diff --git a/internal/ent/schema/request.go b/internal/ent/schema/request.go
index 3a4c7bb8c..cca587381 100644
--- a/internal/ent/schema/request.go
+++ b/internal/ent/schema/request.go
@@ -3,6 +3,7 @@ package schema
 import (
 	"entgo.io/contrib/entgql"
 	"entgo.io/ent"
+	"entgo.io/ent/dialect"
 	"entgo.io/ent/schema"
 	"entgo.io/ent/schema/edge"
 	"entgo.io/ent/schema/field"
@@ -88,7 +89,9 @@ func (Request) Fields() []ent.Field {
 		// External ID for tracking requests in external systems
 		field.String("external_id").
 			Optional().
-			MaxLen(512),
+			SchemaType(map[string]string{
+				dialect.MySQL: "text",
+			}),
 		// The status of the request.
 		field.Enum("status").Values("pending", "processing", "completed", "failed", "canceled"),
 		// Whether the request is a streaming request
diff --git a/internal/ent/schema/request_execution.go b/internal/ent/schema/request_execution.go
index 43d1db2f1..ca6bf75de 100644
--- a/internal/ent/schema/request_execution.go
+++ b/internal/ent/schema/request_execution.go
@@ -3,6 +3,7 @@ package schema
 import (
 	"entgo.io/contrib/entgql"
 	"entgo.io/ent"
+	"entgo.io/ent/dialect"
 	"entgo.io/ent/schema"
 	"entgo.io/ent/schema/edge"
 	"entgo.io/ent/schema/field"
@@ -46,7 +47,9 @@ func (RequestExecution) Fields() []ent.Field {
 		// External ID for tracking requests in external systems
 		field.String("external_id").
 			Optional().
-			MaxLen(512),
+			SchemaType(map[string]string{
+				dialect.MySQL: "text",
+			}),
 		field.String("model_id").Immutable(),
 		//  The format of the request, e.g: openai/chat_completions, claude/messages, openai/response.
 		field.String("format").Immutable().Default("openai/chat_completions"),
diff --git a/internal/server/api/openai.go b/internal/server/api/openai.go
index 5634d4260..a83eb33b4 100644
--- a/internal/server/api/openai.go
+++ b/internal/server/api/openai.go
@@ -614,15 +614,19 @@ func (handlers *OpenAIHandlers) ListModels(c *gin.Context) {
 			return m.ID
 		})
 
-		dbModels, err := handlers.EntClient.Model.Query().
-			Where(
-				model.StatusEQ(model.StatusEnabled),
-				model.ModelIDIn(visibleIDs...),
-			).
-			All(ctx)
-		if err != nil {
-			handlers.writeOpenAIInternalError(c, requestID, err)
-			return
+		var dbModels []*ent.Model
+		for _, chunk := range lo.Chunk(visibleIDs, biz.SQLiteMaxVariableLimit) {
+			chunkModels, err := handlers.EntClient.Model.Query().
+				Where(
+					model.StatusEQ(model.StatusEnabled),
+					model.ModelIDIn(chunk...),
+				).
+				All(ctx)
+			if err != nil {
+				handlers.writeOpenAIInternalError(c, requestID, err)
+				return
+			}
+			dbModels = append(dbModels, chunkModels...)
 		}
 
 		dbModelMap := make(map[string]*ent.Model, len(dbModels))
diff --git a/internal/server/biz/model.go b/internal/server/biz/model.go
index 04dff0aa4..f143a84a7 100644
--- a/internal/server/biz/model.go
+++ b/internal/server/biz/model.go
@@ -39,6 +39,12 @@ func NewModelService(params ModelServiceParams) *ModelService {
 	}
 }
 
+// SQLiteMaxVariableLimit is a safe chunk size for SQL IN clauses.
+// SQLite versions prior to 3.32.0 have a limit of 999 variables;
+// newer versions support 32766. We use 500 to stay safely below both limits
+// and leave room for other query parameters.
+const SQLiteMaxVariableLimit = 500
+
 type ModelService struct {
 	*AbstractService
 
@@ -312,22 +318,31 @@ func (svc *ModelService) BulkCreateModels(ctx context.Context, inputs []*ent.Cre
 		inputMap[key] = true
 	}
 
-	// Check if any models already exist
-	existingModels, err := svc.entFromContext(ctx).Model.Query().
-		Where(func(s *sql.Selector) {
-			var predicates []*sql.Predicate
-			for _, input := range inputs {
-				predicates = append(predicates, sql.And(
-					sql.EQ(model.FieldDeveloper, input.Developer),
-					sql.EQ(model.FieldModelID, input.ModelID),
-				))
-			}
+	// Check if any models already exist (chunk inputs to avoid SQLite variable limit;
+	// each predicate uses 2 variables: developer + modelID).
+	chunkSize := SQLiteMaxVariableLimit / 2
 
-			s.Where(sql.Or(predicates...))
-		}).
-		All(ctx)
-	if err != nil {
-		return nil, fmt.Errorf("failed to check existing models: %w", err)
+	var existingModels []*ent.Model
+
+	for _, chunk := range lo.Chunk(inputs, chunkSize) {
+		chunkModels, err := svc.entFromContext(ctx).Model.Query().
+			Where(func(s *sql.Selector) {
+				var predicates []*sql.Predicate
+				for _, input := range chunk {
+					predicates = append(predicates, sql.And(
+						sql.EQ(model.FieldDeveloper, input.Developer),
+						sql.EQ(model.FieldModelID, input.ModelID),
+					))
+				}
+
+				s.Where(sql.Or(predicates...))
+			}).
+			All(ctx)
+		if err != nil {
+			return nil, fmt.Errorf("failed to check existing models: %w", err)
+		}
+
+		existingModels = append(existingModels, chunkModels...)
 	}
 
 	if len(existingModels) > 0 {
@@ -430,51 +445,63 @@ func (svc *ModelService) DeleteModel(ctx context.Context, id int) error {
 }
 
 // BulkArchiveModels archives multiple models by their IDs.
+// IDs are chunked to avoid SQLite "too many SQL variables" error.
 func (svc *ModelService) BulkArchiveModels(ctx context.Context, ids []int) error {
-	_, err := svc.entFromContext(ctx).Model.Update().
-		Where(model.IDIn(ids...)).
-		SetStatus(model.StatusArchived).
-		Save(ctx)
-	if err != nil {
-		return fmt.Errorf("failed to bulk archive models: %w", err)
+	for _, chunk := range lo.Chunk(ids, SQLiteMaxVariableLimit) {
+		_, err := svc.entFromContext(ctx).Model.Update().
+			Where(model.IDIn(chunk...)).
+			SetStatus(model.StatusArchived).
+			Save(ctx)
+		if err != nil {
+			return fmt.Errorf("failed to bulk archive models: %w", err)
+		}
 	}
 
 	return nil
 }
 
 // BulkDisableModels disables multiple models by their IDs.
+// IDs are chunked to avoid SQLite "too many SQL variables" error.
 func (svc *ModelService) BulkDisableModels(ctx context.Context, ids []int) error {
-	_, err := svc.entFromContext(ctx).Model.Update().
-		Where(model.IDIn(ids...)).
-		SetStatus(model.StatusDisabled).
-		Save(ctx)
-	if err != nil {
-		return fmt.Errorf("failed to bulk disable models: %w", err)
+	for _, chunk := range lo.Chunk(ids, SQLiteMaxVariableLimit) {
+		_, err := svc.entFromContext(ctx).Model.Update().
+			Where(model.IDIn(chunk...)).
+			SetStatus(model.StatusDisabled).
+			Save(ctx)
+		if err != nil {
+			return fmt.Errorf("failed to bulk disable models: %w", err)
+		}
 	}
 
 	return nil
 }
 
 // BulkEnableModels enables multiple models by their IDs.
+// IDs are chunked to avoid SQLite "too many SQL variables" error.
 func (svc *ModelService) BulkEnableModels(ctx context.Context, ids []int) error {
-	_, err := svc.entFromContext(ctx).Model.Update().
-		Where(model.IDIn(ids...)).
-		SetStatus(model.StatusEnabled).
-		Save(ctx)
-	if err != nil {
-		return fmt.Errorf("failed to bulk enable models: %w", err)
+	for _, chunk := range lo.Chunk(ids, SQLiteMaxVariableLimit) {
+		_, err := svc.entFromContext(ctx).Model.Update().
+			Where(model.IDIn(chunk...)).
+			SetStatus(model.StatusEnabled).
+			Save(ctx)
+		if err != nil {
+			return fmt.Errorf("failed to bulk enable models: %w", err)
+		}
 	}
 
 	return nil
 }
 
 // BulkDeleteModels deletes multiple models by their IDs.
+// IDs are chunked to avoid SQLite "too many SQL variables" error.
 func (svc *ModelService) BulkDeleteModels(ctx context.Context, ids []int) error {
-	_, err := svc.entFromContext(ctx).Model.Delete().
-		Where(model.IDIn(ids...)).
-		Exec(ctx)
-	if err != nil {
-		return fmt.Errorf("failed to bulk delete models: %w", err)
+	for _, chunk := range lo.Chunk(ids, SQLiteMaxVariableLimit) {
+		_, err := svc.entFromContext(ctx).Model.Delete().
+			Where(model.IDIn(chunk...)).
+			Exec(ctx)
+		if err != nil {
+			return fmt.Errorf("failed to bulk delete models: %w", err)
+		}
 	}
 
 	return nil
@@ -651,17 +678,32 @@ func (svc *ModelService) ListEnabledModels(ctx context.Context) ([]ModelFacade,
 // queryConfiguredModelFacades queries enabled Model entities and returns them as ModelFacades
 // filtered by allowed model IDs and channel associations.
 func (svc *ModelService) queryConfiguredModelFacades(ctx context.Context, allowedModelIDs []string, channels []*Channel) ([]ModelFacade, error) {
-	query := svc.entFromContext(ctx).
-		Model.
-		Query().
-		Where(model.StatusEQ(model.StatusEnabled))
+	var enabledModels []*ent.Model
+
 	if len(allowedModelIDs) > 0 {
-		query = query.Where(model.ModelIDIn(allowedModelIDs...))
-	}
+		// Chunk allowedModelIDs to avoid SQLite "too many SQL variables" error.
+		for _, chunk := range lo.Chunk(allowedModelIDs, SQLiteMaxVariableLimit) {
+			chunkModels, err := svc.entFromContext(ctx).Model.Query().
+				Where(
+					model.StatusEQ(model.StatusEnabled),
+					model.ModelIDIn(chunk...),
+				).
+				All(ctx)
+			if err != nil {
+				return nil, fmt.Errorf("failed to list configured models: %w", err)
+			}
 
-	enabledModels, err := query.All(ctx)
-	if err != nil {
-		return nil, fmt.Errorf("failed to list configured models: %w", err)
+			enabledModels = append(enabledModels, chunkModels...)
+		}
+	} else {
+		var err error
+
+		enabledModels, err = svc.entFromContext(ctx).Model.Query().
+			Where(model.StatusEQ(model.StatusEnabled)).
+			All(ctx)
+		if err != nil {
+			return nil, fmt.Errorf("failed to list configured models: %w", err)
+		}
 	}
 
 	var models []ModelFacade