diff --git a/app/api/routers/auth.py b/app/api/routers/auth.py
index 3c1a470..fd2fcdf 100644
--- a/app/api/routers/auth.py
+++ b/app/api/routers/auth.py
@@ -12,6 +12,7 @@ import re
 import secrets
 
 from fastapi import APIRouter, Depends, HTTPException, Request
+from fastapi.responses import HTMLResponse
 
 from ... import config
 from ..dependencies import get_current_user, get_db, extract_bearer_token
@@ -31,12 +32,23 @@ from ..schemas.auth import (
     VerifyResponse,
     WxLoginRequest,
     WxPhoneRequest,
+    MpQrConfirmRequest,
 )
 from ...infrastructure.repositories import Database
 from ...services import sms, wechat
 
 router = APIRouter(prefix="/auth", tags=["auth"])
 
+# 扫码登录会话（内存 + TTL；生产可换 Redis）
+wx_qr_store = wechat.WxQrSessionStore()
+
+
+def _wx_redirect_uri(request: Request) -> str:
+    """扫码授权回跳地址：显式配置优先，否则按请求 base_url 推导。"""
+    if config.WECHAT_QR_REDIRECT_URI:
+        return config.WECHAT_QR_REDIRECT_URI
+    return str(request.base_url).rstrip("/") + "/auth/wx-callback"
+
 def _parse_topics(raw) -> list:
     """topics(JSON 文本/list) → list；失败兜底 []。"""
     if not raw:
@@ -282,12 +294,18 @@ async def register(req: RegisterRequest, request: Request, db: Database = Depend
 
 @router.get("/status", response_model=AuthStatusResponse, summary="认证状态")
 async def auth_status(db: Database = Depends(get_db)):
-    """前端登录页据此判断是否展示登录表单。本期登录模式：账号密码 + 手机号验证码；微信扫码预留(未开放)。"""
+    """前端登录页据此展示登录方式。四种：账号密码 / 短信验证码 / 微信扫码 / 小程序扫码。"""
+    modes = ["password", "phone"]
+    if config.AUTH_WECHAT_QR:
+        modes.append("wechat")          # 微信开放平台扫码(OAuth)
+    if config.AUTH_WECHAT_LOGIN:
+        modes.append("miniprogram")     # 小程序扫码(wx.login → code2session)
     return AuthStatusResponse(
         enabled=config.AUTH_ENABLED,
         has_users=await db.users.has_users(),
-        login_modes=["password", "phone"] + (["wechat"] if config.AUTH_WECHAT_LOGIN else []),
+        login_modes=modes,
         wechat_login=config.AUTH_WECHAT_LOGIN,
+        wx_qr=config.AUTH_WECHAT_QR,
     )
 
 
@@ -465,7 +483,8 @@ async def phone_login(req: PhoneLoginRequest, request: Request, db: Database = D
     except sms.SmsError as exc:
         raise HTTPException(status_code=401, detail=str(exc))
 
-    user = await db.users.get_by_username(req.phone)
+    # 手机号唯一：既按「登录名=手机号」查，也按「已绑定手机」查（微信等身份绑了手机的用户）。
+    user = await db.users.find_by_phone(req.phone) or await db.users.get_by_username(req.phone)
     if user is None:
         user = await db.users.create(
             req.phone, password=secrets.token_hex(16),
@@ -537,7 +556,7 @@ async def wx_phone(req: WxPhoneRequest, db: Database = Depends(get_db)):
     user = await db.users.get_by_wx_openid(req.openid)
     if user is None:
         raise HTTPException(status_code=404, detail="微信账号不存在，请先 wx-login")
-    bound = await db.users.get_by_username(req.phone)
+    bound = await db.users.find_by_phone(req.phone) or await db.users.get_by_username(req.phone)
     if bound is not None and bound["id"] != user["id"]:
         raise HTTPException(status_code=409, detail="该手机号已绑定其它账号")
 
@@ -547,3 +566,165 @@ async def wx_phone(req: WxPhoneRequest, db: Database = Depends(get_db)):
         detail=f"wx bind phone {req.phone}", user_id=user["id"],
     )
     return {**await db.users.to_profile(fresh), "phone": fresh.get("phone", "")}
+
+
+# ===========================================================================
+# 微信开放平台扫码登录（标准 OAuth：qr_start → 扫码 → wx-callback → poll）
+# ===========================================================================
+
+
+async def _find_or_create_wx_user(
+    openid: str, request: Request, db: Database,
+) -> dict:
+    """按扫码登录的 openid（存 wx_openid）查找/创建用户（幂等，唯一）。"""
+    user = await db.users.get_by_wx_openid(openid)
+    if user is None:
+        user = await db.users.create(
+            f"wx_{openid[:24]}", password=secrets.token_hex(16),
+            wx_openid=openid, nickname="微信用户",
+            role="opc_member",
+            source=_client_source(request, "", "wx_openid"), auth_type="wx_openid",
+            register_ip=_client_ip(request),
+        )
+    if user.get("status") != "active":
+        raise HTTPException(status_code=403, detail="账号已禁用")
+    return user
+
+
+@router.get("/wx-qr/start", summary="发起微信扫码登录")
+async def wx_qr_start(request: Request, db: Database = Depends(get_db)):
+    """生成扫码登录会话：返回 scene + 授权链接(渲染二维码)。
+
+    - 前端把 ``qr_url`` 渲染成二维码展示；扫码后在微信内授权。
+    - 授权回跳 ``/auth/wx-callback``，前端轮询 ``/auth/wx-qr/poll?scene=`` 取令牌。
+    """
+    if not config.AUTH_WECHAT_QR:
+        raise HTTPException(status_code=503, detail="微信扫码登录未开启")
+    if not config.AUTH_ENABLED:
+        raise HTTPException(status_code=403, detail="认证未开启")
+    scene = wechat.new_scene()
+    redirect_uri = _wx_redirect_uri(request)
+    qr_url = wechat.qr_connect_url(scene, redirect_uri)
+    wx_qr_store.start(scene)
+    return {
+        "scene": scene,
+        "qr_url": qr_url,
+        "redirect_uri": redirect_uri,
+        "stub": not (config.WECHAT_OPEN_APPID and config.WECHAT_OPEN_SECRET),
+    }
+
+
+@router.get("/wx-callback", summary="微信扫码授权回跳")
+async def wx_callback_get(
+    request: Request,
+    code: str = "",
+    state: str = "",
+    db: Database = Depends(get_db),
+):
+    """微信扫码授权回跳：换 openid → 建/复用账号 → 签发令牌，存到 scene 会话。"""
+    if not code:
+        raise HTTPException(status_code=400, detail="缺少 code")
+    try:
+        openid = await wechat.oauth_code2openid(code)
+    except wechat.WechatError as exc:
+        raise HTTPException(status_code=401, detail=str(exc))
+    user = await _find_or_create_wx_user(openid, request, db)
+    identity = await _ensure_opc_identity(db, user["id"])
+    resp = await _login_response(db, user, identity)
+    wx_qr_store.complete(state or openid, resp.token, resp.model_dump())
+    return _wx_success_html()
+
+
+@router.post("/wx-callback", summary="微信扫码授权回跳(SPA 直交)")
+async def wx_callback_post(
+    request: Request,
+    code: str = "",
+    state: str = "",
+    db: Database = Depends(get_db),
+):
+    """SPA 自行拿到 code 后 POST 到此：直接返回登录响应(不走轮询)。"""
+    if not code:
+        raise HTTPException(status_code=400, detail="缺少 code")
+    try:
+        openid = await wechat.oauth_code2openid(code)
+    except wechat.WechatError as exc:
+        raise HTTPException(status_code=401, detail=str(exc))
+    user = await _find_or_create_wx_user(openid, request, db)
+    identity = await _ensure_opc_identity(db, user["id"])
+    return await _login_response(db, user, identity)
+
+
+@router.get("/wx-qr/poll", summary="轮询扫码登录状态")
+async def wx_qr_poll(scene: str):
+    """轮询扫码登录会话：done 时返回令牌+资料（一次性消费）。"""
+    result = wx_qr_store.poll(scene)
+    if result["status"] == "done":
+        return {"status": "done", "token": result["token"], "profile": result["profile"]}
+    return {"status": result["status"]}
+
+
+# ===========================================================================
+# 小程序扫码登录（web/桌面端展示小程序二维码 → 小程序内确认 → 轮询取令牌）
+# ===========================================================================
+
+
+@router.get("/mp-qr/start", summary="发起小程序扫码登录")
+async def mp_qr_start(request: Request, db: Database = Depends(get_db)):
+    """生成小程序扫码登录会话，返回 scene + 供渲染的链接。"""
+    if not config.AUTH_WECHAT_LOGIN:
+        raise HTTPException(status_code=503, detail="小程序登录未开启")
+    if not config.AUTH_ENABLED:
+        raise HTTPException(status_code=403, detail="认证未开启")
+    scene = wechat.new_scene()
+    wx_qr_store.start(scene)
+    # 小程序码需真实 wxacode；此处给可扫描的网页兜底链接 + 场景参数，
+    # 真实小程序可通过 /auth/mp-qr/confirm 回传登录结果。前端据 qr_url 渲染二维码。
+    qr_url = f"https://opc.pinesound.cn/mp/login?scene={scene}"
+    return {"scene": scene, "qr_url": qr_url, "mp_enabled": True}
+
+
+@router.get("/mp-qr/poll", summary="轮询小程序扫码登录状态")
+async def mp_qr_poll(scene: str):
+    result = wx_qr_store.poll(scene)
+    if result["status"] == "done":
+        return {"status": "done", "token": result["token"], "profile": result["profile"]}
+    return {"status": result["status"]}
+
+
+@router.post("/mp-qr/confirm", summary="小程序内确认扫码登录")
+async def mp_qr_confirm(request: Request, req: MpQrConfirmRequest, db: Database = Depends(get_db)):
+    """小程序内 wx.login 后调用：以 scene 关联 web 端会话，回写已登录令牌。"""
+    if not config.AUTH_ENABLED:
+        raise HTTPException(status_code=403, detail="认证未开启")
+    try:
+        openid = await wechat.code2session(req.code)
+    except wechat.WechatError as exc:
+        raise HTTPException(status_code=401, detail=str(exc))
+    source = _client_source(request, "mini_program", "wx_openid")
+    user = await db.users.get_by_wx_mini_openid(openid)
+    if user is None:
+        user = await db.users.create(
+            f"wx_{openid[:24]}", password=secrets.token_hex(16),
+            wx_mini_openid=openid, nickname="微信小程序用户",
+            role="opc_member", source="mini_program", auth_type="wx_openid",
+            register_ip=_client_ip(request),
+        )
+    if user.get("status") != "active":
+        raise HTTPException(status_code=403, detail="账号已禁用")
+    identity = await _ensure_opc_identity(db, user["id"])
+    resp = await _login_response(db, user, identity)
+    wx_qr_store.complete(req.scene, resp.token, resp.model_dump())
+    return {"ok": True, "username": user["username"]}
+
+
+def _wx_success_html() -> HTMLResponse:
+    """授权成功后给微信浏览器的简单页面（扫码端展示，闭环）。"""
+    return HTMLResponse(
+        "<!doctype html><html lang=zh><meta charset=utf-8>"
+        "<meta name=viewport content='width=device-width'>"
+        "<body style='display:flex;align-items:center;justify-content:center;"
+        "height:100vh;font-family:sans-serif'><div style='text-align:center'>"
+        "<div style='font-size:48px'>✅</div>"
+        "<h3>微信登录成功</h3>"
+        "<p>请返回原应用继续操作（本页可关闭）</p></div></body></html>"
+    )
diff --git a/app/api/schemas/auth.py b/app/api/schemas/auth.py
index 016b546..b391041 100644
--- a/app/api/schemas/auth.py
+++ b/app/api/schemas/auth.py
@@ -58,8 +58,9 @@ class RevokeTokenRequest(BaseModel):
 class AuthStatusResponse(BaseModel):
     enabled: bool
     has_users: bool
-    login_modes: list[str] = ["password", "phone"]  # 本期：账号密码 + 手机号验证码；微信扫码预留
-    wechat_login: bool = False  # 微信扫码(预留,本期未开放)
+    login_modes: list[str] = ["password", "phone"]  # password/phone/wechat/miniprogram（四种）
+    wechat_login: bool = False  # 小程序扫码(code2session)
+    wx_qr: bool = False          # 微信开放平台扫码(OAuth)
 
 class VerifyResponse(BaseModel):
     valid: bool
@@ -139,5 +140,12 @@ class WxPhoneRequest(BaseModel):
     code: str = Field(description="手机号接收到的验证码")
 
 
+class MpQrConfirmRequest(BaseModel):
+    """小程序扫码登录确认（小程序内 wx.login 后调用）。"""
+
+    scene: str = Field(description="web/桌面端 /auth/mp-qr/start 返回的场景")
+    code: str = Field(description="wx.login 返回的 code")
+
+
 # RBAC 管理请求/响应
 
diff --git a/app/config.py b/app/config.py
index 142cfdd..957d10b 100644
--- a/app/config.py
+++ b/app/config.py
@@ -130,10 +130,19 @@ SMS_CODE_TTL_SECONDS = int(os.environ.get("PINEAGENTS_SMS_CODE_TTL_SECONDS", "30
 SMS_RATE_LIMIT = int(os.environ.get("PINEAGENTS_SMS_RATE_LIMIT", "5"))
 
 # ---------------------------------------------------------------------------
-# 微信小程序登录（空 appid/secret 时把 code 直通当作 openid，便于无真实 appid 联调）
+# 微信登录（小程序 code2session + 开放平台网站应用扫码登录）
+# 未配置 appid/secret 时走「测试直通」：扫码登录把 code 当 openid 返回，便于无真实凭据联调。
+# WECHAT_APPID/SECRET 为小程序；WECHAT_OPEN_APPID/SECRET 为开放平台「网站应用」(扫码登录)，缺省回退前者。
 # ---------------------------------------------------------------------------
 WECHAT_APPID = os.environ.get("PINEAGENTS_WECHAT_APPID", "")
 WECHAT_SECRET = os.environ.get("PINEAGENTS_WECHAT_SECRET", "")
+WECHAT_OPEN_APPID = os.environ.get("PINEAGENTS_WECHAT_OPEN_APPID", "") or WECHAT_APPID
+WECHAT_OPEN_SECRET = os.environ.get("PINEAGENTS_WECHAT_OPEN_SECRET", "") or WECHAT_SECRET
+# 扫码登录授权后的回跳地址（须在开放平台后台配置为该 URL）：默认服务端 /auth/wx-callback。
+# 未设置时由前端 request.base_url 推导。
+WECHAT_QR_REDIRECT_URI = os.environ.get("PINEAGENTS_WECHAT_QR_REDIRECT_URI", "")
+# 扫码登录开关（true 才返回可用的 qr_start；false 时前端隐藏「微信扫码」入口）
+AUTH_WECHAT_QR = os.environ.get("PINEAGENTS_WECHAT_QR", "true").strip().lower() in ("true", "1", "yes")
 # 本期统一登录仅两模式(账号密码/手机号验证码)；微信扫码预留后期，未开放(默认 False)。
 AUTH_WECHAT_LOGIN = os.environ.get("PINEAGENTS_WECHAT_LOGIN", "false").strip().lower() in ("true", "1", "yes")
 
diff --git a/app/services/sms.py b/app/services/sms.py
index cc6aeb9..83f967b 100644
--- a/app/services/sms.py
+++ b/app/services/sms.py
@@ -36,9 +36,17 @@ def _send(phone: str, code: str) -> None:
     raise SmsError(f"unsupported sms provider: {config.SMS_PROVIDER}")
 
 
+# 演示验证码：stub provider 统一用固定码（先跑通流程，生产换真实短信）。
+DEMO_CODE = "123456"
+
+
 def issue(phone: str) -> str:
-    """为手机号生成并发送 6 位验证码，返回明文（stub 下发时打印）。"""
-    code = f"{secrets.randbelow(1_000_000):06d}"
+    """为手机号生成并发送 6 位验证码，返回明文（stub 下发时打印）。
+
+    演示期 stub provider 统一返回固定码 ``123456``（见配置 SMS_PROVIDER=stub），
+    便于四端联调；接入真实短信后按 provider 生成随机码。
+    """
+    code = DEMO_CODE if config.SMS_PROVIDER == "stub" else f"{secrets.randbelow(1_000_000):06d}"
     with _LOCK:
         _STORE[phone] = {
             "code": code,
diff --git a/app/services/wechat.py b/app/services/wechat.py
index 24cb1f8..f931bf9 100644
--- a/app/services/wechat.py
+++ b/app/services/wechat.py
@@ -1,17 +1,27 @@
 # -*- coding: utf-8 -*-
-"""微信小程序登录服务。
+"""微信登录服务（小程序 code2session + 开放平台网站应用扫码登录）。
 
-``code2session`` 用小程序 ``wx.login`` 的 code 换取 openid。
-未配置 ``WECHAT_APPID`` / ``WECHAT_SECRET`` 时走「测试直通」：直接把 code 当
-openid 返回，便于无真实微信 appid 的环境联调（生产必须配置真实凭据）。
+- ``code2session``：小程序 ``wx.login`` 的 code 换 openid。
+- ``qr_connect_url``：生成开放平台「网站应用扫码登录」授权链接（前端渲染成二维码）。
+- ``oauth_code2openid``：扫码授权回跳的 code 换 openid（OAuth2 access_token 端点）。
+
+未配置对应凭据（小程序 WECHAT_APPID/SECRET、扫码 WECHAT_OPEN_APPID/SECRET）时走
+「测试直通」：把 code 当 openid 返回，便于无真实凭据联调（生产必须配置真实凭据）。
 """
 from __future__ import annotations
 
+import secrets
+import threading
+import time
+from urllib.parse import urlencode
+
 import httpx
 
 from .. import config
 
 _WX_SESSION_URL = "https://api.weixin.qq.com/sns/jscode2session"
+_WX_OAUTH_TOKEN_URL = "https://api.weixin.qq.com/sns/oauth2/access_token"
+_WX_QR_BASE_URL = "https://open.weixin.qq.com/connect/qrconnect"
 
 
 class WechatError(Exception):
@@ -19,7 +29,7 @@ class WechatError(Exception):
 
 
 async def code2session(code: str) -> str:
-    """用登录 code 换取 openid。未配置 appid 时直通：``openid = code``。"""
+    """小程序登录 code 换 openid。未配置 appid 时直通：``openid = code``。"""
     code = code.strip()
     if not config.WECHAT_APPID or not config.WECHAT_SECRET:
         return code
@@ -48,3 +58,102 @@ async def code2session(code: str) -> str:
     if not openid:
         raise WechatError("wechat code2session returned no openid")
     return openid
+
+
+# ---------------------------------------------------------------------------
+# 开放平台「网站应用」扫码登录
+# ---------------------------------------------------------------------------
+
+def qr_connect_url(state: str, redirect_uri: str) -> str:
+    """生成扫码登录授权链接（前端据其渲染二维码）。
+
+    扫码后在微信内完成授权 → 微信重定向到 ``redirect_uri?code=&state=``，
+    服务端 ``/auth/wx-callback`` 收到后换 openid 并存到对应 state 会话。
+    """
+    params = {
+        "appid": config.WECHAT_OPEN_APPID,
+        "redirect_uri": redirect_uri,
+        "response_type": "code",
+        "scope": "snsapi_login",
+        "state": state,
+    }
+    return f"{_WX_QR_BASE_URL}?{urlencode(params)}#wechat_redirect"
+
+
+async def oauth_code2openid(code: str) -> str:
+    """扫码授权回跳的 code 换 openid。未配置开放平台凭据时直通：``openid = code + '_qr'``。"""
+    code = code.strip()
+    if not config.WECHAT_OPEN_APPID or not config.WECHAT_OPEN_SECRET:
+        return f"{code}_qr"
+
+    try:
+        async with httpx.AsyncClient(timeout=10) as client:
+            resp = await client.get(
+                _WX_OAUTH_TOKEN_URL,
+                params={
+                    "appid": config.WECHAT_OPEN_APPID,
+                    "secret": config.WECHAT_OPEN_SECRET,
+                    "code": code,
+                    "grant_type": "authorization_code",
+                },
+            )
+            data = resp.json()
+    except Exception as exc:  # noqa: BLE001
+        raise WechatError(f"wechat oauth token request failed: {exc}") from exc
+
+    errcode = data.get("errcode", 0) or data.get("errCode", 0)
+    if errcode:
+        raise WechatError(f"wechat oauth error {errcode}: {data.get('errmsg', '')}")
+    openid = data.get("openid")
+    if not openid:
+        raise WechatError("wechat oauth returned no openid")
+    return openid
+
+
+class WxQrSessionStore:
+    """扫码登录会话：scene → {status, token, profile, expires_at}（内存 + TTL）。
+
+    - ``start``(scene)：pending。
+    - ``complete``(scene, token, profile)：done（回调存登录结果）。
+    - ``poll``(scene)：done 时返回并消费（一次性），否则 pending/expired。
+    进程重启即失效——生产可在 Redis 持久化（见架构 §8.4）。
+    """
+
+    _TTL = 120  # 会话有效期（秒）
+
+    def __init__(self) -> None:
+        self._data: dict[str, dict] = {}
+        self._lock = threading.Lock()
+
+    def start(self, scene: str) -> None:
+        with self._lock:
+            self._data[scene] = {
+                "status": "pending", "token": "", "profile": None,
+                "expires_at": time.monotonic() + self._TTL,
+            }
+
+    def complete(self, scene: str, token: str, profile: dict) -> None:
+        with self._lock:
+            if scene in self._data:
+                self._data[scene].update(
+                    {"status": "done", "token": token, "profile": profile},
+                )
+
+    def poll(self, scene: str) -> dict:
+        with self._lock:
+            rec = self._data.get(scene)
+            if not rec:
+                return {"status": "expired"}
+            if time.monotonic() > rec["expires_at"]:
+                self._data.pop(scene, None)
+                return {"status": "expired"}
+            if rec["status"] == "done":
+                # 消费一次（防重复取），但保留短暂窗口
+                rec["status"] = "consumed"
+                return {"status": "done", "token": rec["token"], "profile": rec["profile"]}
+            return {"status": rec["status"], "token": "", "profile": None}
+
+
+def new_scene() -> str:
+    return secrets.token_urlsafe(24)
+