fix: normalize grok imagine image alias

backend/internal/service/grok_media.go

@@ -17,6 +17,7 @@ import (
 	"github.com/Wei-Shaw/sub2api/internal/util/responseheaders"
 	"github.com/gin-gonic/gin"
 	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
 )
 
 type GrokMediaEndpoint string
@@ -296,6 +297,10 @@ func (s *OpenAIGatewayService) ForwardGrokMedia(
 	if err != nil {
 		return nil, err
 	}
+	body, contentType, err = normalizeGrokMediaForwardBody(endpoint, body, contentType)
+	if err != nil {
+		return nil, err
+	}
 
 	var bodyReader io.Reader
 	if endpoint.RequiresRequestBody() {
@@ -424,6 +429,33 @@ func prepareGrokMediaForwardBody(endpoint GrokMediaEndpoint, body []byte, conten
 	return out, "application/json", nil
 }
 
+func normalizeGrokMediaForwardBody(endpoint GrokMediaEndpoint, body []byte, contentType string) ([]byte, string, error) {
+	if !endpoint.RequiresRequestBody() || !gjson.ValidBytes(body) {
+		return body, contentType, nil
+	}
+	model := strings.TrimSpace(gjson.GetBytes(body, "model").String())
+	upstreamModel := normalizeGrokMediaModelForEndpoint(endpoint, model)
+	if upstreamModel == "" || upstreamModel == model {
+		return body, contentType, nil
+	}
+	out, err := sjson.SetBytes(body, "model", upstreamModel)
+	if err != nil {
+		return nil, "", fmt.Errorf("rewrite grok media model: %w", err)
+	}
+	return out, contentType, nil
+}
+
+func normalizeGrokMediaModelForEndpoint(endpoint GrokMediaEndpoint, model string) string {
+	model = strings.TrimSpace(model)
+	switch endpoint {
+	case GrokMediaEndpointImagesGenerations, GrokMediaEndpointImagesEdits:
+		if model == "grok-imagine" {
+			return "grok-imagine-image-quality"
+		}
+	}
+	return model
+}
+
 type grokMediaUsageMetadata struct {
 	ResponseID       string
 	Usage            OpenAIUsage

backend/internal/service/openai_gateway_grok_test.go

@@ -201,7 +201,28 @@ func TestParseGrokMediaRequestBuildsMultipartModerationBody(t *testing.T) {
 	require.True(t, strings.HasPrefix(gjson.GetBytes(moderationBody, "images.0.image_url").String(), "data:image/"))
 }
 
-func TestForwardGrokMediaImagesGenerationPassthrough(t *testing.T) {
+func TestNormalizeGrokMediaModelForEndpoint(t *testing.T) {
+	tests := []struct {
+		name     string
+		endpoint GrokMediaEndpoint
+		model    string
+		want     string
+	}{
+		{name: "image generation alias", endpoint: GrokMediaEndpointImagesGenerations, model: "grok-imagine", want: "grok-imagine-image-quality"},
+		{name: "image edit alias", endpoint: GrokMediaEndpointImagesEdits, model: "grok-imagine", want: "grok-imagine-image-quality"},
+		{name: "image quality passthrough", endpoint: GrokMediaEndpointImagesGenerations, model: "grok-imagine-image-quality", want: "grok-imagine-image-quality"},
+		{name: "image fast passthrough", endpoint: GrokMediaEndpointImagesGenerations, model: "grok-imagine-image", want: "grok-imagine-image"},
+		{name: "video passthrough", endpoint: GrokMediaEndpointVideosGenerations, model: "grok-imagine-video", want: "grok-imagine-video"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.want, normalizeGrokMediaModelForEndpoint(tt.endpoint, tt.model))
+		})
+	}
+}
+
+func TestForwardGrokMediaImagesGenerationNormalizesImagineAlias(t *testing.T) {
 	t.Setenv(xai.EnvAllowUnsafeURLOverrides, "true")
 	gin.SetMode(gin.TestMode)
 
@@ -238,12 +259,12 @@ func TestForwardGrokMediaImagesGenerationPassthrough(t *testing.T) {
 	require.Equal(t, http.MethodPost, upstream.lastReq.Method)
 	require.Equal(t, "Bearer api-key", upstream.lastReq.Header.Get("Authorization"))
 	require.Equal(t, "application/json", upstream.lastReq.Header.Get("Content-Type"))
-	require.JSONEq(t, string(body), string(upstream.lastBody))
+	require.JSONEq(t, `{"model":"grok-imagine-image-quality","prompt":"draw a cat"}`, string(upstream.lastBody))
 	require.Equal(t, http.StatusOK, recorder.Code)
 	require.JSONEq(t, `{"data":[]}`, recorder.Body.String())
 	require.Equal(t, "xai-image-req", result.RequestID)
-	require.Equal(t, "grok-imagine", result.Model)
-	require.Equal(t, "grok-imagine", result.BillingModel)
+	require.Equal(t, "grok-imagine-image-quality", result.Model)
+	require.Equal(t, "grok-imagine-image-quality", result.BillingModel)
 	require.Equal(t, 1, result.ImageCount)
 	require.Equal(t, ImageBillingSize2K, result.ImageSize)
 }