

# Establish a connection to the PostgreSQL database
def get_db_connection():
    try:
        connection = psycopg2.connect(
            dbname="mydatabase",
            user="myuser",
            password="mypassword",
            host="localhost",
            port="5432"
        )
        return connection
    except Error
⚡ Live Code Sandbox: AI Dev Tool: Hono Cloudflare Workers D1
