diff --git a/backend/internal/pkg/xai/models.go b/backend/internal/pkg/xai/models.go
index 990a6d28e0..d392249617 100644
--- a/backend/internal/pkg/xai/models.go
+++ b/backend/internal/pkg/xai/models.go
@@ -57,9 +57,10 @@ const DefaultTextModel = "grok-4.5"
 const (
 	DefaultImagineImageQualityModel  = "grok-imagine-image-quality"
 	DefaultImagineImageFastModel     = "grok-imagine-image"
+	DefaultImagineImage20Model       = "grok-imagine-image-2.0"
 	DefaultImagineVideoModel         = "grok-imagine-video"
-	DefaultImagineVideo15LegacyModel = "grok-imagine-video-1.5"
-	DefaultImagineVideo15Model       = "grok-imagine-video-1.5-preview"
+	DefaultImagineVideo15Model       = "grok-imagine-video-1.5"
+	DefaultImagineVideo15LegacyModel = "grok-imagine-video-1.5-preview"
 )
 
 // ModelMappingOptions controls optional expansions of the default mapping.
@@ -86,8 +87,6 @@ var defaultModels = []Model{
 	{ID: "grok-4.6", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.6"},
 	{ID: "grok-4.5", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.5"},
 	{ID: "grok-4.3", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.3"},
-	{ID: "grok-3-mini", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 3 Mini"},
-	{ID: "grok-3-mini-fast", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 3 Mini Fast"},
 	{ID: "grok-build-0.1", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Build 0.1"},
 	{ID: "grok-composer-2.5-fast", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Composer 2.5 Fast"},
 	{ID: "grok-4.20-0309-reasoning", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.20 Reasoning"},
@@ -96,9 +95,9 @@ var defaultModels = []Model{
 	// Imagine
 	{ID: DefaultImagineImageQualityModel, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Image Quality"},
 	{ID: DefaultImagineImageFastModel, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Image"},
+	{ID: DefaultImagineImage20Model, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Image 2.0"},
 	{ID: DefaultImagineVideoModel, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Video"},
-	{ID: DefaultImagineVideo15Model, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Video 1.5 Preview"},
-	{ID: DefaultImagineVideo15LegacyModel, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Video 1.5 Legacy"},
+	{ID: DefaultImagineVideo15Model, Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok Imagine Video 1.5"},
 }
 
 // grokTextResponsesModelAliases is the source of truth for Grok text models
@@ -109,8 +108,8 @@ var grokTextResponsesModelAliases = map[string]string{
 	"grok-latest":                  DefaultTextModel,
 	"grok-4.6":                     "grok-4.6",
 	"grok-4.6-latest":              "grok-4.6",
-	"grok-4.5":                     DefaultTextModel,
-	"grok-4.5-latest":              DefaultTextModel,
+	"grok-4.5":                     "grok-4.5",
+	"grok-4.5-latest":              "grok-4.5",
 	"grok-4.3":                     "grok-4.3",
 	"grok-4.3-latest":              "grok-4.3",
 	"grok-3-mini":                  "grok-3-mini",
@@ -162,7 +161,7 @@ func ModelMappingWithOptions(opts ModelMappingOptions) map[string]string {
 	}
 	for alias, canonical := range grokTextResponsesModelAliases {
 		// Remap aliases that pointed at DefaultTextModel constant to runtime default.
-		if canonical == DefaultTextModel {
+		if (alias == "grok" || alias == "grok-latest" || alias == "grok-build-latest") && canonical == DefaultTextModel {
 			mapping[alias] = defaultText
 		} else {
 			mapping[alias] = canonical
@@ -179,7 +178,7 @@ func ModelMappingWithOptions(opts ModelMappingOptions) map[string]string {
 	// Keep official IDs as identity so client-requested model strings are not
 	// rewritten on the wire (pricing still canonicalizes 1.5* via CanonicalImagineVideoModel).
 	mapping["grok-imagine-video"] = DefaultImagineVideoModel
-	mapping["grok-imagine-video-1.5"] = DefaultImagineVideo15LegacyModel
+	mapping["grok-imagine-video-1.5"] = DefaultImagineVideo15Model
 	mapping["grok-imagine-video-1.5-preview"] = DefaultImagineVideo15Model
 	// Informal alias only:
 	mapping["grok-video-1.5"] = DefaultImagineVideo15Model
@@ -273,7 +272,7 @@ func ResolveGrokTextResponsesModelID(model string, defaultText ...string) string
 	}
 	normalized := strings.ToLower(StripGrokProviderPrefix(trimmed))
 	if canonical, ok := grokTextResponsesModelAliases[normalized]; ok {
-		if canonical == DefaultTextModel {
+		if (normalized == "grok" || normalized == "grok-latest" || normalized == "grok-build-latest") && canonical == DefaultTextModel {
 			return fallback
 		}
 		return canonical
diff --git a/backend/internal/pkg/xai/models_test.go b/backend/internal/pkg/xai/models_test.go
index a01d993ccb..0fc463814b 100644
--- a/backend/internal/pkg/xai/models_test.go
+++ b/backend/internal/pkg/xai/models_test.go
@@ -17,7 +17,7 @@ func TestDefaultModelMappingExcludesCrossClientWildcards(t *testing.T) {
 	require.Equal(t, "grok-build-0.1", mapping["grok-build"])
 	require.Equal(t, DefaultTextModel, mapping["grok-build-latest"])
 	require.Equal(t, DefaultImagineImageQualityModel, mapping["grok-imagine-edit"])
-	require.Equal(t, DefaultImagineVideo15LegacyModel, mapping["grok-imagine-video-1.5"])
+	require.Equal(t, DefaultImagineVideo15Model, mapping["grok-imagine-video-1.5"])
 	require.Equal(t, DefaultImagineVideo15Model, mapping["grok-imagine-video-1.5-preview"])
 	require.Equal(t, "grok-4.5", mapping["xai/grok"])
 
@@ -72,3 +72,9 @@ func TestResolveGrokTextResponsesModelID(t *testing.T) {
 	require.Equal(t, "grok-4.3", ResolveGrokTextResponsesModelID("grok", "grok-4.3"))
 	require.Equal(t, "grok-4.20-multi-agent-0309", ResolveGrokTextResponsesModelID("grok-4.20-multi-agent"))
 }
+
+func TestExplicitGrok45DoesNotFollowRuntimeDefault(t *testing.T) {
+	require.Equal(t, "grok-4.5", ResolveGrokTextResponsesModelID("grok-4.5", "grok-4.6"))
+	require.Equal(t, "grok-4.5", ResolveGrokTextResponsesModelID("grok-4.5-latest", "grok-4.6"))
+	require.Equal(t, "grok-4.6", ResolveGrokTextResponsesModelID("grok", "grok-4.6"))
+}
diff --git a/backend/internal/service/billing_service.go b/backend/internal/service/billing_service.go
index af8c694495..2447c31719 100644
--- a/backend/internal/service/billing_service.go
+++ b/backend/internal/service/billing_service.go
@@ -704,6 +704,21 @@ func (s *BillingService) initFallbackPricing() {
 		LongContextInputMultiplier:    2,
 		LongContextOutputMultiplier:   2,
 	}
+
+	// Keep legacy Grok 3 Mini requests on their own historical xAI price card;
+	// otherwise the generic Grok fallback bills them as Grok 4.5.
+	s.fallbackPrices["grok-3-mini"] = &ModelPricing{
+		InputPricePerToken:     0.30e-6,
+		OutputPricePerToken:    0.50e-6,
+		CacheReadPricePerToken: 0.075e-6,
+		SupportsCacheBreakdown: false,
+	}
+	s.fallbackPrices["grok-3-mini-fast"] = &ModelPricing{
+		InputPricePerToken:     0.60e-6,
+		OutputPricePerToken:    4e-6,
+		CacheReadPricePerToken: 0.15e-6,
+		SupportsCacheBreakdown: false,
+	}
 	// xAI Grok Build 0.1 (official docs: $1 input / $0.20 cached input /
 	// $2 output per MTok). Composer is available only through Grok Build and
 	// has no standalone public API rate card, so its aliases use this coding
@@ -913,6 +928,10 @@ func (s *BillingService) getFallbackPricing(model string) *ModelPricing {
 		return s.fallbackPrices["grok-4.5"]
 	case "grok-4.6", "grok-4.6-latest":
 		return s.fallbackPrices["grok-4.6"]
+	case "grok-3-mini":
+		return s.fallbackPrices["grok-3-mini"]
+	case "grok-3-mini-fast":
+		return s.fallbackPrices["grok-3-mini-fast"]
 	case "grok-4.3",
 		"grok-4.20-0309-reasoning",
 		"grok-4.20-0309-non-reasoning",
diff --git a/backend/internal/service/openai_gateway_grok.go b/backend/internal/service/openai_gateway_grok.go
index d9c7c5b0e4..9cb3b01246 100644
--- a/backend/internal/service/openai_gateway_grok.go
+++ b/backend/internal/service/openai_gateway_grok.go
@@ -173,11 +173,14 @@ func (s *OpenAIGatewayService) forwardGrokResponses(
 			markGrokTeamModelRateLimit(account, upstreamModel, resolveGrokTeamRateLimitUntil(time.Now().Add(grokTeamRateLimitDefaultTTL), time.Now()))
 		}
 		if s.shouldFailoverGrokUpstreamError(resp.StatusCode, respBody) {
+			retryable, retryDelay, retryDeadline := grokSameAccountRetryMetadata(account, resp.StatusCode, respBody)
 			return nil, &UpstreamFailoverError{
-				StatusCode:             resp.StatusCode,
-				ResponseBody:           respBody,
-				ResponseHeaders:        resp.Header.Clone(),
-				RetryableOnSameAccount: account.IsPoolMode() && account.IsPoolModeRetryableStatus(resp.StatusCode),
+				StatusCode:               resp.StatusCode,
+				ResponseBody:             respBody,
+				ResponseHeaders:          resp.Header.Clone(),
+				RetryableOnSameAccount:   retryable,
+				SameAccountRetryDelay:    retryDelay,
+				SameAccountRetryDeadline: retryDeadline,
 			}
 		}
 		return s.handleErrorResponse(ctx, resp, c, account, patchedBody, upstreamModel)
@@ -899,7 +902,14 @@ func sanitizeGrokResponsesTools(body []byte) ([]byte, error) {
 		return body, nil
 	}
 	if !tools.IsArray() {
-		return body, nil
+		// xAI rejects tool_choice when tools is null/object. Treat malformed
+		// tool collections as absent at egress rather than forwarding a pair
+		// that cannot be interpreted by the Grok Responses endpoint.
+		body, err := sjson.DeleteBytes(body, "tools")
+		if err != nil {
+			return nil, err
+		}
+		return sjson.DeleteBytes(body, "tool_choice")
 	}
 
 	rawTools := tools.Array()
@@ -1173,11 +1183,14 @@ func (s *OpenAIGatewayService) describeGrokComposerImage(
 		})
 		s.handleGrokAccountUpstreamError(withGrokTeamRateLimitModel(ctx, grokComposerImageBridgeVisionModel), account, resp.StatusCode, resp.Header, respBody)
 		if s.shouldFailoverGrokUpstreamError(resp.StatusCode, respBody) {
+			retryable, retryDelay, retryDeadline := grokSameAccountRetryMetadata(account, resp.StatusCode, respBody)
 			return "", OpenAIUsage{}, &UpstreamFailoverError{
-				StatusCode:             resp.StatusCode,
-				ResponseBody:           respBody,
-				ResponseHeaders:        resp.Header.Clone(),
-				RetryableOnSameAccount: account.IsPoolMode() && account.IsPoolModeRetryableStatus(resp.StatusCode),
+				StatusCode:               resp.StatusCode,
+				ResponseBody:             respBody,
+				ResponseHeaders:          resp.Header.Clone(),
+				RetryableOnSameAccount:   retryable,
+				SameAccountRetryDelay:    retryDelay,
+				SameAccountRetryDeadline: retryDeadline,
 			}
 		}
 		return "", OpenAIUsage{}, fmt.Errorf("grok composer image bridge upstream error: %s", upstreamMsg)
@@ -1314,6 +1327,7 @@ func buildGrokResponsesRequest(ctx context.Context, c *gin.Context, account *Acc
 	if err != nil {
 		return nil, err
 	}
+	req = req.WithContext(WithHTTPUpstreamProfile(req.Context(), HTTPUpstreamProfileGrok))
 	req.Header.Set("Authorization", "Bearer "+token)
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("Accept", "application/json, text/event-stream")
diff --git a/backend/internal/service/openai_gateway_grok_test.go b/backend/internal/service/openai_gateway_grok_test.go
index 7b30e683aa..cbeacdff6e 100644
--- a/backend/internal/service/openai_gateway_grok_test.go
+++ b/backend/internal/service/openai_gateway_grok_test.go
@@ -406,10 +406,10 @@ func TestSanitizeGrokResponsesToolsKeepsToolChoiceOnlyWithSupportedTools(t *test
 			wantToolChoice: true,
 		},
 		{
-			name:           "malformed non-array tools remain untouched",
+			name:           "malformed non-array tools are removed",
 			body:           `{"input":"hello","tools":{"type":"function","name":"lookup"},"tool_choice":"auto"}`,
-			wantTools:      true,
-			wantToolChoice: true,
+			wantTools:      false,
+			wantToolChoice: false,
 		},
 	}