diff --git a/apps/waterfall-wiki/db/017_password_reset.sql b/apps/waterfall-wiki/db/017_password_reset.sql
new file mode 100644
index 0000000..f58ae7e
--- /dev/null
+++ b/apps/waterfall-wiki/db/017_password_reset.sql
@@ -0,0 +1,5 @@
+BEGIN;
+ALTER TABLE account_tokens DROP CONSTRAINT account_tokens_kind_check;
+ALTER TABLE account_tokens ADD CONSTRAINT account_tokens_kind_check CHECK (kind IN ('verify','session','reset'));
+INSERT INTO schema_migrations(version) VALUES ('017_password_reset');
+COMMIT;
diff --git a/apps/waterfall-wiki/src/lib/account-handler.ts b/apps/waterfall-wiki/src/lib/account-handler.ts
index 1c9c8b9..5894384 100644
--- a/apps/waterfall-wiki/src/lib/account-handler.ts
+++ b/apps/waterfall-wiki/src/lib/account-handler.ts
@@ -1,6 +1,6 @@
 import { NextResponse } from 'next/server';
 import { normalizeEmail,validPassword, trustedOrigin,accountCookie } from './account-crypto';
-import { rateLimit,registerAccount,resendVerification,verifyAccount,loginAccount,currentAccount,logoutAccount } from './account';
+import { requestPasswordReset,resetPassword,rateLimit,registerAccount,resendVerification,verifyAccount,loginAccount,currentAccount,logoutAccount } from './account';
 export const runtime = 'nodejs';
 const headers = {'Cache-Control':'private, no-store','Referrer-Policy':'no-referrer'};
 const json = (body: object,status=200) => NextResponse.json(body,{status,headers});
@@ -12,7 +12,7 @@ export async function GET(request: Request,context: Context) {
 export async function POST(request: Request,context: Context) {
  if (!trustedOrigin(request)) return json({error:'请求来源不受信任'},403);
  const {action} = await context.params;
- if (!['register','resend','verify','login','logout'].includes(action)) return json({error:'不存在'},404);
+ if (!['register','resend','verify','login','logout','forgot','reset'].includes(action)) return json({error:'不存在'},404);
  try {
   // Revocation remains available even when login or mail limits are exhausted.
   if (action === 'logout') { await logoutAccount(request); const r=json({ok:true});r.headers.set('Set-Cookie',accountCookie('',true));return r; }
@@ -27,6 +27,19 @@ export async function POST(request: Request,context: Context) {
    if(typeof body.token!=='string'||! /^[a-f0-9]{64}$/.test(body.token))return json({error:'验证链接无效或已过期'},400);
    return await verifyAccount(body.token) ? json({ok:true,message:'邮箱已验证，请登录'}) : json({error:'验证链接无效或已过期'},400);
   }
+  if(action==='reset') {
+   if(typeof body.token!=='string'||!/^[a-f0-9]{64}$/.test(body.token)||!validPassword(body.password))return json({error:'重设链接无效，或密码不符合要求'},400);
+   if(!await rateLimit('reset:'+body.token,5))return json({error:'请求过于频繁，请稍后再试'},429);
+   if(!await resetPassword(body.token,body.password))return json({error:'重设链接无效或已过期，请重新申请'},400);
+   const r=json({ok:true,message:'密码已更新，请使用新密码登录'});r.headers.set('Set-Cookie',accountCookie('',true));return r;
+  }
+  if(action==='forgot') {
+   const email=normalizeEmail(body.email);
+   if(!email)return json({error:'请输入有效邮箱'},400);
+   if(!await rateLimit('forgot:'+email,3))return json({error:'请求过于频繁，请 15 分钟后再试'},429);
+   await requestPasswordReset(email);
+   return json({ok:true,message:'若该邮箱对应已验证账户，重设链接将发送至邮箱，有效期 30 分钟。'});
+  }
   const email=normalizeEmail(body.email);
   if(!email||!validPassword(body.password))return json({error:'请输入有效邮箱及 12–256 字节密码'},400);
   if(!await rateLimit(action+':'+email,action==='login'?10:3))return json({error:'请求过于频繁，请 15 分钟后再试'},429);
diff --git a/apps/waterfall-wiki/src/lib/account.ts b/apps/waterfall-wiki/src/lib/account.ts
index e7046f2..64ca807 100644
--- a/apps/waterfall-wiki/src/lib/account.ts
+++ b/apps/waterfall-wiki/src/lib/account.ts
@@ -1,20 +1,44 @@
 import { randomUUID } from 'node:crypto';
 import nodemailer from 'nodemailer';
 import { db, transaction } from './db';
-import { ACCOUNT_COOKIE, SESSION_TTL, newToken, tokenDigest, hashPassword, checkPassword } from './account-crypto';
+import { ACCOUNT_COOKIE, SESSION_TTL, newToken, tokenDigest, hashPassword, checkPassword, validPassword } from './account-crypto';
 export async function rateLimit(key: string, limit: number) {
  const result = await db().query(`INSERT INTO account_limits(key,attempts,window_start) VALUES ($1,1,now())
  ON CONFLICT(key) DO UPDATE SET attempts=CASE WHEN account_limits.window_start < now()-interval '15 minutes' THEN 1 ELSE account_limits.attempts+1 END,
  window_start=CASE WHEN account_limits.window_start < now()-interval '15 minutes' THEN now() ELSE account_limits.window_start END RETURNING attempts`,[tokenDigest(key)]);
  return result.rows[0].attempts <= limit;
 }
-export async function sendVerification(email: string, token: string) {
+async function sendAccountMail(email: string, token: string, kind: 'verify' | 'reset') {
  const origin = process.env.ACCOUNT_PUBLIC_ORIGIN;
  if (!origin || !process.env.SMTP_PASSWORD || !process.env.SMTP_USERNAME) throw Error('SMTP unavailable');
- const url = new URL('/account',origin); url.searchParams.set('verify',token);
+ const url = new URL('/account',origin); url.searchParams.set(kind,token);
  const smtp = nodemailer.createTransport({host:process.env.SMTP_HOST || 'smtpdm.aliyun.com',port:Number(process.env.SMTP_PORT || 465),secure:true,
  auth:{user:process.env.SMTP_USERNAME,pass:process.env.SMTP_PASSWORD},connectionTimeout:10000,socketTimeout:15000});
- await smtp.sendMail({from:process.env.SMTP_FROM || process.env.SMTP_USERNAME,to:email,subject:'验证你的知识站邮箱',text:`请在 30 分钟内打开链接并点击确认验证邮箱：\n${url.href}\n如果你没有注册，请忽略。`});
+ await smtp.sendMail({from:process.env.SMTP_FROM || process.env.SMTP_USERNAME,to:email,subject:kind==='reset'?'重设你的啡跃账户密码':'验证你的知识站邮箱',text:kind==='reset'?`请在 30 分钟内打开链接，由你设置新的密码：\n${url.href}\n如果你没有请求重设密码，请忽略；你的密码不会改变。`:`请在 30 分钟内打开链接并点击确认验证邮箱：\n${url.href}\n如果你没有注册，请忽略。`});
+}
+export async function sendVerification(email: string,token: string) { await sendAccountMail(email,token,'verify'); }
+export async function requestPasswordReset(email: string) {
+ const result=await db().query('SELECT id FROM account_users WHERE email=$1 AND verified_at IS NOT NULL',[email]);
+ if(!result.rowCount)return;
+ const token=newToken(),digest=tokenDigest(token);
+ await db().query("INSERT INTO account_tokens(digest,user_id,kind,expires_at) VALUES ($1,$2,'reset',now()+interval '30 minutes')",[digest,result.rows[0].id]);
+ try { await sendAccountMail(email,token,'reset'); } catch { await db().query('DELETE FROM account_tokens WHERE digest=$1',[digest]);throw Error('SMTP unavailable'); }
+}
+export async function resetPassword(token: string,password: string) {
+ if(!/^[a-f0-9]{64}$/.test(token)||!validPassword(password))return false;
+ const hash=await hashPassword(password),digest=tokenDigest(token);
+ return transaction(async client=>{
+  const lookup=await client.query("SELECT user_id FROM account_tokens WHERE digest=$1 AND kind='reset' AND expires_at>now()",[digest]);
+  if(!lookup.rowCount)return false;
+  const id=lookup.rows[0].user_id;
+  // Serialize all reset links for one account, then recheck after acquiring the lock.
+  await client.query('SELECT id FROM account_users WHERE id=$1 FOR UPDATE',[id]);
+  const consumed=await client.query("DELETE FROM account_tokens WHERE digest=$1 AND kind='reset' AND expires_at>now() RETURNING user_id",[digest]);
+  if(!consumed.rowCount)return false;
+  await client.query('UPDATE account_users SET password_hash=$1 WHERE id=$2',[hash,id]);
+  await client.query('DELETE FROM account_tokens WHERE user_id=$1',[id]);
+  return true;
+ });
 }
 export async function registerAccount(email: string,password: string) {
  const hash = await hashPassword(password);
@@ -42,14 +66,16 @@ export async function verifyAccount(token: string) {
  });
 }
 export async function loginAccount(email: string,password: string) {
- const result = await db().query('SELECT * FROM account_users WHERE email=$1',[email]);
+ return transaction(async client=>{
+ const result = await client.query('SELECT * FROM account_users WHERE email=$1 FOR UPDATE',[email]);
  const user = result.rows[0];
  // A fixed dummy hash makes unknown accounts perform the same expensive KDF.
  const hash = user?.password_hash || 'scrypt:00000000000000000000000000000000:'+'0'.repeat(128);
  if (!await checkPassword(password,hash) || !user?.verified_at) return null;
  const token = newToken();
- await db().query("INSERT INTO account_tokens(digest,user_id,kind,expires_at) VALUES ($1,$2,'session',now()+$3*interval '1 second')",[tokenDigest(token),user.id,SESSION_TTL]);
+ await client.query("INSERT INTO account_tokens(digest,user_id,kind,expires_at) VALUES ($1,$2,'session',now()+$3*interval '1 second')",[tokenDigest(token),user.id,SESSION_TTL]);
  return token;
+ });
 }
 export function requestToken(request: Request) {
  const value = request.headers.get('cookie')?.split(';').map(s=>s.trim()).find(s=>s.startsWith(ACCOUNT_COOKIE+'='))?.slice(ACCOUNT_COOKIE.length+1);
diff --git a/apps/waterfall-wiki/tests/account-integration.ts b/apps/waterfall-wiki/tests/account-integration.ts
index 7d0c3c4..85609b1 100644
--- a/apps/waterfall-wiki/tests/account-integration.ts
+++ b/apps/waterfall-wiki/tests/account-integration.ts
@@ -2,7 +2,7 @@ import assert from 'node:assert/strict';
 import { randomUUID } from 'node:crypto';
 import { db } from '../src/lib/db';
 import { hashPassword,newToken,tokenDigest } from '../src/lib/account-crypto';
-import { loginAccount,verifyAccount,currentAccount,logoutAccount,rateLimit } from '../src/lib/account';
+import { resetPassword,loginAccount,verifyAccount,currentAccount,logoutAccount,rateLimit } from '../src/lib/account';
 export async function verifyEmailAccounts() {
  const id=randomUUID(), email=id+'@example.com', password='a secure test password';
  const request=(token:string)=>new Request('https://wiki.example',{headers:{cookie:'wiki_account='+token}});
@@ -17,6 +17,20 @@ export async function verifyEmailAccounts() {
   await db().query("UPDATE account_tokens SET expires_at=now()-interval '1 second' WHERE digest=$1",[tokenDigest(token)]);
   assert.equal(await currentAccount(request(token)),null,'expired sessions rejected');
   const fresh=await loginAccount(email,password);assert.ok(fresh);await logoutAccount(request(fresh));assert.equal(await currentAccount(request(fresh)),null,'logout revokes token');
+  const oldSession=await loginAccount(email,password);assert.ok(oldSession);
+  const resets=[newToken(),newToken()],replacement='a new secure test password';
+  for(const value of resets)await db().query("INSERT INTO account_tokens VALUES ($1,$2,'reset',now()+interval '30 minutes')",[tokenDigest(value),id]);
+  const resetResults=await Promise.all(resets.map(value=>resetPassword(value,replacement)));
+  assert.deepEqual(resetResults.sort(),[false,true],'Only one concurrent reset may succeed for one account');
+  assert.equal(await currentAccount(request(oldSession)),null,'Reset revokes existing sessions');
+  assert.equal(await loginAccount(email,password),null,'Original password is no longer accepted');
+  assert.ok(await loginAccount(email,replacement));
+  assert.equal(await resetPassword(resets[0],password),false,'Reset links are single-use, including sibling links');
+  const expired=newToken();await db().query("INSERT INTO account_tokens VALUES ($1,$2,'reset',now()-interval '1 minute')",[tokenDigest(expired),id]);
+  assert.equal(await resetPassword(expired,password),false);
+  const wrongKind=newToken();await db().query("INSERT INTO account_tokens VALUES ($1,$2,'verify',now()+interval '30 minutes')",[tokenDigest(wrongKind),id]);
+  assert.equal(await resetPassword(wrongKind,password),false,'Email verification cannot reset a password');
+  assert.equal(await resetPassword(newToken(),'short'),false);
   const key=randomUUID();assert.deepEqual(await Promise.all(Array.from({length:5},()=>rateLimit(key,3))).then(a=>a.sort()),[false,false,true,true,true]);
   await db().query('DELETE FROM account_limits WHERE key=$1',[tokenDigest(key)]);
  } finally {await db().query('DELETE FROM account_users WHERE id=$1',[id]);}