BACKEND/Codex.CQRS/Commands/SendMessageCommand.cs

@@ -200,8 +200,6 @@ public class SendMessageCommandHandler : ICommandHandler<SendMessageCommand, Sen
         var contextMessages = await _dbContext.ConversationMessages
             .AsNoTracking()
             .Where(m => m.ConversationId == conversation.Id && m.IsInActiveWindow)
-            .OrderByDescending(m => m.MessageIndex)
-            .Take(agent.ConversationWindowSize)
             .OrderBy(m => m.MessageIndex)
             .ToListAsync(cancellationToken);
 

BACKEND/Codex.Dal/Codex.Dal.csproj

@@ -13,7 +13,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Http" Version="9.0.10" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="8.0.11" />
     <PackageReference Include="OpenHarbor.CQRS" Version="8.1.0-rc1" />
     <PackageReference Include="OpenHarbor.CQRS.DynamicQuery.Abstractions" Version="8.1.0-rc1" />

BACKEND/Codex.Dal/CodexDbContext.cs

@@ -60,7 +60,6 @@ public class CodexDbContext : DbContext
         // Indexes
         entity.HasIndex(a => new { a.Status, a.IsDeleted });
         entity.HasIndex(a => a.Type);
-        entity.HasIndex(a => a.Name); // Performance: name searches
 
         // Relationships
         entity.HasMany(a => a.Tools)
@@ -126,7 +125,6 @@ public class CodexDbContext : DbContext
 
         entity.HasIndex(e => e.ConversationId);
         entity.HasIndex(e => e.Status);
-        entity.HasIndex(e => e.CompletedAt); // Performance: time-based queries
 
         // Relationships
         entity.HasOne(e => e.Conversation)
@@ -158,7 +156,6 @@ public class CodexDbContext : DbContext
         // Indexes
         entity.HasIndex(c => new { c.IsActive, c.LastMessageAt })
             .IsDescending(false, true); // IsActive ASC, LastMessageAt DESC
-        entity.HasIndex(c => c.Title); // Performance: title searches
 
         // Relationships
         entity.HasMany(c => c.Messages)
@@ -181,10 +178,10 @@ public class CodexDbContext : DbContext
         // Composite index for efficient conversation window queries
         entity.HasIndex(m => new { m.ConversationId, m.IsInActiveWindow, m.MessageIndex });
 
+        // Index for ordering messages
+        entity.HasIndex(m => new { m.ConversationId, m.MessageIndex });
+
         // Index for role filtering
         entity.HasIndex(m => m.Role);
-
-        // Performance: time-based queries
-        entity.HasIndex(m => m.CreatedAt);
     }
 }

BACKEND/Codex.Dal/Migrations/20251027032413_AddPerformanceIndexes.Designer.cs

@@ -1,384 +0,0 @@
-// <auto-generated />
-using System;
-using System.Text.Json;
-using Codex.Dal;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Migrations;
-using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
-using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
-
-#nullable disable
-
-namespace Codex.Dal.Migrations
-{
-    [DbContext(typeof(CodexDbContext))]
-    [Migration("20251027032413_AddPerformanceIndexes")]
-    partial class AddPerformanceIndexes
-    {
-        /// <inheritdoc />
-        protected override void BuildTargetModel(ModelBuilder modelBuilder)
-        {
-#pragma warning disable 612, 618
-            modelBuilder
-                .HasAnnotation("ProductVersion", "8.0.11")
-                .HasAnnotation("Relational:MaxIdentifierLength", 63);
-
-            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
-
-            modelBuilder.Entity("Codex.Dal.Entities.Agent", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("uuid");
-
-                    b.Property<string>("ApiKeyEncrypted")
-                        .HasColumnType("text");
-
-                    b.Property<int>("ConversationWindowSize")
-                        .HasColumnType("integer");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<string>("Description")
-                        .IsRequired()
-                        .HasMaxLength(1000)
-                        .HasColumnType("character varying(1000)");
-
-                    b.Property<bool>("EnableMemory")
-                        .HasColumnType("boolean");
-
-                    b.Property<bool>("IsDeleted")
-                        .HasColumnType("boolean");
-
-                    b.Property<int>("MaxTokens")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("ModelEndpoint")
-                        .HasMaxLength(500)
-                        .HasColumnType("character varying(500)");
-
-                    b.Property<string>("ModelName")
-                        .IsRequired()
-                        .HasMaxLength(100)
-                        .HasColumnType("character varying(100)");
-
-                    b.Property<string>("ModelProvider")
-                        .IsRequired()
-                        .HasMaxLength(100)
-                        .HasColumnType("character varying(100)");
-
-                    b.Property<string>("Name")
-                        .IsRequired()
-                        .HasMaxLength(200)
-                        .HasColumnType("character varying(200)");
-
-                    b.Property<int>("ProviderType")
-                        .HasColumnType("integer");
-
-                    b.Property<int>("Status")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("SystemPrompt")
-                        .IsRequired()
-                        .HasColumnType("text");
-
-                    b.Property<double>("Temperature")
-                        .HasColumnType("double precision");
-
-                    b.Property<int>("Type")
-                        .HasColumnType("integer");
-
-                    b.Property<DateTime>("UpdatedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("Name");
-
-                    b.HasIndex("Type");
-
-                    b.HasIndex("Status", "IsDeleted");
-
-                    b.ToTable("Agents");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.AgentExecution", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("uuid");
-
-                    b.Property<Guid>("AgentId")
-                        .HasColumnType("uuid");
-
-                    b.Property<DateTime?>("CompletedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<Guid?>("ConversationId")
-                        .HasColumnType("uuid");
-
-                    b.Property<string>("ErrorMessage")
-                        .HasColumnType("text");
-
-                    b.Property<decimal?>("EstimatedCost")
-                        .HasPrecision(18, 6)
-                        .HasColumnType("numeric(18,6)");
-
-                    b.Property<long?>("ExecutionTimeMs")
-                        .HasColumnType("bigint");
-
-                    b.Property<string>("Input")
-                        .HasColumnType("text");
-
-                    b.Property<int?>("InputTokens")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("Output")
-                        .IsRequired()
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("text")
-                        .HasDefaultValue("");
-
-                    b.Property<int?>("OutputTokens")
-                        .HasColumnType("integer");
-
-                    b.Property<DateTime>("StartedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<int>("Status")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("ToolCallResults")
-                        .HasColumnType("text");
-
-                    b.Property<string>("ToolCalls")
-                        .HasColumnType("text");
-
-                    b.Property<int?>("TotalTokens")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("UserPrompt")
-                        .IsRequired()
-                        .HasColumnType("text");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("CompletedAt");
-
-                    b.HasIndex("ConversationId");
-
-                    b.HasIndex("Status");
-
-                    b.HasIndex("AgentId", "StartedAt")
-                        .IsDescending(false, true);
-
-                    b.ToTable("AgentExecutions");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.AgentTool", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("uuid");
-
-                    b.Property<Guid>("AgentId")
-                        .HasColumnType("uuid");
-
-                    b.Property<string>("ApiBaseUrl")
-                        .HasMaxLength(500)
-                        .HasColumnType("character varying(500)");
-
-                    b.Property<string>("ApiKeyEncrypted")
-                        .HasColumnType("text");
-
-                    b.Property<JsonDocument>("Configuration")
-                        .HasColumnType("jsonb");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<bool>("IsEnabled")
-                        .HasColumnType("boolean");
-
-                    b.Property<string>("McpAuthTokenEncrypted")
-                        .HasColumnType("text");
-
-                    b.Property<string>("McpServerUrl")
-                        .HasMaxLength(500)
-                        .HasColumnType("character varying(500)");
-
-                    b.Property<string>("ToolName")
-                        .IsRequired()
-                        .HasMaxLength(200)
-                        .HasColumnType("character varying(200)");
-
-                    b.Property<int>("Type")
-                        .HasColumnType("integer");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("Type");
-
-                    b.HasIndex("AgentId", "IsEnabled");
-
-                    b.ToTable("AgentTools");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.Conversation", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("uuid");
-
-                    b.Property<bool>("IsActive")
-                        .HasColumnType("boolean");
-
-                    b.Property<DateTime>("LastMessageAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<int>("MessageCount")
-                        .HasColumnType("integer");
-
-                    b.Property<DateTime>("StartedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<string>("Summary")
-                        .HasMaxLength(2000)
-                        .HasColumnType("character varying(2000)");
-
-                    b.Property<string>("Title")
-                        .IsRequired()
-                        .HasMaxLength(500)
-                        .HasColumnType("character varying(500)");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("Title");
-
-                    b.HasIndex("IsActive", "LastMessageAt")
-                        .IsDescending(false, true);
-
-                    b.ToTable("Conversations");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.ConversationMessage", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("uuid");
-
-                    b.Property<string>("Content")
-                        .IsRequired()
-                        .HasColumnType("text");
-
-                    b.Property<Guid>("ConversationId")
-                        .HasColumnType("uuid");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<Guid?>("ExecutionId")
-                        .HasColumnType("uuid");
-
-                    b.Property<bool>("IsInActiveWindow")
-                        .HasColumnType("boolean");
-
-                    b.Property<int>("MessageIndex")
-                        .HasColumnType("integer");
-
-                    b.Property<int>("Role")
-                        .HasColumnType("integer");
-
-                    b.Property<int?>("TokenCount")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("ToolCalls")
-                        .HasColumnType("text");
-
-                    b.Property<string>("ToolResults")
-                        .HasColumnType("text");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("CreatedAt");
-
-                    b.HasIndex("ExecutionId");
-
-                    b.HasIndex("Role");
-
-                    b.HasIndex("ConversationId", "IsInActiveWindow", "MessageIndex");
-
-                    b.ToTable("ConversationMessages");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.AgentExecution", b =>
-                {
-                    b.HasOne("Codex.Dal.Entities.Agent", "Agent")
-                        .WithMany("Executions")
-                        .HasForeignKey("AgentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Codex.Dal.Entities.Conversation", "Conversation")
-                        .WithMany("Executions")
-                        .HasForeignKey("ConversationId")
-                        .OnDelete(DeleteBehavior.SetNull);
-
-                    b.Navigation("Agent");
-
-                    b.Navigation("Conversation");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.AgentTool", b =>
-                {
-                    b.HasOne("Codex.Dal.Entities.Agent", "Agent")
-                        .WithMany("Tools")
-                        .HasForeignKey("AgentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("Agent");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.ConversationMessage", b =>
-                {
-                    b.HasOne("Codex.Dal.Entities.Conversation", "Conversation")
-                        .WithMany("Messages")
-                        .HasForeignKey("ConversationId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Codex.Dal.Entities.AgentExecution", "Execution")
-                        .WithMany("Messages")
-                        .HasForeignKey("ExecutionId")
-                        .OnDelete(DeleteBehavior.SetNull);
-
-                    b.Navigation("Conversation");
-
-                    b.Navigation("Execution");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.Agent", b =>
-                {
-                    b.Navigation("Executions");
-
-                    b.Navigation("Tools");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.AgentExecution", b =>
-                {
-                    b.Navigation("Messages");
-                });
-
-            modelBuilder.Entity("Codex.Dal.Entities.Conversation", b =>
-                {
-                    b.Navigation("Executions");
-
-                    b.Navigation("Messages");
-                });
-#pragma warning restore 612, 618
-        }
-    }
-}

BACKEND/Codex.Dal/Migrations/20251027032413_AddPerformanceIndexes.cs

@@ -1,63 +0,0 @@
-using Microsoft.EntityFrameworkCore.Migrations;
-
-#nullable disable
-
-namespace Codex.Dal.Migrations
-{
-    /// <inheritdoc />
-    public partial class AddPerformanceIndexes : Migration
-    {
-        /// <inheritdoc />
-        protected override void Up(MigrationBuilder migrationBuilder)
-        {
-            migrationBuilder.DropIndex(
-                name: "IX_ConversationMessages_ConversationId_MessageIndex",
-                table: "ConversationMessages");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_Conversations_Title",
-                table: "Conversations",
-                column: "Title");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_ConversationMessages_CreatedAt",
-                table: "ConversationMessages",
-                column: "CreatedAt");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_Agents_Name",
-                table: "Agents",
-                column: "Name");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_AgentExecutions_CompletedAt",
-                table: "AgentExecutions",
-                column: "CompletedAt");
-        }
-
-        /// <inheritdoc />
-        protected override void Down(MigrationBuilder migrationBuilder)
-        {
-            migrationBuilder.DropIndex(
-                name: "IX_Conversations_Title",
-                table: "Conversations");
-
-            migrationBuilder.DropIndex(
-                name: "IX_ConversationMessages_CreatedAt",
-                table: "ConversationMessages");
-
-            migrationBuilder.DropIndex(
-                name: "IX_Agents_Name",
-                table: "Agents");
-
-            migrationBuilder.DropIndex(
-                name: "IX_AgentExecutions_CompletedAt",
-                table: "AgentExecutions");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_ConversationMessages_ConversationId_MessageIndex",
-                table: "ConversationMessages",
-                columns: new[] { "ConversationId", "MessageIndex" });
-        }
-    }
-}

BACKEND/Codex.Dal/Migrations/CodexDbContextModelSnapshot.cs

@@ -92,8 +92,6 @@ namespace Codex.Dal.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("Name");
-
                     b.HasIndex("Type");
 
                     b.HasIndex("Status", "IsDeleted");
@@ -162,8 +160,6 @@ namespace Codex.Dal.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("CompletedAt");
-
                     b.HasIndex("ConversationId");
 
                     b.HasIndex("Status");
@@ -252,8 +248,6 @@ namespace Codex.Dal.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("Title");
-
                     b.HasIndex("IsActive", "LastMessageAt")
                         .IsDescending(false, true);
 
@@ -299,12 +293,12 @@ namespace Codex.Dal.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("CreatedAt");
-
                     b.HasIndex("ExecutionId");
 
                     b.HasIndex("Role");
 
+                    b.HasIndex("ConversationId", "MessageIndex");
+
                     b.HasIndex("ConversationId", "IsInActiveWindow", "MessageIndex");
 
                     b.ToTable("ConversationMessages");

BACKEND/docs/CHANGELOG.md

@@ -80,52 +80,6 @@ This is the initial MVP release with all core functionality complete and tested.
 
 ---
 
-## [1.1.0-performance] - 2025-10-27
-
-### Performance Optimizations (Non-Breaking)
-
-**Impact Level**: 🟢 **LOW** - No API contract changes
-
-This release includes database and query optimizations for improved performance at scale. **All endpoints remain unchanged** - frontend teams only need to refresh their API schema.
-
-#### Performance Improvements
-- **Database Indexes Added** for faster search/filter operations:
-  - `Agents.Name` - Fast agent name lookups
-  - `Conversations.Title` - Fast conversation title searches
-  - `AgentExecutions.CompletedAt` - Efficient time-based queries
-  - `ConversationMessages.CreatedAt` - Message timeline queries
-
-- **SendMessage Optimization**: Context loading now uses `.Take()` limit
-  - Prevents loading entire conversation history (could be 1000+ messages)
-  - Only fetches configured window size (default: 10 messages)
-  - Response time stays constant as conversations grow
-
-- **Package Compatibility**: Downgraded `Microsoft.Extensions.Http` 9.0.10 → 8.0.1
-  - Ensures .NET 8 LTS compatibility
-
-#### Removed
-- **Redundant Index**: `ConversationMessages(ConversationId, MessageIndex)`
-  - Already covered by composite index `(ConversationId, IsInActiveWindow, MessageIndex)`
-
-#### Frontend Migration
-**Time Required**: ~15 minutes
-
-1. Refresh `api-schema.json` (already synced from backend)
-2. Run existing integration tests to verify no regressions
-3. (Optional) Verify performance improvements on search/filter operations
-
-**Migration Guide**: `/Users/jean-philippe/Desktop/BACKEND_PERFORMANCE_UPDATES.md`
-
-#### Performance Metrics
-| Operation | Before | After | Improvement |
-|-----------|--------|-------|-------------|
-| List 50 agents | ~150ms | ~50ms | 3x faster |
-| SendMessage (100-msg conv) | ~500ms | ~200ms | 2.5x faster |
-| Search by agent name | ~200ms | ~30ms | 6x faster |
-| Get conversation by title | ~180ms | ~35ms | 5x faster |
-
----
-
 ## [Unreleased]
 
 ### Future Enhancements

FRONTEND/lib/api/endpoints/agent_endpoint.dart

@@ -243,11 +243,11 @@ class AgentDto {
   final String modelName;
   final ModelProviderType providerType;
   final String? modelEndpoint;
-  final double? temperature;
+  final double temperature;
-  final int? maxTokens;
+  final int maxTokens;
-  final String? systemPrompt;
+  final String systemPrompt;
-  final bool? enableMemory;
+  final bool enableMemory;
-  final int? conversationWindowSize;
+  final int conversationWindowSize;
   final AgentStatus status;
   final DateTime createdAt;
   final DateTime updatedAt;
@@ -261,11 +261,11 @@ class AgentDto {
     required this.modelName,
     required this.providerType,
     this.modelEndpoint,
-    this.temperature,
+    required this.temperature,
-    this.maxTokens,
+    required this.maxTokens,
-    this.systemPrompt,
+    required this.systemPrompt,
-    this.enableMemory,
+    required this.enableMemory,
-    this.conversationWindowSize,
+    required this.conversationWindowSize,
     required this.status,
     required this.createdAt,
     required this.updatedAt,
@@ -300,11 +300,11 @@ class AgentDto {
       modelName: json['modelName'] as String,
       providerType: parseProviderType(json['providerType']),
       modelEndpoint: json['modelEndpoint'] as String?,
-      temperature: json['temperature'] != null ? (json['temperature'] as num).toDouble() : null,
+      temperature: (json['temperature'] as num).toDouble(),
-      maxTokens: json['maxTokens'] as int?,
+      maxTokens: json['maxTokens'] as int,
-      systemPrompt: json['systemPrompt'] as String?,
+      systemPrompt: json['systemPrompt'] as String,
-      enableMemory: json['enableMemory'] as bool?,
+      enableMemory: json['enableMemory'] as bool,
-      conversationWindowSize: json['conversationWindowSize'] as int?,
+      conversationWindowSize: json['conversationWindowSize'] as int,
       status: parseAgentStatus(json['status']),
       createdAt: DateTime.parse(json['createdAt'] as String),
       updatedAt: DateTime.parse(json['updatedAt'] as String),