cursor pagination

internal/tender/handler.go

@@ -157,7 +157,8 @@ func (h *TenderHandler) Delete(c echo.Context) error {
 // @Param languages query []string false "Filter by languages (comma-separated)"
 // @Param buyer_organization_id query string false "Filter by buyer organization ID"
 // @Param limit query int false "Number of items per page (default: 20, max: 100)"
-// @Param offset query int false "Number of items to skip (default: 0)"
+// @Param offset query int false "Number of items to skip (default: 0). Prefer cursor for deep pages."
+// @Param cursor query string false "Opaque cursor from previous page meta.next_cursor"
 // @Param sort_by query string false "Sort by field"
 // @Param sort_order query string false "Sort order (asc or desc)"
 // @Success 200 {object} response.APIResponse{data=map[string]interface{}}
@@ -179,6 +180,9 @@ func (h *TenderHandler) Search(c echo.Context) error {
 	// Call service
 	tenders, err := h.service.Search(c.Request().Context(), form, response.NewPagination(c))
 	if err != nil {
+		if isInvalidPaginationCursor(err) {
+			return response.ValidationError(c, "Invalid pagination cursor", err.Error())
+		}
 		return response.InternalServerError(c, "Failed to list tenders")
 	}
 
@@ -219,7 +223,8 @@ func (h *TenderHandler) Search(c echo.Context) error {
 // @Param languages query []string false "Filter by languages (comma-separated)"
 // @Param buyer_organization_id query string false "Filter by buyer organization ID"
 // @Param limit query int false "Number of items per page (default: 20, max: 100)"
-// @Param offset query int false "Number of items to skip (default: 0)"
+// @Param offset query int false "Number of items to skip (default: 0). Prefer cursor for deep pages."
+// @Param cursor query string false "Opaque cursor from previous page meta.next_cursor"
 // @Param sort_by query string false "Sort by field"
 // @Param sort_order query string false "Sort order (asc or desc)"
 // @Success 200 {object} response.APIResponse{data=SearchResponse}
@@ -256,6 +261,9 @@ func (h *TenderHandler) GetPublicTenders(c echo.Context) error {
 
 	result, err := h.service.Search(c.Request().Context(), form, response.NewPagination(c))
 	if err != nil {
+		if isInvalidPaginationCursor(err) {
+			return response.ValidationError(c, "Invalid pagination cursor", err.Error())
+		}
 		return response.InternalServerError(c, "Failed to retrieve tenders")
 	}
 
@@ -292,7 +300,8 @@ func (h *TenderHandler) GetPublicTenders(c echo.Context) error {
 // @Param languages query []string false "Filter by languages (comma-separated)"
 // @Param buyer_organization_id query string false "Filter by buyer organization ID"
 // @Param limit query int false "Number of items per page (default: 20, max: 100)"
-// @Param offset query int false "Number of items to skip (default: 0)"
+// @Param offset query int false "Number of items to skip (default: 0). Prefer cursor for deep pages."
+// @Param cursor query string false "Opaque cursor from previous page meta.next_cursor"
 // @Param sort_by query string false "Sort by field"
 // @Param sort_order query string false "Sort order (asc or desc)"
 // @Success 200 {object} response.APIResponse{data=SearchResponse}
@@ -328,6 +337,9 @@ func (h *TenderHandler) RecommendTenders(c echo.Context) error {
 
 	result, err := h.service.Recommend(c.Request().Context(), form, response.NewPagination(c))
 	if err != nil {
+		if isInvalidPaginationCursor(err) {
+			return response.ValidationError(c, "Invalid pagination cursor", err.Error())
+		}
 		return response.InternalServerError(c, "Failed to retrieve tenders")
 	}
 
@@ -651,3 +663,7 @@ func (h *TenderHandler) GetAllAISummaries(c echo.Context) error {
 
 	return response.Success(c, summaries, "AI summaries retrieved successfully")
 }
+
+func isInvalidPaginationCursor(err error) bool {
+	return errors.Is(err, orm.ErrInvalidCursor)
+}

internal/tender/repository.go

@@ -26,7 +26,7 @@ type TenderRepository interface {
 	GetTenderCountByCountry(ctx context.Context) (map[string]int64, error)
 	GetTenderCountByType(ctx context.Context) (map[string]int64, error)
 	GetTenderCountByClassification(ctx context.Context) (map[string]int64, error)
-	Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) ([]Tender, int64, error)
+	Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) (*SearchPageResult, error)
 	GetExpiredTenders(ctx context.Context, beforeDate int64) ([]Tender, error)
 	GetUnScrapedTenders(ctx context.Context, limit, skip int) ([]Tender, int64, error)
 	GetUnSummarizedTenders(ctx context.Context, limit, skip int) ([]Tender, int64, error)
@@ -40,11 +40,27 @@ func collectionName() string {
 	return "tenders"
 }
 
+// deepOffsetSkipCountThreshold skips CountDocuments when offset pagination goes this deep.
+const deepOffsetSkipCountThreshold = 1000
+
+// SearchPageResult is the paginated outcome of a tender search/list query.
+type SearchPageResult struct {
+	Items      []Tender
+	TotalCount int64 // -1 when count was skipped
+	NextCursor string
+	HasMore    bool
+}
+
 // tenderSearchListProjection excludes large fields not needed for list/search API payloads.
 func tenderSearchListProjection() bson.M {
 	return bson.M{
-		"content_xml":        0,
-		"document_summaries": 0,
+		"content_xml":         0,
+		"document_summaries":  0,
+		"scraped_documents":   0,
+		"selection_criteria":  0,
+		"modifications":       0,
+		"source_file_url":     0,
+		"source_file_name":    0,
 	}
 }
 
@@ -85,6 +101,26 @@ func NewRepository(mongoManager *orm.ConnectionManager, logger logger.Logger) Te
 		*orm.NewIndex("tender_deadline_idx", bson.D{{Key: "tender_deadline", Value: 1}}),
 		*orm.NewIndex("estimated_value_idx", bson.D{{Key: "estimated_value", Value: -1}}),
 		*orm.NewIndex("created_at_idx", bson.D{{Key: "created_at", Value: -1}}),
+		// Stable keyset pagination for default admin list (created_at desc).
+		*orm.NewIndex("created_at_id_idx", bson.D{
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
+		*orm.NewIndex("status_created_at_id_idx", bson.D{
+			{Key: "status", Value: 1},
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
+		*orm.NewIndex("country_code_created_at_id_idx", bson.D{
+			{Key: "country_code", Value: 1},
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
+		*orm.NewIndex("notice_type_code_created_at_id_idx", bson.D{
+			{Key: "notice_type_code", Value: 1},
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
 		*orm.NewIndex("updated_at_idx", bson.D{{Key: "updated_at", Value: -1}}),
 		// Compound indexes for common queries
 		*orm.NewIndex("status_country_idx", bson.D{
@@ -321,10 +357,9 @@ func (r *tenderRepository) Delete(ctx context.Context, id string) error {
 }
 
 // Search searches tenders based on criteria
-func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) ([]Tender, int64, error) {
+func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) (*SearchPageResult, error) {
 	filter := r.buildSearchFilter(form)
 
-	// Build sort
 	sort := "created_at"
 	if pagination.SortBy != "" {
 		sort = pagination.SortBy
@@ -335,23 +370,34 @@ func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, paginat
 		sortOrder = pagination.SortOrder
 	}
 
-	// Build pagination
+	skipCount := pagination.Cursor != "" || pagination.Offset >= deepOffsetSkipCountThreshold
+
 	paginationBuilder := orm.NewPaginationBuilder().
 		Limit(pagination.Limit).
-		Skip(pagination.Offset).
 		SortBy(sort, sortOrder).
 		Projection(tenderSearchListProjection()).
-		Build()
+		SkipCount(skipCount)
 
-	result, err := r.ormRepo.FindAll(ctx, filter, paginationBuilder)
+	if pagination.Cursor != "" {
+		paginationBuilder.Cursor(pagination.Cursor)
+	} else {
+		paginationBuilder.Skip(pagination.Offset)
+	}
+
+	result, err := r.ormRepo.FindAll(ctx, filter, paginationBuilder.Build())
 	if err != nil {
 		r.logger.Error("Failed to search tenders", map[string]interface{}{
 			"error": err.Error(),
 		})
-		return nil, 0, err
+		return nil, err
 	}
 
-	return result.Items, result.TotalCount, nil
+	return &SearchPageResult{
+		Items:      result.Items,
+		TotalCount: result.TotalCount,
+		NextCursor: result.NextCursor,
+		HasMore:    result.HasMore,
+	}, nil
 }
 
 // GetExpiredTenders retrieves tenders that are expired

internal/tender/service.go

@@ -613,7 +613,7 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 		}
 	}
 
-	tenders, total, err := s.repository.Search(ctx, form, pagination)
+	page, err := s.repository.Search(ctx, form, pagination)
 	if err != nil {
 		s.logger.Error("Failed to list tenders", map[string]interface{}{
 			"error": err.Error(),
@@ -623,14 +623,14 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 
 	// If no company ID provided, return tenders without match percentage
 	if form.CompanyID == nil || *form.CompanyID == "" {
-		tenderResponses := make([]TenderResponse, 0, len(tenders))
-		for _, tender := range tenders {
+		tenderResponses := make([]TenderResponse, 0, len(page.Items))
+		for _, tender := range page.Items {
 			tenderResponses = append(tenderResponses, *tender.ToResponseWithLanguage(s.pickResponseLanguage(form.Language)))
 		}
 
 		return &SearchResponse{
 			Tenders:  tenderResponses,
-			Metadata: pagination.Response(total),
+			Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
 		}, nil
 	}
 
@@ -642,14 +642,14 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 			"error":      err.Error(),
 		})
 		// Continue without match percentage if company not found
-		tenderResponses := make([]TenderResponse, 0, len(tenders))
-		for _, tender := range tenders {
+		tenderResponses := make([]TenderResponse, 0, len(page.Items))
+		for _, tender := range page.Items {
 			tenderResponses = append(tenderResponses, *tender.ToResponseWithLanguage(s.pickResponseLanguage(form.Language)))
 		}
 
 		return &SearchResponse{
 				Tenders:  tenderResponses,
-				Metadata: pagination.Response(total),
+				Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
 			},
 			nil
 	}
@@ -662,17 +662,17 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 	s.logger.Info("Tenders sorted by match percentage", map[string]interface{}{
 		"company_id":        *form.CompanyID,
 		"company_cpv_codes": len(companyCPVCodes),
-		"total_tenders":     len(tenders),
+		"total_tenders":     len(page.Items),
 	})
 
-	tenderResponses := make([]TenderResponse, 0, len(tenders))
-	for _, tender := range tenders {
+	tenderResponses := make([]TenderResponse, 0, len(page.Items))
+	for _, tender := range page.Items {
 		tenderResponses = append(tenderResponses, *tender.ToResponseWithLanguage(s.pickResponseLanguage(form.Language)))
 	}
 
 	return &SearchResponse{
 			Tenders:  tenderResponses,
-			Metadata: pagination.Response(total),
+			Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
 		},
 		nil
 }
@@ -724,7 +724,7 @@ func (s *tenderService) Recommend(ctx context.Context, form *SearchForm, paginat
 		}
 	}
 
-	tenders, total, err := s.repository.Search(ctx, form, pagination)
+	page, err := s.repository.Search(ctx, form, pagination)
 	if err != nil {
 		s.logger.Error("Failed to list tenders", map[string]interface{}{
 			"error": err.Error(),
@@ -732,14 +732,14 @@ func (s *tenderService) Recommend(ctx context.Context, form *SearchForm, paginat
 		return nil, fmt.Errorf("failed to list tenders: %w", err)
 	}
 
-	tenderResponses := make([]TenderResponse, 0, len(tenders))
-	for _, tender := range tenders {
+	tenderResponses := make([]TenderResponse, 0, len(page.Items))
+	for _, tender := range page.Items {
 		tenderResponses = append(tenderResponses, *tender.ToResponseWithLanguage(s.pickResponseLanguage(form.Language)))
 	}
 
 	return &SearchResponse{
 		Tenders:  tenderResponses,
-		Metadata: pagination.Response(total),
+		Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
 	}, nil
 }
 
@@ -812,7 +812,7 @@ func (s *tenderService) CleanupOldData(ctx context.Context, olderThan time.Durat
 		Status: []string{string(TenderStatusExpired), string(TenderStatusCancelled), string(TenderStatusAwarded)},
 	}
 
-	oldTenders, _, err := s.repository.Search(ctx, form, pagination)
+	oldPage, err := s.repository.Search(ctx, form, pagination)
 	if err != nil {
 		s.logger.Error("Failed to find old tenders for cleanup", map[string]interface{}{
 			"error": err.Error(),
@@ -821,7 +821,7 @@ func (s *tenderService) CleanupOldData(ctx context.Context, olderThan time.Durat
 	}
 
 	cleanupCount := 0
-	for _, tender := range oldTenders {
+	for _, tender := range oldPage.Items {
 		if tender.CreatedAt < cutoffTime {
 			cleanupCount++
 			// Here you would delete the tender if implementing actual cleanup

pkg/mongo/cursor.go

@@ -0,0 +1,234 @@
+package mongo
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"strconv"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
+
+const pageCursorVersion = 1
+
+// pageCursor is an opaque pagination token for keyset (cursor) pagination.
+type pageCursor struct {
+	V         int    `json:"v"`
+	SortField string `json:"sort_field"`
+	SortOrder int    `json:"sort_order"`
+	ValueType string `json:"value_type"` // i64, f64, str, oid
+	SortValue string `json:"sort_value"`
+	ID        string `json:"id"`
+}
+
+func encodePageCursor(sortField string, sortOrder int, sortValue interface{}, id string) (string, error) {
+	if sortField == "" {
+		return "", fmt.Errorf("%w: sort field is required", ErrInvalidCursor)
+	}
+	if id == "" {
+		return "", fmt.Errorf("%w: document id is required", ErrInvalidCursor)
+	}
+
+	valueType, sortValueStr, err := formatCursorSortValue(sortField, sortValue)
+	if err != nil {
+		return "", err
+	}
+
+	payload, err := json.Marshal(pageCursor{
+		V:         pageCursorVersion,
+		SortField: sortField,
+		SortOrder: sortOrder,
+		ValueType: valueType,
+		SortValue: sortValueStr,
+		ID:        id,
+	})
+	if err != nil {
+		return "", fmt.Errorf("failed to marshal cursor: %w", err)
+	}
+
+	return base64.StdEncoding.EncodeToString(payload), nil
+}
+
+func decodePageCursor(encoded string) (*pageCursor, error) {
+	cursorBytes, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return nil, fmt.Errorf("%w: invalid cursor encoding", ErrInvalidCursor)
+	}
+
+	var cursor pageCursor
+	if err := json.Unmarshal(cursorBytes, &cursor); err != nil {
+		return nil, fmt.Errorf("%w: invalid cursor payload", ErrInvalidCursor)
+	}
+	if cursor.V != pageCursorVersion || cursor.SortField == "" || cursor.ID == "" {
+		return nil, fmt.Errorf("%w: unsupported or incomplete cursor", ErrInvalidCursor)
+	}
+	if cursor.SortOrder != 1 && cursor.SortOrder != -1 {
+		return nil, fmt.Errorf("%w: invalid sort order in cursor", ErrInvalidCursor)
+	}
+
+	return &cursor, nil
+}
+
+func (c *pageCursor) matches(sortField string, sortOrder int) bool {
+	return c.SortField == sortField && c.SortOrder == sortOrder
+}
+
+func (c *pageCursor) mongoFilter() (bson.M, error) {
+	if c.SortField == "_id" {
+		objectID, err := bson.ObjectIDFromHex(c.ID)
+		if err != nil {
+			return nil, fmt.Errorf("%w: invalid ObjectID in cursor", ErrInvalidCursor)
+		}
+		operator := "$lt"
+		if c.SortOrder == 1 {
+			operator = "$gt"
+		}
+		return bson.M{"_id": bson.M{operator: objectID}}, nil
+	}
+
+	sortValue, err := c.parseSortValue()
+	if err != nil {
+		return nil, err
+	}
+
+	objectID, err := bson.ObjectIDFromHex(c.ID)
+	if err != nil {
+		return nil, fmt.Errorf("%w: invalid ObjectID in cursor", ErrInvalidCursor)
+	}
+
+	primaryOp := "$lt"
+	secondaryOp := "$lt"
+	if c.SortOrder == 1 {
+		primaryOp = "$gt"
+		secondaryOp = "$gt"
+	}
+
+	return bson.M{
+		"$or": []bson.M{
+			{c.SortField: bson.M{primaryOp: sortValue}},
+			{
+				c.SortField: sortValue,
+				"_id":       bson.M{secondaryOp: objectID},
+			},
+		},
+	}, nil
+}
+
+func (c *pageCursor) parseSortValue() (interface{}, error) {
+	switch c.ValueType {
+	case "i64":
+		v, err := strconv.ParseInt(c.SortValue, 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("%w: invalid int64 sort value", ErrInvalidCursor)
+		}
+		return v, nil
+	case "f64":
+		v, err := strconv.ParseFloat(c.SortValue, 64)
+		if err != nil {
+			return nil, fmt.Errorf("%w: invalid float sort value", ErrInvalidCursor)
+		}
+		return v, nil
+	case "str":
+		return c.SortValue, nil
+	case "oid":
+		return bson.ObjectIDFromHex(c.SortValue)
+	default:
+		return nil, fmt.Errorf("%w: unknown sort value type", ErrInvalidCursor)
+	}
+}
+
+func formatCursorSortValue(sortField string, sortValue interface{}) (string, string, error) {
+	if sortField == "_id" {
+		switch v := sortValue.(type) {
+		case bson.ObjectID:
+			return "oid", v.Hex(), nil
+		case string:
+			if _, err := bson.ObjectIDFromHex(v); err != nil {
+				return "", "", fmt.Errorf("%w: invalid ObjectID sort value", ErrInvalidCursor)
+			}
+			return "oid", v, nil
+		default:
+			return "", "", fmt.Errorf("%w: unsupported _id sort value", ErrInvalidCursor)
+		}
+	}
+
+	switch v := sortValue.(type) {
+	case int64:
+		return "i64", strconv.FormatInt(v, 10), nil
+	case int32:
+		return "i64", strconv.FormatInt(int64(v), 10), nil
+	case int:
+		return "i64", strconv.FormatInt(int64(v), 10), nil
+	case float64:
+		return "f64", strconv.FormatFloat(v, 'f', -1, 64), nil
+	case float32:
+		return "f64", strconv.FormatFloat(float64(v), 'f', -1, 64), nil
+	case string:
+		return "str", v, nil
+	case bson.ObjectID:
+		return "oid", v.Hex(), nil
+	default:
+		return "", "", fmt.Errorf("%w: unsupported sort value type for field %s", ErrInvalidCursor, sortField)
+	}
+}
+
+func documentSortValue(docMap bson.M, sortField string) (interface{}, error) {
+	if sortField == "_id" {
+		id, exists := docMap["_id"]
+		if !exists {
+			return nil, fmt.Errorf("sort field _id not found in document")
+		}
+		return id, nil
+	}
+
+	sortValue, exists := docMap[sortField]
+	if !exists {
+		return nil, fmt.Errorf("sort field %s not found in document", sortField)
+	}
+	return sortValue, nil
+}
+
+func documentIDHex(docMap bson.M) (string, error) {
+	id, exists := docMap["_id"]
+	if !exists {
+		return "", fmt.Errorf("document _id not found")
+	}
+	switch v := id.(type) {
+	case bson.ObjectID:
+		return v.Hex(), nil
+	case string:
+		if _, err := bson.ObjectIDFromHex(v); err != nil {
+			return "", fmt.Errorf("invalid document _id")
+		}
+		return v, nil
+	default:
+		return "", fmt.Errorf("unsupported document _id type")
+	}
+}
+
+func cloneFilter(filter bson.M) (bson.M, error) {
+	if len(filter) == 0 {
+		return bson.M{}, nil
+	}
+	raw, err := bson.Marshal(filter)
+	if err != nil {
+		return nil, err
+	}
+	var cloned bson.M
+	if err := bson.Unmarshal(raw, &cloned); err != nil {
+		return nil, err
+	}
+	return cloned, nil
+}
+
+func mergeFilters(base, extra bson.M) bson.M {
+	if len(extra) == 0 {
+		return base
+	}
+	if len(base) == 0 {
+		return extra
+	}
+	return bson.M{
+		"$and": []bson.M{base, extra},
+	}
+}

pkg/mongo/repository.go

@@ -2,7 +2,6 @@ package mongo
 
 import (
 	"context"
-	"encoding/base64"
 	"errors"
 	"fmt"
 	"time"
@@ -26,6 +25,8 @@ type Pagination struct {
 	Cursor    string `json:"cursor"`    // Base64 encoded cursor for cursor-based pagination
 	SortField string `json:"sortField"` // Field to sort by (default: "_id")
 	SortOrder int    `json:"sortOrder"` // Sort order: 1 for ascending, -1 for descending
+	// SkipCount skips CountDocuments (use with cursor or deep offset pagination).
+	SkipCount bool `json:"skipCount,omitempty"`
 	// Projection limits fields returned from Find (e.g. exclude large blobs on list endpoints).
 	Projection bson.M `json:"projection,omitempty"`
 }
@@ -132,8 +133,16 @@ func (r *repository[T]) FindAll(ctx context.Context, filter bson.M, pagination P
 		pagination.SortOrder = -1 // Default to descending
 	}
 
-	// Build sort options
+	// Build sort with _id tie-breaker for stable keyset pagination.
 	sort := bson.D{{Key: pagination.SortField, Value: pagination.SortOrder}}
+	if pagination.SortField != "_id" {
+		sort = append(sort, bson.E{Key: "_id", Value: pagination.SortOrder})
+	}
+
+	countFilter, err := cloneFilter(filter)
+	if err != nil {
+		return nil, fmt.Errorf("failed to clone filter for count: %w", err)
+	}
 
 	// Build find options
 	findOptions := options.Find().
@@ -150,10 +159,7 @@ func (r *repository[T]) FindAll(ctx context.Context, filter bson.M, pagination P
 		if err != nil {
 			return nil, err
 		}
-		// Merge cursor filter with existing filter
-		for key, value := range cursorFilter {
-			filter[key] = value
-		}
+		filter = mergeFilters(filter, cursorFilter)
 	} else if pagination.Skip > 0 {
 		// Use offset-based pagination
 		findOptions.SetSkip(int64(pagination.Skip))
@@ -187,21 +193,23 @@ func (r *repository[T]) FindAll(ctx context.Context, filter bson.M, pagination P
 		items = items[:pagination.Limit] // Remove the extra item
 	}
 
-	// Get total count for pagination metadata
-	var totalCount int64
-	var countErr error
-	totalCount, countErr = r.Count(ctx, filter)
-	if countErr != nil {
-		r.logger.Error("Failed to get total count", map[string]interface{}{
-			"error": countErr.Error(),
-		})
-		totalCount = 0
+	// Get total count for pagination metadata (never include cursor constraints).
+	var totalCount int64 = -1
+	if !pagination.SkipCount {
+		var countErr error
+		totalCount, countErr = r.Count(ctx, countFilter)
+		if countErr != nil {
+			r.logger.Error("Failed to get total count", map[string]interface{}{
+				"error": countErr.Error(),
+			})
+			totalCount = 0
+		}
 	}
 
 	// Generate next cursor
 	var nextCursor string
 	if hasMore && len(items) > 0 {
-		nextCursor, err = r.generateCursor(items[len(items)-1], pagination.SortField)
+		nextCursor, err = r.generateCursor(items[len(items)-1], pagination.SortField, pagination.SortOrder)
 		if err != nil {
 			r.logger.Error("Failed to generate next cursor", map[string]interface{}{
 				"error": err.Error(),
@@ -445,43 +453,20 @@ func (r *repository[T]) validatePagination(pagination Pagination) error {
 	return nil
 }
 
-// buildCursorFilter builds a filter for cursor-based pagination
+// buildCursorFilter builds a filter for cursor-based pagination.
 func (r *repository[T]) buildCursorFilter(cursor, sortField string, sortOrder int) (bson.M, error) {
-	// Decode cursor
-	cursorBytes, err := base64.StdEncoding.DecodeString(cursor)
+	pageCursor, err := decodePageCursor(cursor)
 	if err != nil {
-		return nil, fmt.Errorf("%w: invalid cursor encoding", ErrInvalidCursor)
+		return nil, err
 	}
-
-	var cursorValue interface{}
-
-	// Try to parse as ObjectID first
-	if sortField == "_id" {
-		if objectID, err := bson.ObjectIDFromHex(string(cursorBytes)); err == nil {
-			cursorValue = objectID
-		} else {
-			return nil, fmt.Errorf("%w: invalid ObjectID in cursor", ErrInvalidCursor)
-		}
-	} else {
-		// For other fields, try to parse as appropriate type
-		// This is a simplified implementation - you might want to make this more sophisticated
-		cursorValue = string(cursorBytes)
+	if !pageCursor.matches(sortField, sortOrder) {
+		return nil, fmt.Errorf("%w: cursor does not match requested sort", ErrInvalidCursor)
 	}
-
-	// Build comparison operator based on sort order
-	var operator string
-	if sortOrder == 1 {
-		operator = "$gt"
-	} else {
-		operator = "$lt"
-	}
-
-	return bson.M{sortField: bson.M{operator: cursorValue}}, nil
+	return pageCursor.mongoFilter()
 }
 
-// generateCursor generates a cursor from a document
-func (r *repository[T]) generateCursor(doc T, sortField string) (string, error) {
-	// Convert document to BSON
+// generateCursor generates an opaque cursor from the last document in a page.
+func (r *repository[T]) generateCursor(doc T, sortField string, sortOrder int) (string, error) {
 	docBytes, err := bson.Marshal(doc)
 	if err != nil {
 		return "", fmt.Errorf("failed to marshal document: %w", err)
@@ -492,29 +477,17 @@ func (r *repository[T]) generateCursor(doc T, sortField string) (string, error)
 		return "", fmt.Errorf("failed to unmarshal document: %w", err)
 	}
 
-	// Get the sort field value
-	sortValue, exists := docMap[sortField]
-	if !exists {
-		return "", fmt.Errorf("sort field %s not found in document", sortField)
+	sortValue, err := documentSortValue(docMap, sortField)
+	if err != nil {
+		return "", err
 	}
 
-	// Convert to string for encoding
-	var cursorStr string
-	switch v := sortValue.(type) {
-	case bson.ObjectID:
-		cursorStr = v.Hex()
-	case string:
-		cursorStr = v
-	case int64:
-		cursorStr = fmt.Sprintf("%d", v)
-	case float64:
-		cursorStr = fmt.Sprintf("%f", v)
-	default:
-		cursorStr = fmt.Sprintf("%v", v)
+	idHex, err := documentIDHex(docMap)
+	if err != nil {
+		return "", err
 	}
 
-	// Encode as base64
-	return base64.StdEncoding.EncodeToString([]byte(cursorStr)), nil
+	return encodePageCursor(sortField, sortOrder, sortValue, idHex)
 }
 
 // getModelID extracts the ID from a model

pkg/mongo/utils.go

@@ -299,6 +299,12 @@ func (pb *PaginationBuilder) Projection(projection bson.M) *PaginationBuilder {
 	return pb
 }
 
+// SkipCount disables CountDocuments for this query.
+func (pb *PaginationBuilder) SkipCount(skip bool) *PaginationBuilder {
+	pb.pagination.SkipCount = skip
+	return pb
+}
+
 // Build returns the final pagination options
 func (pb *PaginationBuilder) Build() Pagination {
 	return pb.pagination

pkg/response/response.go

@@ -26,16 +26,19 @@ type APIError struct {
 
 // Meta represents metadata for paginated responses
 type Meta struct {
-	Total  int `json:"total"`
-	Limit  int `json:"limit"`
-	Offset int `json:"offset"`
-	Page   int `json:"page"`
-	Pages  int `json:"pages"`
+	Total      int    `json:"total,omitempty"`
+	Limit      int    `json:"limit"`
+	Offset     int    `json:"offset"`
+	Page       int    `json:"page,omitempty"`
+	Pages      int    `json:"pages,omitempty"`
+	NextCursor string `json:"next_cursor,omitempty"`
+	HasMore    bool   `json:"has_more,omitempty"`
 }
 
 type Pagination struct {
 	Limit     int    `query:"limit" valid:"optional,range(1|100)" default:"20"`
 	Offset    int    `query:"offset" valid:"optional,range(0|1000000)" default:"0"`
+	Cursor    string `query:"cursor" valid:"optional"`
 	SortBy    string `query:"sort_by" valid:"optional"`
 	SortOrder string `query:"sort_order" valid:"optional,in(asc|desc)"`
 }
@@ -210,22 +213,38 @@ func NewPagination(c echo.Context) *Pagination {
 		sortOrder = "desc"
 	}
 
+	cursor := c.QueryParam("cursor")
+
 	return &Pagination{
 		Limit:     limit,
 		Offset:    offset,
+		Cursor:    cursor,
 		SortBy:    sortBy,
 		SortOrder: sortOrder,
 	}
 }
 
-// Pagination calculates pagination metadata
+// Response calculates offset-based pagination metadata.
 func (p *Pagination) Response(total int64) *Meta {
-	pages := (total + int64(p.Limit) - 1) / int64(p.Limit)
-	return &Meta{
-		Total:  int(total),
-		Limit:  p.Limit,
-		Offset: p.Offset,
-		Page:   int(p.Offset/p.Limit) + 1,
-		Pages:  int(pages),
-	}
+	return p.ListMeta(total, "", false)
+}
+
+// ListMeta builds pagination metadata for list endpoints (offset and/or cursor).
+// When total is negative, total/page/pages are omitted (count was skipped).
+func (p *Pagination) ListMeta(total int64, nextCursor string, hasMore bool) *Meta {
+	meta := &Meta{
+		Limit:      p.Limit,
+		Offset:     p.Offset,
+		NextCursor: nextCursor,
+		HasMore:    hasMore,
+	}
+	if total >= 0 {
+		pages := (total + int64(p.Limit) - 1) / int64(p.Limit)
+		meta.Total = int(total)
+		if p.Limit > 0 {
+			meta.Page = p.Offset/p.Limit + 1
+		}
+		meta.Pages = int(pages)
+	}
+	return meta
 }