feat(api): add provider creation endpoints and weight support

- Add `POST /admin/providers/preset` for streamlined creation of official providers (OpenAI, Anthropic, Gemini)
- Add `POST /admin/providers/custom` for generic OpenAI-compatible providers
- Add `weight` field to provider model and DTOs to enable weighted routing
- Update sync service to propagate provider weights
- Add unit tests for new creation handlers

cmd/server/main.go

@@ -167,6 +167,8 @@ func main() {
 		adminGroup.PUT("/features", featureHandler.UpdateFeatures)
 		// Other admin routes for managing providers, models, etc.
 		adminGroup.POST("/providers", handler.CreateProvider)
+		adminGroup.POST("/providers/preset", handler.CreateProviderPreset)
+		adminGroup.POST("/providers/custom", handler.CreateProviderCustom)
 		adminGroup.PUT("/providers/:id", handler.UpdateProvider)
 		adminGroup.POST("/models", handler.CreateModel)
 		adminGroup.GET("/models", handler.ListModels)

internal/api/handler.go

@@ -74,6 +74,7 @@ func (h *Handler) CreateProvider(c *gin.Context) {
 		Status:         status,
 		AutoBan:        autoBan,
 		BanReason:      req.BanReason,
+		Weight:         req.Weight,
 	}
 	if !req.BanUntil.IsZero() {
 		tu := req.BanUntil.UTC()
@@ -162,6 +163,9 @@ func (h *Handler) UpdateProvider(c *gin.Context) {
 	if req.Models != nil {
 		update["models"] = strings.Join(req.Models, ",")
 	}
+	if req.Weight > 0 {
+		update["weight"] = req.Weight
+	}
 	if strings.TrimSpace(req.Group) != "" {
 		update["group"] = groupx.Normalize(req.Group)
 	}

internal/api/provider_create_handler.go

@@ -0,0 +1,194 @@
+package api
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"net/http"
+	"strings"
+
+	"github.com/ez-api/ez-api/internal/dto"
+	"github.com/ez-api/ez-api/internal/model"
+	groupx "github.com/ez-api/foundation/group"
+	providerx "github.com/ez-api/foundation/provider"
+	"github.com/gin-gonic/gin"
+)
+
+// CreateProviderPreset godoc
+// @Summary      Create a preset provider
+// @Description  Create an official OpenAI/Anthropic/Gemini provider (only api_key is typically required)
+// @Tags         admin
+// @Accept       json
+// @Produce      json
+// @Security     AdminAuth
+// @Param        provider  body      dto.ProviderPresetCreateDTO  true  "Provider preset payload"
+// @Success      201       {object}  model.Provider
+// @Failure      400       {object}  gin.H
+// @Failure      500       {object}  gin.H
+// @Router       /admin/providers/preset [post]
+func (h *Handler) CreateProviderPreset(c *gin.Context) {
+	var req dto.ProviderPresetCreateDTO
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	preset := providerx.NormalizeType(req.Preset)
+	if preset == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "preset required"})
+		return
+	}
+
+	var providerType string
+	var baseURL string
+	switch preset {
+	case providerx.TypeOpenAI:
+		providerType = providerx.TypeOpenAI
+		baseURL = "https://api.openai.com"
+	case providerx.TypeAnthropic, providerx.TypeClaude:
+		providerType = providerx.TypeAnthropic
+		baseURL = "https://api.anthropic.com"
+	case providerx.TypeGemini, providerx.TypeAIStudio, providerx.TypeGoogle:
+		// Gemini API / AI Studio (SDK transport). BaseURL is optional but we provide the official endpoint.
+		providerType = providerx.TypeGemini
+		baseURL = "https://generativelanguage.googleapis.com"
+	default:
+		c.JSON(http.StatusBadRequest, gin.H{"error": "unsupported preset: " + preset})
+		return
+	}
+
+	name := strings.TrimSpace(req.Name)
+	if name == "" {
+		name = providerType + "-" + randomSuffix(4)
+	}
+	group := strings.TrimSpace(req.Group)
+	if group == "" {
+		group = "default"
+	}
+	status := strings.TrimSpace(req.Status)
+	if status == "" {
+		status = "active"
+	}
+	autoBan := true
+	if req.AutoBan != nil {
+		autoBan = *req.AutoBan
+	}
+
+	googleLocation := providerx.DefaultGoogleLocation(providerType, req.GoogleLocation)
+
+	p := model.Provider{
+		Name:           name,
+		Type:           providerType,
+		BaseURL:        baseURL,
+		APIKey:         strings.TrimSpace(req.APIKey),
+		GoogleProject:  strings.TrimSpace(req.GoogleProject),
+		GoogleLocation: googleLocation,
+		Group:          groupx.Normalize(group),
+		Models:         strings.Join(req.Models, ","),
+		Status:         status,
+		AutoBan:        autoBan,
+	}
+	if req.Weight > 0 {
+		p.Weight = req.Weight
+	}
+
+	if err := h.db.Create(&p).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create provider", "details": err.Error()})
+		return
+	}
+
+	if err := h.sync.SyncProvider(&p); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync provider", "details": err.Error()})
+		return
+	}
+	if err := h.sync.SyncBindings(h.db); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync bindings", "details": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusCreated, p)
+}
+
+// CreateProviderCustom godoc
+// @Summary      Create a custom provider
+// @Description  Create an OpenAI-compatible provider (base_url + api_key required)
+// @Tags         admin
+// @Accept       json
+// @Produce      json
+// @Security     AdminAuth
+// @Param        provider  body      dto.ProviderCustomCreateDTO  true  "Provider custom payload"
+// @Success      201       {object}  model.Provider
+// @Failure      400       {object}  gin.H
+// @Failure      500       {object}  gin.H
+// @Router       /admin/providers/custom [post]
+func (h *Handler) CreateProviderCustom(c *gin.Context) {
+	var req dto.ProviderCustomCreateDTO
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	name := strings.TrimSpace(req.Name)
+	if name == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "name required"})
+		return
+	}
+	baseURL := strings.TrimSpace(req.BaseURL)
+	if baseURL == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "base_url required"})
+		return
+	}
+
+	group := strings.TrimSpace(req.Group)
+	if group == "" {
+		group = "default"
+	}
+	status := strings.TrimSpace(req.Status)
+	if status == "" {
+		status = "active"
+	}
+	autoBan := true
+	if req.AutoBan != nil {
+		autoBan = *req.AutoBan
+	}
+
+	p := model.Provider{
+		Name:    name,
+		Type:    providerx.TypeCompatible,
+		BaseURL: baseURL,
+		APIKey:  strings.TrimSpace(req.APIKey),
+		Group:   groupx.Normalize(group),
+		Models:  strings.Join(req.Models, ","),
+		Status:  status,
+		AutoBan: autoBan,
+	}
+	if req.Weight > 0 {
+		p.Weight = req.Weight
+	}
+
+	if err := h.db.Create(&p).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create provider", "details": err.Error()})
+		return
+	}
+
+	if err := h.sync.SyncProvider(&p); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync provider", "details": err.Error()})
+		return
+	}
+	if err := h.sync.SyncBindings(h.db); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync bindings", "details": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusCreated, p)
+}
+
+func randomSuffix(bytesLen int) string {
+	if bytesLen <= 0 {
+		bytesLen = 4
+	}
+	b := make([]byte, bytesLen)
+	if _, err := rand.Read(b); err != nil {
+		return "rand"
+	}
+	return hex.EncodeToString(b)
+}

internal/api/provider_create_handler_test.go

@@ -0,0 +1,70 @@
+package api
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/ez-api/ez-api/internal/model"
+	"github.com/gin-gonic/gin"
+)
+
+func TestCreateProviderPreset_OpenAI_SetsBaseURL(t *testing.T) {
+	h, _ := newTestHandler(t)
+
+	r := gin.New()
+	r.POST("/admin/providers/preset", h.CreateProviderPreset)
+
+	reqBody := map[string]any{
+		"preset":  "openai",
+		"api_key": "k",
+		"models":  []string{"gpt-4o-mini"},
+	}
+	b, _ := json.Marshal(reqBody)
+
+	req := httptest.NewRequest(http.MethodPost, "/admin/providers/preset", bytes.NewReader(b))
+	req.Header.Set("Content-Type", "application/json")
+	rr := httptest.NewRecorder()
+	r.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusCreated {
+		t.Fatalf("expected 201, got %d body=%s", rr.Code, rr.Body.String())
+	}
+	var got model.Provider
+	if err := json.Unmarshal(rr.Body.Bytes(), &got); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if got.Type != "openai" {
+		t.Fatalf("expected type openai, got %q", got.Type)
+	}
+	if got.BaseURL != "https://api.openai.com" {
+		t.Fatalf("expected base_url=https://api.openai.com, got %q", got.BaseURL)
+	}
+	if got.Name == "" {
+		t.Fatalf("expected generated name")
+	}
+}
+
+func TestCreateProviderCustom_RequiresBaseURL(t *testing.T) {
+	h, _ := newTestHandler(t)
+
+	r := gin.New()
+	r.POST("/admin/providers/custom", h.CreateProviderCustom)
+
+	reqBody := map[string]any{
+		"name":    "c1",
+		"api_key": "k",
+	}
+	b, _ := json.Marshal(reqBody)
+
+	req := httptest.NewRequest(http.MethodPost, "/admin/providers/custom", bytes.NewReader(b))
+	req.Header.Set("Content-Type", "application/json")
+	rr := httptest.NewRecorder()
+	r.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d body=%s", rr.Code, rr.Body.String())
+	}
+}

internal/dto/provider.go

@@ -13,6 +13,7 @@ type ProviderDTO struct {
 	Group          string    `json:"group"`
 	Models         []string  `json:"models"` // List of supported model names
 	Status         string    `json:"status"`
+	Weight         int       `json:"weight,omitempty"`
 	AutoBan        *bool     `json:"auto_ban,omitempty"`
 	BanReason      string    `json:"ban_reason,omitempty"`
 	BanUntil       time.Time `json:"ban_until,omitempty"`

internal/dto/provider_create.go

@@ -0,0 +1,35 @@
+package dto
+
+// ProviderPresetCreateDTO creates an official provider with sensible defaults.
+// For preset providers, base_url is derived automatically; users typically only provide api_key.
+type ProviderPresetCreateDTO struct {
+	Preset string `json:"preset"` // openai | anthropic | gemini
+
+	// Optional fields.
+	Name   string   `json:"name"`
+	Group  string   `json:"group"`
+	Models []string `json:"models"`
+
+	APIKey         string `json:"api_key"`
+	GoogleProject  string `json:"google_project,omitempty"`
+	GoogleLocation string `json:"google_location,omitempty"`
+
+	Status  string `json:"status"`
+	Weight  int    `json:"weight,omitempty"`
+	AutoBan *bool  `json:"auto_ban,omitempty"`
+}
+
+// ProviderCustomCreateDTO creates an OpenAI-compatible provider.
+// For custom providers, base_url is required.
+type ProviderCustomCreateDTO struct {
+	Name   string   `json:"name"`
+	Group  string   `json:"group"`
+	Models []string `json:"models"`
+
+	BaseURL string `json:"base_url"`
+	APIKey  string `json:"api_key"`
+
+	Status  string `json:"status"`
+	Weight  int    `json:"weight,omitempty"`
+	AutoBan *bool  `json:"auto_ban,omitempty"`
+}

internal/model/models.go

@@ -49,6 +49,7 @@ type Provider struct {
 	GoogleLocation string     `gorm:"size:64" json:"google_location,omitempty"`
 	Group          string     `gorm:"default:'default'" json:"group"`         // routing group/tier
 	Models         string     `json:"models"`                                 // comma-separated list of supported models (e.g. "gpt-4,gpt-3.5-turbo")
+	Weight         int        `gorm:"default:1" json:"weight"`                // routing weight inside route_group
 	Status         string     `gorm:"size:50;default:'active'" json:"status"` // active, auto_disabled, manual_disabled
 	AutoBan        bool       `gorm:"default:true" json:"auto_ban"`           // whether DP-triggered disable is allowed
 	BanReason      string     `gorm:"size:255" json:"ban_reason"`             // reason for current disable

internal/service/sync.go

@@ -79,6 +79,7 @@ func (s *SyncService) SyncProvider(provider *model.Provider) error {
 		GoogleLocation: provider.GoogleLocation,
 		Group:          group,
 		Models:         models,
+		Weight:         provider.Weight,
 		Status:         normalizeStatus(provider.Status),
 		AutoBan:        provider.AutoBan,
 		BanReason:      provider.BanReason,
@@ -139,6 +140,7 @@ type providerSnapshot struct {
 	GoogleLocation string   `json:"google_location,omitempty"`
 	Group          string   `json:"group"`
 	Models         []string `json:"models"`
+	Weight         int      `json:"weight,omitempty"`
 	Status         string   `json:"status"`
 	AutoBan        bool     `json:"auto_ban"`
 	BanReason      string   `json:"ban_reason,omitempty"`
@@ -220,6 +222,7 @@ func (s *SyncService) SyncAll(db *gorm.DB) error {
 			GoogleLocation: p.GoogleLocation,
 			Group:          group,
 			Models:         models,
+			Weight:         p.Weight,
 			Status:         normalizeStatus(p.Status),
 			AutoBan:        p.AutoBan,
 			BanReason:      p.BanReason,