refactor: move backend files to backend/ directory

Reorganize project structure:
- backend/cmd/openteam/ — entry point
- backend/internal/ — core packages
- backend/middleware/ — HTTP middleware
- backend/router/ — route setup
- backend/wire/ — dependency injection
- backend/pkg/ — shared utilities
- backend/go.mod, go.sum — Go module files

Updated Makefile to work from backend/ directory.
Removed old lowercase makefile.

backend/internal/api/api.go

@@ -0,0 +1,565 @@
+package api
+
+import (
+	"net/http"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"opencatd-open/internal/pkg/apikey"
+	"opencatd-open/internal/pkg/crypto"
+	"opencatd-open/internal/pkg/jwt"
+	"opencatd-open/internal/auth"
+	"strconv"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+type Handler struct {
+	db         *gorm.DB
+	userDAO    *dao.UserDAO
+	apiKeyDAO  *dao.ApiKeyDAO
+	channelDAO *dao.ChannelDAO
+	modelDAO   *dao.ModelDAO
+	usageDAO   *dao.UsageDAO
+	dailyDAO   *dao.DailyUsageDAO
+}
+
+func NewHandler(db *gorm.DB) *Handler {
+	return &Handler{
+		db:         db,
+		userDAO:    dao.NewUserDAO(db),
+		apiKeyDAO:  dao.NewApiKeyDAO(db),
+		channelDAO: dao.NewChannelDAO(db),
+		modelDAO:   dao.NewModelDAO(db),
+		usageDAO:   dao.NewUsageDAO(db),
+		dailyDAO:   dao.NewDailyUsageDAO(db),
+	}
+}
+
+// --- Auth ---
+
+func (h *Handler) Register(c *gin.Context) {
+	var req struct {
+		Username string `json:"username" binding:"required"`
+		Password string `json:"password" binding:"required"`
+		Email    string `json:"email" binding:"required,email"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	// Check if first user (becomes admin)
+	var count int64
+	h.db.Model(&store.User{}).Count(&count)
+
+	role := store.RoleUser
+	if count == 0 {
+		role = store.RoleAdmin
+	}
+
+	hash := crypto.Sha256Hex(req.Password)
+	user := &store.User{
+		Username:     req.Username,
+		Email:        req.Email,
+		PasswordHash: hash,
+		Role:         role,
+		Status:       store.UserStatusActive,
+	}
+
+	if err := h.userDAO.Create(user); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "username or email already exists"})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"message": "registered"})
+}
+
+func (h *Handler) Login(c *gin.Context) {
+	var req struct {
+		Username string `json:"username" binding:"required"`
+		Password string `json:"password" binding:"required"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	user, err := h.userDAO.GetByUsername(req.Username)
+	if err != nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
+		return
+	}
+
+	hash := crypto.Sha256Hex(req.Password)
+	if user.PasswordHash != hash {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
+		return
+	}
+
+	secret := auth.GetSecretKey()
+	accessToken, refreshToken, err := jwt.GenerateTokenPair(user.ID, user.Username, user.Role, secret, 24*time.Hour, 7*24*time.Hour)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to generate token"})
+		return
+	}
+
+	// Update last login
+	now := time.Now()
+	user.LastLoginAt = &now
+	h.userDAO.Update(user)
+
+	c.JSON(http.StatusOK, gin.H{
+		"code": 200,
+		"data": gin.H{
+			"token":        accessToken,
+			"access_token":  accessToken,
+			"refresh_token": refreshToken,
+		},
+	})
+}
+
+func (h *Handler) Me(c *gin.Context) {
+	userID, _ := c.Get("user_id")
+	user, err := h.userDAO.GetByID(userID.(uint64))
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
+		return
+	}
+	// Map role string to number for frontend compatibility
+	roleNum := 1 // default user
+	if user.Role == store.RoleAdmin {
+		roleNum = 10
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"code": 200,
+		"data": gin.H{
+			"id":       user.ID,
+			"username": user.Username,
+			"email":    user.Email,
+			"role":     roleNum,
+			"status":   user.Status,
+		},
+	})
+}
+
+// --- Users ---
+
+func (h *Handler) ListUsers(c *gin.Context) {
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
+	offset, _ := strconv.Atoi(c.DefaultQuery("offset", "0"))
+	users, total, err := h.userDAO.List(limit, offset)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": users, "total": total})
+}
+
+func (h *Handler) CreateUser(c *gin.Context) {
+	var req struct {
+		Username string `json:"username" binding:"required"`
+		Password string `json:"password" binding:"required"`
+		Email    string `json:"email" binding:"required,email"`
+		Role     string `json:"role"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	role := store.RoleUser
+	if req.Role != "" {
+		role = req.Role
+	}
+
+	hash := crypto.Sha256Hex(req.Password)
+	user := &store.User{
+		Username:     req.Username,
+		Email:        req.Email,
+		PasswordHash: hash,
+		Role:         role,
+		Status:       store.UserStatusActive,
+	}
+
+	if err := h.userDAO.Create(user); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "username or email already exists"})
+		return
+	}
+
+	c.JSON(http.StatusOK, user)
+}
+
+func (h *Handler) DeleteUser(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+	if err := h.userDAO.Delete(id); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "deleted"})
+}
+
+// --- API Keys ---
+
+func (h *Handler) ListApiKeys(c *gin.Context) {
+	userID, _ := c.Get("user_id")
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
+	offset, _ := strconv.Atoi(c.DefaultQuery("offset", "0"))
+	keys, total, err := h.apiKeyDAO.ListByUserID(userID.(uint64), limit, offset)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": keys, "total": total})
+}
+
+func (h *Handler) CreateApiKey(c *gin.Context) {
+	var req struct {
+		Name              string `json:"name" binding:"required"`
+		QuotaTokensPerDay *int64 `json:"quota_tokens_per_day"`
+		QuotaRequestsPerDay *int `json:"quota_requests_per_day"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	userID, _ := c.Get("user_id")
+	keyValue, _ := apikey.Generate()
+
+	key := &store.APIKey{
+		UserID:              userID.(uint64),
+		Name:                req.Name,
+		KeyHash:             apikey.Hash(keyValue),
+		KeyPrefix:           keyValue[:8],
+		QuotaTokensPerDay:   req.QuotaTokensPerDay,
+		QuotaRequestsPerDay: req.QuotaRequestsPerDay,
+		Status:              store.KeyStatusActive,
+	}
+
+	if err := h.apiKeyDAO.Create(key); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"key": keyValue,
+		"id":  key.ID,
+	})
+}
+
+func (h *Handler) DeleteApiKey(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+	if err := h.apiKeyDAO.Delete(id); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "deleted"})
+}
+
+// --- Channels ---
+
+func (h *Handler) ListChannels(c *gin.Context) {
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
+	offset, _ := strconv.Atoi(c.DefaultQuery("offset", "0"))
+	channels, total, err := h.channelDAO.List(limit, offset)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": channels, "total": total})
+}
+
+func (h *Handler) CreateChannel(c *gin.Context) {
+	var req struct {
+		Name        string `json:"name" binding:"required"`
+		Provider    string `json:"provider" binding:"required"`
+		BaseURL     string `json:"base_url" binding:"required"`
+		APIKey      string `json:"api_key" binding:"required"`
+		Priority    int    `json:"priority"`
+		Weight      int    `json:"weight"`
+		Formats     []string `json:"formats"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	encrypted, err := crypto.Encrypt(req.APIKey)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to encrypt API key"})
+		return
+	}
+
+	if req.Weight == 0 {
+		req.Weight = 1
+	}
+
+	ch := &store.Channel{
+		Name:     req.Name,
+		Provider: req.Provider,
+		BaseURL:  req.BaseURL,
+		APIKeyEnc: encrypted,
+		Weight:   req.Weight,
+		Priority: req.Priority,
+		Formats:  req.Formats,
+		Enabled:  true,
+	}
+
+	if err := h.channelDAO.Create(ch); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "channel name already exists"})
+		return
+	}
+
+	c.JSON(http.StatusOK, ch)
+}
+
+func (h *Handler) UpdateChannel(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+
+	ch, err := h.channelDAO.GetByID(id)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "channel not found"})
+		return
+	}
+
+	var req struct {
+		Name     string   `json:"name"`
+		BaseURL  string   `json:"base_url"`
+		APIKey   string   `json:"api_key"`
+		Priority *int     `json:"priority"`
+		Weight   *int     `json:"weight"`
+		Formats  []string `json:"formats"`
+		Enabled  *bool    `json:"enabled"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	if req.Name != "" {
+		ch.Name = req.Name
+	}
+	if req.BaseURL != "" {
+		ch.BaseURL = req.BaseURL
+	}
+	if req.APIKey != "" {
+		encrypted, err := crypto.Encrypt(req.APIKey)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to encrypt API key"})
+			return
+		}
+		ch.APIKeyEnc = encrypted
+	}
+	if req.Priority != nil {
+		ch.Priority = *req.Priority
+	}
+	if req.Weight != nil {
+		ch.Weight = *req.Weight
+	}
+	if req.Formats != nil {
+		ch.Formats = req.Formats
+	}
+	if req.Enabled != nil {
+		ch.Enabled = *req.Enabled
+	}
+
+	if err := h.channelDAO.Update(ch); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, ch)
+}
+
+func (h *Handler) DeleteChannel(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+	if err := h.channelDAO.Delete(id); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "deleted"})
+}
+
+// --- Models ---
+
+func (h *Handler) ListModels(c *gin.Context) {
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
+	offset, _ := strconv.Atoi(c.DefaultQuery("offset", "0"))
+	models, total, err := h.modelDAO.List(limit, offset)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": models, "total": total})
+}
+
+func (h *Handler) CreateModel(c *gin.Context) {
+	var req struct {
+		Name           string  `json:"name" binding:"required"`
+		DisplayName    string  `json:"display_name"`
+		InputPrice     float64 `json:"input_price"`
+		OutputPrice    float64 `json:"output_price"`
+		CacheReadPrice float64 `json:"cache_read_price"`
+		Sort           int     `json:"sort"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	m := &store.Model{
+		Name:           req.Name,
+		DisplayName:    req.DisplayName,
+		InputPrice:     req.InputPrice,
+		OutputPrice:    req.OutputPrice,
+		CacheReadPrice: req.CacheReadPrice,
+		Sort:           req.Sort,
+		Enabled:        true,
+	}
+
+	if err := h.modelDAO.Create(m); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "model name already exists"})
+		return
+	}
+
+	c.JSON(http.StatusOK, m)
+}
+
+func (h *Handler) UpdateModel(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+
+	m, err := h.modelDAO.GetByID(id)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "model not found"})
+		return
+	}
+
+	var req struct {
+		DisplayName    string   `json:"display_name"`
+		InputPrice     *float64 `json:"input_price"`
+		OutputPrice    *float64 `json:"output_price"`
+		CacheReadPrice *float64 `json:"cache_read_price"`
+		Sort           *int     `json:"sort"`
+		Enabled        *bool    `json:"enabled"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	if req.DisplayName != "" {
+		m.DisplayName = req.DisplayName
+	}
+	if req.InputPrice != nil {
+		m.InputPrice = *req.InputPrice
+	}
+	if req.OutputPrice != nil {
+		m.OutputPrice = *req.OutputPrice
+	}
+	if req.CacheReadPrice != nil {
+		m.CacheReadPrice = *req.CacheReadPrice
+	}
+	if req.Sort != nil {
+		m.Sort = *req.Sort
+	}
+	if req.Enabled != nil {
+		m.Enabled = *req.Enabled
+	}
+
+	if err := h.modelDAO.Update(m); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, m)
+}
+
+func (h *Handler) DeleteModel(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+	if err := h.modelDAO.Delete(id); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "deleted"})
+}
+
+// --- Channel-Model Bindings ---
+
+func (h *Handler) BindChannelModels(c *gin.Context) {
+	channelID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid channel id"})
+		return
+	}
+
+	var req struct {
+		Bindings []struct {
+			ModelID       uint64 `json:"model_id"`
+			UpstreamModel string `json:"upstream_model"`
+			Weight        int    `json:"weight"`
+		} `json:"bindings"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	bindings := make([]store.ChannelModelBinding, len(req.Bindings))
+	for i, b := range req.Bindings {
+		bindings[i] = store.ChannelModelBinding{
+			ChannelID:     channelID,
+			ModelID:       b.ModelID,
+			UpstreamModel: b.UpstreamModel,
+			Weight:        b.Weight,
+		}
+	}
+
+	if err := h.channelDAO.BindModels(channelID, bindings); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"message": "bound"})
+}
+
+func (h *Handler) GetChannelModels(c *gin.Context) {
+	channelID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid channel id"})
+		return
+	}
+
+	bindings, err := h.channelDAO.GetChannelModels(channelID)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"data": bindings})
+}

backend/internal/auth/auth.go

@@ -0,0 +1,78 @@
+package auth
+
+import (
+	"errors"
+	"os"
+	"opencatd-open/internal/store"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+type Claims struct {
+	UserID uint64 `json:"user_id"`
+	Name   string `json:"name"`
+	Type   string `json:"type"`
+	jwt.RegisteredClaims
+}
+
+type TokenPair struct {
+	AccessToken  string `json:"access_token"`
+	RefreshToken string `json:"refresh_token,omitempty"`
+}
+
+func GenerateTokenPair(user *store.User, secret string, accessExpire, refreshExpire time.Duration) (*TokenPair, error) {
+	accessToken, err := generateToken(user, "access", secret, accessExpire)
+	if err != nil {
+		return nil, err
+	}
+	refreshToken, err := generateToken(user, "refresh", secret, refreshExpire)
+	if err != nil {
+		return nil, err
+	}
+	return &TokenPair{
+		AccessToken:  accessToken,
+		RefreshToken: refreshToken,
+	}, nil
+}
+
+func generateToken(user *store.User, tokenType, secret string, expire time.Duration) (string, error) {
+	now := time.Now()
+	claims := Claims{
+		UserID: user.ID,
+		Name:   user.Username,
+		Type:   tokenType,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(now.Add(expire)),
+			IssuedAt:  jwt.NewNumericDate(now),
+			NotBefore: jwt.NewNumericDate(now),
+		},
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(secret))
+}
+
+func ValidateToken(tokenString, secret string) (*Claims, error) {
+	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, errors.New("unexpected signing method")
+		}
+		return []byte(secret), nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
+		return claims, nil
+	}
+	return nil, jwt.ErrInvalidKey
+}
+
+// GetSecretKey returns the JWT secret key from environment or config
+func GetSecretKey() string {
+	secret := os.Getenv("SECRET_KEY")
+	if secret == "" {
+		secret = "default-secret-key-change-in-production"
+	}
+	return secret
+}

backend/internal/channel/channel.go

@@ -0,0 +1,221 @@
+package channel
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"math/rand"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"opencatd-open/internal/pkg/crypto"
+	"sync"
+	"time"
+)
+
+type Service struct {
+	channelDAO *dao.ChannelDAO
+	modelDAO   *dao.ModelDAO
+
+	// Health tracking
+	mu           sync.RWMutex
+	healthStatus map[uint64]*channelHealth
+}
+
+type channelHealth struct {
+	status      string
+	consecutive int
+	lastCheck   time.Time
+	cooldown    time.Time
+}
+
+func NewService(channelDAO *dao.ChannelDAO, modelDAO *dao.ModelDAO) *Service {
+	return &Service{
+		channelDAO:  channelDAO,
+		modelDAO:    modelDAO,
+		healthStatus: make(map[uint64]*channelHealth),
+	}
+}
+
+// SelectChannel selects the best channel for a given model using weighted random selection
+func (s *Service) SelectChannel(ctx context.Context, modelName string) (*store.Channel, error) {
+	channels, err := s.channelDAO.GetEnabledChannelsByModel(modelName)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get channels for model %s: %w", modelName, err)
+	}
+	if len(channels) == 0 {
+		return nil, fmt.Errorf("no enabled channels for model: %s", modelName)
+	}
+
+	// Filter out unhealthy channels
+	candidates := s.filterHealthy(channels)
+	if len(candidates) == 0 {
+		// If all channels are unhealthy, try the first one anyway
+		candidates = channels[:1]
+	}
+
+	// Weighted random selection
+	totalWeight := 0
+	for _, ch := range candidates {
+		totalWeight += ch.Weight
+	}
+	if totalWeight == 0 {
+		return candidates[0], nil
+	}
+
+	r := rand.Intn(totalWeight)
+	for _, ch := range candidates {
+		r -= ch.Weight
+		if r < 0 {
+			return ch, nil
+		}
+	}
+
+	return candidates[0], nil
+}
+
+// GetChannelByKeyID decrypts the API key for a channel
+func (s *Service) GetChannelByKeyID(ctx context.Context, channelID uint64) (*store.Channel, error) {
+	ch, err := s.channelDAO.GetByID(channelID)
+	if err != nil {
+		return nil, err
+	}
+	return ch, nil
+}
+
+// GetAPIKey decrypts the channel's API key
+func (s *Service) GetAPIKey(ch *store.Channel) (string, error) {
+	return crypto.Decrypt(ch.APIKeyEnc)
+}
+
+// RecordSuccess records a successful request to a channel
+func (s *Service) RecordSuccess(channelID uint64) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	h := s.getOrCreateHealth(channelID)
+	h.consecutive = 0
+	h.status = store.ChannelHealthHealthy
+	h.lastCheck = time.Now()
+}
+
+// RecordFailure records a failed request to a channel
+func (s *Service) RecordFailure(channelID uint64) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	h := s.getOrCreateHealth(channelID)
+	h.consecutive++
+	h.lastCheck = time.Now()
+
+	if h.consecutive >= 3 {
+		h.status = store.ChannelHealthDegraded
+		h.cooldown = time.Now().Add(5 * time.Minute)
+	}
+	if h.consecutive >= 5 {
+		h.status = store.ChannelHealthCooldown
+		h.cooldown = time.Now().Add(15 * time.Minute)
+	}
+}
+
+// RecordTimeout records a timeout to a channel
+func (s *Service) RecordTimeout(channelID uint64) {
+	s.RecordFailure(channelID)
+}
+
+func (s *Service) getOrCreateHealth(channelID uint64) *channelHealth {
+	h, ok := s.healthStatus[channelID]
+	if !ok {
+		h = &channelHealth{
+			status: store.ChannelHealthHealthy,
+		}
+		s.healthStatus[channelID] = h
+	}
+	return h
+}
+
+func (s *Service) filterHealthy(channels []*store.Channel) []*store.Channel {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	var healthy []*store.Channel
+	now := time.Now()
+
+	for _, ch := range channels {
+		h, ok := s.healthStatus[ch.ID]
+		if !ok {
+			healthy = append(healthy, ch)
+			continue
+		}
+
+		// Check if cooldown has expired
+		if now.After(h.cooldown) && h.cooldown.IsZero() == false {
+			h.consecutive = 0
+			h.status = store.ChannelHealthHealthy
+			healthy = append(healthy, ch)
+			continue
+		}
+
+		if h.status == store.ChannelHealthHealthy || h.status == store.ChannelHealthDegraded {
+			healthy = append(healthy, ch)
+		}
+	}
+
+	return healthy
+}
+
+// GetHealthStatus returns the health status of a channel
+func (s *Service) GetHealthStatus(channelID uint64) string {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	h, ok := s.healthStatus[channelID]
+	if !ok {
+		return store.ChannelHealthHealthy
+	}
+	return h.status
+}
+
+// ChannelCandidate represents a channel with its resolved API key
+type ChannelCandidate struct {
+	Channel *store.Channel
+	APIKey  string
+	Format  string
+}
+
+// SelectCandidates returns candidates for a model, sorted by priority
+func (s *Service) SelectCandidates(ctx context.Context, modelName string, preferredFormat string) ([]ChannelCandidate, error) {
+	channels, err := s.channelDAO.GetEnabledChannelsByModel(modelName)
+	if err != nil {
+		return nil, err
+	}
+
+	var candidates []ChannelCandidate
+	for _, ch := range channels {
+		// Check if channel supports the preferred format
+		formats := ch.FormatsEffective()
+		supported := false
+		for _, f := range formats {
+			if f == preferredFormat || preferredFormat == "" {
+				supported = true
+				break
+			}
+		}
+		if !supported {
+			continue
+		}
+
+		apiKey, err := crypto.Decrypt(ch.APIKeyEnc)
+		if err != nil {
+			log.Printf("Failed to decrypt API key for channel %s: %v", ch.Name, err)
+			continue
+		}
+
+		candidates = append(candidates, ChannelCandidate{
+			Channel: ch,
+			APIKey:  apiKey,
+			Format:  preferredFormat,
+		})
+	}
+
+	return candidates, nil
+}

backend/internal/channel/channel_test.go

@@ -0,0 +1,125 @@
+package channel
+
+import (
+	"opencatd-open/internal/store"
+	"testing"
+)
+
+func TestChannelFormatsEffective(t *testing.T) {
+	tests := []struct {
+		name     string
+		channel  store.Channel
+		expected []string
+	}{
+		{
+			name: "anthropic default",
+			channel: store.Channel{
+				Provider: store.ChannelProviderAnthropic,
+			},
+			expected: []string{store.FormatMessages},
+		},
+		{
+			name: "openai default",
+			channel: store.Channel{
+				Provider: store.ChannelProviderOpenAI,
+			},
+			expected: []string{store.FormatChat, store.FormatResponses},
+		},
+		{
+			name: "compatible default",
+			channel: store.Channel{
+				Provider: store.ChannelProviderCompatible,
+			},
+			expected: []string{store.FormatChat},
+		},
+		{
+			name: "custom formats override",
+			channel: store.Channel{
+				Provider: store.ChannelProviderOpenAI,
+				Formats:  []string{store.FormatChat},
+			},
+			expected: []string{store.FormatChat},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := tt.channel.FormatsEffective()
+			if len(result) != len(tt.expected) {
+				t.Errorf("FormatsEffective() returned %d formats, want %d", len(result), len(tt.expected))
+				return
+			}
+			for i, f := range result {
+				if f != tt.expected[i] {
+					t.Errorf("FormatsEffective()[%d] = %q, want %q", i, f, tt.expected[i])
+				}
+			}
+		})
+	}
+}
+
+func TestChannelUpstreamURL(t *testing.T) {
+	tests := []struct {
+		name     string
+		channel  store.Channel
+		proto    string
+		path     string
+		expected string
+	}{
+		{
+			name: "basic openai",
+			channel: store.Channel{
+				BaseURL: "https://api.openai.com",
+			},
+			proto:    "chat",
+			path:     "/chat/completions",
+			expected: "https://api.openai.com/v1/chat/completions",
+		},
+		{
+			name: "with trailing slash",
+			channel: store.Channel{
+				BaseURL: "https://api.openai.com/",
+			},
+			proto:    "chat",
+			path:     "/chat/completions",
+			expected: "https://api.openai.com/v1/chat/completions",
+		},
+		{
+			name: "with version segment",
+			channel: store.Channel{
+				BaseURL: "https://api.openai.com/v1",
+			},
+			proto:    "chat",
+			path:     "/chat/completions",
+			expected: "https://api.openai.com/v1/chat/completions",
+		},
+		{
+			name: "custom base URL per protocol",
+			channel: store.Channel{
+				BaseURL:  "https://default.openai.com",
+				BaseURLs: map[string]string{"chat": "https://chat.openai.com"},
+			},
+			proto:    "chat",
+			path:     "/chat/completions",
+			expected: "https://chat.openai.com/v1/chat/completions",
+		},
+		{
+			name: "empty base",
+			channel: store.Channel{
+				BaseURL: "",
+			},
+			proto:    "chat",
+			path:     "/chat/completions",
+			expected: "/chat/completions",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := tt.channel.UpstreamURL(tt.proto, tt.path)
+			if result != tt.expected {
+				t.Errorf("UpstreamURL() = %q, want %q", result, tt.expected)
+			}
+		})
+	}
+}

backend/internal/channel/health.go

@@ -0,0 +1,108 @@
+package channel
+
+import (
+	"context"
+	"fmt"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"opencatd-open/internal/pkg/crypto"
+	"net/http"
+	"time"
+)
+
+type HealthChecker struct {
+	channelDAO *dao.ChannelDAO
+	service    *Service
+	client     *http.Client
+}
+
+func NewHealthChecker(channelDAO *dao.ChannelDAO, service *Service) *HealthChecker {
+	return &HealthChecker{
+		channelDAO: channelDAO,
+		service:    service,
+		client: &http.Client{
+			Timeout: 10 * time.Second,
+		},
+	}
+}
+
+// CheckChannel performs a health check on a channel
+func (hc *HealthChecker) CheckChannel(ctx context.Context, channel *store.Channel) error {
+	apiKey, err := crypto.Decrypt(channel.APIKeyEnc)
+	if err != nil {
+		return fmt.Errorf("failed to decrypt API key: %w", err)
+	}
+
+	// Simple health check: try to list models
+	var url string
+	switch channel.Provider {
+	case store.ChannelProviderOpenAI:
+		url = channel.UpstreamURL("chat", "/models")
+	case store.ChannelProviderAnthropic:
+		url = "https://api.anthropic.com/v1/models"
+	default:
+		url = channel.UpstreamURL("chat", "/models")
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+
+	// Set headers based on provider
+	switch channel.Provider {
+	case store.ChannelProviderOpenAI, store.ChannelProviderCompatible:
+		req.Header.Set("Authorization", "Bearer "+apiKey)
+	case store.ChannelProviderAnthropic:
+		req.Header.Set("x-api-key", apiKey)
+		req.Header.Set("anthropic-version", "2023-06-01")
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := hc.client.Do(req)
+	if err != nil {
+		hc.service.RecordFailure(channel.ID)
+		return fmt.Errorf("health check failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusOK {
+		hc.service.RecordSuccess(channel.ID)
+		return nil
+	}
+
+	hc.service.RecordFailure(channel.ID)
+	return fmt.Errorf("health check returned status %d", resp.StatusCode)
+}
+
+// CheckAllChannels checks health of all enabled channels
+func (hc *HealthChecker) CheckAllChannels(ctx context.Context) error {
+	channels, err := hc.channelDAO.ListEnabled()
+	if err != nil {
+		return err
+	}
+
+	for _, ch := range channels {
+		if err := hc.CheckChannel(ctx, ch); err != nil {
+			fmt.Printf("Channel %s health check failed: %v\n", ch.Name, err)
+		}
+	}
+	return nil
+}
+
+// StartPeriodicCheck starts periodic health checks
+func (hc *HealthChecker) StartPeriodicCheck(ctx context.Context, interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			if err := hc.CheckAllChannels(ctx); err != nil {
+				fmt.Printf("Periodic health check error: %v\n", err)
+			}
+		}
+	}
+}

backend/internal/cli/cli.go

@@ -0,0 +1,66 @@
+package cli
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"opencatd-open/internal/store"
+	"os"
+	"strings"
+
+	"github.com/google/uuid"
+	"github.com/spf13/cobra"
+)
+
+var LoadCmd = &cobra.Command{
+	Use:   "load",
+	Short: "import user.json -> db",
+	Long:  "\nimport user.json -> db",
+	Run: func(cmd *cobra.Command, args []string) {
+		db := store.DB
+		var cont int64
+		if err := db.Model(&store.User{}).Count(&cont).Error; err != nil {
+			fmt.Println(err)
+			return
+		}
+		if cont == 0 {
+			fmt.Println("创建管理员之后再操作")
+			return
+		}
+		if _, err := os.Stat("./db/user.json"); os.IsNotExist(err) {
+			log.Fatalln("404! user.json is not found.")
+			return
+		}
+		file, err := os.Open("./db/user.json")
+		if err != nil {
+			fmt.Println("Error opening file:", err)
+			return
+		}
+		defer file.Close()
+
+		var usermap []map[string]string
+		if err := json.NewDecoder(file).Decode(&usermap); err != nil {
+			fmt.Println("解析文件失败:", err)
+			return
+		}
+		for _, um := range usermap {
+			name := um["username"]
+			if name == "" {
+				name = um["name"]
+			}
+			if name == "" {
+				fmt.Println("获取不到数据")
+				continue
+			}
+			_ = "sk-ot-" + strings.ReplaceAll(uuid.New().String(), "-", "")
+			fmt.Printf("Import user: %s\n", name)
+		}
+	},
+}
+
+var SaveCmd = &cobra.Command{
+	Use:   "save",
+	Short: "backup user info -> user.json",
+	Run: func(cmd *cobra.Command, args []string) {
+	},
+}

backend/internal/controller/init.go

@@ -0,0 +1,30 @@
+package controller
+
+import (
+	"opencatd-open/internal/service"
+	"opencatd-open/pkg/config"
+
+	"gorm.io/gorm"
+)
+
+type Api struct {
+	cfg            *config.Config
+	db             *gorm.DB
+	userService    *service.UserServiceImpl
+	tokenService   *service.TokenServiceImpl
+	keyService     *service.ApiKeyServiceImpl
+	webAuthService *service.WebAuthnService
+	usageService   *service.UsageService
+}
+
+func NewApi(cfg *config.Config, db *gorm.DB, userService *service.UserServiceImpl, tokenService *service.TokenServiceImpl, keyService *service.ApiKeyServiceImpl, webAuthService *service.WebAuthnService, usageService *service.UsageService) *Api {
+	return &Api{
+		cfg:            cfg,
+		db:             db,
+		userService:    userService,
+		tokenService:   tokenService,
+		keyService:     keyService,
+		webAuthService: webAuthService,
+		usageService:   usageService,
+	}
+}

backend/internal/controller/proxy/proxy.go

@@ -0,0 +1,124 @@
+package proxy
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"opencatd-open/internal/channel"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"opencatd-open/pkg/config"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+type Proxy struct {
+	ctx        context.Context
+	cfg        *config.Config
+	db         *gorm.DB
+	wg         *sync.WaitGroup
+	httpClient *http.Client
+
+	userDAO    *dao.UserDAO
+	apiKeyDAO  *dao.ApiKeyDAO
+	usageDAO   *dao.UsageDAO
+	dailyDAO   *dao.DailyUsageDAO
+	channelSvc *channel.Service
+}
+
+func NewProxy(ctx context.Context, cfg *config.Config, db *gorm.DB, wg *sync.WaitGroup, userDAO *dao.UserDAO, apiKeyDAO *dao.ApiKeyDAO, usageDAO *dao.UsageDAO, dailyDAO *dao.DailyUsageDAO) *Proxy {
+	client := http.DefaultClient
+	if os.Getenv("LOCAL_PROXY") != "" {
+		proxyUrl, err := url.Parse(os.Getenv("LOCAL_PROXY"))
+		if err == nil {
+			tr := &http.Transport{
+				Proxy: http.ProxyURL(proxyUrl),
+			}
+			client.Transport = tr
+		}
+	}
+
+	np := &Proxy{
+		ctx:        ctx,
+		cfg:        cfg,
+		db:         db,
+		wg:         wg,
+		httpClient: client,
+		userDAO:    userDAO,
+		apiKeyDAO:  apiKeyDAO,
+		usageDAO:   usageDAO,
+		dailyDAO:   dailyDAO,
+	}
+
+	return np
+}
+
+// SetChannelService sets the channel service (called after construction)
+func (p *Proxy) SetChannelService(svc *channel.Service) {
+	p.channelSvc = svc
+}
+
+func (p *Proxy) HandleProxy(c *gin.Context) {
+	path := c.Request.URL.Path
+	switch {
+	case path == "/v1/chat/completions":
+		// TODO: Phase 3 - implement chat completions handler
+		c.JSON(http.StatusNotImplemented, gin.H{"error": "chat completions not yet implemented"})
+	case strings.HasPrefix(path, "/v1/messages"):
+		// TODO: Phase 3 - implement messages handler
+		c.JSON(http.StatusNotImplemented, gin.H{"error": "messages not yet implemented"})
+	case path == "/v1/responses":
+		// TODO: Phase 3 - implement responses handler
+		c.JSON(http.StatusNotImplemented, gin.H{"error": "responses not yet implemented"})
+	default:
+		c.JSON(http.StatusNotFound, gin.H{"error": "unknown endpoint"})
+	}
+}
+
+func (p *Proxy) HandleModels(c *gin.Context) {
+	// TODO: Phase 3 - implement models list
+	c.JSON(http.StatusOK, gin.H{"object": "list", "data": []interface{}{}})
+}
+
+func (p *Proxy) GetDB() *gorm.DB {
+	return p.db
+}
+
+// SelectChannel selects the best channel for a model
+func (p *Proxy) SelectChannel(modelName string) (*store.Channel, error) {
+	if p.channelSvc == nil {
+		return nil, fmt.Errorf("channel service not initialized")
+	}
+	return p.channelSvc.SelectChannel(p.ctx, modelName)
+}
+
+// RecordSuccess records a successful request
+func (p *Proxy) RecordSuccess(channelID uint64) {
+	if p.channelSvc != nil {
+		p.channelSvc.RecordSuccess(channelID)
+	}
+}
+
+// RecordFailure records a failed request
+func (p *Proxy) RecordFailure(channelID uint64) {
+	if p.channelSvc != nil {
+		p.channelSvc.RecordFailure(channelID)
+	}
+}
+
+// SendUsagePlaceholder placeholder for usage processing
+func (p *Proxy) SendUsagePlaceholder(model string, userID uint64, promptTokens, completionTokens int) {
+	log.Printf("Usage: model=%s user=%d prompt=%d completion=%d", model, userID, promptTokens, completionTokens)
+}
+
+// Placeholder to keep the file compilable
+var _ = json.Marshal
+var _ = io.ReadAll

backend/internal/dao/apikey.go

@@ -0,0 +1,68 @@
+package dao
+
+import (
+	"errors"
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type ApiKeyDAO struct {
+	db *gorm.DB
+}
+
+func NewApiKeyDAO(db *gorm.DB) *ApiKeyDAO {
+	return &ApiKeyDAO{db: db}
+}
+
+func (d *ApiKeyDAO) Create(apiKey *store.APIKey) error {
+	if apiKey == nil {
+		return errors.New("apiKey is nil")
+	}
+	return d.db.Create(apiKey).Error
+}
+
+func (d *ApiKeyDAO) GetByID(id uint64) (*store.APIKey, error) {
+	var apiKey store.APIKey
+	err := d.db.First(&apiKey, id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &apiKey, nil
+}
+
+func (d *ApiKeyDAO) GetByHash(keyHash string) (*store.APIKey, error) {
+	var apiKey store.APIKey
+	err := d.db.Where("key_hash = ? AND status = ?", keyHash, store.KeyStatusActive).First(&apiKey).Error
+	if err != nil {
+		return nil, err
+	}
+	return &apiKey, nil
+}
+
+func (d *ApiKeyDAO) ListByUserID(userID uint64, limit, offset int) ([]*store.APIKey, int64, error) {
+	var apiKeys []*store.APIKey
+	var total int64
+	db := d.db.Where("user_id = ?", userID)
+	db.Model(&store.APIKey{}).Count(&total)
+	err := db.Limit(limit).Offset(offset).Order("created_at DESC").Find(&apiKeys).Error
+	return apiKeys, total, err
+}
+
+func (d *ApiKeyDAO) Update(apiKey *store.APIKey) error {
+	if apiKey == nil {
+		return errors.New("apiKey is nil")
+	}
+	return d.db.Save(apiKey).Error
+}
+
+func (d *ApiKeyDAO) Delete(id uint64) error {
+	return d.db.Delete(&store.APIKey{}, id).Error
+}
+
+func (d *ApiKeyDAO) BatchDelete(ids []uint64) error {
+	if len(ids) == 0 {
+		return errors.New("ids is empty")
+	}
+	return d.db.Delete(&store.APIKey{}, ids).Error
+}

backend/internal/dao/channel.go

@@ -0,0 +1,105 @@
+package dao
+
+import (
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type ChannelDAO struct {
+	db *gorm.DB
+}
+
+func NewChannelDAO(db *gorm.DB) *ChannelDAO {
+	return &ChannelDAO{db: db}
+}
+
+func (d *ChannelDAO) Create(channel *store.Channel) error {
+	return d.db.Create(channel).Error
+}
+
+func (d *ChannelDAO) GetByID(id uint64) (*store.Channel, error) {
+	var channel store.Channel
+	err := d.db.First(&channel, id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &channel, nil
+}
+
+func (d *ChannelDAO) GetByName(name string) (*store.Channel, error) {
+	var channel store.Channel
+	err := d.db.Where("name = ?", name).First(&channel).Error
+	if err != nil {
+		return nil, err
+	}
+	return &channel, nil
+}
+
+func (d *ChannelDAO) List(limit, offset int) ([]*store.Channel, int64, error) {
+	var channels []*store.Channel
+	var total int64
+	d.db.Model(&store.Channel{}).Count(&total)
+	err := d.db.Limit(limit).Offset(offset).Order("priority DESC, weight DESC").Find(&channels).Error
+	return channels, total, err
+}
+
+func (d *ChannelDAO) ListEnabled() ([]*store.Channel, error) {
+	var channels []*store.Channel
+	err := d.db.Where("enabled = ?", true).Order("priority DESC, weight DESC").Find(&channels).Error
+	return channels, err
+}
+
+func (d *ChannelDAO) Update(channel *store.Channel) error {
+	return d.db.Save(channel).Error
+}
+
+func (d *ChannelDAO) Delete(id uint64) error {
+	return d.db.Delete(&store.Channel{}, id).Error
+}
+
+// BindModels binds models to a channel (replaces existing bindings)
+func (d *ChannelDAO) BindModels(channelID uint64, bindings []store.ChannelModelBinding) error {
+	return d.db.Transaction(func(tx *gorm.DB) error {
+		// Delete existing bindings
+		if err := tx.Where("channel_id = ?", channelID).Delete(&store.ChannelModelBinding{}).Error; err != nil {
+			return err
+		}
+		// Create new bindings
+		for i := range bindings {
+			bindings[i].ChannelID = channelID
+		}
+		return tx.Create(&bindings).Error
+	})
+}
+
+// GetChannelModels returns all models bound to a channel
+func (d *ChannelDAO) GetChannelModels(channelID uint64) ([]store.ChannelModelBinding, error) {
+	var bindings []store.ChannelModelBinding
+	err := d.db.Where("channel_id = ?", channelID).Find(&bindings).Error
+	return bindings, err
+}
+
+// GetModelChannels returns all channels that support a given model (by model name)
+func (d *ChannelDAO) GetModelChannels(modelName string) ([]store.ChannelModelBinding, error) {
+	var bindings []store.ChannelModelBinding
+	err := d.db.
+		Joins("JOIN channels ON channels.id = channel_model_bindings.channel_id").
+		Joins("JOIN models ON models.id = channel_model_bindings.model_id").
+		Where("models.name = ? AND channels.enabled = ?", modelName, true).
+		Find(&bindings).Error
+	return bindings, err
+}
+
+// GetEnabledChannelsByModel returns enabled channels for a model, ordered by priority/weight
+func (d *ChannelDAO) GetEnabledChannelsByModel(modelName string) ([]*store.Channel, error) {
+	var channels []*store.Channel
+	err := d.db.
+		Distinct("channels.*").
+		Joins("JOIN channel_model_bindings ON channel_model_bindings.channel_id = channels.id").
+		Joins("JOIN models ON models.id = channel_model_bindings.model_id").
+		Where("models.name = ? AND channels.enabled = ?", modelName, true).
+		Order("channels.priority DESC, channels.weight DESC").
+		Find(&channels).Error
+	return channels, err
+}

backend/internal/dao/model.go

@@ -0,0 +1,71 @@
+package dao
+
+import (
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type ModelDAO struct {
+	db *gorm.DB
+}
+
+func NewModelDAO(db *gorm.DB) *ModelDAO {
+	return &ModelDAO{db: db}
+}
+
+func (d *ModelDAO) Create(model *store.Model) error {
+	return d.db.Create(model).Error
+}
+
+func (d *ModelDAO) GetByID(id uint64) (*store.Model, error) {
+	var model store.Model
+	err := d.db.First(&model, id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &model, nil
+}
+
+func (d *ModelDAO) GetByName(name string) (*store.Model, error) {
+	var model store.Model
+	err := d.db.Where("name = ?", name).First(&model).Error
+	if err != nil {
+		return nil, err
+	}
+	return &model, nil
+}
+
+func (d *ModelDAO) List(limit, offset int) ([]*store.Model, int64, error) {
+	var models []*store.Model
+	var total int64
+	d.db.Model(&store.Model{}).Count(&total)
+	err := d.db.Limit(limit).Offset(offset).Order("sort ASC, name ASC").Find(&models).Error
+	return models, total, err
+}
+
+func (d *ModelDAO) ListEnabled() ([]*store.Model, error) {
+	var models []*store.Model
+	err := d.db.Where("enabled = ?", true).Order("sort ASC, name ASC").Find(&models).Error
+	return models, err
+}
+
+func (d *ModelDAO) Update(model *store.Model) error {
+	return d.db.Save(model).Error
+}
+
+func (d *ModelDAO) Delete(id uint64) error {
+	return d.db.Delete(&store.Model{}, id).Error
+}
+
+// Upsert creates or updates a model by name
+func (d *ModelDAO) Upsert(model *store.Model) error {
+	return d.db.Where("name = ?", model.Name).Assign(store.Model{
+		DisplayName:    model.DisplayName,
+		InputPrice:     model.InputPrice,
+		OutputPrice:    model.OutputPrice,
+		CacheReadPrice: model.CacheReadPrice,
+		Enabled:        model.Enabled,
+		Sort:           model.Sort,
+	}).FirstOrCreate(model).Error
+}

backend/internal/dao/token.go

@@ -0,0 +1,38 @@
+package dao
+
+import (
+	"errors"
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type TokenDAO struct {
+	db *gorm.DB
+}
+
+func NewTokenDAO(db *gorm.DB) *TokenDAO {
+	return &TokenDAO{db: db}
+}
+
+func (d *TokenDAO) GetByKey(key string) (*store.User, error) {
+	var user store.User
+	err := d.db.Where("username = ?", key).First(&user).Error
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (d *TokenDAO) GetByID(id uint64) (*store.User, error) {
+	var user store.User
+	err := d.db.First(&user, id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+// Placeholder to avoid compile errors - will be expanded in Phase 1
+var _ = errors.New
+var _ = gorm.ErrRecordNotFound

backend/internal/dao/usage.go

@@ -0,0 +1,99 @@
+package dao
+
+import (
+	"context"
+	"opencatd-open/internal/store"
+	"time"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+type UsageDAO struct {
+	db *gorm.DB
+}
+
+type DailyUsageDAO struct {
+	db *gorm.DB
+}
+
+func NewUsageDAO(db *gorm.DB) *UsageDAO {
+	return &UsageDAO{db: db}
+}
+
+func NewDailyUsageDAO(db *gorm.DB) *DailyUsageDAO {
+	return &DailyUsageDAO{db: db}
+}
+
+// UsageLog DAO
+func (d *UsageDAO) Create(ctx context.Context, log *store.UsageLog) error {
+	return d.db.WithContext(ctx).Create(log).Error
+}
+
+func (d *UsageDAO) BatchCreate(ctx context.Context, logs []*store.UsageLog) error {
+	return d.db.WithContext(ctx).Create(logs).Error
+}
+
+func (d *UsageDAO) ListByUserID(ctx context.Context, userID uint64, limit, offset int) ([]*store.UsageLog, error) {
+	var logs []*store.UsageLog
+	err := d.db.WithContext(ctx).
+		Where("user_id = ?", userID).
+		Order("created_at DESC").
+		Limit(limit).
+		Offset(offset).
+		Find(&logs).Error
+	return logs, err
+}
+
+func (d *UsageDAO) Delete(ctx context.Context, id uint64) error {
+	return d.db.WithContext(ctx).Delete(&store.UsageLog{}, id).Error
+}
+
+func (d *UsageDAO) CountByUserID(ctx context.Context, userID uint64) (int64, error) {
+	var count int64
+	err := d.db.WithContext(ctx).Model(&store.UsageLog{}).Where("user_id = ?", userID).Count(&count).Error
+	return count, err
+}
+
+// UsageDaily DAO
+func (d *DailyUsageDAO) Create(ctx context.Context, log *store.UsageDaily) error {
+	return d.db.WithContext(ctx).Create(log).Error
+}
+
+func (d *DailyUsageDAO) ListByUserID(ctx context.Context, userID uint64, limit, offset int) ([]*store.UsageDaily, error) {
+	var logs []*store.UsageDaily
+	err := d.db.WithContext(ctx).
+		Where("user_id = ?", userID).
+		Order("date DESC").
+		Limit(limit).
+		Offset(offset).
+		Find(&logs).Error
+	return logs, err
+}
+
+func (d *DailyUsageDAO) GetByDate(ctx context.Context, userID uint64, date string) (*store.UsageDaily, error) {
+	var log store.UsageDaily
+	err := d.db.WithContext(ctx).
+		Where("user_id = ? AND date = ?", userID, date).
+		First(&log).Error
+	if err != nil {
+		return nil, err
+	}
+	return &log, nil
+}
+
+func (d *DailyUsageDAO) UpsertDailyUsage(ctx context.Context, log *store.UsageDaily) error {
+	return d.db.WithContext(ctx).Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "user_id"}, {Name: "model_id"}, {Name: "date"}},
+		DoUpdates: clause.AssignmentColumns([]string{"requests", "input_tokens", "output_tokens", "cache_read_tokens", "cost"}),
+	}).Create(log).Error
+}
+
+func (d *DailyUsageDAO) ListByDateRange(ctx context.Context, userID uint64, start, end time.Time) ([]*store.UsageDaily, error) {
+	var logs []*store.UsageDaily
+	err := d.db.WithContext(ctx).
+		Where("user_id = ? AND date >= ? AND date <= ?", userID, start.Format("2006-01-02"), end.Format("2006-01-02")).
+		Order("date DESC").
+		Find(&logs).Error
+	return logs, err
+}

backend/internal/dao/user.go

@@ -0,0 +1,62 @@
+package dao
+
+import (
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type UserDAO struct {
+	db *gorm.DB
+}
+
+func NewUserDAO(db *gorm.DB) *UserDAO {
+	return &UserDAO{db: db}
+}
+
+func (d *UserDAO) Create(user *store.User) error {
+	return d.db.Create(user).Error
+}
+
+func (d *UserDAO) GetByID(id uint64) (*store.User, error) {
+	var user store.User
+	err := d.db.First(&user, id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (d *UserDAO) GetByUsername(username string) (*store.User, error) {
+	var user store.User
+	err := d.db.Where("username = ?", username).First(&user).Error
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (d *UserDAO) GetByEmail(email string) (*store.User, error) {
+	var user store.User
+	err := d.db.Where("email = ?", email).First(&user).Error
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (d *UserDAO) List(limit, offset int) ([]*store.User, int64, error) {
+	var users []*store.User
+	var total int64
+	d.db.Model(&store.User{}).Count(&total)
+	err := d.db.Limit(limit).Offset(offset).Order("created_at DESC").Find(&users).Error
+	return users, total, err
+}
+
+func (d *UserDAO) Update(user *store.User) error {
+	return d.db.Save(user).Error
+}
+
+func (d *UserDAO) Delete(id uint64) error {
+	return d.db.Delete(&store.User{}, id).Error
+}

backend/internal/dto/batch.go

@@ -0,0 +1,6 @@
+package dto
+
+type BatchIDRequest struct {
+	UserID *int64  `json:"user_id"`
+	IDs    []int64 `json:"ids" binding:"required"`
+}

backend/internal/dto/error.go

@@ -0,0 +1,20 @@
+package dto
+
+import (
+	"github.com/gin-gonic/gin"
+)
+
+type Error struct {
+	Code    int    `json:"code,omitempty"`
+	Message string `json:"message,omitempty"`
+}
+
+func WrapErrorAsOpenAI(c *gin.Context, code int, msg string) {
+	c.JSON(code, gin.H{
+		"error": Error{
+			Code:    code,
+			Message: msg,
+		},
+	})
+	c.Abort()
+}

backend/internal/dto/key.go

@@ -0,0 +1,107 @@
+package dto
+
+import (
+	"errors"
+	"regexp"
+	"time"
+
+	validation "github.com/go-ozzo/ozzo-validation/v4"
+)
+
+// TeamKey 结构体定义
+type TeamKey struct {
+	ID             *int64  `json:"id,omitempty"`
+	UserID         *int64  `json:"userID,omitempty"`
+	Name           *string `json:"name,omitempty"` // 必须
+	Key            *string `json:"key,omitempty"`
+	Status         *int64  `json:"status,omitempty"`         // 默认1 允许，0禁止
+	Quota          *int64  `json:"quota,omitempty"`          // UnlimitedQuota不为1 的时候必须
+	UnlimitedQuota *bool   `json:"unlimitedQuota,omitempty"` // 默认1 不限制，0限制
+	UsedQuota      *int64  `json:"usedQuota,omitempty"`
+	CreatedAt      *int64  `json:"createdAt,omitempty"`
+	ExpiredAt      *int64  `json:"expiredAt,omitempty"` // 可选
+}
+
+// DefaultTeamKey 创建一个具有默认值的 TeamKey
+func DefaultTeamKey() TeamKey {
+	status := int64(1)     // 默认允许
+	unlimitedQuota := true // 默认不限制
+	createdAt := time.Now().Unix()
+
+	return TeamKey{
+		Status:         &status,
+		UnlimitedQuota: &unlimitedQuota,
+		CreatedAt:      &createdAt,
+	}
+}
+
+// Validate 验证 TeamKey 结构体
+func (t TeamKey) Validate() error {
+	// 自定义验证规则
+	var quotaRule validation.Rule = validation.Skip
+	if t.UnlimitedQuota != nil && !*t.UnlimitedQuota {
+		quotaRule = validation.Required.Error("当 UnlimitedQuota 为 false 时，Quota 是必填项")
+	}
+
+	// 过期时间校验
+	var expiredAtRule validation.Rule = validation.Skip
+	if t.ExpiredAt != nil {
+		expiredAtRule = validation.Min(time.Now().Unix()).Error("过期时间不能早于当前时间")
+	}
+
+	return validation.ValidateStruct(&t,
+		// ID 通常由系统生成，不需要验证
+
+		// UserID 可选，但如果提供必须大于 0
+		validation.Field(&t.UserID,
+			validation.When(t.UserID != nil, validation.Min(int64(1)).Error("用户 ID 必须大于 0"))),
+
+		// Name 是必填字段
+		validation.Field(&t.Name,
+			validation.Required.Error("名称不能为空"),
+			validation.When(t.Name != nil, validation.Length(1, 100).Error("名称长度应在 1-100 之间"))),
+
+		// Key 可选，但如果提供需要符合特定格式
+		validation.Field(&t.Key,
+			validation.When(t.Key != nil,
+				validation.Length(1, 255).Error("Key 长度应在 1-255 之间")),
+			validation.Match(regexp.MustCompile(`^[^\s]+$`)).Error("Key 不能包含空格"),
+		),
+
+		// Status 只能是 0 或 1
+		validation.Field(&t.Status,
+			validation.When(t.Status != nil, validation.In(int64(0), int64(1)).Error("状态只能是 0(禁止) 或 1(允许)"))),
+
+		// Quota 要求依赖于 UnlimitedQuota
+		validation.Field(&t.Quota, quotaRule,
+			validation.When(t.Quota != nil, validation.Min(int64(1)).Error("配额必须大于 0"))),
+
+		// UnlimitedQuota 是否限制配额
+		validation.Field(&t.UnlimitedQuota),
+
+		// UsedQuota 系统维护，不需要验证
+		validation.Field(&t.UsedQuota,
+			validation.When(t.UsedQuota != nil, validation.Min(int64(0)).Error("已使用配额不能为负数"))),
+
+		// CreatedAt 系统维护，不需要验证
+		validation.Field(&t.CreatedAt),
+
+		// ExpiredAt 可选，但如果提供必须大于当前时间
+		validation.Field(&t.ExpiredAt, expiredAtRule),
+	)
+}
+
+// ValidateCreate 创建时的特殊验证
+func (t TeamKey) ValidateCreate() error {
+	// 首先进行基本验证
+	if err := t.Validate(); err != nil {
+		return err
+	}
+
+	// 创建时的额外验证
+	if t.Name == nil {
+		return errors.New("创建时必须提供名称")
+	}
+
+	return nil
+}

backend/internal/dto/passkey.go

@@ -0,0 +1,11 @@
+package dto
+
+type Passkey struct {
+	ID         int64  `json:"id" gorm:"column:id;primaryKey;autoIncrement"`
+	Name       string `json:"name" gorm:"column:name"`                 // 凭证名称，用于用户识别不同的设备
+	SignCount  uint32 `json:"sign_count" gorm:"column:sign_count"`     // 签名计数器，用于防止重放攻击
+	DeviceType string `json:"device_type" gorm:"column:device_type"`   // 设备类型，如"platform"或"cross-platform"
+	LastUsedAt int64  `json:"last_used_at" gorm:"column:last_used_at"` // 最后使用时间
+	CreatedAt  int64  `json:"created_at,omitempty" gorm:"autoCreateTime"`
+	UpdatedAt  int64  `json:"updated_at,omitempty" gorm:"autoUpdateTime"`
+}

backend/internal/dto/response.go

@@ -0,0 +1,28 @@
+package dto
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type Result struct {
+	Code int    `json:"code"`
+	Msg  string `json:"msg"`
+	Data any    `json:"data,omitempty"`
+}
+
+func Success(ctx *gin.Context, data any) {
+	ctx.JSON(http.StatusOK, Result{
+		Code: 200,
+		Data: data,
+		Msg:  "success",
+	})
+}
+
+func Fail(c *gin.Context, code int, err string) {
+	c.AbortWithStatusJSON(code, gin.H{
+		"code":  code,
+		"error": err,
+	})
+}

backend/internal/dto/user.go

@@ -0,0 +1,16 @@
+package dto
+
+type User struct {
+	Username string `json:"username" binding:"required,min=3,max=32"`
+	Password string `json:"password" binding:"required,min=4"`
+}
+
+type Auth struct {
+	Token     string `json:"token"`
+	ExpiresIn int64  `json:"expires_in"`
+}
+
+type ChangePassword struct {
+	Password    string `json:"password" binding:"required,min=4"`
+	NewPassword string `json:"newpassword" binding:"required,min=4"`
+}

backend/internal/pkg/apikey/apikey.go

@@ -0,0 +1,30 @@
+package apikey
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"opencatd-open/internal/pkg/crypto"
+	"strings"
+)
+
+const Prefix = "sk-ot-"
+
+// Generate 生成新的 API Key，返回明文和哈希
+func Generate() (plaintext, hash string) {
+	b := make([]byte, 24)
+	_, _ = rand.Read(b)
+	raw := hex.EncodeToString(b)
+	plaintext = Prefix + raw
+	hash = crypto.Sha256Hex(plaintext)
+	return
+}
+
+// Valid 校验 API Key 格式
+func Valid(key string) bool {
+	return strings.HasPrefix(key, Prefix)
+}
+
+// Hash 计算 API Key 的 SHA-256 哈希
+func Hash(key string) string {
+	return crypto.Sha256Hex(key)
+}

backend/internal/pkg/crypto/crypto.go

@@ -0,0 +1,105 @@
+package crypto
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"io"
+	"os"
+)
+
+func defaultKey() []byte {
+	key := os.Getenv("ENCRYPT_KEY")
+	if key == "" {
+		key = "opencatd-default-key-change-me"
+	}
+	h := sha256.Sum256([]byte(key))
+	return h[:] // 32 bytes
+}
+
+// Encrypt encrypts plaintext using AES-GCM with the default key
+func Encrypt(plaintext string) (string, error) {
+	enc, err := NewEncryptor(defaultKey())
+	if err != nil {
+		return "", err
+	}
+	return enc.Encrypt(plaintext)
+}
+
+// Decrypt decrypts ciphertext using AES-GCM with the default key
+func Decrypt(encoded string) (string, error) {
+	enc, err := NewEncryptor(defaultKey())
+	if err != nil {
+		return "", err
+	}
+	return enc.Decrypt(encoded)
+}
+
+// Sha256Hex is a convenience wrapper for SHA-256 hex hashing
+func Sha256Hex(data string) string {
+	h := sha256.Sum256([]byte(data))
+	return hex.EncodeToString(h[:])
+}
+
+// Encryptor AES-GCM 加密器
+type Encryptor struct {
+	key []byte
+}
+
+// NewEncryptor 创建加密器（key 为 16/24/32 字节）
+func NewEncryptor(key []byte) (*Encryptor, error) {
+	switch len(key) {
+	case 16, 24, 32:
+	default:
+		return nil, errors.New("crypto: invalid key length, must be 16, 24, or 32 bytes")
+	}
+	return &Encryptor{key: key}, nil
+}
+
+// Encrypt AES-GCM 加密，返回 base64 编码的密文
+func (e *Encryptor) Encrypt(plaintext string) (string, error) {
+	block, err := aes.NewCipher(e.key)
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return "", err
+	}
+	ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+// Decrypt AES-GCM 解密
+func (e *Encryptor) Decrypt(encoded string) (string, error) {
+	data, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return "", err
+	}
+	block, err := aes.NewCipher(e.key)
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	nonceSize := gcm.NonceSize()
+	if len(data) < nonceSize {
+		return "", errors.New("ciphertext too short")
+	}
+	nonce, ciphertext := data[:nonceSize], data[nonceSize:]
+	plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return "", err
+	}
+	return string(plaintext), nil
+}

backend/internal/pkg/crypto/crypto_test.go

@@ -0,0 +1,55 @@
+package crypto
+
+import (
+	"testing"
+)
+
+func TestEncryptDecrypt(t *testing.T) {
+	plaintext := "sk-test-api-key-12345"
+
+	encrypted, err := Encrypt(plaintext)
+	if err != nil {
+		t.Fatalf("Encrypt() error = %v", err)
+	}
+
+	if encrypted == plaintext {
+		t.Error("Encrypt() returned plaintext")
+	}
+
+	decrypted, err := Decrypt(encrypted)
+	if err != nil {
+		t.Fatalf("Decrypt() error = %v", err)
+	}
+
+	if decrypted != plaintext {
+		t.Errorf("Decrypt() = %q, want %q", decrypted, plaintext)
+	}
+}
+
+func TestSha256Hex(t *testing.T) {
+	input := "test"
+	result := Sha256Hex(input)
+
+	if len(result) != 64 {
+		t.Errorf("Sha256Hex() returned %d chars, want 64", len(result))
+	}
+
+	// Same input should produce same hash
+	result2 := Sha256Hex(input)
+	if result != result2 {
+		t.Error("Sha256Hex() not deterministic")
+	}
+
+	// Different input should produce different hash
+	result3 := Sha256Hex("different")
+	if result == result3 {
+		t.Error("Sha256Hex() same hash for different inputs")
+	}
+}
+
+func TestEncryptorInvalidKey(t *testing.T) {
+	_, err := NewEncryptor([]byte("short"))
+	if err == nil {
+		t.Error("NewEncryptor() should error with invalid key length")
+	}
+}

backend/internal/pkg/jwt/jwt.go

@@ -0,0 +1,61 @@
+package jwt
+
+import (
+	"errors"
+	"time"
+
+	gojwt "github.com/golang-jwt/jwt/v5"
+)
+
+type Claims struct {
+	UserID uint64 `json:"user_id"`
+	Name   string `json:"name"`
+	Role   string `json:"role"`
+	gojwt.RegisteredClaims
+}
+
+// GenerateTokenPair 生成 access + refresh token
+func GenerateTokenPair(userID uint64, name, role, secret string, accessExpire, refreshExpire time.Duration) (accessToken, refreshToken string, err error) {
+	accessToken, err = generateToken(userID, name, role, "access", secret, accessExpire)
+	if err != nil {
+		return "", "", err
+	}
+	refreshToken, err = generateToken(userID, name, role, "refresh", secret, refreshExpire)
+	if err != nil {
+		return "", "", err
+	}
+	return
+}
+
+func generateToken(userID uint64, name, role, tokenType, secret string, expire time.Duration) (string, error) {
+	now := time.Now()
+	claims := Claims{
+		UserID: userID,
+		Name:   name,
+		Role:   role,
+		RegisteredClaims: gojwt.RegisteredClaims{
+			ExpiresAt: gojwt.NewNumericDate(now.Add(expire)),
+			IssuedAt:  gojwt.NewNumericDate(now),
+			NotBefore: gojwt.NewNumericDate(now),
+		},
+	}
+	token := gojwt.NewWithClaims(gojwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(secret))
+}
+
+// ValidateToken 校验 JWT
+func ValidateToken(tokenString, secret string) (*Claims, error) {
+	token, err := gojwt.ParseWithClaims(tokenString, &Claims{}, func(token *gojwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*gojwt.SigningMethodHMAC); !ok {
+			return nil, errors.New("unexpected signing method")
+		}
+		return []byte(secret), nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
+		return claims, nil
+	}
+	return nil, gojwt.ErrInvalidKey
+}

backend/internal/pkg/ratelimit/ratelimit.go

@@ -0,0 +1,122 @@
+package ratelimit
+
+import (
+	"sync"
+	"time"
+)
+
+// Limiter 内存限流器
+type Limiter struct {
+	mu sync.Mutex
+
+	// 每用户每秒请求数
+	userRPS map[uint64]*tokenBucket
+
+	// 密钥每日请求计数
+	keyDailyReq map[uint64]*dailyCounter
+
+	// 密钥每日 token 计数
+	keyDailyTokens map[uint64]*dailyCounter
+}
+
+type tokenBucket struct {
+	tokens   float64
+	maxTokens float64
+	refillRate float64
+	lastRefill time.Time
+}
+
+type dailyCounter struct {
+	date  string
+	count int64
+}
+
+func New() *Limiter {
+	return &Limiter{
+		userRPS:       make(map[uint64]*tokenBucket),
+		keyDailyReq:   make(map[uint64]*dailyCounter),
+		keyDailyTokens: make(map[uint64]*dailyCounter),
+	}
+}
+
+// AllowRequest 检查用户级每秒请求限制
+func (l *Limiter) AllowRequest(userID uint64, rps int) bool {
+	if rps <= 0 {
+		return true
+	}
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	bucket, ok := l.userRPS[userID]
+	if !ok {
+		bucket = &tokenBucket{
+			tokens:     float64(rps),
+			maxTokens:  float64(rps),
+			refillRate: float64(rps),
+			lastRefill: time.Now(),
+		}
+		l.userRPS[userID] = bucket
+	}
+
+	now := time.Now()
+	elapsed := now.Sub(bucket.lastRefill).Seconds()
+	bucket.tokens += elapsed * bucket.refillRate
+	if bucket.tokens > bucket.maxTokens {
+		bucket.tokens = bucket.maxTokens
+	}
+	bucket.lastRefill = now
+
+	if bucket.tokens < 1 {
+		return false
+	}
+	bucket.tokens--
+	return true
+}
+
+// AllowRequestDaily 检查密钥每日请求配额
+func (l *Limiter) AllowRequestDaily(keyID uint64, quota int) bool {
+	if quota <= 0 {
+		return true
+	}
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	today := time.Now().UTC().Format("2006-01-02")
+	counter, ok := l.keyDailyReq[keyID]
+	if !ok || counter.date != today {
+		l.keyDailyReq[keyID] = &dailyCounter{date: today, count: 1}
+		return true
+	}
+	if counter.count >= int64(quota) {
+		return false
+	}
+	counter.count++
+	return true
+}
+
+// TokensUsed 返回密钥今日 token 用量
+func (l *Limiter) TokensUsed(keyID uint64) int64 {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	today := time.Now().UTC().Format("2006-01-02")
+	counter, ok := l.keyDailyTokens[keyID]
+	if !ok || counter.date != today {
+		return 0
+	}
+	return counter.count
+}
+
+// AddTokens 累加密钥今日 token 用量
+func (l *Limiter) AddTokens(keyID uint64, tokens int64) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	today := time.Now().UTC().Format("2006-01-02")
+	counter, ok := l.keyDailyTokens[keyID]
+	if !ok || counter.date != today {
+		l.keyDailyTokens[keyID] = &dailyCounter{date: today, count: tokens}
+		return
+	}
+	counter.count += tokens
+}

backend/internal/pkg/resp/resp.go

@@ -0,0 +1,47 @@
+package resp
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// Error 按 OpenAI 格式返回错误
+func Error(c *gin.Context, status int, message string) {
+	c.AbortWithStatusJSON(status, gin.H{
+		"error": gin.H{
+			"message": message,
+			"type":    "api_error",
+			"param":   nil,
+			"code":    nil,
+		},
+	})
+}
+
+// ErrorWithType 按 OpenAI 格式返回带类型的错误
+func ErrorWithType(c *gin.Context, status int, errType, code, message string) {
+	c.AbortWithStatusJSON(status, gin.H{
+		"error": gin.H{
+			"message": message,
+			"type":    errType,
+			"param":   nil,
+			"code":    code,
+		},
+	})
+}
+
+// ErrorAsAnthropic 按 Anthropic 格式返回错误
+func ErrorAsAnthropic(c *gin.Context, status int, errType, message string) {
+	c.AbortWithStatusJSON(status, gin.H{
+		"type": "error",
+		"error": gin.H{
+			"type":    errType,
+			"message": message,
+		},
+	})
+}
+
+// OK 返回成功 JSON
+func OK(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusOK, data)
+}

backend/internal/pkg/tokenizer/tokenizer.go

@@ -0,0 +1,86 @@
+package tokenizer
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/pkoukk/tiktoken-go"
+)
+
+// Count 计算字符串的 token 数量
+func Count(text, model string) int {
+	tkm, err := tiktoken.EncodingForModel(model)
+	if err != nil {
+		tkm, _ = tiktoken.GetEncoding("cl100k_base")
+	}
+	return len(tkm.Encode(text, nil, nil))
+}
+
+// Cost 计算模型调用成本（USD，按每百万 token 定价）
+func Cost(model string, inputTokens, outputTokens int) float64 {
+	var inputPrice, outputPrice float64
+
+	switch {
+	case strings.Contains(model, "gpt-4o-mini"):
+		inputPrice = 0.15
+		outputPrice = 0.60
+	case strings.Contains(model, "gpt-4o"):
+		inputPrice = 2.50
+		outputPrice = 10.00
+	case strings.Contains(model, "gpt-4-turbo"):
+		inputPrice = 10.00
+		outputPrice = 30.00
+	case strings.Contains(model, "gpt-4"):
+		inputPrice = 30.00
+		outputPrice = 60.00
+	case strings.Contains(model, "gpt-3.5-turbo"):
+		inputPrice = 0.50
+		outputPrice = 1.50
+	case strings.Contains(model, "claude-3-5-sonnet"):
+		inputPrice = 3.00
+		outputPrice = 15.00
+	case strings.Contains(model, "claude-3-opus"):
+		inputPrice = 15.00
+		outputPrice = 75.00
+	case strings.Contains(model, "claude-3-haiku"):
+		inputPrice = 0.25
+		outputPrice = 1.25
+	case strings.Contains(model, "claude"):
+		inputPrice = 8.00
+		outputPrice = 24.00
+	case strings.Contains(model, "gemini-1.5-pro"):
+		inputPrice = 3.50
+		outputPrice = 10.50
+	case strings.Contains(model, "gemini-1.5-flash"):
+		inputPrice = 0.35
+		outputPrice = 0.53
+	case strings.Contains(model, "gemini"):
+		inputPrice = 0.50
+		outputPrice = 1.50
+	default:
+		inputPrice = 0.15
+		outputPrice = 0.60
+	}
+
+	cost := float64(inputTokens)/1e6*inputPrice + float64(outputTokens)/1e6*outputPrice
+	if cost < 0.000001 {
+		cost = 0.000001
+	}
+	return cost
+}
+
+// CostWithModel 从数据库模型记录获取定价
+func CostWithModel(inputTokens, outputTokens, cacheReadTokens, cacheCreationTokens int64, inputPrice, outputPrice, cacheReadPrice float64) float64 {
+	cost := float64(inputTokens)/1e6*inputPrice +
+		float64(outputTokens)/1e6*outputPrice +
+		float64(cacheReadTokens)/1e6*cacheReadPrice +
+		float64(cacheCreationTokens)/1e6*inputPrice*1.25
+	if cost < 0.000001 {
+		cost = 0.000001
+	}
+	return cost
+}
+
+func init() {
+	_ = fmt.Sprintf // ensure fmt is used
+}

backend/internal/proxy/convert/chat.go

@@ -0,0 +1,61 @@
+package convert
+
+// ChatCompletionRequest represents an OpenAI Chat Completions request
+type ChatCompletionRequest struct {
+	Model              string        `json:"model"`
+	Messages           []Message     `json:"messages"`
+	Temperature        *float64      `json:"temperature,omitempty"`
+	TopP               *float64      `json:"top_p,omitempty"`
+	N                  *int          `json:"n,omitempty"`
+	Stream             bool          `json:"stream,omitempty"`
+	Stop               interface{}   `json:"stop,omitempty"`
+	MaxTokens          *int          `json:"max_tokens,omitempty"`
+	PresencePenalty     *float64      `json:"presence_penalty,omitempty"`
+	FrequencyPenalty   *float64      `json:"frequency_penalty,omitempty"`
+	LogitBias          map[string]int `json:"logit_bias,omitempty"`
+	User               string        `json:"user,omitempty"`
+	Tools              []Tool        `json:"tools,omitempty"`
+	ToolChoice         interface{}   `json:"tool_choice,omitempty"`
+	ResponseFormat     interface{}   `json:"response_format,omitempty"`
+	Seed               *int          `json:"seed,omitempty"`
+}
+
+// ChatCompletionResponse represents an OpenAI Chat Completions response
+type ChatCompletionResponse struct {
+	ID                string   `json:"id"`
+	Object            string   `json:"object"`
+	Created           int64    `json:"created"`
+	Model             string   `json:"model"`
+	Choices           []Choice `json:"choices"`
+	Usage             *Usage   `json:"usage,omitempty"`
+	SystemFingerprint string   `json:"system_fingerprint,omitempty"`
+}
+
+type Choice struct {
+	Index        int      `json:"index"`
+	Message      Message  `json:"message"`
+	FinishReason string   `json:"finish_reason"`
+}
+
+// ChatCompletionStreamChunk represents a streaming chunk
+type ChatCompletionStreamChunk struct {
+	ID                string          `json:"id"`
+	Object            string          `json:"object"`
+	Created           int64           `json:"created"`
+	Model             string          `json:"model"`
+	Choices           []StreamChoice  `json:"choices"`
+	Usage             *Usage          `json:"usage,omitempty"`
+	SystemFingerprint string          `json:"system_fingerprint,omitempty"`
+}
+
+type StreamChoice struct {
+	Index        int           `json:"index"`
+	Delta        StreamDelta   `json:"delta"`
+	FinishReason *string       `json:"finish_reason"`
+}
+
+type StreamDelta struct {
+	Role    string     `json:"role,omitempty"`
+	Content string     `json:"content,omitempty"`
+	ToolCalls []ToolCall `json:"tool_calls,omitempty"`
+}

backend/internal/proxy/convert/chat_messages.go

@@ -0,0 +1,212 @@
+package convert
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// ChatToMessages converts a Chat Completions request to Anthropic Messages format
+func ChatToMessages(req *ChatCompletionRequest) (*MessagesRequest, error) {
+	msgs := make([]Message, 0, len(req.Messages))
+	var systemParts []ContentPart
+
+	for _, m := range req.Messages {
+		if m.Role == "system" {
+			// Extract system message content
+			switch v := m.Content.(type) {
+			case string:
+				systemParts = append(systemParts, ContentPart{
+					Type: "text",
+					Text: v,
+				})
+			case []interface{}:
+				for _, part := range v {
+					if p, ok := part.(map[string]interface{}); ok {
+						if t, ok := p["type"].(string); ok && t == "text" {
+							if text, ok := p["text"].(string); ok {
+								systemParts = append(systemParts, ContentPart{
+									Type: "text",
+									Text: text,
+								})
+							}
+						}
+					}
+				}
+			}
+			continue
+		}
+		msgs = append(msgs, m)
+	}
+
+	out := &MessagesRequest{
+		Model:     req.Model,
+		Messages:  msgs,
+		Stream:    req.Stream,
+	}
+
+	if len(systemParts) > 0 {
+		out.System = systemParts
+	}
+
+	if req.MaxTokens != nil {
+		out.MaxTokens = *req.MaxTokens
+	} else {
+		defaultMax := 4096
+		out.MaxTokens = defaultMax
+	}
+
+	if req.Temperature != nil {
+		out.Temperature = req.Temperature
+	}
+	if req.TopP != nil {
+		out.TopP = req.TopP
+	}
+	if req.Tools != nil {
+		out.Tools = req.Tools
+	}
+
+	return out, nil
+}
+
+// MessagesToChat converts an Anthropic Messages response to Chat Completions format
+func MessagesToChat(resp *MessagesResponse) (*ChatCompletionResponse, error) {
+	choices := make([]Choice, 0)
+
+	for _, block := range resp.Content {
+		switch block.Type {
+		case "text":
+			choices = append(choices, Choice{
+				Index: len(choices),
+				Message: Message{
+					Role:    "assistant",
+					Content: block.Text,
+				},
+				FinishReason: mapStopReason(resp.StopReason),
+			})
+		case "tool_use":
+			toolCall := ToolCall{
+				ID:   block.ID,
+				Type: "function",
+				Function: FunctionCall{
+					Name:      block.Name,
+					Arguments: toJSON(block.Input),
+				},
+			}
+			if len(choices) == 0 {
+				choices = append(choices, Choice{
+					Index: 0,
+					Message: Message{
+						Role:      "assistant",
+						ToolCalls: []ToolCall{toolCall},
+					},
+					FinishReason: "tool_calls",
+				})
+			} else {
+				choices[0].Message.ToolCalls = append(choices[0].Message.ToolCalls, toolCall)
+				choices[0].FinishReason = "tool_calls"
+			}
+		}
+	}
+
+	if len(choices) == 0 {
+		choices = append(choices, Choice{
+			Index: 0,
+			Message: Message{
+				Role:    "assistant",
+				Content: "",
+			},
+			FinishReason: "stop",
+		})
+	}
+
+	return &ChatCompletionResponse{
+		ID:      resp.ID,
+		Object:  "chat.completion",
+		Model:   resp.Model,
+		Choices: choices,
+		Usage: &Usage{
+			PromptTokens:     resp.Usage.PromptTokens,
+			CompletionTokens: resp.Usage.CompletionTokens,
+			TotalTokens:      resp.Usage.PromptTokens + resp.Usage.CompletionTokens,
+		},
+	}, nil
+}
+
+// MessagesStreamToChatStream converts Anthropic streaming chunks to Chat Completions format
+func MessagesStreamToChatStream(anthropicEvents []AnthropicStreamEvent, model string) []ChatCompletionStreamChunk {
+	var chunks []ChatCompletionStreamChunk
+	id := fmt.Sprintf("chatcmpl-%d", len(anthropicEvents))
+
+	for _, event := range anthropicEvents {
+		switch event.Type {
+		case "message_start":
+			// Initial chunk with role
+			chunks = append(chunks, ChatCompletionStreamChunk{
+				ID:      id,
+				Object:  "chat.completion.chunk",
+				Model:   model,
+				Choices: []StreamChoice{{
+					Index: 0,
+					Delta: StreamDelta{
+						Role: "assistant",
+					},
+				}},
+			})
+		case "content_block_delta":
+			if event.Delta != nil && event.Delta.Text != "" {
+				chunks = append(chunks, ChatCompletionStreamChunk{
+					ID:      id,
+					Object:  "chat.completion.chunk",
+					Model:   model,
+					Choices: []StreamChoice{{
+						Index: 0,
+						Delta: StreamDelta{
+							Content: event.Delta.Text,
+						},
+					}},
+				})
+			}
+		case "message_delta":
+			finishReason := "stop"
+			if event.Delta != nil && event.Delta.StopReason != "" {
+				finishReason = mapStopReason(event.Delta.StopReason)
+			}
+			chunk := ChatCompletionStreamChunk{
+				ID:      id,
+				Object:  "chat.completion.chunk",
+				Model:   model,
+				Choices: []StreamChoice{{
+					Index:        0,
+					FinishReason: &finishReason,
+				}},
+			}
+			if event.Usage != nil {
+				chunk.Usage = event.Usage
+			}
+			chunks = append(chunks, chunk)
+		}
+	}
+
+	return chunks
+}
+
+func mapStopReason(reason string) string {
+	switch reason {
+	case "end_turn", "stop_sequence":
+		return "stop"
+	case "tool_use":
+		return "tool_calls"
+	case "max_tokens":
+		return "length"
+	default:
+		return "stop"
+	}
+}
+
+func toJSON(v interface{}) string {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return "{}"
+	}
+	return string(b)
+}

backend/internal/proxy/convert/chat_responses.go

@@ -0,0 +1,298 @@
+package convert
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// ChatToResponses converts a Chat Completions request to Responses API format
+func ChatToResponses(req *ChatCompletionRequest) (*ResponsesRequest, error) {
+	var inputItems []InputItem
+	var instructions string
+
+	for _, m := range req.Messages {
+		if m.Role == "system" {
+			if s, ok := m.Content.(string); ok {
+				if instructions != "" {
+					instructions += "\n\n"
+				}
+				instructions += s
+			}
+			continue
+		}
+
+		item := InputItem{
+			Role:    m.Role,
+			Content: m.Content,
+		}
+		inputItems = append(inputItems, item)
+	}
+
+	out := &ResponsesRequest{
+		Model:       req.Model,
+		Input:       inputItems,
+		Instructions: instructions,
+		Stream:      req.Stream,
+	}
+
+	if req.MaxTokens != nil {
+		out.MaxOutputTokens = req.MaxTokens
+	}
+	if req.Temperature != nil {
+		out.Temperature = req.Temperature
+	}
+	if req.TopP != nil {
+		out.TopP = req.TopP
+	}
+	if req.Tools != nil {
+		out.Tools = req.Tools
+	}
+
+	return out, nil
+}
+
+// ResponsesToChat converts a Responses API response to Chat Completions format
+func ResponsesToChat(resp *ResponsesResponse) (*ChatCompletionResponse, error) {
+	choices := make([]Choice, 0)
+
+	for _, output := range resp.Output {
+		switch output.Type {
+		case "message":
+			for _, content := range output.Content {
+				switch content.Type {
+				case "output_text":
+					choices = append(choices, Choice{
+						Index: len(choices),
+						Message: Message{
+							Role:    "assistant",
+							Content: content.Text,
+						},
+						FinishReason: "stop",
+					})
+				case "function_call":
+					toolCall := ToolCall{
+						ID:   content.ID,
+						Type: "function",
+						Function: FunctionCall{
+							Name:      content.Name,
+							Arguments: toJSON(content.Input),
+						},
+					}
+					if len(choices) == 0 {
+						choices = append(choices, Choice{
+							Index: 0,
+							Message: Message{
+								Role:      "assistant",
+								ToolCalls: []ToolCall{toolCall},
+							},
+							FinishReason: "tool_calls",
+						})
+					} else {
+						choices[0].Message.ToolCalls = append(choices[0].Message.ToolCalls, toolCall)
+						choices[0].FinishReason = "tool_calls"
+					}
+				}
+			}
+		case "function_call_output":
+			// This would be in a user message context
+			continue
+		}
+	}
+
+	if len(choices) == 0 {
+		choices = append(choices, Choice{
+			Index: 0,
+			Message: Message{
+				Role:    "assistant",
+				Content: "",
+			},
+			FinishReason: "stop",
+		})
+	}
+
+	return &ChatCompletionResponse{
+		ID:      resp.ID,
+		Object:  "chat.completion",
+		Model:   resp.Model,
+		Choices: choices,
+		Usage: &Usage{
+			PromptTokens:     resp.Usage.PromptTokens,
+			CompletionTokens: resp.Usage.CompletionTokens,
+			TotalTokens:      resp.Usage.PromptTokens + resp.Usage.CompletionTokens,
+		},
+	}, nil
+}
+
+// ResponsesStreamToChatStream converts Responses API streaming to Chat Completions format
+func ResponsesStreamToChatStream(events []ResponsesStreamEvent, model string) []ChatCompletionStreamChunk {
+	var chunks []ChatCompletionStreamChunk
+	id := fmt.Sprintf("chatcmpl-%d", len(events))
+
+	for _, event := range events {
+		switch event.Type {
+		case "response.created":
+			chunks = append(chunks, ChatCompletionStreamChunk{
+				ID:      id,
+				Object:  "chat.completion.chunk",
+				Model:   model,
+				Choices: []StreamChoice{{
+					Index: 0,
+					Delta: StreamDelta{
+						Role: "assistant",
+					},
+				}},
+			})
+		case "response.output_item.added":
+			if event.Item != nil && event.Item.Type == "message" {
+				chunks = append(chunks, ChatCompletionStreamChunk{
+					ID:      id,
+					Object:  "chat.completion.chunk",
+					Model:   model,
+					Choices: []StreamChoice{{
+						Index: 0,
+						Delta: StreamDelta{
+							Role: "assistant",
+						},
+					}},
+				})
+			}
+		case "response.content_part.delta":
+			if event.Delta != "" {
+				chunks = append(chunks, ChatCompletionStreamChunk{
+					ID:      id,
+					Object:  "chat.completion.chunk",
+					Model:   model,
+					Choices: []StreamChoice{{
+						Index: 0,
+						Delta: StreamDelta{
+							Content: event.Delta,
+						},
+					}},
+				})
+			}
+		case "response.completed":
+			finishReason := "stop"
+			chunk := ChatCompletionStreamChunk{
+				ID:      id,
+				Object:  "chat.completion.chunk",
+				Model:   model,
+				Choices: []StreamChoice{{
+					Index:        0,
+					FinishReason: &finishReason,
+				}},
+			}
+			chunks = append(chunks, chunk)
+		}
+	}
+
+	return chunks
+}
+
+// MessagesToResponses converts an Anthropic Messages request to Responses API format
+func MessagesToResponses(req *MessagesRequest) (*ResponsesRequest, error) {
+	var inputItems []InputItem
+	var instructions string
+
+	// Handle system message
+	if req.System != nil {
+		switch v := req.System.(type) {
+		case string:
+			instructions = v
+		case []ContentPart:
+			for _, p := range v {
+				if p.Type == "text" {
+					if instructions != "" {
+						instructions += "\n\n"
+					}
+					instructions += p.Text
+				}
+			}
+		}
+	}
+
+	for _, m := range req.Messages {
+		item := InputItem{
+			Role:    m.Role,
+			Content: m.Content,
+		}
+		inputItems = append(inputItems, item)
+	}
+
+	out := &ResponsesRequest{
+		Model:       req.Model,
+		Input:       inputItems,
+		Instructions: instructions,
+		Stream:      req.Stream,
+	}
+
+	out.MaxOutputTokens = &req.MaxTokens
+
+	if req.Temperature != nil {
+		out.Temperature = req.Temperature
+	}
+	if req.TopP != nil {
+		out.TopP = req.TopP
+	}
+	if req.Tools != nil {
+		out.Tools = req.Tools
+	}
+
+	return out, nil
+}
+
+// ResponsesToMessages converts a Responses API response to Anthropic Messages format
+func ResponsesToMessages(resp *ResponsesResponse) (*MessagesResponse, error) {
+	var content []ContentBlock
+
+	for _, output := range resp.Output {
+		switch output.Type {
+		case "message":
+			for _, c := range output.Content {
+				switch c.Type {
+				case "output_text":
+					content = append(content, ContentBlock{
+						Type: "text",
+						Text: c.Text,
+					})
+				case "function_call":
+					content = append(content, ContentBlock{
+						Type: "tool_use",
+						ID:   c.ID,
+						Name: c.Name,
+					})
+				}
+			}
+		}
+	}
+
+	var stopReason string
+	if len(content) > 0 {
+		last := content[len(content)-1]
+		if last.Type == "tool_use" {
+			stopReason = "tool_use"
+		} else {
+			stopReason = "end_turn"
+		}
+	} else {
+		stopReason = "end_turn"
+	}
+
+	return &MessagesResponse{
+		ID:         resp.ID,
+		Type:       "message",
+		Role:       "assistant",
+		Content:    content,
+		Model:      resp.Model,
+		StopReason: stopReason,
+		Usage:      resp.Usage,
+	}, nil
+}
+
+// toJSON is a helper to convert a value to JSON string
+func toJSONStr(v interface{}) string {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return "{}"
+	}
+	return string(b)
+}

backend/internal/proxy/convert/convert_test.go

@@ -0,0 +1,231 @@
+package convert
+
+import (
+	"testing"
+)
+
+func TestChatToMessages(t *testing.T) {
+	maxTokens := 1024
+	temp := 0.7
+
+	req := &ChatCompletionRequest{
+		Model: "claude-3-sonnet-20240229",
+		Messages: []Message{
+			{Role: "system", Content: "You are a helpful assistant."},
+			{Role: "user", Content: "Hello!"},
+		},
+		MaxTokens: &maxTokens,
+		Temperature: &temp,
+	}
+
+	result, err := ChatToMessages(req)
+	if err != nil {
+		t.Fatalf("ChatToMessages() error = %v", err)
+	}
+
+	if result.Model != "claude-3-sonnet-20240229" {
+		t.Errorf("Model = %q, want %q", result.Model, "claude-3-sonnet-20240229")
+	}
+
+	if len(result.Messages) != 1 {
+		t.Errorf("Messages length = %d, want 1", len(result.Messages))
+	}
+
+	if result.Messages[0].Role != "user" {
+		t.Errorf("Messages[0].Role = %q, want %q", result.Messages[0].Role, "user")
+	}
+
+	if result.System == nil {
+		t.Error("System is nil, want non-nil")
+	}
+
+	if result.MaxTokens != 1024 {
+		t.Errorf("MaxTokens = %d, want 1024", result.MaxTokens)
+	}
+}
+
+func TestMessagesToChat(t *testing.T) {
+	resp := &MessagesResponse{
+		ID:   "msg-123",
+		Model: "claude-3-sonnet-20240229",
+		Content: []ContentBlock{
+			{Type: "text", Text: "Hello! How can I help?"},
+		},
+		StopReason: "end_turn",
+		Usage: Usage{
+			PromptTokens:     10,
+			CompletionTokens: 20,
+		},
+	}
+
+	result, err := MessagesToChat(resp)
+	if err != nil {
+		t.Fatalf("MessagesToChat() error = %v", err)
+	}
+
+	if result.ID != "msg-123" {
+		t.Errorf("ID = %q, want %q", result.ID, "msg-123")
+	}
+
+	if result.Object != "chat.completion" {
+		t.Errorf("Object = %q, want %q", result.Object, "chat.completion")
+	}
+
+	if len(result.Choices) != 1 {
+		t.Errorf("Choices length = %d, want 1", len(result.Choices))
+		return
+	}
+
+	if result.Choices[0].Message.Role != "assistant" {
+		t.Errorf("Choices[0].Message.Role = %q, want %q", result.Choices[0].Message.Role, "assistant")
+	}
+
+	if result.Choices[0].Message.Content != "Hello! How can I help?" {
+		t.Errorf("Choices[0].Message.Content = %q, want %q", result.Choices[0].Message.Content, "Hello! How can I help?")
+	}
+
+	if result.Choices[0].FinishReason != "stop" {
+		t.Errorf("FinishReason = %q, want %q", result.Choices[0].FinishReason, "stop")
+	}
+
+	if result.Usage.TotalTokens != 30 {
+		t.Errorf("Usage.TotalTokens = %d, want 30", result.Usage.TotalTokens)
+	}
+}
+
+func TestChatToResponses(t *testing.T) {
+	maxTokens := 2048
+
+	req := &ChatCompletionRequest{
+		Model: "gpt-4o",
+		Messages: []Message{
+			{Role: "system", Content: "You are a helpful assistant."},
+			{Role: "user", Content: "What is 2+2?"},
+		},
+		MaxTokens: &maxTokens,
+	}
+
+	result, err := ChatToResponses(req)
+	if err != nil {
+		t.Fatalf("ChatToResponses() error = %v", err)
+	}
+
+	if result.Model != "gpt-4o" {
+		t.Errorf("Model = %q, want %q", result.Model, "gpt-4o")
+	}
+
+	if len(result.Input) != 1 {
+		t.Errorf("Input length = %d, want 1", len(result.Input))
+	}
+
+	if result.Input[0].Role != "user" {
+		t.Errorf("Input[0].Role = %q, want %q", result.Input[0].Role, "user")
+	}
+
+	if result.Instructions != "You are a helpful assistant." {
+		t.Errorf("Instructions = %q, want %q", result.Instructions, "You are a helpful assistant.")
+	}
+}
+
+func TestResponsesToChat(t *testing.T) {
+	resp := &ResponsesResponse{
+		ID:     "resp-123",
+		Model:  "gpt-4o",
+		Status: "completed",
+		Output: []OutputItem{
+			{
+				Type: "message",
+				Content: []OutputContent{
+					{Type: "output_text", Text: "2+2 equals 4."},
+				},
+			},
+		},
+		Usage: Usage{
+			PromptTokens:     15,
+			CompletionTokens: 10,
+		},
+	}
+
+	result, err := ResponsesToChat(resp)
+	if err != nil {
+		t.Fatalf("ResponsesToChat() error = %v", err)
+	}
+
+	if result.ID != "resp-123" {
+		t.Errorf("ID = %q, want %q", result.ID, "resp-123")
+	}
+
+	if len(result.Choices) != 1 {
+		t.Errorf("Choices length = %d, want 1", len(result.Choices))
+		return
+	}
+
+	if result.Choices[0].Message.Content != "2+2 equals 4." {
+		t.Errorf("Content = %q, want %q", result.Choices[0].Message.Content, "2+2 equals 4.")
+	}
+}
+
+func TestMapStopReason(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"end_turn", "stop"},
+		{"stop_sequence", "stop"},
+		{"tool_use", "tool_calls"},
+		{"max_tokens", "length"},
+		{"unknown", "stop"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			result := mapStopReason(tt.input)
+			if result != tt.expected {
+				t.Errorf("mapStopReason(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestMessagesToChatToolUse(t *testing.T) {
+	resp := &MessagesResponse{
+		ID:   "msg-456",
+		Model: "claude-3-sonnet-20240229",
+		Content: []ContentBlock{
+			{Type: "text", Text: "Let me search for that."},
+			{Type: "tool_use", ID: "toolu-123", Name: "web_search"},
+		},
+		StopReason: "tool_use",
+		Usage: Usage{
+			PromptTokens:     20,
+			CompletionTokens: 30,
+		},
+	}
+
+	result, err := MessagesToChat(resp)
+	if err != nil {
+		t.Fatalf("MessagesToChat() error = %v", err)
+	}
+
+	if len(result.Choices) != 1 {
+		t.Errorf("Choices length = %d, want 1", len(result.Choices))
+		return
+	}
+
+	if result.Choices[0].FinishReason != "tool_calls" {
+		t.Errorf("FinishReason = %q, want %q", result.Choices[0].FinishReason, "tool_calls")
+	}
+
+	if len(result.Choices[0].Message.ToolCalls) != 1 {
+		t.Errorf("ToolCalls length = %d, want 1", len(result.Choices[0].Message.ToolCalls))
+		return
+	}
+
+	if result.Choices[0].Message.ToolCalls[0].ID != "toolu-123" {
+		t.Errorf("ToolCall ID = %q, want %q", result.Choices[0].Message.ToolCalls[0].ID, "toolu-123")
+	}
+
+	if result.Choices[0].Message.ToolCalls[0].Function.Name != "web_search" {
+		t.Errorf("Function.Name = %q, want %q", result.Choices[0].Message.ToolCalls[0].Function.Name, "web_search")
+	}
+}

backend/internal/proxy/convert/messages.go

@@ -0,0 +1,37 @@
+package convert
+
+// MessagesRequest represents an Anthropic Messages API request
+type MessagesRequest struct {
+	Model         string        `json:"model"`
+	Messages      []Message     `json:"messages"`
+	MaxTokens     int           `json:"max_tokens"`
+	System        interface{}   `json:"system,omitempty"` // string or []ContentPart
+	Temperature   *float64      `json:"temperature,omitempty"`
+	TopP          *float64      `json:"top_p,omitempty"`
+	TopK          *int          `json:"top_k,omitempty"`
+	StopSequences []string      `json:"stop_sequences,omitempty"`
+	Stream        bool          `json:"stream,omitempty"`
+	Tools         []Tool        `json:"tools,omitempty"`
+	ToolChoice    interface{}   `json:"tool_choice,omitempty"`
+	Metadata      interface{}   `json:"metadata,omitempty"`
+}
+
+// MessagesResponse represents an Anthropic Messages API response
+type MessagesResponse struct {
+	ID            string         `json:"id"`
+	Type          string         `json:"type"`
+	Role          string         `json:"role"`
+	Content       []ContentBlock `json:"content"`
+	Model         string         `json:"model"`
+	StopReason    string         `json:"stop_reason"`
+	StopSequence  string         `json:"stop_sequence,omitempty"`
+	Usage         Usage          `json:"usage"`
+}
+
+// AnthropicStreamEvent represents an Anthropic streaming event
+type AnthropicStreamEvent struct {
+	Type  string      `json:"type"`
+	Index int         `json:"index,omitempty"`
+	Delta *Delta     `json:"delta,omitempty"`
+	Usage *Usage     `json:"usage,omitempty"`
+}

backend/internal/proxy/convert/responses.go

@@ -0,0 +1,59 @@
+package convert
+
+// ResponsesRequest represents an OpenAI Responses API request
+type ResponsesRequest struct {
+	Model           string      `json:"model"`
+	Input           []InputItem `json:"input"`
+	Instructions    string      `json:"instructions,omitempty"`
+	MaxOutputTokens *int        `json:"max_output_tokens,omitempty"`
+	Tools           []Tool      `json:"tools,omitempty"`
+	ToolChoice      interface{} `json:"tool_choice,omitempty"`
+	Stream          bool        `json:"stream,omitempty"`
+	Temperature     *float64    `json:"temperature,omitempty"`
+	TopP            *float64    `json:"top_p,omitempty"`
+	Metadata        interface{} `json:"metadata,omitempty"`
+}
+
+// InputItem represents a single input item
+type InputItem struct {
+	Role    string      `json:"role"`
+	Content interface{} `json:"content,omitempty"`
+}
+
+// ResponsesResponse represents an OpenAI Responses API response
+type ResponsesResponse struct {
+	ID        string        `json:"id"`
+	Object    string        `json:"object"`
+	CreatedAt int64         `json:"created_at"`
+	Status    string        `json:"status"`
+	Model     string        `json:"model"`
+	Output    []OutputItem  `json:"output"`
+	Usage     Usage         `json:"usage"`
+	Error     interface{}   `json:"error,omitempty"`
+	Incomplete *Incomplete  `json:"incomplete,omitempty"`
+}
+
+type OutputItem struct {
+	Type    string         `json:"type"`
+	Content []OutputContent `json:"content,omitempty"`
+	Role    string         `json:"role,omitempty"`
+}
+
+type OutputContent struct {
+	Type  string  `json:"type"`
+	Text  string  `json:"text,omitempty"`
+	ID    string  `json:"id,omitempty"`
+	Name  string  `json:"name,omitempty"`
+	Input interface{} `json:"input,omitempty"`
+}
+
+type Incomplete struct {
+	Reason string `json:"reason"`
+}
+
+// ResponsesStreamEvent represents a Responses API streaming event
+type ResponsesStreamEvent struct {
+	Type  string `json:"type"`
+	Item  *OutputItem `json:"item,omitempty"`
+	Delta string `json:"delta,omitempty"`
+}

backend/internal/proxy/convert/stream.go

@@ -0,0 +1,171 @@
+package convert
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// SSEWriter writes Server-Sent Events
+type SSEWriter struct {
+	writer io.Writer
+	flusher http.Flusher
+}
+
+// NewSSEWriter creates a new SSE writer
+func NewSSEWriter(w http.ResponseWriter) *SSEWriter {
+	flusher, _ := w.(http.Flusher)
+	return &SSEWriter{
+		writer:  w,
+		flusher: flusher,
+	}
+}
+
+// WriteEvent writes a single SSE event
+func (w *SSEWriter) WriteEvent(event string, data interface{}) error {
+	var dataStr string
+	switch v := data.(type) {
+	case string:
+		dataStr = v
+	default:
+		b, err := json.Marshal(v)
+		if err != nil {
+			return err
+		}
+		dataStr = string(b)
+	}
+
+	_, err := fmt.Fprintf(w.writer, "event: %s\ndata: %s\n\n", event, dataStr)
+	if err != nil {
+		return err
+	}
+
+	if w.flusher != nil {
+		w.flusher.Flush()
+	}
+	return nil
+}
+
+// WriteChunk writes a streaming chunk in SSE format
+func (w *SSEWriter) WriteChunk(chunk interface{}) error {
+	b, err := json.Marshal(chunk)
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintf(w.writer, "data: %s\n\n", string(b))
+	if err != nil {
+		return err
+	}
+
+	if w.flusher != nil {
+		w.flusher.Flush()
+	}
+	return nil
+}
+
+// WriteDone writes the [DONE] marker
+func (w *SSEWriter) WriteDone() error {
+	_, err := fmt.Fprintf(w.writer, "data: [DONE]\n\n")
+	if err != nil {
+		return err
+	}
+
+	if w.flusher != nil {
+		w.flusher.Flush()
+	}
+	return nil
+}
+
+// SSEParser parses Server-Sent Events from a reader
+type SSEParser struct {
+	reader *bufio.Reader
+}
+
+// NewSSEParser creates a new SSE parser
+func NewSSEParser(r io.Reader) *SSEParser {
+	return &SSEParser{
+		reader: bufio.NewReader(r),
+	}
+}
+
+// SSEEvent represents a parsed SSE event
+type SSEEvent struct {
+	Event string
+	Data  string
+}
+
+// ReadEvent reads the next SSE event
+func (p *SSEParser) ReadEvent() (*SSEEvent, error) {
+	event := &SSEEvent{}
+
+	for {
+		line, err := p.reader.ReadString('\n')
+		if err != nil {
+			return nil, err
+		}
+
+		line = strings.TrimRight(line, "\r\n")
+
+		if line == "" {
+			// Empty line means end of event
+			if event.Data != "" || event.Event != "" {
+				return event, nil
+			}
+			continue
+		}
+
+		if strings.HasPrefix(line, "event:") {
+			event.Event = strings.TrimSpace(line[6:])
+		} else if strings.HasPrefix(line, "data:") {
+			data := strings.TrimSpace(line[5:])
+			if event.Data != "" {
+				event.Data += "\n" + data
+			} else {
+				event.Data = data
+			}
+		}
+		// Ignore comments (lines starting with :) and unknown fields
+	}
+}
+
+// ParseChatStreamChunk parses an OpenAI Chat Completions streaming chunk
+func ParseChatStreamChunk(data string) (*ChatCompletionStreamChunk, error) {
+	if data == "[DONE]" {
+		return nil, io.EOF
+	}
+
+	var chunk ChatCompletionStreamChunk
+	err := json.Unmarshal([]byte(data), &chunk)
+	if err != nil {
+		return nil, err
+	}
+	return &chunk, nil
+}
+
+// ParseMessagesStreamEvent parses an Anthropic Messages streaming event
+func ParseMessagesStreamEvent(data string) (*AnthropicStreamEvent, error) {
+	var event AnthropicStreamEvent
+	err := json.Unmarshal([]byte(data), &event)
+	if err != nil {
+		return nil, err
+	}
+	return &event, nil
+}
+
+// ParseResponsesStreamChunk parses an OpenAI Responses API streaming chunk
+func ParseResponsesStreamChunk(data string) (*ResponsesStreamEvent, error) {
+	if data == "[DONE]" {
+		return nil, io.EOF
+	}
+
+	var event ResponsesStreamEvent
+	err := json.Unmarshal([]byte(data), &event)
+	if err != nil {
+		return nil, err
+	}
+	return &event, nil
+}

backend/internal/proxy/convert/types.go

@@ -0,0 +1,99 @@
+package convert
+
+// Common types shared across all protocols
+
+// Message represents a unified message format
+type Message struct {
+	Role       string      `json:"role"`
+	Content    interface{} `json:"content,omitempty"` // string or []ContentPart
+	Name       string      `json:"name,omitempty"`
+	ToolCalls  []ToolCall  `json:"tool_calls,omitempty"`
+	ToolCallID string      `json:"tool_call_id,omitempty"`
+}
+
+// ContentPart represents a part of a multi-part message content
+type ContentPart struct {
+	Type     string         `json:"type"`
+	Text     string         `json:"text,omitempty"`
+	ImageURL *ImageURL      `json:"image_url,omitempty"`
+	Source   *ImageSource   `json:"source,omitempty"`
+	ToolUse  *ToolUse       `json:"tool_use,omitempty"`
+	ToolResult *ToolResult  `json:"tool_result,omitempty"`
+}
+
+type ImageURL struct {
+	URL    string `json:"url"`
+	Detail string `json:"detail,omitempty"`
+}
+
+type ImageSource struct {
+	Type      string `json:"type"`
+	MediaType string `json:"media_type"`
+	Data      string `json:"data"`
+}
+
+type ToolCall struct {
+	ID       string       `json:"id"`
+	Type     string       `json:"type"`
+	Function FunctionCall `json:"function"`
+}
+
+type FunctionCall struct {
+	Name      string `json:"name"`
+	Arguments string `json:"arguments"`
+}
+
+type ToolUse struct {
+	ID    string      `json:"id"`
+	Name  string      `json:"name"`
+	Input interface{} `json:"input"`
+}
+
+type ToolResult struct {
+	ToolUseID string `json:"tool_use_id"`
+	Content   string `json:"content"`
+}
+
+// Tool definition
+type Tool struct {
+	Type     string         `json:"type"`
+	Function ToolDefinition `json:"function,omitempty"`
+	Name     string         `json:"name,omitempty"`     // Anthropic style
+	Input    interface{}    `json:"input_schema,omitempty"` // Anthropic style
+}
+
+type ToolDefinition struct {
+	Name        string      `json:"name"`
+	Description string      `json:"description,omitempty"`
+	Parameters  interface{} `json:"parameters,omitempty"`
+}
+
+// StreamEvent represents a unified streaming event
+type StreamEvent struct {
+	Type  string      `json:"type"` // "message_start", "content_block_start", "content_block_delta", "message_delta", "message_stop"
+	Delta *Delta     `json:"delta,omitempty"`
+	Usage *Usage     `json:"usage,omitempty"`
+}
+
+type Delta struct {
+	Type         string     `json:"type,omitempty"`
+	Text         string     `json:"text,omitempty"`
+	StopReason   string     `json:"stop_reason,omitempty"`
+	ContentBlock *ContentBlock `json:"content_block,omitempty"`
+}
+
+type ContentBlock struct {
+	Type  string      `json:"type"`
+	Text  string      `json:"text,omitempty"`
+	ID    string      `json:"id,omitempty"`
+	Name  string      `json:"name,omitempty"`
+	Input interface{} `json:"input,omitempty"`
+}
+
+// Usage represents token usage
+type Usage struct {
+	PromptTokens     int `json:"prompt_tokens"`
+	CompletionTokens int `json:"completion_tokens"`
+	TotalTokens      int `json:"total_tokens,omitempty"`
+	CacheReadTokens  int `json:"cache_read_input_tokens,omitempty"`
+}

backend/internal/proxy/gateway.go

@@ -0,0 +1,380 @@
+package proxy
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"opencatd-open/internal/channel"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/proxy/convert"
+	"opencatd-open/internal/store"
+	"opencatd-open/pkg/config"
+	"os"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+type Gateway struct {
+	ctx        context.Context
+	cfg        *config.Config
+	db         *gorm.DB
+	wg         *sync.WaitGroup
+	httpClient *http.Client
+
+	userDAO    *dao.UserDAO
+	apiKeyDAO  *dao.ApiKeyDAO
+	usageDAO   *dao.UsageDAO
+	dailyDAO   *dao.DailyUsageDAO
+	channelSvc *channel.Service
+}
+
+func NewGateway(ctx context.Context, cfg *config.Config, db *gorm.DB, wg *sync.WaitGroup, userDAO *dao.UserDAO, apiKeyDAO *dao.ApiKeyDAO, usageDAO *dao.UsageDAO, dailyDAO *dao.DailyUsageDAO) *Gateway {
+	client := &http.Client{Timeout: 120 * time.Second}
+	if os.Getenv("LOCAL_PROXY") != "" {
+		proxyUrl, err := url.Parse(os.Getenv("LOCAL_PROXY"))
+		if err == nil {
+			tr := &http.Transport{
+				Proxy: http.ProxyURL(proxyUrl),
+			}
+			client.Transport = tr
+		}
+	}
+
+	return &Gateway{
+		ctx:        ctx,
+		cfg:        cfg,
+		db:         db,
+		wg:         wg,
+		httpClient: client,
+		userDAO:    userDAO,
+		apiKeyDAO:  apiKeyDAO,
+		usageDAO:   usageDAO,
+		dailyDAO:   dailyDAO,
+		channelSvc: nil,
+	}
+}
+
+func (g *Gateway) SetChannelService(svc *channel.Service) {
+	g.channelSvc = svc
+}
+
+// Request represents a parsed incoming request
+type Request struct {
+	Model     string
+	Stream    bool
+	Protocol  string // "chat", "messages", "responses"
+	Body      []byte
+	APIKey    *store.APIKey
+	UserID    uint64
+}
+
+// ParseRequest parses the incoming request and extracts key fields
+func (g *Gateway) ParseRequest(c *gin.Context, protocol string) (*Request, error) {
+	body, err := io.ReadAll(c.Request.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read body: %w", err)
+	}
+
+	apiKey, _ := c.Get("api_key")
+	userID, _ := c.Get("user_id")
+
+	req := &Request{
+		Protocol: protocol,
+		Body:     body,
+		UserID:   userID.(uint64),
+	}
+
+	if ak, ok := apiKey.(*store.APIKey); ok {
+		req.APIKey = ak
+	}
+
+	// Parse model and stream based on protocol
+	switch protocol {
+	case "chat":
+		var parsed convert.ChatCompletionRequest
+		if err := json.Unmarshal(body, &parsed); err != nil {
+			return nil, fmt.Errorf("invalid chat request: %w", err)
+		}
+		req.Model = parsed.Model
+		req.Stream = parsed.Stream
+	case "messages":
+		var parsed convert.MessagesRequest
+		if err := json.Unmarshal(body, &parsed); err != nil {
+			return nil, fmt.Errorf("invalid messages request: %w", err)
+		}
+		req.Model = parsed.Model
+		req.Stream = parsed.Stream
+	case "responses":
+		var parsed convert.ResponsesRequest
+		if err := json.Unmarshal(body, &parsed); err != nil {
+			return nil, fmt.Errorf("invalid responses request: %w", err)
+		}
+		req.Model = parsed.Model
+		req.Stream = parsed.Stream
+	}
+
+	return req, nil
+}
+
+// Dispatch routes the request to the appropriate upstream
+func (g *Gateway) Dispatch(c *gin.Context, req *Request) {
+	if g.channelSvc == nil {
+		g.writeError(c, http.StatusBadGateway, "channel service not available")
+		return
+	}
+
+	ch, err := g.channelSvc.SelectChannel(g.ctx, req.Model)
+	if err != nil {
+		g.writeError(c, http.StatusBadGateway, err.Error())
+		return
+	}
+
+	apiKey, err := g.channelSvc.GetAPIKey(ch)
+	if err != nil {
+		g.writeError(c, http.StatusBadGateway, "failed to decrypt API key")
+		return
+	}
+
+	// Determine target format and convert if needed
+	targetFormat := req.Protocol
+	if len(ch.FormatsEffective()) > 0 {
+		// Prefer the channel's native format
+		for _, f := range ch.FormatsEffective() {
+			if f == req.Protocol {
+				targetFormat = f
+				break
+			}
+		}
+	}
+
+	// Build upstream URL
+	upstreamPath := g.getUpstreamPath(req.Protocol)
+	upstreamURL := ch.UpstreamURL(req.Protocol, upstreamPath)
+
+	// Convert request if needed
+	var requestBody []byte
+	if targetFormat != req.Protocol {
+		requestBody, err = g.convertRequest(req.Body, req.Protocol, targetFormat)
+		if err != nil {
+			g.writeError(c, http.StatusBadRequest, "conversion failed: "+err.Error())
+			return
+		}
+	} else {
+		requestBody = req.Body
+	}
+
+	// Create upstream request
+	httpReq, err := http.NewRequestWithContext(g.ctx, "POST", upstreamURL, bytes.NewReader(requestBody))
+	if err != nil {
+		g.writeError(c, http.StatusBadGateway, "failed to create request")
+		return
+	}
+
+	// Set headers
+	g.setHeaders(httpReq, ch, apiKey, targetFormat)
+
+	// Execute request
+	start := time.Now()
+	resp, err := g.httpClient.Do(httpReq)
+	latency := time.Since(start)
+	if err != nil {
+		g.channelSvc.RecordFailure(ch.ID)
+		g.writeError(c, http.StatusBadGateway, fmt.Sprintf("upstream error: %v (latency: %v)", err, latency))
+		return
+	}
+	defer resp.Body.Close()
+
+	// Record success
+	g.channelSvc.RecordSuccess(ch.ID)
+
+	// Handle response
+	if resp.StatusCode >= 400 {
+		body, _ := io.ReadAll(resp.Body)
+		log.Printf("Upstream error: status=%d body=%s", resp.StatusCode, string(body))
+		c.Data(resp.StatusCode, "application/json", body)
+		return
+	}
+
+	// Stream or buffer response
+	if req.Stream {
+		g.streamResponse(c, resp, req.Protocol, ch)
+	} else {
+		g.bufferResponse(c, resp, req.Protocol, ch)
+	}
+}
+
+func (g *Gateway) getUpstreamPath(protocol string) string {
+	switch protocol {
+	case "chat":
+		return "/chat/completions"
+	case "messages":
+		return "/messages"
+	case "responses":
+		return "/responses"
+	default:
+		return "/chat/completions"
+	}
+}
+
+func (g *Gateway) setHeaders(req *http.Request, ch *store.Channel, apiKey string, format string) {
+	req.Header.Set("Content-Type", "application/json")
+
+	switch ch.Provider {
+	case store.ChannelProviderOpenAI, store.ChannelProviderCompatible:
+		req.Header.Set("Authorization", "Bearer "+apiKey)
+	case store.ChannelProviderAnthropic:
+		req.Header.Set("x-api-key", apiKey)
+		req.Header.Set("anthropic-version", "2023-06-01")
+	}
+}
+
+func (g *Gateway) convertRequest(body []byte, from, to string) ([]byte, error) {
+	switch {
+	case from == "chat" && to == "messages":
+		var req convert.ChatCompletionRequest
+		if err := json.Unmarshal(body, &req); err != nil {
+			return nil, err
+		}
+		msgReq, err := convert.ChatToMessages(&req)
+		if err != nil {
+			return nil, err
+		}
+		return json.Marshal(msgReq)
+
+	case from == "chat" && to == "responses":
+		var req convert.ChatCompletionRequest
+		if err := json.Unmarshal(body, &req); err != nil {
+			return nil, err
+		}
+		respReq, err := convert.ChatToResponses(&req)
+		if err != nil {
+			return nil, err
+		}
+		return json.Marshal(respReq)
+
+	case from == "messages" && to == "chat":
+		var req convert.MessagesRequest
+		if err := json.Unmarshal(body, &req); err != nil {
+			return nil, err
+		}
+		// Messages -> Chat: we need to construct a ChatCompletionRequest
+		chatReq := &convert.ChatCompletionRequest{
+			Model: req.Model,
+		}
+		for _, m := range req.Messages {
+			chatReq.Messages = append(chatReq.Messages, m)
+		}
+		if req.Temperature != nil {
+			chatReq.Temperature = req.Temperature
+		}
+		if req.TopP != nil {
+			chatReq.TopP = req.TopP
+		}
+		chatReq.Tools = req.Tools
+		chatReq.Stream = req.Stream
+		return json.Marshal(chatReq)
+
+	case from == "responses" && to == "chat":
+		var req convert.ResponsesRequest
+		if err := json.Unmarshal(body, &req); err != nil {
+			return nil, err
+		}
+		chatReq := &convert.ChatCompletionRequest{
+			Model: req.Model,
+		}
+		for _, item := range req.Input {
+			chatReq.Messages = append(chatReq.Messages, convert.Message{
+				Role:    item.Role,
+				Content: item.Content,
+			})
+		}
+		chatReq.Tools = req.Tools
+		chatReq.Stream = req.Stream
+		return json.Marshal(chatReq)
+
+	default:
+		return body, nil
+	}
+}
+
+func (g *Gateway) streamResponse(c *gin.Context, resp *http.Response, protocol string, ch *store.Channel) {
+	c.Header("Content-Type", "text/event-stream")
+	c.Header("Cache-Control", "no-cache")
+	c.Header("Connection", "keep-alive")
+	c.Status(http.StatusOK)
+
+	writer := convert.NewSSEWriter(c.Writer)
+	parser := convert.NewSSEParser(resp.Body)
+
+	for {
+		event, err := parser.ReadEvent()
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			log.Printf("Stream parse error: %v", err)
+			break
+		}
+
+		if event.Event == "error" {
+			log.Printf("Upstream stream error: %s", event.Data)
+			break
+		}
+
+		// Write raw SSE event based on protocol
+		if err := writer.WriteEvent("chat CompletionChunk", event.Data); err != nil {
+			break
+		}
+	}
+
+	writer.WriteDone()
+}
+
+func (g *Gateway) bufferResponse(c *gin.Context, resp *http.Response, protocol string, ch *store.Channel) {
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		g.writeError(c, http.StatusBadGateway, "failed to read response")
+		return
+	}
+
+	c.Data(resp.StatusCode, "application/json", body)
+}
+
+func (g *Gateway) writeError(c *gin.Context, status int, message string) {
+	protocol := c.GetHeader("X-Protocol")
+	if protocol == "" {
+		protocol = "chat"
+	}
+
+	switch {
+	case strings.Contains(c.GetHeader("Accept"), "text/event-stream"):
+		c.Header("Content-Type", "text/event-stream")
+		c.Status(status)
+		fmt.Fprintf(c.Writer, "data: {\"error\":{\"message\":\"%s\"}}\n\n", message)
+		fmt.Fprintf(c.Writer, "data: [DONE]\n\n")
+	case protocol == "messages":
+		c.JSON(status, gin.H{
+			"type": "error",
+			"error": gin.H{
+				"type":    "api_error",
+				"message": message,
+			},
+		})
+	default:
+		c.JSON(status, gin.H{
+			"error": gin.H{
+				"message": message,
+				"type":    "invalid_request_error",
+			},
+		})
+	}
+}

backend/internal/proxy/handlers.go

@@ -0,0 +1,49 @@
+package proxy
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// HandleChat handles POST /v1/chat/completions
+func (g *Gateway) HandleChat(c *gin.Context) {
+	req, err := g.ParseRequest(c, "chat")
+	if err != nil {
+		g.writeError(c, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	g.Dispatch(c, req)
+}
+
+// HandleMessages handles POST /v1/messages
+func (g *Gateway) HandleMessages(c *gin.Context) {
+	req, err := g.ParseRequest(c, "messages")
+	if err != nil {
+		g.writeError(c, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	g.Dispatch(c, req)
+}
+
+// HandleResponses handles POST /v1/responses
+func (g *Gateway) HandleResponses(c *gin.Context) {
+	req, err := g.ParseRequest(c, "responses")
+	if err != nil {
+		g.writeError(c, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	g.Dispatch(c, req)
+}
+
+// HandleModels handles GET /v1/models
+func (g *Gateway) HandleModels(c *gin.Context) {
+	// TODO: Return list of available models based on enabled channels
+	c.JSON(http.StatusOK, gin.H{
+		"object": "list",
+		"data":   []interface{}{},
+	})
+}

backend/internal/service/apikey.go

@@ -0,0 +1,38 @@
+package service
+
+import (
+	"context"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type ApiKeyServiceImpl struct {
+	db         *gorm.DB
+	apiKeyRepo *dao.ApiKeyDAO
+}
+
+func NewApiKeyService(db *gorm.DB, apiKeyDao *dao.ApiKeyDAO) *ApiKeyServiceImpl {
+	return &ApiKeyServiceImpl{db: db, apiKeyRepo: apiKeyDao}
+}
+
+func (s *ApiKeyServiceImpl) CreateApiKey(ctx context.Context, apikey *store.APIKey) error {
+	return s.apiKeyRepo.Create(apikey)
+}
+
+func (s *ApiKeyServiceImpl) GetApiKey(ctx context.Context, id uint64) (*store.APIKey, error) {
+	return s.apiKeyRepo.GetByID(id)
+}
+
+func (s *ApiKeyServiceImpl) ListApiKey(ctx context.Context, userID uint64, limit, offset int) ([]*store.APIKey, int64, error) {
+	return s.apiKeyRepo.ListByUserID(userID, limit, offset)
+}
+
+func (s *ApiKeyServiceImpl) UpdateApiKey(ctx context.Context, apikey *store.APIKey) error {
+	return s.apiKeyRepo.Update(apikey)
+}
+
+func (s *ApiKeyServiceImpl) DeleteApiKey(ctx context.Context, id uint64) error {
+	return s.apiKeyRepo.Delete(id)
+}

backend/internal/service/channel.go

@@ -0,0 +1,84 @@
+package service
+
+import (
+	"context"
+	"opencatd-open/internal/channel"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"opencatd-open/internal/pkg/crypto"
+)
+
+type ChannelServiceImpl struct {
+	channelDAO  *dao.ChannelDAO
+	channelSvc  *channel.Service
+}
+
+func NewChannelService(channelDAO *dao.ChannelDAO, channelSvc *channel.Service) *ChannelServiceImpl {
+	return &ChannelServiceImpl{
+		channelDAO: channelDAO,
+		channelSvc: channelSvc,
+	}
+}
+
+func (s *ChannelServiceImpl) Create(ctx context.Context, ch *store.Channel) error {
+	return s.channelDAO.Create(ch)
+}
+
+func (s *ChannelServiceImpl) GetByID(ctx context.Context, id uint64) (*store.Channel, error) {
+	return s.channelDAO.GetByID(id)
+}
+
+func (s *ChannelServiceImpl) List(ctx context.Context, limit, offset int) ([]*store.Channel, int64, error) {
+	return s.channelDAO.List(limit, offset)
+}
+
+func (s *ChannelServiceImpl) ListEnabled(ctx context.Context) ([]*store.Channel, error) {
+	return s.channelDAO.ListEnabled()
+}
+
+func (s *ChannelServiceImpl) Update(ctx context.Context, ch *store.Channel) error {
+	return s.channelDAO.Update(ch)
+}
+
+func (s *ChannelServiceImpl) Delete(ctx context.Context, id uint64) error {
+	return s.channelDAO.Delete(id)
+}
+
+// GetAPIKey decrypts the channel's API key
+func (s *ChannelServiceImpl) GetAPIKey(ctx context.Context, channelID uint64) (string, error) {
+	ch, err := s.channelDAO.GetByID(channelID)
+	if err != nil {
+		return "", err
+	}
+	return crypto.Decrypt(ch.APIKeyEnc)
+}
+
+// SelectForModel selects the best channel for a model
+func (s *ChannelServiceImpl) SelectForModel(ctx context.Context, modelName string) (*store.Channel, error) {
+	return s.channelSvc.SelectChannel(ctx, modelName)
+}
+
+// BindModels binds models to a channel
+func (s *ChannelServiceImpl) BindModels(ctx context.Context, channelID uint64, bindings []store.ChannelModelBinding) error {
+	return s.channelDAO.BindModels(channelID, bindings)
+}
+
+// GetChannelModels returns models bound to a channel
+func (s *ChannelServiceImpl) GetChannelModels(ctx context.Context, channelID uint64) ([]store.ChannelModelBinding, error) {
+	return s.channelDAO.GetChannelModels(channelID)
+}
+
+// GetModelChannels returns channels for a model
+func (s *ChannelServiceImpl) GetModelChannels(ctx context.Context, modelName string) ([]*store.Channel, error) {
+	return s.channelDAO.GetEnabledChannelsByModel(modelName)
+}
+
+// RecordSuccess records a successful request
+func (s *ChannelServiceImpl) RecordSuccess(channelID uint64) {
+	s.channelSvc.RecordSuccess(channelID)
+}
+
+// RecordFailure records a failed request
+func (s *ChannelServiceImpl) RecordFailure(channelID uint64) {
+	s.channelSvc.RecordFailure(channelID)
+}

backend/internal/service/model.go

@@ -0,0 +1,72 @@
+package service
+
+import (
+	"context"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+)
+
+type ModelServiceImpl struct {
+	modelDAO   *dao.ModelDAO
+	channelDAO *dao.ChannelDAO
+}
+
+func NewModelService(modelDAO *dao.ModelDAO, channelDAO *dao.ChannelDAO) *ModelServiceImpl {
+	return &ModelServiceImpl{
+		modelDAO:   modelDAO,
+		channelDAO: channelDAO,
+	}
+}
+
+func (s *ModelServiceImpl) Create(ctx context.Context, model *store.Model) error {
+	return s.modelDAO.Create(model)
+}
+
+func (s *ModelServiceImpl) GetByID(ctx context.Context, id uint64) (*store.Model, error) {
+	return s.modelDAO.GetByID(id)
+}
+
+func (s *ModelServiceImpl) GetByName(ctx context.Context, name string) (*store.Model, error) {
+	return s.modelDAO.GetByName(name)
+}
+
+func (s *ModelServiceImpl) List(ctx context.Context, limit, offset int) ([]*store.Model, int64, error) {
+	return s.modelDAO.List(limit, offset)
+}
+
+func (s *ModelServiceImpl) ListEnabled(ctx context.Context) ([]*store.Model, error) {
+	return s.modelDAO.ListEnabled()
+}
+
+func (s *ModelServiceImpl) Update(ctx context.Context, model *store.Model) error {
+	return s.modelDAO.Update(model)
+}
+
+func (s *ModelServiceImpl) Delete(ctx context.Context, id uint64) error {
+	return s.modelDAO.Delete(id)
+}
+
+func (s *ModelServiceImpl) Upsert(ctx context.Context, model *store.Model) error {
+	return s.modelDAO.Upsert(model)
+}
+
+// BindChannel binds a model to a channel
+func (s *ModelServiceImpl) BindChannel(ctx context.Context, modelID, channelID uint64, upstreamModel string, weight int) error {
+	binding := store.ChannelModelBinding{
+		ModelID:       modelID,
+		ChannelID:     channelID,
+		UpstreamModel: upstreamModel,
+		Weight:        weight,
+	}
+	return s.channelDAO.BindModels(channelID, []store.ChannelModelBinding{binding})
+}
+
+// ListChannelModels lists all models bound to a channel
+func (s *ModelServiceImpl) ListChannelModels(ctx context.Context, channelID uint64) ([]store.ChannelModelBinding, error) {
+	return s.channelDAO.GetChannelModels(channelID)
+}
+
+// ListModelChannels lists all channels for a model
+func (s *ModelServiceImpl) ListModelChannels(ctx context.Context, modelName string) ([]*store.Channel, error) {
+	return s.channelDAO.GetEnabledChannelsByModel(modelName)
+}

backend/internal/service/token.go

@@ -0,0 +1,29 @@
+package service
+
+import (
+	"context"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+
+	"gorm.io/gorm"
+)
+
+type TokenServiceImpl struct {
+	db        *gorm.DB
+	tokenRepo *dao.TokenDAO
+}
+
+func NewTokenService(db *gorm.DB, tokenRepo *dao.TokenDAO) *TokenServiceImpl {
+	return &TokenServiceImpl{
+		db:        db,
+		tokenRepo: tokenRepo,
+	}
+}
+
+func (t *TokenServiceImpl) GetByKey(ctx context.Context, key string) (*store.User, error) {
+	return t.tokenRepo.GetByKey(key)
+}
+
+func (t *TokenServiceImpl) GetByID(ctx context.Context, id uint64) (*store.User, error) {
+	return t.tokenRepo.GetByID(id)
+}

backend/internal/service/usage.go

@@ -0,0 +1,22 @@
+package service
+
+import (
+	"context"
+	"opencatd-open/pkg/config"
+
+	"gorm.io/gorm"
+)
+
+type UsageService struct {
+	Ctx context.Context
+	Cfg *config.Config
+	DB  *gorm.DB
+}
+
+func NewUsageService(ctx context.Context, cfg *config.Config, db *gorm.DB) *UsageService {
+	return &UsageService{
+		Ctx: ctx,
+		Cfg: cfg,
+		DB:  db,
+	}
+}

backend/internal/service/user.go

@@ -0,0 +1,48 @@
+package service
+
+import (
+	"context"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"opencatd-open/pkg/config"
+
+	"gorm.io/gorm"
+)
+
+type UserServiceImpl struct {
+	cfg      *config.Config
+	db       *gorm.DB
+	userRepo *dao.UserDAO
+}
+
+func NewUserService(cfg *config.Config, db *gorm.DB, userRepo *dao.UserDAO) *UserServiceImpl {
+	return &UserServiceImpl{
+		cfg:      cfg,
+		db:       db,
+		userRepo: userRepo,
+	}
+}
+
+func (s *UserServiceImpl) GetByID(ctx context.Context, id uint64) (*store.User, error) {
+	return s.userRepo.GetByID(id)
+}
+
+func (s *UserServiceImpl) GetByUsername(ctx context.Context, username string) (*store.User, error) {
+	return s.userRepo.GetByUsername(username)
+}
+
+func (s *UserServiceImpl) List(ctx context.Context, limit, offset int) ([]*store.User, int64, error) {
+	return s.userRepo.List(limit, offset)
+}
+
+func (s *UserServiceImpl) Create(ctx context.Context, user *store.User) error {
+	return s.userRepo.Create(user)
+}
+
+func (s *UserServiceImpl) Update(ctx context.Context, user *store.User) error {
+	return s.userRepo.Update(user)
+}
+
+func (s *UserServiceImpl) Delete(ctx context.Context, id uint64) error {
+	return s.userRepo.Delete(id)
+}

backend/internal/service/webauth.go

@@ -0,0 +1,203 @@
+package service
+
+import (
+	"encoding/base64"
+	"fmt"
+	"net/http"
+	"opencatd-open/internal/store"
+	"opencatd-open/pkg/config"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/go-webauthn/webauthn/protocol"
+	"github.com/go-webauthn/webauthn/webauthn"
+	"gorm.io/gorm"
+)
+
+type WebAuthnUser struct {
+	User        *store.User
+	Credentials []webauthn.Credential
+}
+
+func (u *WebAuthnUser) WebAuthnID() []byte {
+	return []byte(strconv.FormatUint(u.User.ID, 10))
+}
+
+func (u *WebAuthnUser) WebAuthnName() string {
+	return u.User.Username
+}
+
+func (u *WebAuthnUser) WebAuthnDisplayName() string {
+	return u.User.Username
+}
+
+func (u *WebAuthnUser) WebAuthnCredentials() []webauthn.Credential {
+	return u.Credentials
+}
+
+func (u *WebAuthnUser) WebAuthnCredentialDescriptors() (descriptors []protocol.CredentialDescriptor) {
+	credentials := u.WebAuthnCredentials()
+	descriptors = make([]protocol.CredentialDescriptor, len(credentials))
+	for i, credential := range credentials {
+		descriptors[i] = credential.Descriptor()
+	}
+	return descriptors
+}
+
+type WebAuthnService struct {
+	cfg      *config.Config
+	DB       *gorm.DB
+	WebAuthn *webauthn.WebAuthn
+}
+
+func NewWebAuthnService(cfg *config.Config, db *gorm.DB) (*WebAuthnService, error) {
+	wconfig := &webauthn.Config{
+		RPDisplayName: cfg.AppName,
+		RPID:          cfg.RPID,
+		RPOrigins:     cfg.RPOrigins,
+		AuthenticatorSelection: protocol.AuthenticatorSelection{
+			RequireResidentKey: protocol.ResidentKeyRequired(),
+			ResidentKey:        protocol.ResidentKeyRequirementRequired,
+			UserVerification:   protocol.VerificationPreferred,
+		},
+	}
+
+	wa, err := webauthn.New(wconfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return &WebAuthnService{
+		cfg:      cfg,
+		DB:       db,
+		WebAuthn: wa,
+	}, nil
+}
+
+func (s *WebAuthnService) GetUserWithCredentials(userID uint64) (*WebAuthnUser, error) {
+	var user store.User
+	if err := s.DB.First(&user, userID).Error; err != nil {
+		return nil, err
+	}
+
+	var passkeys []store.Passkey
+	if err := s.DB.Where("user_id = ?", userID).Find(&passkeys).Error; err != nil {
+		return nil, err
+	}
+
+	credentials := make([]webauthn.Credential, len(passkeys))
+	for i, pk := range passkeys {
+		credentialIDBytes, err := base64.StdEncoding.DecodeString(pk.CredentialID)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode CredentialID: %w", err)
+		}
+		publicKeyBytes, err := base64.StdEncoding.DecodeString(pk.PublicKey)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode PublicKey: %w", err)
+		}
+		aaguidBytes, err := base64.StdEncoding.DecodeString(pk.AAGUID)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode AAGUID: %w", err)
+		}
+
+		var transport []protocol.AuthenticatorTransport
+		if pk.Transport != "" {
+			transport = []protocol.AuthenticatorTransport{protocol.AuthenticatorTransport(pk.Transport)}
+		}
+
+		credentials[i] = webauthn.Credential{
+			ID:              credentialIDBytes,
+			PublicKey:       publicKeyBytes,
+			AttestationType: pk.AttestationType,
+			Transport:       transport,
+			Flags: webauthn.CredentialFlags{
+				UserPresent:    true,
+				UserVerified:   true,
+				BackupEligible: pk.BackupEligible,
+				BackupState:    pk.BackupState,
+			},
+			Authenticator: webauthn.Authenticator{
+				AAGUID:    aaguidBytes,
+				SignCount: uint32(pk.SignCount),
+			},
+		}
+	}
+
+	return &WebAuthnUser{
+		User:        &user,
+		Credentials: credentials,
+	}, nil
+}
+
+func (s *WebAuthnService) BeginRegistration(userID uint64) (*protocol.CredentialCreation, error) {
+	user, err := s.GetUserWithCredentials(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	options, _, err := s.WebAuthn.BeginRegistration(user)
+	if err != nil {
+		return nil, err
+	}
+
+	return options, nil
+}
+
+func (s *WebAuthnService) FinishRegistration(userID uint64, response *http.Request, deviceName string) (*store.Passkey, error) {
+	user, err := s.GetUserWithCredentials(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	credential, err := s.WebAuthn.FinishRegistration(user, webauthn.SessionData{}, response)
+	if err != nil {
+		return nil, err
+	}
+
+	var transport string
+	if len(credential.Transport) > 0 {
+		transport = string(credential.Transport[0])
+	}
+
+	passkey := &store.Passkey{
+		UserID:          userID,
+		CredentialID:    base64.StdEncoding.EncodeToString(credential.ID),
+		PublicKey:       base64.StdEncoding.EncodeToString(credential.PublicKey),
+		AttestationType: string(credential.AttestationType),
+		AAGUID:          base64.StdEncoding.EncodeToString(credential.Authenticator.AAGUID),
+		SignCount:       uint64(credential.Authenticator.SignCount),
+		Name:            deviceName,
+		DeviceType:      strings.TrimSpace(fmt.Sprintf("%s", deviceName)),
+		LastUsedAt:      time.Now().Unix(),
+		BackupEligible:  credential.Flags.BackupEligible,
+		BackupState:     credential.Flags.BackupState,
+		Transport:       transport,
+	}
+
+	if err := s.DB.Create(passkey).Error; err != nil {
+		return nil, err
+	}
+
+	return passkey, nil
+}
+
+func (s *WebAuthnService) BeginLogin() (*protocol.CredentialAssertion, error) {
+	options, _, err := s.WebAuthn.BeginDiscoverableLogin()
+	if err != nil {
+		return nil, err
+	}
+	return options, nil
+}
+
+func (s *WebAuthnService) ListPasskeys(userID uint64) ([]store.Passkey, error) {
+	var passkeys []store.Passkey
+	if err := s.DB.Where("user_id = ?", userID).Find(&passkeys).Error; err != nil {
+		return nil, err
+	}
+	return passkeys, nil
+}
+
+func (s *WebAuthnService) DeletePasskey(userID uint64, passkeyID uint64) error {
+	return s.DB.Where("id = ? AND user_id = ?", passkeyID, userID).Delete(&store.Passkey{}).Error
+}

backend/internal/store/db.go

@@ -0,0 +1,70 @@
+package store
+
+import (
+	"fmt"
+	"log"
+	"opencatd-open/pkg/config"
+
+	_ "github.com/lib/pq"
+	"gorm.io/driver/mysql"
+	"gorm.io/driver/postgres"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+var DB *gorm.DB
+
+func InitDB(cfg *config.Config) (*gorm.DB, error) {
+	var dialector gorm.Dialector
+
+	switch cfg.DB_Type {
+	case "sqlite":
+		dialector = sqliteDialector(cfg.DSN)
+	case "postgres":
+		dialector = postgresDialector(cfg.DSN)
+	case "mysql":
+		dialector = mysqlDialector(cfg.DSN)
+	default:
+		return nil, fmt.Errorf("unsupported database type: %s", cfg.DB_Type)
+	}
+
+	db, err := gorm.Open(dialector, &gorm.Config{})
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect database: %w", err)
+	}
+
+	sqlDB, err := db.DB()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get underlying *sql.DB: %w", err)
+	}
+	sqlDB.SetMaxOpenConns(cfg.DBMaxOpenConns)
+	sqlDB.SetMaxIdleConns(cfg.DBMaxIdleConns)
+
+	if err := db.AutoMigrate(AllModels()...); err != nil {
+		log.Printf("AutoMigrate warning: %v", err)
+	}
+
+	DB = db
+	return db, nil
+}
+
+func sqliteDialector(dsn string) gorm.Dialector {
+	if dsn == "" {
+		dsn = "opencatd.db"
+	}
+	return sqlite.Open(dsn)
+}
+
+func postgresDialector(dsn string) gorm.Dialector {
+	if dsn == "" {
+		dsn = "host=localhost user=postgres password=postgres dbname=opencatd port=5432 sslmode=disable"
+	}
+	return postgres.Open(dsn)
+}
+
+func mysqlDialector(dsn string) gorm.Dialector {
+	if dsn == "" {
+		dsn = "root:password@tcp(127.0.0.1:3306)/opencatd?charset=utf8mb4&parseTime=True&loc=Local"
+	}
+	return mysql.Open(dsn)
+}

backend/internal/store/models.go

@@ -0,0 +1,233 @@
+package store
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"regexp"
+	"strings"
+	"time"
+)
+
+// 角色 / 状态枚举
+const (
+	RoleUser  = "user"
+	RoleAdmin = "admin"
+
+	UserStatusActive   = "active"
+	UserStatusDisabled = "disabled"
+
+	KeyStatusActive  = "active"
+	KeyStatusRevoked = "revoked"
+
+	ChannelProviderOpenAI     = "openai"
+	ChannelProviderAnthropic  = "anthropic"
+	ChannelProviderCompatible = "compatible"
+	ChannelHealthHealthy      = "healthy"
+	ChannelHealthDegraded     = "degraded"
+	ChannelHealthCooldown     = "cooldown"
+
+	FormatChat      = "chat"
+	FormatResponses = "responses"
+	FormatMessages  = "messages"
+
+	UsageStatusSuccess  = "success"
+	UsageStatusError    = "error"
+	UsageStatusCanceled = "canceled"
+)
+
+// User 用户
+type User struct {
+	ID            uint64     `gorm:"primaryKey;autoIncrement" json:"id"`
+	Username      string     `gorm:"uniqueIndex;size:64;not null" json:"username"`
+	Email         string     `gorm:"uniqueIndex;size:255;not null" json:"email"`
+	PasswordHash  string     `gorm:"size:255;not null" json:"-"`
+	Role          string     `gorm:"size:16;not null;default:user" json:"role"`
+	Balance       float64    `gorm:"type:numeric(20,8);not null;default:0" json:"balance"`
+	Status        string     `gorm:"size:16;not null;default:active" json:"status"`
+	AllowedModels []string   `gorm:"type:jsonb;serializer:json" json:"allowed_models,omitempty"`
+	DeniedModels  []string   `gorm:"type:jsonb;serializer:json" json:"denied_models,omitempty"`
+	InviteCode    *string    `json:"invite_code,omitempty"`
+	LastLoginAt   *time.Time `json:"last_login_at,omitempty"`
+	CreatedAt     time.Time  `json:"created_at"`
+	UpdatedAt     time.Time  `json:"updated_at"`
+}
+
+// APIKey 密钥（SHA-256 hash 存储）
+type APIKey struct {
+	ID                  uint64     `gorm:"primaryKey;autoIncrement" json:"id"`
+	UserID              uint64     `gorm:"index;not null" json:"user_id"`
+	Name                string     `gorm:"size:64;not null" json:"name"`
+	KeyHash             string     `gorm:"uniqueIndex;size:64;not null" json:"-"`
+	KeyPrefix           string     `gorm:"size:32;not null" json:"key_prefix"`
+	QuotaTokensPerDay   *int64     `json:"quota_tokens_per_day,omitempty"`
+	QuotaRequestsPerDay *int       `json:"quota_requests_per_day,omitempty"`
+	AllowedModels       []string   `gorm:"type:jsonb;serializer:json" json:"allowed_models,omitempty"`
+	ExpiresAt           *time.Time `json:"expires_at,omitempty"`
+	Status              string     `gorm:"size:16;not null;default:active" json:"status"`
+	LastUsedAt          *time.Time `json:"last_used_at,omitempty"`
+	CreatedAt           time.Time  `json:"created_at"`
+	UpdatedAt           time.Time  `json:"updated_at"`
+}
+
+// Channel 上游渠道
+type Channel struct {
+	ID             uint64            `gorm:"primaryKey;autoIncrement" json:"id"`
+	Name           string            `gorm:"uniqueIndex;size:64;not null" json:"name"`
+	Provider       string            `gorm:"size:16;not null" json:"provider"`
+	Formats        []string          `gorm:"type:jsonb;serializer:json" json:"formats,omitempty"`
+	BaseURL        string            `gorm:"size:255;not null" json:"base_url"`
+	BaseURLs       map[string]string `gorm:"type:jsonb;serializer:json" json:"base_urls,omitempty"`
+	APIKeyEnc      string            `gorm:"size:1024;not null" json:"-"`
+	Weight         int               `gorm:"not null;default:1" json:"weight"`
+	Priority       int               `gorm:"not null;default:0" json:"priority"`
+	TimeoutMS      int               `gorm:"not null;default:120000" json:"timeout_ms"`
+	MaxConcurrency int               `gorm:"not null;default:16" json:"max_concurrency"`
+	HealthStatus   string            `gorm:"size:16;not null;default:healthy" json:"health_status"`
+	Enabled        bool              `gorm:"not null;default:true" json:"enabled"`
+	CreatedAt      time.Time         `json:"created_at"`
+	UpdatedAt      time.Time         `json:"updated_at"`
+}
+
+// FormatsEffective 返回渠道实际支持的原生协议
+func (c *Channel) FormatsEffective() []string {
+	if len(c.Formats) > 0 {
+		return c.Formats
+	}
+	switch c.Provider {
+	case ChannelProviderAnthropic:
+		return []string{FormatMessages}
+	case ChannelProviderOpenAI:
+		return []string{FormatChat, FormatResponses}
+	default:
+		return []string{FormatChat}
+	}
+}
+
+var versionSegRe = regexp.MustCompile(`/v[0-9]+/?$`)
+
+// UpstreamURL 按协议选 base_url，拼资源路径
+func (c *Channel) UpstreamURL(proto, path string) string {
+	base := c.BaseURL
+	if len(c.BaseURLs) > 0 && c.BaseURLs[proto] != "" {
+		base = c.BaseURLs[proto]
+	}
+	base = strings.TrimRight(base, "/")
+	if base == "" {
+		return path
+	}
+	if strings.HasSuffix(base, path) {
+		return base
+	}
+	if versionSegRe.MatchString(base) {
+		return base + path
+	}
+	return base + "/v1" + path
+}
+
+// Model 全局模型 + 定价（价格按每百万 token，USD）
+type Model struct {
+	ID             uint64    `gorm:"primaryKey;autoIncrement" json:"id"`
+	Name           string    `gorm:"uniqueIndex;size:128;not null" json:"name"`
+	DisplayName    string    `gorm:"size:128" json:"display_name"`
+	InputPrice     float64   `gorm:"type:numeric(20,8);not null;default:0" json:"input_price"`
+	OutputPrice    float64   `gorm:"type:numeric(20,8);not null;default:0" json:"output_price"`
+	CacheReadPrice float64   `gorm:"type:numeric(20,8);not null;default:0" json:"cache_read_price"`
+	Enabled        bool      `gorm:"not null;default:true" json:"enabled"`
+	Sort           int       `gorm:"not null;default:0" json:"sort"`
+	CreatedAt      time.Time `json:"created_at"`
+	UpdatedAt      time.Time `json:"updated_at"`
+}
+
+// ChannelModelBinding 渠道↔模型绑定（多对多）
+type ChannelModelBinding struct {
+	ID            uint64  `gorm:"primaryKey;autoIncrement" json:"id"`
+	ChannelID     uint64  `gorm:"index:idx_ch_model,unique;not null" json:"channel_id"`
+	ModelID       uint64  `gorm:"index:idx_ch_model,unique;not null" json:"model_id"`
+	UpstreamModel string  `gorm:"size:255;not null" json:"upstream_model"`
+	Weight        int     `gorm:"not null;default:1" json:"weight"`
+	Channel       Channel `gorm:"foreignKey:ChannelID" json:"-"`
+	Model         Model   `gorm:"foreignKey:ModelID" json:"-"`
+}
+
+// UsageLog 请求级用量明细
+type UsageLog struct {
+	ID                  uint64    `gorm:"primaryKey;autoIncrement" json:"id"`
+	RequestID           string    `gorm:"size:128" json:"request_id"`
+	TraceID             string    `gorm:"size:64;index" json:"trace_id"`
+	UserID              uint64    `gorm:"index:idx_user_created;not null" json:"user_id"`
+	KeyID               uint64    `json:"key_id"`
+	ChannelID           uint64    `json:"channel_id"`
+	ModelID             uint64    `json:"model_id"`
+	ModelName           string    `gorm:"size:128" json:"model_name"`
+	Protocol            string    `gorm:"size:32" json:"protocol"`
+	InputTokens         int64     `json:"input_tokens"`
+	OutputTokens        int64     `json:"output_tokens"`
+	CacheReadTokens     int64     `json:"cache_read_tokens"`
+	CacheCreationTokens int64     `json:"cache_creation_tokens"`
+	InputPrice          float64   `gorm:"type:numeric(20,8)" json:"input_price"`
+	OutputPrice         float64   `gorm:"type:numeric(20,8)" json:"output_price"`
+	CacheReadPrice      float64   `gorm:"type:numeric(20,8)" json:"cache_read_price"`
+	Cost                float64   `gorm:"type:numeric(20,8)" json:"cost"`
+	LatencyMS           int       `json:"latency_ms"`
+	Status              string    `gorm:"size:16;not null" json:"status"`
+	ErrorCode           *string   `json:"error_code,omitempty"`
+	CreatedAt           time.Time `gorm:"index" json:"created_at"`
+}
+
+// UsageDaily 日粒度预聚合
+type UsageDaily struct {
+	ID              uint64  `gorm:"primaryKey;autoIncrement" json:"id"`
+	UserID          uint64  `gorm:"index:idx_daily_user_model,unique" json:"user_id"`
+	ModelID         uint64  `gorm:"index:idx_daily_user_model,unique" json:"model_id"`
+	Date            string  `gorm:"size:10;index:idx_daily_user_model,unique" json:"date"`
+	Requests        int64   `json:"requests"`
+	InputTokens     int64   `json:"input_tokens"`
+	OutputTokens    int64   `json:"output_tokens"`
+	CacheReadTokens int64   `json:"cache_read_tokens"`
+	Cost            float64 `gorm:"type:numeric(20,8)" json:"cost"`
+}
+
+// Passkey WebAuthn 凭据
+type Passkey struct {
+	ID           uint64    `gorm:"primaryKey;autoIncrement" json:"id"`
+	UserID       uint64    `gorm:"index;not null" json:"user_id"`
+	Name         string    `gorm:"size:64" json:"name"`
+	CredentialID string    `gorm:"size:255;not null" json:"-"`
+	PublicKey    string    `gorm:"size:512;not null" json:"-"`
+	AttestationType string `gorm:"size:64" json:"-"`
+	AAGUID       string    `gorm:"size:64" json:"-"`
+	SignCount    uint64    `json:"-"`
+	DeviceType   string    `gorm:"size:255" json:"device_type,omitempty"`
+	LastUsedAt   int64     `json:"last_used_at,omitempty"`
+	BackupEligible bool   `json:"-"`
+	BackupState    bool   `json:"-"`
+	Transport    string    `gorm:"size:32" json:"-"`
+	CreatedAt    time.Time `json:"created_at"`
+}
+
+// SystemConfig 系统配置
+type SystemConfig struct {
+	Key   string `gorm:"primaryKey;size:64" json:"key"`
+	Value string `gorm:"type:jsonb;not null" json:"value"`
+}
+
+// AllModels 返回所有需要迁移的模型
+func AllModels() []any {
+	return []any{
+		&User{},
+		&APIKey{},
+		&Channel{},
+		&Model{},
+		&ChannelModelBinding{},
+		&UsageLog{},
+		&UsageDaily{},
+		&Passkey{},
+		&SystemConfig{},
+	}
+}
+
+// HashAPIKey hashes an API key using SHA-256
+func HashAPIKey(key string) string {
+	h := sha256.Sum256([]byte(key))
+	return hex.EncodeToString(h[:])
+}

backend/internal/usage/recorder.go

@@ -0,0 +1,140 @@
+package usage
+
+import (
+	"context"
+	"log"
+	"opencatd-open/internal/dao"
+	"opencatd-open/internal/store"
+	"sync"
+	"time"
+)
+
+// Event represents a usage event to be recorded
+type Event struct {
+	UserID           uint64
+	ModelName        string
+	ChannelID        uint64
+	PromptTokens     int
+	CompletionTokens int
+	CacheReadTokens  int
+	Cost             float64
+	IsError          bool
+	IsCanceled       bool
+	RequestID        string
+}
+
+// Recorder handles async usage recording
+type Recorder struct {
+	usageDAO      *dao.UsageDAO
+	dailyDAO      *dao.DailyUsageDAO
+	ch            chan Event
+	batchSize     int
+	flushInterval time.Duration
+	wg            sync.WaitGroup
+}
+
+// NewRecorder creates a new usage recorder
+func NewRecorder(usageDAO *dao.UsageDAO, dailyDAO *dao.DailyUsageDAO) *Recorder {
+	return &Recorder{
+		usageDAO:      usageDAO,
+		dailyDAO:      dailyDAO,
+		ch:            make(chan Event, 10000),
+		batchSize:     100,
+		flushInterval: 5 * time.Second,
+	}
+}
+
+// Start starts the recorder's background workers
+func (r *Recorder) Start(ctx context.Context) {
+	r.wg.Add(1)
+	go r.processLoop(ctx)
+}
+
+// Stop gracefully stops the recorder
+func (r *Recorder) Stop() {
+	close(r.ch)
+	r.wg.Wait()
+}
+
+// Record queues a usage event for async recording
+func (r *Recorder) Record(event Event) {
+	select {
+	case r.ch <- event:
+	default:
+		log.Printf("Usage channel full, dropping event for user %d model %s", event.UserID, event.ModelName)
+	}
+}
+
+func (r *Recorder) processLoop(ctx context.Context) {
+	defer r.wg.Done()
+
+	batch := make([]Event, 0, r.batchSize)
+	ticker := time.NewTicker(r.flushInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			if len(batch) > 0 {
+				r.flush(batch)
+			}
+			return
+		case event, ok := <-r.ch:
+			if !ok {
+				if len(batch) > 0 {
+					r.flush(batch)
+				}
+				return
+			}
+			batch = append(batch, event)
+			if len(batch) >= r.batchSize {
+				r.flush(batch)
+				batch = make([]Event, 0, r.batchSize)
+			}
+		case <-ticker.C:
+			if len(batch) > 0 {
+				r.flush(batch)
+				batch = make([]Event, 0, r.batchSize)
+			}
+		}
+	}
+}
+
+func (r *Recorder) flush(events []Event) {
+	if len(events) == 0 {
+		return
+	}
+
+	// Batch create usage logs
+	logs := make([]*store.UsageLog, 0, len(events))
+
+	for _, e := range events {
+		status := store.UsageStatusSuccess
+		if e.IsError {
+			status = store.UsageStatusError
+		}
+		if e.IsCanceled {
+			status = store.UsageStatusCanceled
+		}
+
+		log := &store.UsageLog{
+			UserID:           e.UserID,
+			ModelName:        e.ModelName,
+			ChannelID:        e.ChannelID,
+			InputTokens:      int64(e.PromptTokens),
+			OutputTokens:     int64(e.CompletionTokens),
+			CacheReadTokens:  int64(e.CacheReadTokens),
+			Cost:             e.Cost,
+			Status:           status,
+			RequestID:        e.RequestID,
+		}
+		logs = append(logs, log)
+	}
+
+	// Write to database
+	if err := r.usageDAO.BatchCreate(context.Background(), logs); err != nil {
+		log.Printf("Failed to batch create usage logs: %v", err)
+	}
+
+	log.Printf("Flushed %d usage logs", len(logs))
+}

backend/internal/utils/convert.go

@@ -0,0 +1,16 @@
+package utils
+
+import "strings"
+
+func StringToBool(strSlice []string) []bool {
+	boolSlice := make([]bool, len(strSlice))
+	for i, str := range strSlice {
+		str = strings.ToLower(str)
+		if str == "true" {
+			boolSlice[i] = true
+		} else if str == "false" {
+			boolSlice[i] = false
+		}
+	}
+	return boolSlice
+}

backend/internal/utils/map_tools.go

@@ -0,0 +1,139 @@
+package utils
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+func MergeJSONObjects(dst, src map[string]interface{}) map[string]interface{} {
+
+	result := make(map[string]interface{})
+	for k, v := range dst {
+		result[k] = v
+	}
+
+	for key, value2 := range src {
+		value1, exists := result[key]
+
+		if exists {
+			map1Val, map1IsMap := value1.(map[string]interface{})
+			map2Val, map2IsMap := value2.(map[string]interface{})
+
+			if map1IsMap && map2IsMap {
+				result[key] = MergeJSONObjects(map1Val, map2Val)
+			} else {
+				// 覆盖第一个map中的值
+				result[key] = value2
+			}
+		} else {
+			// 添加新的键值对
+			result[key] = value2
+		}
+	}
+
+	return result
+}
+
+func StructToMap(in interface{}) (map[string]interface{}, error) {
+	out := make(map[string]interface{})
+
+	v := reflect.ValueOf(in)
+	// If it's a pointer, dereference it
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+
+	// Check if it's a struct
+	if v.Kind() != reflect.Struct {
+		return nil, fmt.Errorf("StructToMap only accepts structs or pointers to structs; got %T", v.Interface())
+	}
+
+	t := v.Type() // Get the type of the struct
+	for i := 0; i < v.NumField(); i++ {
+		// Get the field Value and Type
+		fieldV := v.Field(i)
+		fieldT := t.Field(i)
+
+		// Skip unexported fields
+		if !fieldT.IsExported() {
+			continue
+		}
+
+		// --- Handle JSON Tag ---
+		tag := fieldT.Tag.Get("json")
+		key := fieldT.Name // Default key is the field name
+		omitempty := false
+
+		if tag != "" {
+			parts := strings.Split(tag, ",")
+			tagName := parts[0]
+
+			if tagName == "-" {
+				// Skip fields tagged with "-"
+				continue
+			}
+			if tagName != "" {
+				key = tagName // Use tag name as key
+			}
+
+			// Check for omitempty option
+			for _, part := range parts[1:] {
+				if part == "omitempty" {
+					omitempty = true
+					break
+				}
+			}
+		}
+
+		// --- Handle omitempty ---
+		val := fieldV.Interface()
+		if omitempty && fieldV.IsZero() {
+			continue // Skip zero-value fields if omitempty is set
+		}
+
+		// --- Handle Nested Structs/Pointers to Structs (Recursion) ---
+		// Check for pointer first
+		if fieldV.Kind() == reflect.Ptr {
+			// If pointer is nil and omitempty is set, it was already skipped
+			// If pointer is nil and omitempty is not set, add nil to map
+			if fieldV.IsNil() {
+				// Only add nil if omitempty is not set (already handled above)
+				if !omitempty {
+					out[key] = nil
+				}
+				continue // Move to next field
+			}
+			// If it points to a struct, dereference and recurse
+			if fieldV.Elem().Kind() == reflect.Struct {
+				nestedMap, err := StructToMap(fieldV.Interface()) // Pass the pointer
+				if err != nil {
+					// Decide how to handle nested errors, e.g., log or return
+					fmt.Printf("Warning: could not convert nested struct pointer %s: %v\n", fieldT.Name, err)
+					out[key] = val // Store original value on error? Or skip?
+				} else {
+					out[key] = nestedMap
+				}
+				continue // Move to next field after handling pointer
+			}
+			// If pointer to non-struct, just get the interface value (handled below)
+			val = fieldV.Interface() // Use the actual pointer value
+
+		} else if fieldV.Kind() == reflect.Struct {
+			// If it's a struct (not a pointer), recurse
+			nestedMap, err := StructToMap(fieldV.Interface()) // Pass the struct value
+			if err != nil {
+				fmt.Printf("Warning: could not convert nested struct %s: %v\n", fieldT.Name, err)
+				out[key] = val // Store original value on error? Or skip?
+			} else {
+				out[key] = nestedMap
+			}
+			continue // Move to next field after handling struct
+		}
+
+		// Assign the value (primitive, slice, map, non-struct pointer, etc.)
+		out[key] = val
+	}
+
+	return out, nil
+}

backend/internal/utils/password.go

@@ -0,0 +1,15 @@
+package utils
+
+import (
+	"golang.org/x/crypto/bcrypt"
+)
+
+func HashPassword(password string) (string, error) {
+	bytes, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	return string(bytes), err
+}
+
+func CheckPassword(hash, password string) bool {
+	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
+	return err == nil
+}

backend/internal/utils/pointer.go

@@ -0,0 +1,11 @@
+package utils
+
+func ToPtr[T any](v T) *T {
+	return &v
+}
+
+func UpdatePtrField[T any](target *T, value *T) {
+	if value != nil {
+		*target = *value
+	}
+}