diff --git a/app/__pycache__/config.cpython-313.pyc b/app/__pycache__/config.cpython-313.pyc
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index 0000000..257ba84
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diff --git a/app/__pycache__/db.cpython-313.pyc b/app/__pycache__/db.cpython-313.pyc
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diff --git a/app/__pycache__/main.cpython-313.pyc b/app/__pycache__/main.cpython-313.pyc
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diff --git a/app/config.py b/app/config.py
new file mode 100644
index 0000000..bcc64cd
--- /dev/null
+++ b/app/config.py
@@ -0,0 +1,48 @@
+# app/config.py
+import os
+from functools import lru_cache
+
+
+class Settings:
+    """
+    后端配置：
+    - APP_ENV: dev / prod
+    - DB_*: 数据库连接参数
+    - 默认库：dev 用 LLZQ-test；prod 用 LLZQ
+    """
+
+    def __init__(self) -> None:
+        self.app_env = os.getenv("APP_ENV", "dev").lower()
+
+        self.db_host = os.getenv("DB_HOST", "127.0.0.1")
+        self.db_port = int(os.getenv("DB_PORT", "5432"))
+        self.db_user = os.getenv("DB_USER", "local-Python")
+        self.db_password = os.getenv("DB_PASSWORD", "")
+
+        # 默认连接的库，根据 APP_ENV 决定
+        if self.app_env == "prod":
+            self.db_name_default = "LLZQ"
+        else:
+            self.db_name_default = "LLZQ-test"
+
+        self.db_schema = os.getenv("DB_SCHEMA", "XCX")
+
+    def resolve_db_name(self, env_header: str | None) -> str:
+        """
+        根据前端传来的 X-LLZQ-Env 决定最终使用哪个 DB：
+        - "prod" => LLZQ
+        - 其它/为空 => LLZQ-test
+        """
+        if env_header is None:
+            return self.db_name_default
+
+        env_header = env_header.lower()
+        if env_header == "prod":
+            return "LLZQ"
+        else:
+            return "LLZQ-test"
+
+
+@lru_cache()
+def get_settings() -> Settings:
+    return Settings()
\ No newline at end of file
diff --git a/app/db.py b/app/db.py
new file mode 100644
index 0000000..614d9ae
--- /dev/null
+++ b/app/db.py
@@ -0,0 +1,42 @@
+# app/db.py
+from contextlib import contextmanager
+from typing import Iterator
+
+import psycopg2
+from psycopg2.extras import RealDictCursor
+
+from .config import get_settings
+
+
+@contextmanager
+def get_connection(db_name: str) -> Iterator[psycopg2.extensions.connection]:
+    """
+    简单连接管理：每次请求开一个连接，用完就关。
+    当前访问量不高，这种写法足够。
+    """
+    settings = get_settings()
+    conn = psycopg2.connect(
+        host=settings.db_host,
+        port=settings.db_port,
+        user=settings.db_user,
+        password=settings.db_password,
+        dbname=db_name,
+    )
+    try:
+        # 设置 schema = XCX
+        with conn.cursor() as cur:
+            cur.execute("SET search_path TO %s;", (settings.db_schema,))
+        yield conn
+    finally:
+        conn.close()
+
+
+def check_health(db_name: str) -> bool:
+    """
+    DB 健康检查：SELECT 1
+    """
+    with get_connection(db_name) as conn:
+        with conn.cursor(cursor_factory=RealDictCursor) as cur:
+            cur.execute("SELECT 1 AS v;")
+            row = cur.fetchone()
+            return row["v"] == 1
\ No newline at end of file
diff --git a/app/main.py b/app/main.py
new file mode 100644
index 0000000..62cf7c4
--- /dev/null
+++ b/app/main.py
@@ -0,0 +1,51 @@
+# app/main.py
+from fastapi import FastAPI, Header, Depends
+
+from .config import get_settings
+from .db import check_health
+
+app = FastAPI(
+    title="LLZQ Backend",
+    version="0.1.0",
+)
+
+
+def resolve_db_name(x_llzq_env: str | None = Header(default=None, alias="X-LLZQ-Env")) -> str:
+    """
+    从请求头 X-LLZQ-Env 中解析要用的 DB 名。
+    """
+    settings = get_settings()
+    return settings.resolve_db_name(x_llzq_env)
+
+
+@app.get("/api/ping")
+def ping(db_name: str = Depends(resolve_db_name)):
+    """
+    最简单调通接口：
+    - 返回当前后端环境
+    - 返回实际连接的 DB 名
+    - 简单做一个 DB 健康检查
+    """
+    settings = get_settings()
+    ok = False
+    error_msg = None
+
+    try:
+        ok = check_health(db_name)
+    except Exception as e:
+        error_msg = str(e)
+
+    return {
+        "ok": ok,
+        "app_env": settings.app_env,
+        "db": db_name,
+        "error": error_msg,
+    }
+
+
+@app.get("/api/healthz")
+def healthz():
+    """
+    给 Nginx / 监控用的探活接口，不查 DB。
+    """
+    return {"status": "ok"}
\ No newline at end of file
diff --git a/logs/llzq_api_8000.0.err.log b/logs/llzq_api_8000.0.err.log
new file mode 100644
index 0000000..395d577
--- /dev/null
+++ b/logs/llzq_api_8000.0.err.log
@@ -0,0 +1 @@
+INFO:     Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
diff --git a/logs/llzq_api_8000.0.out.log b/logs/llzq_api_8000.0.out.log
new file mode 100644
index 0000000..25b182d
--- /dev/null
+++ b/logs/llzq_api_8000.0.out.log
@@ -0,0 +1 @@
+INFO:     100.64.0.1:59692 - "GET /api/ping HTTP/1.1" 200 OK
diff --git a/logs/llzq_api_8000.1.err.log b/logs/llzq_api_8000.1.err.log
new file mode 100644
index 0000000..bca2c3e
--- /dev/null
+++ b/logs/llzq_api_8000.1.err.log
@@ -0,0 +1 @@
+INFO:     Application startup complete.
diff --git a/logs/llzq_api_8000.1.out.log b/logs/llzq_api_8000.1.out.log
new file mode 100644
index 0000000..deeb384
--- /dev/null
+++ b/logs/llzq_api_8000.1.out.log
@@ -0,0 +1 @@
+INFO:     100.64.0.1:59690 - "GET /api/healthz HTTP/1.1" 200 OK
diff --git a/logs/llzq_api_8000.2.err.log b/logs/llzq_api_8000.2.err.log
new file mode 100644
index 0000000..7f800df
--- /dev/null
+++ b/logs/llzq_api_8000.2.err.log
@@ -0,0 +1 @@
+INFO:     Waiting for application startup.
diff --git a/logs/llzq_api_8000.2.out.log b/logs/llzq_api_8000.2.out.log
new file mode 100644
index 0000000..420732f
--- /dev/null
+++ b/logs/llzq_api_8000.2.out.log
@@ -0,0 +1 @@
+INFO:     100.64.0.1:60268 - "GET /api/ping HTTP/1.1" 200 OK
diff --git a/logs/llzq_api_8000.3.err.log b/logs/llzq_api_8000.3.err.log
new file mode 100644
index 0000000..8396257
--- /dev/null
+++ b/logs/llzq_api_8000.3.err.log
@@ -0,0 +1 @@
+INFO:     Started server process [11432]
diff --git a/logs/llzq_api_8000.3.out.log b/logs/llzq_api_8000.3.out.log
new file mode 100644
index 0000000..1ccd2bf
--- /dev/null
+++ b/logs/llzq_api_8000.3.out.log
@@ -0,0 +1 @@
+INFO:     100.64.0.1:60266 - "GET /api/healthz HTTP/1.1" 200 OK
diff --git a/logs/llzq_api_8000.4.out.log b/logs/llzq_api_8000.4.out.log
new file mode 100644
index 0000000..e3d21f8
--- /dev/null
+++ b/logs/llzq_api_8000.4.out.log
@@ -0,0 +1 @@
+INFO:     127.0.0.1:56463 - "GET /api/ping HTTP/1.1" 200 OK
diff --git a/logs/llzq_api_8000.5.out.log b/logs/llzq_api_8000.5.out.log
new file mode 100644
index 0000000..6e25fb7
--- /dev/null
+++ b/logs/llzq_api_8000.5.out.log
@@ -0,0 +1 @@
+INFO:     127.0.0.1:56463 - "GET /api/healthz HTTP/1.1" 200 OK
diff --git a/logs/llzq_api_8000.err.log b/logs/llzq_api_8000.err.log
new file mode 100644
index 0000000..e69de29
diff --git a/logs/llzq_api_8000.out.log b/logs/llzq_api_8000.out.log
new file mode 100644
index 0000000..e69de29
diff --git a/logs/llzq_api_8000.wrapper.log b/logs/llzq_api_8000.wrapper.log
new file mode 100644
index 0000000..2ee775f
--- /dev/null
+++ b/logs/llzq_api_8000.wrapper.log
@@ -0,0 +1,11 @@
+2025-11-19 04:51:16,714 DEBUG - Starting WinSW in console mode
+2025-11-19 04:51:16,728 INFO  - Installing service 'LLZQ API (FastAPI 8000) (llzq-api-8000)'...
+2025-11-19 04:51:16,755 INFO  - Service 'LLZQ API (FastAPI 8000) (llzq-api-8000)' was installed successfully.
+2025-11-19 04:51:16,909 DEBUG - Starting WinSW in console mode
+2025-11-19 04:51:16,925 INFO  - Starting service 'LLZQ API (FastAPI 8000) (llzq-api-8000)'...
+2025-11-19 04:51:17,008 DEBUG - Starting WinSW in service mode
+2025-11-19 04:51:17,017 INFO  - Service 'LLZQ API (FastAPI 8000) (llzq-api-8000)' started successfully.
+2025-11-19 04:51:17,024 INFO  - Starting D:\LLZQ\LLZQ-server\.venv\Scripts\uvicorn.exe app.main:app --host 0.0.0.0 --port 8000
+2025-11-19 04:51:17,041 INFO  - Started process 10844
+2025-11-19 04:51:17,047 DEBUG - Forwarding logs of the process System.Diagnostics.Process (uvicorn) to WinSW.SizeBasedRollingLogAppender
+2025-11-19 04:51:18,533 DEBUG - Starting WinSW in console mode