diff --git a/admin-frontend/src/api.ts b/admin-frontend/src/api.ts
index 83be9ec..16dbb38 100644
--- a/admin-frontend/src/api.ts
+++ b/admin-frontend/src/api.ts
@@ -168,6 +168,7 @@ export const api = {
     owner_email?: string;
     tier?: string;
     rate_limit_per_min?: number;
+    quota_total?: number;
   }) =>
     request<{ key: string; item: import("./types").ApiKey; warning: string }>(
       "/keys",
diff --git a/admin-frontend/src/components/ApiKeysPage.tsx b/admin-frontend/src/components/ApiKeysPage.tsx
index 6eeb021..4b02ff4 100644
--- a/admin-frontend/src/components/ApiKeysPage.tsx
+++ b/admin-frontend/src/components/ApiKeysPage.tsx
@@ -4,9 +4,10 @@ import type { ApiKey } from "../types";
 import { Copy, KeyRound, Plus, Trash2 } from "lucide-react";
 
 const TIERS = [
-  { key: "free", label: "免费 (free)", rate: 120 },
-  { key: "partner", label: "合作方 (partner)", rate: 600 },
-  { key: "internal", label: "内部 (internal)", rate: 6000 },
+  { key: "free", label: "免费 (free)", rate: 120, quota: 1000 },
+  { key: "registered", label: "注册用户 (registered)", rate: 300, quota: 100000 },
+  { key: "partner", label: "合作方 (partner)", rate: 600, quota: 0 },
+  { key: "internal", label: "内部 (internal)", rate: 6000, quota: 0 },
 ];
 
 function tierLabel(tier: string): string {
@@ -111,6 +112,7 @@ export default function ApiKeysPage() {
               <th className="px-4 py-2 font-medium">级别</th>
               <th className="px-4 py-2 font-medium">速率/分钟</th>
               <th className="px-4 py-2 font-medium">用量(今日/累计)</th>
+              <th className="px-4 py-2 font-medium">累计配额</th>
               <th className="px-4 py-2 font-medium">状态</th>
               <th className="px-4 py-2 font-medium"></th>
             </tr>
@@ -118,7 +120,7 @@ export default function ApiKeysPage() {
           <tbody className="divide-y">
             {rows.length === 0 ? (
               <tr>
-                <td colSpan={7} className="px-4 py-8 text-center text-gray-400">
+                <td colSpan={8} className="px-4 py-8 text-center text-gray-400">
                   暂无密钥
                 </td>
               </tr>
@@ -139,6 +141,15 @@ export default function ApiKeysPage() {
                   <td className="px-4 py-2 text-gray-600">
                     {k.usage.today} / {k.usage.total}
                   </td>
+                  <td className="px-4 py-2 text-gray-600">
+                    {k.quota_total > 0 ? (
+                      <span className={k.usage.total >= k.quota_total ? "text-red-600" : ""}>
+                        {k.usage.total.toLocaleString()} / {k.quota_total.toLocaleString()}
+                      </span>
+                    ) : (
+                      <span className="text-gray-400">不限</span>
+                    )}
+                  </td>
                   <td className="px-4 py-2">
                     {k.revoked_at ? (
                       <span className="text-xs rounded px-2 py-0.5 bg-red-50 text-red-700">
@@ -182,13 +193,17 @@ function CreateKeyForm({
   const [ownerEmail, setOwnerEmail] = useState("");
   const [tier, setTier] = useState("free");
   const [rate, setRate] = useState(120);
+  const [quota, setQuota] = useState(1000);
   const [busy, setBusy] = useState(false);
   const [error, setError] = useState("");
 
   function pickTier(t: string) {
     setTier(t);
     const def = TIERS.find((x) => x.key === t);
-    if (def) setRate(def.rate);
+    if (def) {
+      setRate(def.rate);
+      setQuota(def.quota);
+    }
   }
 
   async function submit() {
@@ -204,6 +219,7 @@ function CreateKeyForm({
         owner_email: ownerEmail.trim() || undefined,
         tier,
         rate_limit_per_min: rate,
+        quota_total: quota,
       });
       onCreated(res.key);
     } catch (e) {
@@ -260,6 +276,16 @@ function CreateKeyForm({
             onChange={(e) => setRate(Math.max(1, parseInt(e.target.value || "1", 10)))}
           />
         </label>
+        <label className="block">
+          <span className="text-xs text-gray-500">累计配额（总调用次数，0=不限）</span>
+          <input
+            type="number"
+            min={0}
+            className="w-full border rounded-md px-3 py-2 text-sm mt-1"
+            value={quota}
+            onChange={(e) => setQuota(Math.max(0, parseInt(e.target.value || "0", 10)))}
+          />
+        </label>
       </div>
       <div className="mt-4 flex gap-2">
         <button
diff --git a/admin-frontend/src/types.ts b/admin-frontend/src/types.ts
index 4de01c3..7d0c429 100644
--- a/admin-frontend/src/types.ts
+++ b/admin-frontend/src/types.ts
@@ -199,6 +199,7 @@ export interface ApiKey {
   owner_email: string | null;
   tier: string;
   rate_limit_per_min: number;
+  quota_total: number;
   revoked_at: string | null;
   created_by: string | null;
   created_at: string;
diff --git a/api/cmd/server/main.go b/api/cmd/server/main.go
index 8e713cf..0b51902 100644
--- a/api/cmd/server/main.go
+++ b/api/cmd/server/main.go
@@ -37,7 +37,8 @@ func main() {
 		log.Print("warning: Redis not configured; public API rate limiting disabled")
 	}
 	h := handler.New(store.New(pool), publicweb.Dist()).
-		WithRateLimit(limiter, cfg.AnonRateLimitPerMin)
+		WithRateLimit(limiter, cfg.AnonRateLimitPerMin).
+		WithQuotas(cfg.AnonTotalQuota, cfg.RegisteredRateLimitPerMin, cfg.RegisteredQuotaTotal)
 
 	srv := &http.Server{
 		Addr:              cfg.Addr,
diff --git a/api/internal/adminhandler/apikey.go b/api/internal/adminhandler/apikey.go
index c2ff509..a435ede 100644
--- a/api/internal/adminhandler/apikey.go
+++ b/api/internal/adminhandler/apikey.go
@@ -46,7 +46,7 @@ func (h *Handler) CreateAPIKey(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusBadRequest, "bad_request", "名称不能为空")
 		return
 	}
-	if in.Tier != "" && in.Tier != "free" && in.Tier != "partner" && in.Tier != "internal" {
+	if in.Tier != "" && in.Tier != "free" && in.Tier != "registered" && in.Tier != "partner" && in.Tier != "internal" {
 		writeError(w, http.StatusBadRequest, "bad_request", "tier 取值无效")
 		return
 	}
diff --git a/api/internal/adminstore/apikey.go b/api/internal/adminstore/apikey.go
index c5336ed..fdbbb78 100644
--- a/api/internal/adminstore/apikey.go
+++ b/api/internal/adminstore/apikey.go
@@ -19,6 +19,7 @@ type APIKeyRow struct {
 	OwnerEmail      *string `json:"owner_email"`
 	Tier            string  `json:"tier"`
 	RateLimitPerMin int     `json:"rate_limit_per_min"`
+	QuotaTotal      int64   `json:"quota_total"`
 	RevokedAt       *string `json:"revoked_at"`
 	CreatedBy       *string `json:"created_by"`
 	CreatedAt       string  `json:"created_at"`
@@ -30,6 +31,7 @@ type APIKeyInput struct {
 	OwnerEmail      string `json:"owner_email"`
 	Tier            string `json:"tier"`
 	RateLimitPerMin int    `json:"rate_limit_per_min"`
+	QuotaTotal      int64  `json:"quota_total"`
 }
 
 // CreateAPIKey issues a new key, returning the one-time plaintext alongside the
@@ -43,6 +45,10 @@ func (s *Store) CreateAPIKey(ctx context.Context, in APIKeyInput, createdBy stri
 	if rate <= 0 {
 		rate = 120
 	}
+	quota := in.QuotaTotal
+	if quota < 0 {
+		quota = 0
+	}
 	var owner *string
 	if e := strings.TrimSpace(in.OwnerEmail); e != "" {
 		owner = &e
@@ -56,12 +62,12 @@ func (s *Store) CreateAPIKey(ctx context.Context, in APIKeyInput, createdBy stri
 	var revoked, created *time.Time
 	var createdByOut *string
 	err = s.pool.QueryRow(ctx, `
-INSERT INTO api_key (name, key_prefix, key_hash, owner_email, tier, rate_limit_per_min, created_by)
-VALUES ($1, $2, $3, $4, $5, $6, $7)
-RETURNING id, name, key_prefix, owner_email, tier, rate_limit_per_min, revoked_at, created_by, created_at`,
-		strings.TrimSpace(in.Name), prefix, hash, owner, tier, rate, createdBy,
+INSERT INTO api_key (name, key_prefix, key_hash, owner_email, tier, rate_limit_per_min, quota_total, created_by)
+VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+RETURNING id, name, key_prefix, owner_email, tier, rate_limit_per_min, quota_total, revoked_at, created_by, created_at`,
+		strings.TrimSpace(in.Name), prefix, hash, owner, tier, rate, quota, createdBy,
 	).Scan(&row.ID, &row.Name, &row.KeyPrefix, &row.OwnerEmail, &row.Tier,
-		&row.RateLimitPerMin, &revoked, &createdByOut, &created)
+		&row.RateLimitPerMin, &row.QuotaTotal, &revoked, &createdByOut, &created)
 	if err != nil {
 		return "", row, err
 	}
@@ -75,7 +81,7 @@ RETURNING id, name, key_prefix, owner_email, tier, rate_limit_per_min, revoked_a
 // ListAPIKeys returns all keys (active first, newest first).
 func (s *Store) ListAPIKeys(ctx context.Context) ([]APIKeyRow, error) {
 	rows, err := s.pool.Query(ctx, `
-SELECT id, name, key_prefix, owner_email, tier, rate_limit_per_min, revoked_at, created_by, created_at
+SELECT id, name, key_prefix, owner_email, tier, rate_limit_per_min, quota_total, revoked_at, created_by, created_at
 FROM api_key
 ORDER BY (revoked_at IS NULL) DESC, created_at DESC`)
 	if err != nil {
@@ -87,7 +93,7 @@ ORDER BY (revoked_at IS NULL) DESC, created_at DESC`)
 		var r APIKeyRow
 		var revoked, created *time.Time
 		if err := rows.Scan(&r.ID, &r.Name, &r.KeyPrefix, &r.OwnerEmail, &r.Tier,
-			&r.RateLimitPerMin, &revoked, &r.CreatedBy, &created); err != nil {
+			&r.RateLimitPerMin, &r.QuotaTotal, &revoked, &r.CreatedBy, &created); err != nil {
 			return nil, err
 		}
 		if revoked != nil {
diff --git a/api/internal/config/config.go b/api/internal/config/config.go
index 8d5e00e..cd13198 100644
--- a/api/internal/config/config.go
+++ b/api/internal/config/config.go
@@ -9,19 +9,25 @@ import (
 // Values are read from environment variables with sensible defaults so the
 // server can boot in a local Docker Compose setup without extra configuration.
 type Config struct {
-	Addr                string
-	DatabaseURL         string
-	RedisURL            string
-	AnonRateLimitPerMin int
+	Addr                      string
+	DatabaseURL               string
+	RedisURL                  string
+	AnonRateLimitPerMin       int
+	AnonTotalQuota            int
+	RegisteredRateLimitPerMin int
+	RegisteredQuotaTotal      int
 }
 
 // Load reads configuration from the environment.
 func Load() Config {
 	return Config{
-		Addr:                getenv("OPENGOODS_ADDR", ":8080"),
-		DatabaseURL:         getenv("OPENGOODS_DATABASE_URL", "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"),
-		RedisURL:            getenv("OPENGOODS_REDIS_URL", "redis://localhost:6379/0"),
-		AnonRateLimitPerMin: getenvInt("OPENGOODS_ANON_RATE_LIMIT_PER_MIN", 60),
+		Addr:                      getenv("OPENGOODS_ADDR", ":8080"),
+		DatabaseURL:               getenv("OPENGOODS_DATABASE_URL", "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"),
+		RedisURL:                  getenv("OPENGOODS_REDIS_URL", "redis://localhost:6379/0"),
+		AnonRateLimitPerMin:       getenvInt("OPENGOODS_ANON_RATE_LIMIT_PER_MIN", 60),
+		AnonTotalQuota:            getenvInt("OPENGOODS_ANON_TOTAL_QUOTA", 1000),
+		RegisteredRateLimitPerMin: getenvInt("OPENGOODS_REGISTERED_RATE_LIMIT_PER_MIN", 300),
+		RegisteredQuotaTotal:      getenvInt("OPENGOODS_REGISTERED_QUOTA_TOTAL", 100000),
 	}
 }
 
diff --git a/api/internal/handler/account.go b/api/internal/handler/account.go
new file mode 100644
index 0000000..d8b019c
--- /dev/null
+++ b/api/internal/handler/account.go
@@ -0,0 +1,128 @@
+package handler
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/baicai2026-baicai/goods/api/internal/store"
+)
+
+// emailRe is a deliberately permissive sanity check; real validation is the
+// unique constraint plus the user being able to receive their own key.
+var emailRe = regexp.MustCompile(`^[^@\s]+@[^@\s]+\.[^@\s]+$`)
+
+const minPasswordLen = 8
+
+type credentials struct {
+	Email    string `json:"email"`
+	Password string `json:"password"`
+}
+
+func decodeCredentials(w http.ResponseWriter, r *http.Request) (credentials, bool) {
+	var c credentials
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&c); err != nil {
+		writeError(w, r, http.StatusBadRequest, "invalid_body", "请求格式无效")
+		return credentials{}, false
+	}
+	c.Email = strings.TrimSpace(c.Email)
+	if !emailRe.MatchString(c.Email) {
+		writeError(w, r, http.StatusBadRequest, "invalid_email", "邮箱格式无效")
+		return credentials{}, false
+	}
+	if len(c.Password) < minPasswordLen {
+		writeError(w, r, http.StatusBadRequest, "weak_password", "密码至少需要 8 位")
+		return credentials{}, false
+	}
+	return c, true
+}
+
+// keyResponse is returned whenever a fresh plaintext key is issued; the key is
+// shown exactly once and cannot be recovered afterwards.
+type keyResponse struct {
+	Email           string `json:"email"`
+	APIKey          string `json:"api_key"`
+	KeyPrefix       string `json:"key_prefix"`
+	RateLimitPerMin int    `json:"rate_limit_per_min"`
+	QuotaTotal      int64  `json:"quota_total"`
+}
+
+// Register creates an account and issues its first API key. POST {email, password}.
+func (h *Handler) Register(w http.ResponseWriter, r *http.Request) {
+	c, ok := decodeCredentials(w, r)
+	if !ok {
+		return
+	}
+	key, acct, err := h.store.RegisterUser(r.Context(), c.Email, c.Password, h.regRatePerMin, h.regQuotaTotal)
+	if errors.Is(err, store.ErrEmailTaken) {
+		writeError(w, r, http.StatusConflict, "email_taken", "该邮箱已注册，请直接登录查看或重置密钥")
+		return
+	}
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusCreated, keyResponse{
+		Email:           acct.Email,
+		APIKey:          key,
+		KeyPrefix:       acct.KeyPrefix,
+		RateLimitPerMin: acct.RateLimitPerMin,
+		QuotaTotal:      acct.QuotaTotal,
+	})
+}
+
+// AccountInfo verifies credentials and returns the account's key metadata plus
+// cumulative usage. POST {email, password}. The plaintext key is not returned.
+func (h *Handler) AccountInfo(w http.ResponseWriter, r *http.Request) {
+	c, ok := decodeCredentials(w, r)
+	if !ok {
+		return
+	}
+	acct, err := h.store.Authenticate(r.Context(), c.Email, c.Password)
+	if errors.Is(err, store.ErrNotFound) {
+		writeError(w, r, http.StatusUnauthorized, "invalid_credentials", "邮箱或密码错误")
+		return
+	}
+	if h.handleErr(w, r, err) {
+		return
+	}
+	used := h.limiter.TotalUsed(r.Context(), acct.KeyID)
+	remaining := acct.QuotaTotal - used
+	if remaining < 0 {
+		remaining = 0
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"email":              acct.Email,
+		"key_prefix":         acct.KeyPrefix,
+		"rate_limit_per_min": acct.RateLimitPerMin,
+		"quota_total":        acct.QuotaTotal,
+		"quota_used":         used,
+		"quota_remaining":    remaining,
+	})
+}
+
+// RegenerateKey revokes the account's current key and issues a new one, carrying
+// over cumulative usage so the quota cannot be reset. POST {email, password}.
+func (h *Handler) RegenerateKey(w http.ResponseWriter, r *http.Request) {
+	c, ok := decodeCredentials(w, r)
+	if !ok {
+		return
+	}
+	key, acct, oldKeyID, err := h.store.RegenerateKey(r.Context(), c.Email, c.Password, h.regRatePerMin, h.regQuotaTotal)
+	if errors.Is(err, store.ErrNotFound) {
+		writeError(w, r, http.StatusUnauthorized, "invalid_credentials", "邮箱或密码错误")
+		return
+	}
+	if h.handleErr(w, r, err) {
+		return
+	}
+	h.limiter.CopyTotal(r.Context(), oldKeyID, acct.KeyID)
+	writeJSON(w, http.StatusOK, keyResponse{
+		Email:           acct.Email,
+		APIKey:          key,
+		KeyPrefix:       acct.KeyPrefix,
+		RateLimitPerMin: acct.RateLimitPerMin,
+		QuotaTotal:      acct.QuotaTotal,
+	})
+}
diff --git a/api/internal/handler/account_db_test.go b/api/internal/handler/account_db_test.go
new file mode 100644
index 0000000..5928e6a
--- /dev/null
+++ b/api/internal/handler/account_db_test.go
@@ -0,0 +1,149 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/redis/go-redis/v9"
+
+	"github.com/baicai2026-baicai/goods/api/internal/ratelimit"
+	"github.com/baicai2026-baicai/goods/api/internal/store"
+)
+
+func cleanupCounter(t *testing.T, subject string) {
+	t.Helper()
+	redisURL := os.Getenv("OPENGOODS_REDIS_URL")
+	if redisURL == "" {
+		redisURL = "redis://localhost:6379/0"
+	}
+	opt, err := redis.ParseURL(redisURL)
+	if err != nil {
+		return
+	}
+	rdb := redis.NewClient(opt)
+	defer rdb.Close()
+	rdb.Del(context.Background(), "usage:total:"+subject)
+}
+
+// newQuotaHandler builds a handler backed by the test DB and a live Redis
+// limiter, with a small anonymous quota so exhaustion is cheap to exercise.
+func newQuotaHandler(t *testing.T, anonQuota int) *Handler {
+	t.Helper()
+	dsn := os.Getenv("OPENGOODS_DATABASE_URL")
+	if dsn == "" {
+		dsn = "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		t.Skipf("no database: %v", err)
+	}
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		t.Skipf("database not reachable: %v", err)
+	}
+	var hasUser bool
+	if err := pool.QueryRow(ctx, "SELECT to_regclass('public.app_user') IS NOT NULL").Scan(&hasUser); err != nil || !hasUser {
+		pool.Close()
+		t.Skip("migrations not applied")
+	}
+	redisURL := os.Getenv("OPENGOODS_REDIS_URL")
+	if redisURL == "" {
+		redisURL = "redis://localhost:6379/0"
+	}
+	limiter := ratelimit.New(redisURL)
+	pingCtx, pingCancel := context.WithTimeout(context.Background(), time.Second)
+	defer pingCancel()
+	if err := limiter.Ping(pingCtx); err != nil {
+		pool.Close()
+		t.Skipf("redis not reachable: %v", err)
+	}
+	t.Cleanup(pool.Close)
+	return New(store.New(pool), nil).
+		WithRateLimit(limiter, 1000).
+		WithQuotas(anonQuota, 300, 100000)
+}
+
+func cleanupAccount(t *testing.T, email string) {
+	t.Helper()
+	dsn := os.Getenv("OPENGOODS_DATABASE_URL")
+	if dsn == "" {
+		dsn = "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"
+	}
+	ctx := context.Background()
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		return
+	}
+	defer pool.Close()
+	_, _ = pool.Exec(ctx, "DELETE FROM app_user WHERE lower(email)=lower($1)", email)
+	_, _ = pool.Exec(ctx, "DELETE FROM api_key WHERE owner_email=$1", email)
+}
+
+func TestAnonTotalQuotaExhausts(t *testing.T) {
+	h := newQuotaHandler(t, 3)
+	// Unique client IP so the lifetime counter starts fresh for this test; the
+	// counter never expires, so drop it afterwards to keep runs independent.
+	n := time.Now().UnixNano()
+	ip := fmt.Sprintf("203.%d.%d.%d", n/65536%256, n/256%256, n%256)
+	t.Cleanup(func() { cleanupCounter(t, "ip:"+ip) })
+	call := func() *httptest.ResponseRecorder {
+		req := httptest.NewRequest(http.MethodGet, "/api/"+APIVersion+"/stats", nil)
+		req.RemoteAddr = ip + ":12345"
+		rec := httptest.NewRecorder()
+		h.Router().ServeHTTP(rec, req)
+		return rec
+	}
+	for i := 1; i <= 3; i++ {
+		if rec := call(); rec.Code != http.StatusOK {
+			t.Fatalf("call %d should be allowed, got %d (%s)", i, rec.Code, rec.Body.String())
+		}
+	}
+	rec := call()
+	if rec.Code != http.StatusForbidden {
+		t.Fatalf("4th call should be 403 quota_exhausted, got %d (%s)", rec.Code, rec.Body.String())
+	}
+	if !strings.Contains(rec.Body.String(), "quota_exhausted") {
+		t.Fatalf("expected quota_exhausted error, got %s", rec.Body.String())
+	}
+}
+
+func TestRegisterIssuesHigherQuotaKey(t *testing.T) {
+	h := newQuotaHandler(t, 1000)
+	email := fmt.Sprintf("h-user-%d@example.com", time.Now().UnixNano())
+	t.Cleanup(func() { cleanupAccount(t, email) })
+
+	body := fmt.Sprintf(`{"email":%q,"password":"supersecret"}`, email)
+	req := httptest.NewRequest(http.MethodPost, "/api/"+APIVersion+"/register", strings.NewReader(body))
+	req.RemoteAddr = "198.51.100.7:9999"
+	rec := httptest.NewRecorder()
+	h.Router().ServeHTTP(rec, req)
+	if rec.Code != http.StatusCreated {
+		t.Fatalf("register status = %d (%s)", rec.Code, rec.Body.String())
+	}
+	var resp keyResponse
+	if err := json.NewDecoder(rec.Body).Decode(&resp); err != nil {
+		t.Fatal(err)
+	}
+	if resp.APIKey == "" || resp.QuotaTotal != 100000 || resp.RateLimitPerMin != 300 {
+		t.Fatalf("unexpected register response: %+v", resp)
+	}
+
+	// A second registration with the same email conflicts.
+	req2 := httptest.NewRequest(http.MethodPost, "/api/"+APIVersion+"/register", strings.NewReader(body))
+	req2.RemoteAddr = "198.51.100.7:9999"
+	rec2 := httptest.NewRecorder()
+	h.Router().ServeHTTP(rec2, req2)
+	if rec2.Code != http.StatusConflict {
+		t.Fatalf("duplicate register status = %d (%s)", rec2.Code, rec2.Body.String())
+	}
+}
diff --git a/api/internal/handler/handler.go b/api/internal/handler/handler.go
index c15753e..84de445 100644
--- a/api/internal/handler/handler.go
+++ b/api/internal/handler/handler.go
@@ -37,20 +37,43 @@ const (
 	// defaultAnonLimit is the per-minute request budget for unauthenticated
 	// callers (identified by client IP) when none is configured.
 	defaultAnonLimit = 60
+
+	// defaultAnonTotalQuota is the lifetime number of calls an anonymous caller
+	// (by IP) may make before being asked to register for a higher quota.
+	defaultAnonTotalQuota = 1000
+
+	// defaultRegRatePerMin / defaultRegQuotaTotal are the per-minute budget and
+	// cumulative quota granted to a self-registered API key.
+	defaultRegRatePerMin = 300
+	defaultRegQuotaTotal = 100000
+
+	// registerRatePerMin caps account registration/login attempts per IP to
+	// curb abuse; these endpoints sit outside the metered quota group.
+	registerRatePerMin = 10
 )
 
 // Handler holds dependencies shared by the HTTP routes.
 type Handler struct {
-	store     *store.Store
-	spa       fs.FS
-	limiter   *ratelimit.Limiter
-	anonLimit int
+	store          *store.Store
+	spa            fs.FS
+	limiter        *ratelimit.Limiter
+	anonLimit      int
+	anonTotalQuota int64
+	regRatePerMin  int
+	regQuotaTotal  int64
 }
 
 // New constructs a Handler backed by the given store. spa may be nil (JSON-only).
 // Rate limiting is disabled until WithRateLimit is called.
 func New(s *store.Store, spa fs.FS) *Handler {
-	return &Handler{store: s, spa: spa, anonLimit: defaultAnonLimit}
+	return &Handler{
+		store:          s,
+		spa:            spa,
+		anonLimit:      defaultAnonLimit,
+		anonTotalQuota: defaultAnonTotalQuota,
+		regRatePerMin:  defaultRegRatePerMin,
+		regQuotaTotal:  defaultRegQuotaTotal,
+	}
 }
 
 // WithRateLimit attaches a Redis-backed limiter and the anonymous per-minute
@@ -64,6 +87,22 @@ func (h *Handler) WithRateLimit(l *ratelimit.Limiter, anonPerMin int) *Handler {
 	return h
 }
 
+// WithQuotas configures the cumulative free quota for anonymous callers and the
+// per-minute rate + cumulative quota self-registered keys receive. Non-positive
+// values keep the defaults.
+func (h *Handler) WithQuotas(anonTotal, regPerMin, regTotal int) *Handler {
+	if anonTotal > 0 {
+		h.anonTotalQuota = int64(anonTotal)
+	}
+	if regPerMin > 0 {
+		h.regRatePerMin = regPerMin
+	}
+	if regTotal > 0 {
+		h.regQuotaTotal = int64(regTotal)
+	}
+	return h
+}
+
 // Router builds the top-level HTTP handler with middleware and routes mounted.
 func (h *Handler) Router() http.Handler {
 	r := chi.NewRouter()
@@ -91,6 +130,16 @@ func (h *Handler) Router() http.Handler {
 			r.Get("/sources/{id}", h.SourceByID)
 			r.Get("/stats", h.Stats)
 		})
+
+		// Self-service account routes. Lightly IP-throttled to curb abuse but
+		// outside the metered quota group so a user can always register or
+		// check their key even after exhausting the free anonymous quota.
+		r.Group(func(r chi.Router) {
+			r.Use(h.registerLimit)
+			r.Post("/register", h.Register)
+			r.Post("/account", h.AccountInfo)
+			r.Post("/account/regenerate", h.RegenerateKey)
+		})
 	})
 
 	// Public SPA (homepage + search + contribute). API routes above take
diff --git a/api/internal/handler/middleware.go b/api/internal/handler/middleware.go
index d9d4abe..bebd821 100644
--- a/api/internal/handler/middleware.go
+++ b/api/internal/handler/middleware.go
@@ -24,8 +24,11 @@ const apiKeyIDKey ctxKey = 0
 // are set on every response; over-budget callers get 429 + Retry-After.
 func (h *Handler) rateLimit(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		id := "ip:" + clientIP(r)
+		ip := clientIP(r)
+		id := "ip:" + ip
+		subject := "ip:" + ip // cumulative-quota counter subject
 		limit := h.anonLimit
+		quota := h.anonTotalQuota
 		keyID := ""
 
 		if raw := presentedKey(r); raw != "" {
@@ -45,6 +48,8 @@ func (h *Handler) rateLimit(next http.Handler) http.Handler {
 			keyID = k.ID
 			limit = k.RateLimitPerMin
 			id = "key:" + k.ID
+			subject = k.ID
+			quota = k.QuotaTotal
 		}
 
 		res := h.limiter.Allow(r.Context(), id, limit, time.Minute)
@@ -61,8 +66,36 @@ func (h *Handler) rateLimit(next http.Handler) http.Handler {
 			return
 		}
 
+		// Attribute one call to the caller's lifetime counter, then enforce the
+		// cumulative quota (quota <= 0 means unlimited). Keys also get daily and
+		// last-used stats recorded for the admin console.
+		var used int64
 		if keyID != "" {
 			h.limiter.RecordUsage(r.Context(), keyID)
+			used = h.limiter.TotalUsed(r.Context(), keyID)
+		} else {
+			used = h.limiter.IncrTotal(r.Context(), subject)
+		}
+		if quota > 0 {
+			remaining := quota - used
+			if remaining < 0 {
+				remaining = 0
+			}
+			w.Header().Set("X-Quota-Limit", strconv.FormatInt(quota, 10))
+			w.Header().Set("X-Quota-Used", strconv.FormatInt(used, 10))
+			w.Header().Set("X-Quota-Remaining", strconv.FormatInt(remaining, 10))
+			if used > quota {
+				if keyID == "" {
+					writeError(w, r, http.StatusForbidden, "quota_exhausted",
+						"免费额度（共 "+strconv.FormatInt(quota, 10)+" 次）已用尽，请注册账号获取更高配额的 API 密钥")
+				} else {
+					writeError(w, r, http.StatusForbidden, "quota_exhausted", "API 密钥配额已用尽")
+				}
+				return
+			}
+		}
+
+		if keyID != "" {
 			next.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), apiKeyIDKey, keyID)))
 			return
 		}
@@ -70,6 +103,25 @@ func (h *Handler) rateLimit(next http.Handler) http.Handler {
 	})
 }
 
+// registerLimit throttles self-service account endpoints per client IP without
+// consuming the metered free quota, so a caller can still register or recover
+// their key after exhausting the anonymous quota.
+func (h *Handler) registerLimit(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		res := h.limiter.Allow(r.Context(), "register:"+clientIP(r), h.regRatePerMin, time.Minute)
+		if !res.Allowed {
+			retry := res.ResetUnix - time.Now().Unix()
+			if retry < 1 {
+				retry = 1
+			}
+			w.Header().Set("Retry-After", strconv.FormatInt(retry, 10))
+			writeError(w, r, http.StatusTooManyRequests, "rate_limited", "操作过于频繁，请稍后再试")
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
 // presentedKey extracts an API key from the X-API-Key header or a Bearer token.
 func presentedKey(r *http.Request) string {
 	if v := strings.TrimSpace(r.Header.Get("X-API-Key")); v != "" {
diff --git a/api/internal/handler/openapi.json b/api/internal/handler/openapi.json
index 3d60ca2..dd4a2e9 100644
--- a/api/internal/handler/openapi.json
+++ b/api/internal/handler/openapi.json
@@ -10,7 +10,8 @@
   "tags": [
     { "name": "products" },
     { "name": "catalog" },
-    { "name": "meta" }
+    { "name": "meta" },
+    { "name": "account" }
   ],
   "security": [{ "ApiKeyHeader": [] }, { "BearerKey": [] }, {}],
   "paths": {
@@ -114,6 +115,35 @@
         "parameters": [{ "name": "id", "in": "path", "required": true, "schema": { "type": "string", "format": "uuid" } }],
         "responses": { "200": { "description": "Source" }, "404": { "$ref": "#/components/responses/NotFound" } }
       }
+    },
+    "/register": {
+      "post": {
+        "tags": ["account"],
+        "summary": "Register an account and issue an API key",
+        "description": "Self-service registration; returns the plaintext API key exactly once.",
+        "security": [],
+        "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "required": ["email", "password"], "properties": { "email": { "type": "string", "format": "email" }, "password": { "type": "string", "minLength": 8 } } } } } },
+        "responses": { "201": { "description": "Account created; plaintext key returned once" }, "400": { "description": "Invalid email or weak password" }, "409": { "description": "Email already registered" } }
+      }
+    },
+    "/account": {
+      "post": {
+        "tags": ["account"],
+        "summary": "View account key metadata and cumulative quota usage",
+        "security": [],
+        "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "required": ["email", "password"], "properties": { "email": { "type": "string", "format": "email" }, "password": { "type": "string" } } } } } },
+        "responses": { "200": { "description": "Account info with quota usage" }, "401": { "description": "Invalid credentials" } }
+      }
+    },
+    "/account/regenerate": {
+      "post": {
+        "tags": ["account"],
+        "summary": "Revoke the current key and issue a new one",
+        "description": "Cumulative usage carries over; returns the plaintext key exactly once.",
+        "security": [],
+        "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "required": ["email", "password"], "properties": { "email": { "type": "string", "format": "email" }, "password": { "type": "string" } } } } } },
+        "responses": { "200": { "description": "New plaintext key returned once" }, "401": { "description": "Invalid credentials" } }
+      }
     }
   },
   "components": {
diff --git a/api/internal/ratelimit/ratelimit.go b/api/internal/ratelimit/ratelimit.go
index 0ef6f3c..e7d06be 100644
--- a/api/internal/ratelimit/ratelimit.go
+++ b/api/internal/ratelimit/ratelimit.go
@@ -116,6 +116,45 @@ func (l *Limiter) RecordUsage(ctx context.Context, keyID string) {
 	_, _ = pipe.Exec(ctx)
 }
 
+// IncrTotal increments the lifetime call counter for subject and returns the
+// new total. The counter never expires; it is the cumulative number of calls
+// attributed to a caller (an API key id, or "ip:<addr>" for anonymous callers).
+// Fails open returning 0 on any error so quota enforcement never takes the API
+// down.
+func (l *Limiter) IncrTotal(ctx context.Context, subject string) int64 {
+	if !l.Enabled() || subject == "" {
+		return 0
+	}
+	n, err := l.rdb.Incr(ctx, "usage:total:"+subject).Result()
+	if err != nil {
+		return 0
+	}
+	return n
+}
+
+// CopyTotal carries a lifetime counter from one subject to another, used when a
+// key is regenerated so a caller cannot reset their cumulative quota. Best
+// effort: a missing or zero source counter is a no-op.
+func (l *Limiter) CopyTotal(ctx context.Context, from, to string) {
+	if !l.Enabled() || from == "" || to == "" {
+		return
+	}
+	n, err := l.rdb.Get(ctx, "usage:total:"+from).Int64()
+	if err != nil || n == 0 {
+		return
+	}
+	l.rdb.Set(ctx, "usage:total:"+to, n, 0)
+}
+
+// TotalUsed reads the lifetime call counter for subject without incrementing.
+func (l *Limiter) TotalUsed(ctx context.Context, subject string) int64 {
+	if !l.Enabled() || subject == "" {
+		return 0
+	}
+	n, _ := l.rdb.Get(ctx, "usage:total:"+subject).Int64()
+	return n
+}
+
 // Usage reads aggregated usage for a key. Returns a zero-value stat on error.
 func (l *Limiter) Usage(ctx context.Context, keyID string) UsageStat {
 	var st UsageStat
diff --git a/api/internal/store/account.go b/api/internal/store/account.go
new file mode 100644
index 0000000..b0d9411
--- /dev/null
+++ b/api/internal/store/account.go
@@ -0,0 +1,169 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+	"golang.org/x/crypto/bcrypt"
+
+	"github.com/baicai2026-baicai/goods/api/internal/apikey"
+)
+
+// ErrEmailTaken is returned when registering an email that already exists.
+var ErrEmailTaken = errors.New("email already registered")
+
+// Account is a self-registered public-API user and its current key metadata.
+type Account struct {
+	ID              string `json:"id"`
+	Email           string `json:"email"`
+	KeyID           string `json:"-"`
+	KeyPrefix       string `json:"key_prefix"`
+	RateLimitPerMin int    `json:"rate_limit_per_min"`
+	QuotaTotal      int64  `json:"quota_total"`
+}
+
+// bcryptDummyHash is compared against on unknown-email logins to keep timing
+// roughly constant and avoid leaking which emails are registered.
+const bcryptDummyHash = "$2a$10$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy"
+
+func isUniqueViolation(err error) bool {
+	var pgErr *pgconn.PgError
+	return errors.As(err, &pgErr) && pgErr.Code == "23505"
+}
+
+// RegisterUser creates an account plus a self-issued API key with the given
+// per-minute rate and cumulative quota, returning the plaintext key (shown
+// once). Email uniqueness is case-insensitive; ErrEmailTaken signals a dupe.
+func (s *Store) RegisterUser(ctx context.Context, email, password string, ratePerMin int, quotaTotal int64) (plaintext string, acct Account, err error) {
+	email = strings.TrimSpace(email)
+	pwHash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return "", Account{}, err
+	}
+	key, keyHash, prefix, err := apikey.Generate()
+	if err != nil {
+		return "", Account{}, err
+	}
+
+	tx, err := s.pool.Begin(ctx)
+	if err != nil {
+		return "", Account{}, err
+	}
+	defer func() { _ = tx.Rollback(ctx) }()
+
+	var keyID string
+	if err = tx.QueryRow(ctx,
+		`INSERT INTO api_key (name, key_prefix, key_hash, owner_email, tier, rate_limit_per_min, quota_total, created_by)
+		 VALUES ($1,$2,$3,$4,'registered',$5,$6,'self-register') RETURNING id`,
+		"user:"+strings.ToLower(email), prefix, keyHash, email, ratePerMin, quotaTotal,
+	).Scan(&keyID); err != nil {
+		return "", Account{}, err
+	}
+
+	var userID string
+	if err = tx.QueryRow(ctx,
+		`INSERT INTO app_user (email, password_hash, api_key_id) VALUES ($1,$2,$3) RETURNING id`,
+		email, string(pwHash), keyID,
+	).Scan(&userID); err != nil {
+		if isUniqueViolation(err) {
+			return "", Account{}, ErrEmailTaken
+		}
+		return "", Account{}, err
+	}
+
+	if err = tx.Commit(ctx); err != nil {
+		return "", Account{}, err
+	}
+	return key, Account{
+		ID: userID, Email: email, KeyID: keyID, KeyPrefix: prefix,
+		RateLimitPerMin: ratePerMin, QuotaTotal: quotaTotal,
+	}, nil
+}
+
+// Authenticate verifies an email/password pair and returns the account with its
+// current (non-revoked) key metadata. Returns ErrNotFound on unknown email or
+// wrong password.
+func (s *Store) Authenticate(ctx context.Context, email, password string) (Account, error) {
+	email = strings.TrimSpace(email)
+	var (
+		userID, pwHash string
+		keyID          *string
+	)
+	err := s.pool.QueryRow(ctx,
+		`SELECT id, password_hash, api_key_id FROM app_user WHERE lower(email) = lower($1)`, email,
+	).Scan(&userID, &pwHash, &keyID)
+	if errors.Is(err, pgx.ErrNoRows) {
+		_ = bcrypt.CompareHashAndPassword([]byte(bcryptDummyHash), []byte(password))
+		return Account{}, ErrNotFound
+	}
+	if err != nil {
+		return Account{}, err
+	}
+	if err := bcrypt.CompareHashAndPassword([]byte(pwHash), []byte(password)); err != nil {
+		return Account{}, ErrNotFound
+	}
+
+	acct := Account{ID: userID, Email: email}
+	if keyID != nil {
+		acct.KeyID = *keyID
+		_ = s.pool.QueryRow(ctx,
+			`SELECT key_prefix, rate_limit_per_min, quota_total
+			 FROM api_key WHERE id = $1 AND revoked_at IS NULL`, *keyID,
+		).Scan(&acct.KeyPrefix, &acct.RateLimitPerMin, &acct.QuotaTotal)
+	}
+	return acct, nil
+}
+
+// RegenerateKey verifies credentials, revokes the account's current key, and
+// issues a fresh one with the same rate/quota, returning the plaintext key and
+// the previous key id (so cumulative usage can be carried over). Returns
+// ErrNotFound on bad credentials.
+func (s *Store) RegenerateKey(ctx context.Context, email, password string, ratePerMin int, quotaTotal int64) (plaintext string, acct Account, oldKeyID string, err error) {
+	cur, err := s.Authenticate(ctx, email, password)
+	if err != nil {
+		return "", Account{}, "", err
+	}
+	key, keyHash, prefix, err := apikey.Generate()
+	if err != nil {
+		return "", Account{}, "", err
+	}
+
+	oldKeyID = cur.KeyID
+
+	tx, err := s.pool.Begin(ctx)
+	if err != nil {
+		return "", Account{}, "", err
+	}
+	defer func() { _ = tx.Rollback(ctx) }()
+
+	if oldKeyID != "" {
+		if _, err = tx.Exec(ctx,
+			`UPDATE api_key SET revoked_at = now() WHERE id = $1`, oldKeyID); err != nil {
+			return "", Account{}, "", err
+		}
+	}
+	var newKeyID string
+	if err = tx.QueryRow(ctx,
+		`INSERT INTO api_key (name, key_prefix, key_hash, owner_email, tier, rate_limit_per_min, quota_total, created_by)
+		 VALUES ($1,$2,$3,$4,'registered',$5,$6,'self-register') RETURNING id`,
+		"user:"+strings.ToLower(cur.Email), prefix, keyHash, cur.Email, ratePerMin, quotaTotal,
+	).Scan(&newKeyID); err != nil {
+		return "", Account{}, "", err
+	}
+	if _, err = tx.Exec(ctx,
+		`UPDATE app_user SET api_key_id = $1 WHERE id = $2`, newKeyID, cur.ID); err != nil {
+		return "", Account{}, "", err
+	}
+	if err = tx.Commit(ctx); err != nil {
+		return "", Account{}, "", err
+	}
+
+	cur.KeyID = newKeyID
+	cur.KeyPrefix = prefix
+	cur.RateLimitPerMin = ratePerMin
+	cur.QuotaTotal = quotaTotal
+	return key, cur, oldKeyID, nil
+}
diff --git a/api/internal/store/account_test.go b/api/internal/store/account_test.go
new file mode 100644
index 0000000..1b810cc
--- /dev/null
+++ b/api/internal/store/account_test.go
@@ -0,0 +1,99 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"github.com/baicai2026-baicai/goods/api/internal/apikey"
+)
+
+func testStore(t *testing.T) *Store {
+	t.Helper()
+	dsn := os.Getenv("OPENGOODS_DATABASE_URL")
+	if dsn == "" {
+		dsn = "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		t.Skipf("no database: %v", err)
+	}
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		t.Skipf("database not reachable: %v", err)
+	}
+	var hasUser bool
+	if err := pool.QueryRow(ctx, "SELECT to_regclass('public.app_user') IS NOT NULL").Scan(&hasUser); err != nil || !hasUser {
+		pool.Close()
+		t.Skip("migrations not applied")
+	}
+	t.Cleanup(pool.Close)
+	return New(pool)
+}
+
+func TestRegisterAuthenticateRegenerate(t *testing.T) {
+	s := testStore(t)
+	ctx := context.Background()
+	email := fmt.Sprintf("user-%d@example.com", time.Now().UnixNano())
+
+	t.Cleanup(func() {
+		_, _ = s.pool.Exec(ctx, "DELETE FROM app_user WHERE lower(email)=lower($1)", email)
+		_, _ = s.pool.Exec(ctx, "DELETE FROM api_key WHERE owner_email=$1", email)
+	})
+
+	key, acct, err := s.RegisterUser(ctx, email, "supersecret", 300, 100000)
+	if err != nil {
+		t.Fatalf("register: %v", err)
+	}
+	if key == "" || acct.KeyPrefix == "" || acct.QuotaTotal != 100000 || acct.RateLimitPerMin != 300 {
+		t.Fatalf("unexpected account: %+v key=%q", acct, key)
+	}
+
+	// The issued key resolves via the public auth path with its quota attached.
+	k, err := s.APIKeyByHash(ctx, apikey.Hash(key))
+	if err != nil {
+		t.Fatalf("APIKeyByHash: %v", err)
+	}
+	if k.QuotaTotal != 100000 || k.RateLimitPerMin != 300 {
+		t.Fatalf("key metadata mismatch: %+v", k)
+	}
+
+	// Duplicate email is rejected.
+	if _, _, err := s.RegisterUser(ctx, email, "anotherpass", 300, 100000); !errors.Is(err, ErrEmailTaken) {
+		t.Fatalf("expected ErrEmailTaken, got %v", err)
+	}
+
+	// Wrong password fails; correct password authenticates.
+	if _, err := s.Authenticate(ctx, email, "wrong"); !errors.Is(err, ErrNotFound) {
+		t.Fatalf("expected ErrNotFound for bad password, got %v", err)
+	}
+	got, err := s.Authenticate(ctx, email, "supersecret")
+	if err != nil {
+		t.Fatalf("authenticate: %v", err)
+	}
+	if got.KeyPrefix != acct.KeyPrefix {
+		t.Fatalf("authenticate key prefix = %q want %q", got.KeyPrefix, acct.KeyPrefix)
+	}
+
+	// Regeneration revokes the old key and issues a new one.
+	newKey, regen, oldKeyID, err := s.RegenerateKey(ctx, email, "supersecret", 300, 100000)
+	if err != nil {
+		t.Fatalf("regenerate: %v", err)
+	}
+	if newKey == key || oldKeyID != acct.KeyID || regen.KeyID == oldKeyID {
+		t.Fatalf("regenerate did not rotate key: old=%s new=%+v", oldKeyID, regen)
+	}
+	if _, err := s.APIKeyByHash(ctx, apikey.Hash(key)); !errors.Is(err, ErrNotFound) {
+		t.Fatalf("old key should be revoked, got %v", err)
+	}
+	if _, err := s.APIKeyByHash(ctx, apikey.Hash(newKey)); err != nil {
+		t.Fatalf("new key should be active: %v", err)
+	}
+}
diff --git a/api/internal/store/store.go b/api/internal/store/store.go
index 41b9222..b494e47 100644
--- a/api/internal/store/store.go
+++ b/api/internal/store/store.go
@@ -453,6 +453,7 @@ type APIKey struct {
 	ID              string
 	Name            string
 	RateLimitPerMin int
+	QuotaTotal      int64
 }
 
 // APIKeyByHash returns the active (non-revoked) key matching a SHA-256 hash,
@@ -460,9 +461,9 @@ type APIKey struct {
 func (s *Store) APIKeyByHash(ctx context.Context, hash string) (*APIKey, error) {
 	var k APIKey
 	err := s.pool.QueryRow(ctx,
-		`SELECT id, name, rate_limit_per_min
+		`SELECT id, name, rate_limit_per_min, quota_total
 		 FROM api_key WHERE key_hash = $1 AND revoked_at IS NULL`, hash,
-	).Scan(&k.ID, &k.Name, &k.RateLimitPerMin)
+	).Scan(&k.ID, &k.Name, &k.RateLimitPerMin, &k.QuotaTotal)
 	if errors.Is(err, pgx.ErrNoRows) {
 		return nil, ErrNotFound
 	}
diff --git a/migrations/0011_api_quota.down.sql b/migrations/0011_api_quota.down.sql
new file mode 100644
index 0000000..af048be
--- /dev/null
+++ b/migrations/0011_api_quota.down.sql
@@ -0,0 +1,10 @@
+DROP TABLE IF EXISTS app_user;
+
+-- Demote any self-registered keys before restoring the narrower tier check.
+UPDATE api_key SET tier = 'free' WHERE tier = 'registered';
+
+ALTER TABLE api_key DROP CONSTRAINT IF EXISTS api_key_tier_chk;
+ALTER TABLE api_key ADD CONSTRAINT api_key_tier_chk
+    CHECK (tier IN ('free', 'partner', 'internal'));
+
+ALTER TABLE api_key DROP COLUMN IF EXISTS quota_total;
diff --git a/migrations/0011_api_quota.up.sql b/migrations/0011_api_quota.up.sql
new file mode 100644
index 0000000..36cc2cb
--- /dev/null
+++ b/migrations/0011_api_quota.up.sql
@@ -0,0 +1,27 @@
+-- Cumulative usage quotas + self-service user registration for the public API.
+--
+-- The free anonymous tier is capped at a lifetime number of calls (enforced in
+-- Redis, keyed by client IP). To keep calling beyond the free quota a caller
+-- registers an account and self-issues an API key with a higher quota.
+-- quota_total = 0 means unlimited.
+--
+-- Registration is the one place the public server writes to PostgreSQL (it
+-- inserts an app_user and its api_key); every other public route stays
+-- read-only. Request counting still lives entirely in Redis.
+
+ALTER TABLE api_key ADD COLUMN IF NOT EXISTS quota_total BIGINT NOT NULL DEFAULT 0;
+
+ALTER TABLE api_key DROP CONSTRAINT IF EXISTS api_key_tier_chk;
+ALTER TABLE api_key ADD CONSTRAINT api_key_tier_chk
+    CHECK (tier IN ('free', 'registered', 'partner', 'internal'));
+
+CREATE TABLE IF NOT EXISTS app_user (
+    id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    email         TEXT NOT NULL,
+    password_hash TEXT NOT NULL,
+    api_key_id    UUID REFERENCES api_key (id) ON DELETE SET NULL,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+-- Case-insensitive uniqueness so each email registers at most once.
+CREATE UNIQUE INDEX IF NOT EXISTS idx_app_user_email ON app_user (lower(email));
diff --git a/public-frontend/src/App.tsx b/public-frontend/src/App.tsx
index 822fddd..dfb27db 100644
--- a/public-frontend/src/App.tsx
+++ b/public-frontend/src/App.tsx
@@ -1,16 +1,18 @@
 import { useEffect, useState } from "react";
-import { Boxes, Search, PlusCircle, Code2 } from "lucide-react";
+import { Boxes, Search, PlusCircle, Code2, KeyRound } from "lucide-react";
 import Home from "./components/Home";
 import ProductView from "./components/ProductView";
 import Contribute from "./components/Contribute";
 import ApiDocs from "./components/ApiDocs";
+import Account from "./components/Account";
 import { api } from "./api";
 
 type View =
   | { name: "home" }
   | { name: "product"; id: string }
   | { name: "contribute" }
-  | { name: "api" };
+  | { name: "api" }
+  | { name: "account" };
 
 export default function App() {
   const [view, setView] = useState<View>({ name: "home" });
@@ -59,6 +61,14 @@ export default function App() {
             >
               <Code2 className="w-4 h-4" /> API
             </button>
+            <button
+              className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
+                view.name === "account" ? "bg-emerald-50 text-emerald-700" : "text-gray-600 hover:bg-gray-100"
+              }`}
+              onClick={() => setView({ name: "account" })}
+            >
+              <KeyRound className="w-4 h-4" /> API 密钥
+            </button>
           </nav>
         </div>
       </header>
@@ -77,7 +87,8 @@ export default function App() {
         {view.name === "contribute" && (
           <Contribute onDone={() => setView({ name: "home" })} />
         )}
-        {view.name === "api" && <ApiDocs />}
+        {view.name === "api" && <ApiDocs onRegister={() => setView({ name: "account" })} />}
+        {view.name === "account" && <Account />}
       </main>
 
       <footer className="border-t bg-white">
diff --git a/public-frontend/src/api.ts b/public-frontend/src/api.ts
index a1fec27..086d830 100644
--- a/public-frontend/src/api.ts
+++ b/public-frontend/src/api.ts
@@ -36,6 +36,23 @@ export interface Stats {
   min_score: number;
 }
 
+export interface KeyResponse {
+  email: string;
+  api_key: string;
+  key_prefix: string;
+  rate_limit_per_min: number;
+  quota_total: number;
+}
+
+export interface AccountInfo {
+  email: string;
+  key_prefix: string;
+  rate_limit_per_min: number;
+  quota_total: number;
+  quota_used: number;
+  quota_remaining: number;
+}
+
 export const api = {
   stats: () => req<Stats>(`/api/v1/stats`),
   search: (q: string, page = 1, size = 20, filters: SearchFilters = {}) => {
@@ -55,4 +72,19 @@ export const api = {
       method: "POST",
       body: JSON.stringify(input),
     }),
+  register: (email: string, password: string) =>
+    req<KeyResponse>(`/api/v1/register`, {
+      method: "POST",
+      body: JSON.stringify({ email, password }),
+    }),
+  account: (email: string, password: string) =>
+    req<AccountInfo>(`/api/v1/account`, {
+      method: "POST",
+      body: JSON.stringify({ email, password }),
+    }),
+  regenerate: (email: string, password: string) =>
+    req<KeyResponse>(`/api/v1/account/regenerate`, {
+      method: "POST",
+      body: JSON.stringify({ email, password }),
+    }),
 };
diff --git a/public-frontend/src/components/Account.tsx b/public-frontend/src/components/Account.tsx
new file mode 100644
index 0000000..16c8158
--- /dev/null
+++ b/public-frontend/src/components/Account.tsx
@@ -0,0 +1,192 @@
+import { useState } from "react";
+import { Check, Copy, KeyRound, AlertTriangle } from "lucide-react";
+import { api, type AccountInfo, type KeyResponse } from "../api";
+
+function KeyReveal({ data }: { data: KeyResponse }) {
+  const [copied, setCopied] = useState(false);
+  return (
+    <div className="mt-4 rounded-lg border border-emerald-200 bg-emerald-50 p-4">
+      <div className="flex items-start gap-2 text-amber-700 text-sm">
+        <AlertTriangle className="w-4 h-4 mt-0.5 shrink-0" />
+        <span>请立即复制保存此密钥，它只显示这一次，无法再次查看。</span>
+      </div>
+      <div className="mt-3 flex items-center gap-2">
+        <code className="flex-1 break-all bg-white border rounded-md px-3 py-2 text-sm font-mono text-gray-800">
+          {data.api_key}
+        </code>
+        <button
+          onClick={async () => {
+            try {
+              await navigator.clipboard.writeText(data.api_key);
+              setCopied(true);
+              setTimeout(() => setCopied(false), 1200);
+            } catch {
+              /* clipboard unavailable */
+            }
+          }}
+          className="text-gray-400 hover:text-gray-600 shrink-0"
+          title="复制"
+        >
+          {copied ? <Check className="w-5 h-5 text-emerald-600" /> : <Copy className="w-5 h-5" />}
+        </button>
+      </div>
+      <div className="mt-3 text-sm text-gray-600">
+        配额：每分钟 <strong>{data.rate_limit_per_min}</strong> 次 · 累计{" "}
+        <strong>{data.quota_total.toLocaleString()}</strong> 次
+      </div>
+      <div className="mt-2 text-xs text-gray-500">
+        调用时通过请求头携带：
+        <code className="font-mono">X-API-Key: {data.api_key.slice(0, 12)}…</code>
+      </div>
+    </div>
+  );
+}
+
+export default function Account() {
+  const [mode, setMode] = useState<"register" | "manage">("register");
+  const [email, setEmail] = useState("");
+  const [password, setPassword] = useState("");
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [issued, setIssued] = useState<KeyResponse | null>(null);
+  const [info, setInfo] = useState<AccountInfo | null>(null);
+
+  const reset = () => {
+    setError(null);
+    setIssued(null);
+    setInfo(null);
+  };
+
+  async function submit(e: React.FormEvent) {
+    e.preventDefault();
+    reset();
+    if (password.length < 8) {
+      setError("密码至少需要 8 位");
+      return;
+    }
+    setLoading(true);
+    try {
+      if (mode === "register") {
+        setIssued(await api.register(email, password));
+      } else {
+        setInfo(await api.account(email, password));
+      }
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "操作失败");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  async function regenerate() {
+    reset();
+    setLoading(true);
+    try {
+      setIssued(await api.regenerate(email, password));
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "操作失败");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  return (
+    <div className="max-w-xl mx-auto space-y-5">
+      <div className="bg-white border rounded-lg p-5">
+        <h1 className="flex items-center gap-2 text-2xl font-bold text-gray-800">
+          <KeyRound className="w-6 h-6 text-emerald-600" /> API 密钥
+        </h1>
+        <p className="mt-2 text-sm text-gray-600 leading-relaxed">
+          匿名调用免费，但每个来源 IP 累计共 <strong>1000</strong> 次。注册一个账号即可自助领取专属 API
+          密钥，获得更高的每分钟频率与累计调用配额。
+        </p>
+
+        <div className="mt-4 inline-flex rounded-md border bg-gray-50 p-0.5 text-sm">
+          <button
+            className={`px-4 py-1.5 rounded ${
+              mode === "register" ? "bg-white shadow-sm text-emerald-700" : "text-gray-500"
+            }`}
+            onClick={() => {
+              setMode("register");
+              reset();
+            }}
+          >
+            注册领取
+          </button>
+          <button
+            className={`px-4 py-1.5 rounded ${
+              mode === "manage" ? "bg-white shadow-sm text-emerald-700" : "text-gray-500"
+            }`}
+            onClick={() => {
+              setMode("manage");
+              reset();
+            }}
+          >
+            查看 / 重置
+          </button>
+        </div>
+
+        <form onSubmit={submit} className="mt-4 space-y-3">
+          <div>
+            <label className="block text-sm text-gray-600 mb-1">邮箱</label>
+            <input
+              type="email"
+              required
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+              placeholder="you@example.com"
+              className="w-full border rounded-md px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-emerald-500"
+            />
+          </div>
+          <div>
+            <label className="block text-sm text-gray-600 mb-1">密码（至少 8 位）</label>
+            <input
+              type="password"
+              required
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+              placeholder="••••••••"
+              className="w-full border rounded-md px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-emerald-500"
+            />
+          </div>
+          {error && <div className="text-sm text-red-600">{error}</div>}
+          <button
+            type="submit"
+            disabled={loading}
+            className="w-full bg-emerald-600 text-white rounded-md py-2 text-sm font-medium hover:bg-emerald-700 disabled:opacity-50"
+          >
+            {loading ? "处理中…" : mode === "register" ? "注册并领取密钥" : "查询账号"}
+          </button>
+        </form>
+
+        {issued && <KeyReveal data={issued} />}
+
+        {info && (
+          <div className="mt-4 rounded-lg border bg-gray-50 p-4 text-sm text-gray-700 space-y-1.5">
+            <div>
+              邮箱：<span className="font-medium">{info.email}</span>
+            </div>
+            <div>
+              密钥前缀：<code className="font-mono">{info.key_prefix}…</code>
+            </div>
+            <div>
+              每分钟频率：<strong>{info.rate_limit_per_min}</strong> 次
+            </div>
+            <div>
+              累计配额：已用 <strong>{info.quota_used.toLocaleString()}</strong> /{" "}
+              {info.quota_total.toLocaleString()} 次（剩余{" "}
+              <strong className="text-emerald-600">{info.quota_remaining.toLocaleString()}</strong>）
+            </div>
+            <button
+              onClick={regenerate}
+              disabled={loading}
+              className="mt-2 text-emerald-600 hover:underline disabled:opacity-50"
+            >
+              忘记密钥？重置并生成新密钥
+            </button>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
diff --git a/public-frontend/src/components/ApiDocs.tsx b/public-frontend/src/components/ApiDocs.tsx
index a2081f0..eb7680e 100644
--- a/public-frontend/src/components/ApiDocs.tsx
+++ b/public-frontend/src/components/ApiDocs.tsx
@@ -102,7 +102,7 @@ function Endpoint({
   );
 }
 
-export default function ApiDocs() {
+export default function ApiDocs({ onRegister }: { onRegister?: () => void }) {
   return (
     <div className="space-y-5">
       <div className="bg-white border rounded-lg p-5">
@@ -117,7 +117,11 @@ export default function ApiDocs() {
             基础地址：<code className="font-mono bg-gray-100 rounded px-1.5 py-0.5">{BASE}</code>
           </div>
           <ul className="mt-2 list-disc pl-5 text-gray-600 space-y-1">
-            <li>无需 API Key / Token 即可直接 GET；带 Key 可获得更高频率上限（见下文「鉴权与限流」）。</li>
+            <li>
+              无需 API Key / Token 即可直接 GET；匿名调用按来源 IP 累计共 <strong>1000</strong> 次，
+              用满后需<button onClick={onRegister} className="text-emerald-600 hover:underline">注册账号</button>
+              领取更高配额密钥（见下文「鉴权与配额」）。
+            </li>
             <li>
               分页参数 <code className="font-mono">page</code>（默认 1）、
               <code className="font-mono">size</code>（默认 20，最大 100）。
@@ -132,10 +136,13 @@ export default function ApiDocs() {
       </div>
 
       <div className="bg-white border rounded-lg p-5">
-        <h2 className="text-lg font-semibold text-gray-800">鉴权与限流</h2>
+        <h2 className="text-lg font-semibold text-gray-800">鉴权与配额</h2>
         <p className="mt-2 text-gray-600 text-sm leading-relaxed">
-          API 默认<strong>匿名可用</strong>：无需任何凭证即可调用，按来源 IP 计入一个较低的默认频率额度。
-          如需更高额度并让用量归属到你，可在运营方申请一枚 API Key，请求时通过请求头携带：
+          API 默认<strong>匿名可用</strong>：无需任何凭证即可调用，但按来源 IP 计一个
+          <strong>累计总配额（共 1000 次）</strong>，用满后返回
+          <code className="font-mono">403</code>（错误码 <code className="font-mono">quota_exhausted</code>），
+          需<button onClick={onRegister} className="text-emerald-600 hover:underline">注册账号</button>
+          自助领取更高配额的 API Key。注册得到的密钥拥有更高的每分钟频率与累计调用配额，请求时通过请求头携带：
         </p>
         <div className="mt-3">
           <Code>{`# 二选一
@@ -143,7 +150,7 @@ curl -H "X-API-Key: og_live_xxxxxxxx" ${BASE}/products/search?q=牛奶
 curl -H "Authorization: Bearer og_live_xxxxxxxx" ${BASE}/products/search?q=牛奶`}</Code>
         </div>
         <p className="mt-3 text-gray-600 text-sm leading-relaxed">
-          采用<strong>固定窗口</strong>限流（每分钟）。每个响应都会回写以下响应头，便于客户端自适应：
+          同时采用<strong>每分钟固定窗口</strong>频率限制与<strong>累计总配额</strong>两层控制。每个响应都会回写以下响应头，便于客户端自适应：
         </p>
         <table className="mt-3 w-full text-sm">
           <thead className="text-gray-400 text-left">
@@ -169,12 +176,26 @@ curl -H "Authorization: Bearer og_live_xxxxxxxx" ${BASE}/products/search?q=牛
               <td className="pr-4 py-0.5 font-mono text-gray-700">Retry-After</td>
               <td className="py-0.5 text-gray-600">超额时返回，建议等待的秒数</td>
             </tr>
+            <tr>
+              <td className="pr-4 py-0.5 font-mono text-gray-700">X-Quota-Limit</td>
+              <td className="py-0.5 text-gray-600">累计总配额上限</td>
+            </tr>
+            <tr>
+              <td className="pr-4 py-0.5 font-mono text-gray-700">X-Quota-Used</td>
+              <td className="py-0.5 text-gray-600">已累计使用的调用次数</td>
+            </tr>
+            <tr>
+              <td className="pr-4 py-0.5 font-mono text-gray-700">X-Quota-Remaining</td>
+              <td className="py-0.5 text-gray-600">累计配额剩余可用次数</td>
+            </tr>
           </tbody>
         </table>
         <p className="mt-3 text-gray-600 text-sm leading-relaxed">
-          超过额度返回 <code className="font-mono">429 Too Many Requests</code>，错误码
-          <code className="font-mono">rate_limited</code>；无效或已吊销的 Key 返回
-          <code className="font-mono">401</code>，错误码 <code className="font-mono">invalid_api_key</code>。
+          每分钟超额返回 <code className="font-mono">429 Too Many Requests</code>（错误码
+          <code className="font-mono">rate_limited</code>）；累计配额用尽返回
+          <code className="font-mono">403</code>（错误码 <code className="font-mono">quota_exhausted</code>）；
+          无效或已吊销的 Key 返回 <code className="font-mono">401</code>（错误码
+          <code className="font-mono">invalid_api_key</code>）。
         </p>
       </div>
 
@@ -322,6 +343,70 @@ curl -H "Authorization: Bearer og_live_xxxxxxxx" ${BASE}/products/search?q=牛
 }`}
       />
 
+      <Endpoint
+        method="POST"
+        path="/api/v1/register"
+        title="注册账号并领取 API 密钥"
+        desc="用邮箱 + 密码（至少 8 位）注册，自助领取一枚更高配额的 API 密钥。明文密钥只在本次响应返回一次，请妥善保存。"
+        params={[
+          { name: "email", required: true, desc: "邮箱（唯一）" },
+          { name: "password", required: true, desc: "密码，至少 8 位" },
+        ]}
+        example={`curl -X POST ${BASE}/register \\
+  -H "Content-Type: application/json" \\
+  -d '{"email":"you@example.com","password":"your-password"}'`}
+        response={`{
+  "email": "you@example.com",
+  "api_key": "og_live_xxxxxxxxxxxx",
+  "key_prefix": "og_live_xxxx",
+  "rate_limit_per_min": 300,
+  "quota_total": 100000
+}`}
+      />
+
+      <Endpoint
+        method="POST"
+        path="/api/v1/account"
+        title="查看账号与配额用量"
+        desc="用邮箱 + 密码查询当前密钥前缀、频率/累计配额上限及已用量（不返回明文密钥）。"
+        params={[
+          { name: "email", required: true, desc: "注册邮箱" },
+          { name: "password", required: true, desc: "账号密码" },
+        ]}
+        example={`curl -X POST ${BASE}/account \\
+  -H "Content-Type: application/json" \\
+  -d '{"email":"you@example.com","password":"your-password"}'`}
+        response={`{
+  "email": "you@example.com",
+  "key_prefix": "og_live_xxxx",
+  "rate_limit_per_min": 300,
+  "quota_total": 100000,
+  "quota_used": 1234,
+  "quota_remaining": 98766
+}`}
+      />
+
+      <Endpoint
+        method="POST"
+        path="/api/v1/account/regenerate"
+        title="重置 API 密钥"
+        desc="吊销当前密钥并生成新密钥（累计用量会延续，不会因重置而清零）。明文新密钥只返回一次。"
+        params={[
+          { name: "email", required: true, desc: "注册邮箱" },
+          { name: "password", required: true, desc: "账号密码" },
+        ]}
+        example={`curl -X POST ${BASE}/account/regenerate \\
+  -H "Content-Type: application/json" \\
+  -d '{"email":"you@example.com","password":"your-password"}'`}
+        response={`{
+  "email": "you@example.com",
+  "api_key": "og_live_yyyyyyyyyyyy",
+  "key_prefix": "og_live_yyyy",
+  "rate_limit_per_min": 300,
+  "quota_total": 100000
+}`}
+      />
+
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