chore(release): v0.931 — Cursor (cursor-based pagination, performance baseline)

VERSION

@@ -1 +1 @@
-0.922
+0.931

docs/PERFORMANCE_BASELINE.md

@@ -0,0 +1,41 @@
+# Performance Baseline — Veza API
+
+**Version** : v0.931
+**Objectif** : Documenter les latences P50/P95/P99 des endpoints critiques pour détecter les régressions.
+
+## Méthodologie
+
+1. Démarrer l'API en mode profiling : `pprof` est exposé si `ENABLE_PPROF=true`
+2. Exécuter un load test (k6 ou Go) sur les endpoints critiques
+3. Mesurer latences via Prometheus (`http_request_duration_seconds`) ou pprof
+
+## Endpoints critiques à monitorer
+
+| Endpoint | Méthode | Description |
+|----------|---------|-------------|
+| `/api/v1/auth/login` | POST | Login utilisateur |
+| `/api/v1/auth/register` | POST | Inscription |
+| `/api/v1/tracks` | GET | Liste des tracks (cursor pagination v0.931) |
+| `/api/v1/tracks/search` | GET | Recherche |
+| `/api/v1/users/me` | GET | Profil utilisateur |
+| `/api/v1/marketplace/orders` | POST | Création commande |
+| `/api/v1/notifications` | GET | Notifications |
+| `/api/v1/conversations` | GET | Conversations |
+| `/api/v1/analytics/me` | GET | Analytics |
+| `/health` | GET | Health check |
+
+## Cibles v1.0 (voir roadmap v0.951)
+
+- **P99 < 500ms** sur tous les endpoints critiques à 500 req/s
+- **GET /tracks** : pagination cursor-based (v0.931) garantit des performances constantes quelle que soit la page
+
+## Commande pprof
+
+```bash
+# Profiler 30s pendant un load test
+go tool pprof -http=:8081 http://localhost:8080/debug/pprof/profile?seconds=30
+```
+
+## Métriques Prometheus
+
+Les middlewares de monitoring exposent `http_request_duration_seconds` avec les labels `method`, `path`, `status`. Utiliser des histogram quantiles pour P50/P95/P99.

go.work.sum

@@ -68,6 +68,7 @@ github.com/francoispqt/gojay v1.2.13 h1:d2m3sFjloqoIUQU3TsHBgj6qg/BVGlTBeHDUmyJn
 github.com/francoispqt/gojay v1.2.13/go.mod h1:ehT5mTG4ua4581f1++1WLG0vPdaA9HaiDsoyrBGkyDY=
 github.com/go-jose/go-jose/v3 v3.0.3 h1:fFKWeig/irsp7XD2zBxvnmA/XaRWp5V3CBsZXJF7G7k=
 github.com/go-jose/go-jose/v3 v3.0.3/go.mod h1:5b+7YgP7ZICgJDBdfjZaIt+H/9L9T/YQrVfLAMboGkQ=
+github.com/go-test/deep v1.0.8/go.mod h1:5C2ZWiW0ErCdrYzpqxLbTX7MG14M9iiw8DgHncVwcsE=
 github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
 github.com/godbus/dbus/v5 v5.1.0/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
@@ -76,6 +77,7 @@ github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
 github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/grpc-ecosystem/go-grpc-middleware v1.3.0 h1:+9834+KizmvFV7pXQGSXQTsaWhq2GjuNUt0aUU0YBYw=
 github.com/grpc-ecosystem/go-grpc-middleware v1.3.0/go.mod h1:z0ButlSOZa5vEBq9m2m2hlwIgKw+rp3sdCBRoJY+30Y=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 h1:Ovs26xHkKqVztRpIrF/92BcuyuQ/YW4NSIpoGtfXNho=
@@ -121,6 +123,7 @@ github.com/pelletier/go-toml v1.9.5 h1:4yBQzkHv+7BHq2PQUZF3Mx0IYxG7LsP222s7Agd3v
 github.com/pelletier/go-toml v1.9.5/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
 github.com/phpdave11/gofpdi v1.0.13 h1:o61duiW8M9sMlkVXWlvP92sZJtGKENvW3VExs6dZukQ=
 github.com/phpdave11/gofpdi v1.0.13/go.mod h1:vBmVV0Do6hSBHC8uKUQ71JGW+ZGQq74llk/7bXwjDoI=
+github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
 github.com/russross/blackfriday v1.6.0 h1:KqfZb0pUVN2lYqZUYRddxF4OR8ZMURnJIG5Y3VRLtww=
 github.com/russross/blackfriday v1.6.0/go.mod h1:ti0ldHuxg49ri4ksnFxlkCfN+hvslNlmVHqNRXXJNAY=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=

veza-backend-api/internal/core/social/service.go

@@ -2,8 +2,11 @@ package social
 
 import (
 	"context"
+	"encoding/base64"
 	"fmt"
+	"strconv"
 	"strings"
+	"time"
 
 	"github.com/google/uuid"
 	"go.uber.org/zap"
@@ -17,6 +20,7 @@ import (
 type SocialService interface {
 	CreatePost(ctx context.Context, userID uuid.UUID, content string, attachments map[string]uuid.UUID) (*Post, error)
 	GetGlobalFeed(ctx context.Context, limit, offset int, feedType string, userID *uuid.UUID) ([]FeedItem, error)
+	GetGlobalFeedWithCursor(ctx context.Context, limit int, cursor, feedType string, userID *uuid.UUID) ([]FeedItem, string, error) // v0.931: keyset cursor
 	GetUserFeed(ctx context.Context, userID uuid.UUID, limit, offset int) ([]FeedItem, error)
 
 	GetPostsByUser(ctx context.Context, userID uuid.UUID, limit, offset int) ([]Post, error)
@@ -97,7 +101,72 @@ func (s *Service) GetGlobalFeed(ctx context.Context, limit, offset int, feedType
 	if err := query.Order("posts.created_at desc").Limit(limit).Offset(offset).Find(&posts).Error; err != nil {
 		return nil, err
 	}
+	return s.enrichFeedFromPosts(ctx, posts)
+}
 
+// GetGlobalFeedWithCursor uses keyset pagination on (created_at, id) for consistent performance (v0.931).
+// Cursor format: base64(created_at_unix_nano|uuid). Returns feed items and next cursor.
+func (s *Service) GetGlobalFeedWithCursor(ctx context.Context, limit int, cursor, feedType string, userID *uuid.UUID) ([]FeedItem, string, error) {
+	query := s.db.WithContext(ctx).Model(&Post{})
+	if feedType == "following" && userID != nil {
+		query = query.Joins("INNER JOIN follows ON follows.followed_id = posts.user_id AND follows.follower_id = ?", *userID)
+	} else if feedType == "groups" && userID != nil {
+		subQuery := s.db.WithContext(ctx).Model(&GroupMember{}).
+			Select("DISTINCT gm2.user_id").
+			Joins("INNER JOIN group_members gm2 ON group_members.group_id = gm2.group_id AND gm2.user_id != ?", *userID).
+			Where("group_members.user_id = ?", *userID)
+		query = query.Where("posts.user_id IN (?)", subQuery)
+	}
+
+	var cursorCreatedAt int64
+	var cursorID uuid.UUID
+	if cursor != "" {
+		decoded, err := base64.RawURLEncoding.DecodeString(cursor)
+		if err == nil {
+			parts := strings.SplitN(string(decoded), "|", 2)
+			if len(parts) == 2 {
+				if ts, err := strconv.ParseInt(parts[0], 10, 64); err == nil {
+					cursorCreatedAt = ts
+				}
+				if uid, err := uuid.Parse(parts[1]); err == nil {
+					cursorID = uid
+				}
+			}
+		}
+	}
+	if cursor != "" && (cursorCreatedAt != 0 || cursorID != uuid.Nil) {
+		query = query.Where("(posts.created_at, posts.id) < (?, ?)", time.Unix(0, cursorCreatedAt), cursorID)
+	}
+
+	if limit <= 0 {
+		limit = 20
+	}
+	if limit > 50 {
+		limit = 50
+	}
+	query = query.Order("posts.created_at desc, posts.id desc").Limit(limit + 1)
+
+	var posts []Post
+	if err := query.Find(&posts).Error; err != nil {
+		return nil, "", err
+	}
+
+	var nextCursor string
+	if len(posts) > limit {
+		last := posts[limit-1]
+		nextCursor = base64.RawURLEncoding.EncodeToString([]byte(
+			fmt.Sprintf("%d|%s", last.CreatedAt.UnixNano(), last.ID.String())))
+		posts = posts[:limit]
+	}
+
+	feed, err := s.enrichFeedFromPosts(ctx, posts)
+	if err != nil {
+		return nil, "", err
+	}
+	return feed, nextCursor, nil
+}
+
+func (s *Service) enrichFeedFromPosts(ctx context.Context, posts []Post) ([]FeedItem, error) {
 	var feed []FeedItem
 	actorIDs := make(map[uuid.UUID]bool)
 	var trackIDs []uuid.UUID
@@ -108,7 +177,6 @@ func (s *Service) GetGlobalFeed(ctx context.Context, limit, offset int, feedType
 		}
 	}
 
-	// Batch fetch actor names/avatars
 	actors := make(map[uuid.UUID]struct{ Name, Avatar string })
 	if len(actorIDs) > 0 {
 		ids := make([]uuid.UUID, 0, len(actorIDs))
@@ -130,7 +198,6 @@ func (s *Service) GetGlobalFeed(ctx context.Context, limit, offset int, feedType
 		}
 	}
 
-	// Batch fetch tracks for target_type=track
 	tracks := make(map[uuid.UUID]*models.Track)
 	if len(trackIDs) > 0 {
 		var tr []models.Track
@@ -187,7 +254,6 @@ func (s *Service) GetGlobalFeed(ctx context.Context, limit, offset int, feedType
 
 		feed = append(feed, item)
 	}
-
 	return feed, nil
 }
 

veza-backend-api/internal/core/track/service.go

@@ -2,13 +2,15 @@ package track
 
 import (
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"io"
 	"mime/multipart"
 	"os"
 	"path/filepath"
-	"strings" // Removed strconv
+	"strconv"
+	"strings"
 	"time" // MOD-P2-008: Ajouté pour timeout asynchrone
 
 	"veza-backend-api/internal/database"
@@ -554,6 +556,7 @@ func (s *TrackService) GetUserQuota(ctx context.Context, userID uuid.UUID) (*Use
 type TrackListParams struct {
 	Page      int
 	Limit     int
+	Cursor    string // v0.931: opaque cursor for keyset pagination (base64)
 	UserID    *uuid.UUID
 	Genre     *string
 	Format    *string
@@ -561,6 +564,13 @@ type TrackListParams struct {
 	SortOrder string // "asc", "desc"
 }
 
+// TrackListResult holds list result with optional next cursor
+type TrackListResult struct {
+	Tracks     []*models.Track
+	Total      int64
+	NextCursor string
+}
+
 // ListTracks récupère une liste de tracks avec pagination, filtres et tri
 func (s *TrackService) ListTracks(ctx context.Context, params TrackListParams) ([]*models.Track, int64, error) {
 	// Créer la requête de base avec filtre sur le statut (read replica si configuré)
@@ -633,6 +643,103 @@ func (s *TrackService) ListTracks(ctx context.Context, params TrackListParams) (
 	return tracks, total, nil
 }
 
+// ListTracksWithCursor uses keyset pagination on (created_at, id) for consistent performance.
+// When params.Cursor is set, decodes it and fetches records after that point.
+// Returns NextCursor for the next page when more results exist.
+// v0.931: Cursor-based pagination for GET /tracks
+func (s *TrackService) ListTracksWithCursor(ctx context.Context, params TrackListParams) (*TrackListResult, error) {
+	// Cursor-based only supported for sort_by=created_at (default)
+	if params.SortBy != "created_at" && params.SortBy != "" {
+		// Fallback to offset-based
+		tracks, total, err := s.ListTracks(ctx, params)
+		if err != nil {
+			return nil, err
+		}
+		return &TrackListResult{Tracks: tracks, Total: total}, nil
+	}
+
+	if params.Limit <= 0 {
+		params.Limit = 20
+	}
+	if params.Limit > 100 {
+		params.Limit = 100
+	}
+
+	query := s.forRead().WithContext(ctx).Model(&models.Track{}).Where("status = ?", models.TrackStatusCompleted)
+	if params.UserID != nil {
+		query = query.Where("creator_id = ?", *params.UserID)
+	}
+	if params.Genre != nil && *params.Genre != "" {
+		query = query.Where("genre = ?", *params.Genre)
+	}
+	if params.Format != nil && *params.Format != "" {
+		query = query.Where("format = ?", *params.Format)
+	}
+
+	// Decode cursor: base64(created_at_unix_nano|uuid)
+	var cursorCreatedAt int64
+	var cursorID uuid.UUID
+	if params.Cursor != "" {
+		decoded, err := base64.RawURLEncoding.DecodeString(params.Cursor)
+		if err == nil {
+			parts := strings.SplitN(string(decoded), "|", 2)
+			if len(parts) == 2 {
+				if ts, err := strconv.ParseInt(parts[0], 10, 64); err == nil {
+					cursorCreatedAt = ts
+				}
+				if uid, err := uuid.Parse(parts[1]); err == nil {
+					cursorID = uid
+				}
+			}
+		}
+	}
+
+	sortOrder := "DESC"
+	if params.SortOrder == "asc" {
+		sortOrder = "ASC"
+	}
+	if sortOrder == "DESC" {
+		if params.Cursor != "" && (cursorCreatedAt != 0 || cursorID != uuid.Nil) {
+			query = query.Where("(created_at, id) < (?, ?)", time.Unix(0, cursorCreatedAt), cursorID)
+		}
+		query = query.Order("created_at DESC, id DESC")
+	} else {
+		if params.Cursor != "" && (cursorCreatedAt != 0 || cursorID != uuid.Nil) {
+			query = query.Where("(created_at, id) > (?, ?)", time.Unix(0, cursorCreatedAt), cursorID)
+		}
+		query = query.Order("created_at ASC, id ASC")
+	}
+
+	// Fetch limit+1 to know if there's a next page
+	query = query.Limit(params.Limit + 1)
+
+	var tracks []*models.Track
+	if err := query.Preload("User").Find(&tracks).Error; err != nil {
+		return nil, fmt.Errorf("failed to list tracks: %w", err)
+	}
+
+	var nextCursor string
+	var total int64
+	if len(tracks) > params.Limit {
+		// Has more - last fetched is the cursor for next page
+		last := tracks[params.Limit-1]
+		nextCursor = base64.RawURLEncoding.EncodeToString([]byte(
+			fmt.Sprintf("%d|%s", last.CreatedAt.UnixNano(), last.ID.String())))
+		tracks = tracks[:params.Limit]
+	}
+	// Total not computed for cursor mode (expensive); use -1 or len as approximation
+	total = int64(len(tracks))
+	if nextCursor != "" {
+		total = int64(params.Limit) + 1
+	}
+
+	return &TrackListResult{
+		Tracks:     tracks,
+		Total:      total,
+		NextCursor: nextCursor,
+	}, nil
+}
+
 // GetTrackByID récupère un track par son ID
 // MOD-P1-003: Preload User pour éviter N+1 queries si User est accédé plus tard
 // BE-SVC-001: Add caching for track metadata

veza-backend-api/internal/core/track/track_crud_handler.go

@@ -47,8 +47,11 @@ type BatchUpdateRequest struct {
 	Updates  map[string]interface{} `json:"updates" binding:"required" validate:"required,min=1"`
 }
 
-// ListTracks gère la liste des tracks avec pagination, filtres et tri
+// ListTracks gère la liste des tracks avec pagination, filtres et tri.
+// v0.931: Supports cursor-based pagination via ?cursor=xxx&limit=20 for consistent performance.
+// Falls back to page/limit (offset) when cursor is not provided.
 func (h *TrackHandler) ListTracks(c *gin.Context) {
+	cursor := c.Query("cursor")
 	page := c.DefaultQuery("page", "1")
 	limit := c.DefaultQuery("limit", "20")
 	userIDStr := c.Query("user_id")
@@ -57,19 +60,15 @@ func (h *TrackHandler) ListTracks(c *gin.Context) {
 	sortBy := c.DefaultQuery("sort_by", "created_at")
 	sortOrder := c.DefaultQuery("sort_order", "desc")
 
-	var pageInt, limitInt int
+	var limitInt int
-	if _, err := fmt.Sscanf(page, "%d", &pageInt); err != nil || pageInt < 1 {
-		response.BadRequest(c, "pagination: page must be >= 1 and limit must be between 1 and 100")
-		return
-	}
 	if _, err := fmt.Sscanf(limit, "%d", &limitInt); err != nil || limitInt < 1 || limitInt > 100 {
-		response.BadRequest(c, "pagination: page must be >= 1 and limit must be between 1 and 100")
+		response.BadRequest(c, "pagination: limit must be between 1 and 100")
 		return
 	}
 
 	params := TrackListParams{
-		Page:      pageInt,
 		Limit:     limitInt,
+		Cursor:    cursor,
 		SortBy:    sortBy,
 		SortOrder: sortOrder,
 	}
@@ -85,6 +84,36 @@ func (h *TrackHandler) ListTracks(c *gin.Context) {
 		params.Format = &format
 	}
 
+	_, exists := c.Get("user_id")
+
+	if cursor != "" {
+		// Cursor-based pagination
+		result, err := h.trackService.ListTracksWithCursor(c.Request.Context(), params)
+		if err != nil {
+			response.InternalServerError(c, "failed to list tracks")
+			return
+		}
+		if !exists {
+			for _, t := range result.Tracks {
+				t.StreamManifestURL = ""
+			}
+		}
+		pagination := handlers.BuildPaginationDataWithCursor(limitInt, result.Total, result.NextCursor, "")
+		response.Success(c, gin.H{
+			"tracks":     result.Tracks,
+			"pagination": pagination,
+		})
+		return
+	}
+
+	// Offset-based pagination (fallback)
+	var pageInt int
+	if _, err := fmt.Sscanf(page, "%d", &pageInt); err != nil || pageInt < 1 {
+		response.BadRequest(c, "pagination: page must be >= 1 when not using cursor")
+		return
+	}
+	params.Page = pageInt
+
 	tracks, total, err := h.trackService.ListTracks(c.Request.Context(), params)
 	if err != nil {
 		response.InternalServerError(c, "failed to list tracks")
@@ -92,7 +121,6 @@ func (h *TrackHandler) ListTracks(c *gin.Context) {
 	}
 
 	pagination := handlers.BuildPaginationData(pageInt, limitInt, total)
-	_, exists := c.Get("user_id")
 	if !exists {
 		for _, t := range tracks {
 			t.StreamManifestURL = ""

veza-backend-api/internal/handlers/room_handler.go

@@ -23,6 +23,7 @@ type RoomServiceInterface interface {
 	AddMember(ctx context.Context, roomID, userID uuid.UUID) error
 	RemoveMember(ctx context.Context, roomID, userID uuid.UUID) error // BE-API-011: Remove member method
 	GetRoomHistory(ctx context.Context, roomID uuid.UUID, limit, offset int) ([]services.ChatMessageResponse, error)
+	GetRoomHistoryWithCursor(ctx context.Context, roomID uuid.UUID, limit int, cursor string) (*services.RoomHistoryWithCursorResult, error) // v0.931: cursor pagination
 	DeleteRoom(ctx context.Context, roomID uuid.UUID, userID uuid.UUID) error // BE-API-010: Delete room method
 }
 
@@ -245,6 +246,7 @@ func (h *RoomHandler) AddMember(c *gin.Context) {
 
 // GetRoomHistory récupère l'historique des messages d'une room
 // GET /api/v1/conversations/:id/history
+// v0.931: Supports cursor-based pagination via ?cursor=xxx&limit=20. Falls back to offset when cursor not provided.
 func (h *RoomHandler) GetRoomHistory(c *gin.Context) {
 	conversationIDStr := c.Param("id")
 	conversationID, err := uuid.Parse(conversationIDStr)
@@ -254,8 +256,6 @@ func (h *RoomHandler) GetRoomHistory(c *gin.Context) {
 	}
 
 	limit := c.DefaultQuery("limit", "50")
-	offset := c.DefaultQuery("offset", "0")
-
 	limitInt, err := strconv.Atoi(limit)
 	if err != nil || limitInt <= 0 {
 		limitInt = 50
@@ -263,6 +263,30 @@ func (h *RoomHandler) GetRoomHistory(c *gin.Context) {
 	if limitInt > 100 {
 		limitInt = 100
 	}
+	cursor := c.Query("cursor")
+
+	if cursor != "" {
+		result, err := h.roomService.GetRoomHistoryWithCursor(c.Request.Context(), conversationID, limitInt, cursor)
+		if err != nil {
+			if errors.Is(err, services.ErrRoomNotFound) {
+				c.JSON(http.StatusNotFound, gin.H{"error": "Conversation not found"})
+				return
+			}
+			h.logger.Error("failed to get room history",
+				zap.Error(err),
+				zap.String("conversation_id", conversationID.String()))
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get conversation history"})
+			return
+		}
+		resp := gin.H{"messages": result.Messages}
+		if result.NextCursor != "" {
+			resp["next_cursor"] = result.NextCursor
+		}
+		RespondSuccess(c, http.StatusOK, resp)
+		return
+	}
+
+	offset := c.DefaultQuery("offset", "0")
 	offsetInt, err := strconv.Atoi(offset)
 	if err != nil || offsetInt < 0 {
 		offsetInt = 0

veza-backend-api/internal/handlers/room_handler_test.go

@@ -24,6 +24,7 @@ type MockRoomService struct {
 	AddMemberFunc               func(ctx context.Context, roomID, userID uuid.UUID) error
 	RemoveMemberFunc            func(ctx context.Context, roomID, userID uuid.UUID) error
 	GetRoomHistoryFunc          func(ctx context.Context, roomID uuid.UUID, limit, offset int) ([]services.ChatMessageResponse, error)
+	GetRoomHistoryWithCursorFunc func(ctx context.Context, roomID uuid.UUID, limit int, cursor string) (*services.RoomHistoryWithCursorResult, error)
 	DeleteRoomFunc              func(ctx context.Context, roomID uuid.UUID, userID uuid.UUID) error
 }
 
@@ -62,6 +63,13 @@ func (m *MockRoomService) GetRoomHistory(ctx context.Context, roomID uuid.UUID,
 	return nil, nil
 }
 
+func (m *MockRoomService) GetRoomHistoryWithCursor(ctx context.Context, roomID uuid.UUID, limit int, cursor string) (*services.RoomHistoryWithCursorResult, error) {
+	if m.GetRoomHistoryWithCursorFunc != nil {
+		return m.GetRoomHistoryWithCursorFunc(ctx, roomID, limit, cursor)
+	}
+	return &services.RoomHistoryWithCursorResult{Messages: nil, NextCursor: ""}, nil
+}
+
 func (m *MockRoomService) UpdateRoom(ctx context.Context, roomID uuid.UUID, userID uuid.UUID, req services.UpdateRoomRequest) (*services.RoomResponse, error) {
 	if m.UpdateRoomFunc != nil {
 		return m.UpdateRoomFunc(ctx, roomID, userID, req)

veza-backend-api/internal/handlers/social.go

@@ -156,6 +156,7 @@ func (h *SocialHandler) AddComment(c *gin.Context) {
 }
 
 // GetFeed récupère le feed global (S1.2, S1.4, S1.6: cursor, limit, type filter)
+// v0.931: Cursor-based pagination via ?cursor=base64. Falls back to offset when cursor not provided.
 func (h *SocialHandler) GetFeed(c *gin.Context) {
 	feedType := c.DefaultQuery("type", "all") // all | following | groups
 	if feedType != "all" && feedType != "following" && feedType != "groups" {
@@ -170,15 +171,19 @@ func (h *SocialHandler) GetFeed(c *gin.Context) {
 			limit = 50
 		}
 	}
-	// cursor: timestamp or ID for pagination (S1.4) - for now we use offset via cursor
 	cursor := c.Query("cursor")
 	offset := 0
-	if cursor != "" {
+	if o, err := strconv.Atoi(c.Query("offset")); err == nil && o >= 0 {
-		// Simple cursor: if it's a number, use as offset; else ignore
-		if o, err := strconv.Atoi(cursor); err == nil && o >= 0 {
 		offset = o
 	}
+	if cursor != "" {
+		if o, err := strconv.Atoi(cursor); err == nil && o >= 0 {
+			offset = o // Backward compat: cursor as number = offset
 		}
+	}
+	// Use keyset pagination when cursor looks like base64 (Atoi fails)
+	_, numErr := strconv.Atoi(cursor)
+	useCursorKeyset := cursor != "" && numErr != nil
 
 	var userID *uuid.UUID
 	if feedType == "following" {
@@ -188,6 +193,20 @@ func (h *SocialHandler) GetFeed(c *gin.Context) {
 			feedType = "all" // Fallback if not authenticated
 		}
 	}
+
+	if useCursorKeyset {
+		feed, nextCursor, err := h.service.GetGlobalFeedWithCursor(c.Request.Context(), limit, cursor, feedType, userID)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get feed"})
+			return
+		}
+		RespondSuccess(c, http.StatusOK, gin.H{
+			"items":       feed,
+			"next_cursor": nextCursor,
+		})
+		return
+	}
+
 	feed, err := h.service.GetGlobalFeed(c.Request.Context(), limit, offset, feedType, userID)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get feed"})

veza-backend-api/internal/handlers/social_test.go

@@ -48,6 +48,14 @@ func (m *MockSocialService) GetGlobalFeed(ctx context.Context, limit, offset int
 	return args.Get(0).([]social.FeedItem), args.Error(1)
 }
 
+func (m *MockSocialService) GetGlobalFeedWithCursor(ctx context.Context, limit int, cursor, feedType string, userID *uuid.UUID) ([]social.FeedItem, string, error) {
+	args := m.Called(ctx, limit, cursor, feedType, userID)
+	if args.Get(0) == nil {
+		return nil, "", args.Error(2)
+	}
+	return args.Get(0).([]social.FeedItem), args.String(1), args.Error(2)
+}
+
 func (m *MockSocialService) GetUserFeed(ctx context.Context, userID uuid.UUID, limit, offset int) ([]social.FeedItem, error) {
 	args := m.Called(ctx, userID, limit, offset)
 	if args.Get(0) == nil {

veza-backend-api/internal/repositories/chat_message_repository.go

@@ -2,7 +2,10 @@ package repositories
 
 import (
 	"context"
+	"encoding/base64"
 	"fmt"
+	"strconv"
+	"strings"
 	"time"
 	"veza-backend-api/internal/models"
 
@@ -63,6 +66,61 @@ func (r *ChatMessageRepository) GetConversationMessages(ctx context.Context, con
 	return messages, nil
 }
 
+// ConversationMessagesWithCursorResult holds messages and next cursor for cursor-based pagination (v0.931).
+type ConversationMessagesWithCursorResult struct {
+	Messages   []models.ChatMessage
+	NextCursor string
+}
+
+// GetConversationMessagesWithCursor uses keyset pagination on (created_at, id) for consistent performance.
+// Cursor format: base64(created_at_unix_nano|uuid). Order DESC (newest first), so cursor yields older messages.
+func (r *ChatMessageRepository) GetConversationMessagesWithCursor(ctx context.Context, conversationID uuid.UUID, limit int, cursor string) (*ConversationMessagesWithCursorResult, error) {
+	if limit <= 0 {
+		limit = 50
+	}
+	if limit > 100 {
+		limit = 100
+	}
+
+	query := r.db.WithContext(ctx).
+		Where("room_id = ? AND is_deleted = ?", conversationID, false)
+
+	var cursorCreatedAt int64
+	var cursorID uuid.UUID
+	if cursor != "" {
+		decoded, err := base64.RawURLEncoding.DecodeString(cursor)
+		if err == nil {
+			parts := strings.SplitN(string(decoded), "|", 2)
+			if len(parts) == 2 {
+				if ts, err := strconv.ParseInt(parts[0], 10, 64); err == nil {
+					cursorCreatedAt = ts
+				}
+				if uid, err := uuid.Parse(parts[1]); err == nil {
+					cursorID = uid
+				}
+			}
+		}
+	}
+	if cursor != "" && (cursorCreatedAt != 0 || cursorID != uuid.Nil) {
+		query = query.Where("(created_at, id) < (?, ?)", time.Unix(0, cursorCreatedAt), cursorID)
+	}
+	query = query.Order("created_at DESC, id DESC").Limit(limit + 1)
+
+	var messages []models.ChatMessage
+	if err := query.Find(&messages).Error; err != nil {
+		return nil, fmt.Errorf("failed to get conversation messages: %w", err)
+	}
+
+	var nextCursor string
+	if len(messages) > limit {
+		last := messages[limit-1]
+		nextCursor = base64.RawURLEncoding.EncodeToString([]byte(
+			fmt.Sprintf("%d|%s", last.CreatedAt.UnixNano(), last.ID.String())))
+		messages = messages[:limit]
+	}
+	return &ConversationMessagesWithCursorResult{Messages: messages, NextCursor: nextCursor}, nil
+}
+
 func (r *ChatMessageRepository) GetMessagesBefore(ctx context.Context, roomID uuid.UUID, beforeID uuid.UUID, limit int) ([]models.ChatMessage, error) {
 	var refMsg models.ChatMessage
 	if err := r.db.WithContext(ctx).Where("id = ?", beforeID).First(&refMsg).Error; err != nil {

veza-backend-api/internal/services/room_service.go

@@ -357,6 +357,38 @@ func (s *RoomService) GetRoomHistory(ctx context.Context, roomID uuid.UUID, limi
 	return responses, nil
 }
 
+// RoomHistoryWithCursorResult holds messages and next cursor for cursor-based pagination (v0.931).
+type RoomHistoryWithCursorResult struct {
+	Messages   []ChatMessageResponse
+	NextCursor string
+}
+
+// GetRoomHistoryWithCursor uses keyset pagination on (created_at, id) for consistent performance.
+func (s *RoomService) GetRoomHistoryWithCursor(ctx context.Context, roomID uuid.UUID, limit int, cursor string) (*RoomHistoryWithCursorResult, error) {
+	result, err := s.messageRepo.GetConversationMessagesWithCursor(ctx, roomID, limit, cursor)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) || err.Error() == "conversation not found" {
+			return nil, ErrRoomNotFound
+		}
+		s.logger.Error("failed to get room history with cursor",
+			zap.Error(err),
+			zap.String("room_id", roomID.String()))
+		return nil, fmt.Errorf("failed to get room history: %w", err)
+	}
+	responses := make([]ChatMessageResponse, len(result.Messages))
+	for i, msg := range result.Messages {
+		responses[i] = ChatMessageResponse{
+			ID:             msg.ID,
+			ConversationID: msg.ConversationID,
+			SenderID:       msg.SenderID,
+			Content:        msg.Content,
+			MessageType:    msg.MessageType,
+			CreatedAt:      msg.CreatedAt,
+		}
+	}
+	return &RoomHistoryWithCursorResult{Messages: responses, NextCursor: result.NextCursor}, nil
+}
+
 // DeleteRoom supprime une room (soft delete)
 // BE-API-010: Implement conversation delete endpoint
 // Seul le créateur de la room ou un admin peut supprimer la room