diff --git a/Backend/src/NexusRMM.Core/Models/Agent.cs b/Backend/src/NexusRMM.Core/Models/Agent.cs
new file mode 100644
index 0000000..25a3114
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/Agent.cs
@@ -0,0 +1,22 @@
+namespace NexusRMM.Core.Models;
+
+public class Agent
+{
+    public Guid Id { get; set; }
+    public string Hostname { get; set; } = string.Empty;
+    public OsType OsType { get; set; }
+    public string OsVersion { get; set; } = string.Empty;
+    public string IpAddress { get; set; } = string.Empty;
+    public string MacAddress { get; set; } = string.Empty;
+    public string AgentVersion { get; set; } = string.Empty;
+    public AgentStatus Status { get; set; } = AgentStatus.Pending;
+    public List<string> Tags { get; set; } = [];
+    public DateTime LastSeen { get; set; }
+    public DateTime EnrolledAt { get; set; }
+    public string? MeshAgentId { get; set; }
+
+    public ICollection<AgentMetric> Metrics { get; set; } = [];
+    public ICollection<TaskItem> Tasks { get; set; } = [];
+    public ICollection<Ticket> Tickets { get; set; } = [];
+    public ICollection<Alert> Alerts { get; set; } = [];
+}
diff --git a/Backend/src/NexusRMM.Core/Models/AgentMetric.cs b/Backend/src/NexusRMM.Core/Models/AgentMetric.cs
new file mode 100644
index 0000000..173f654
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/AgentMetric.cs
@@ -0,0 +1,13 @@
+using System.Text.Json;
+
+namespace NexusRMM.Core.Models;
+
+public class AgentMetric
+{
+    public long Id { get; set; }
+    public Guid AgentId { get; set; }
+    public DateTime Timestamp { get; set; }
+    public JsonElement Metrics { get; set; }
+
+    public Agent Agent { get; set; } = null!;
+}
diff --git a/Backend/src/NexusRMM.Core/Models/Alert.cs b/Backend/src/NexusRMM.Core/Models/Alert.cs
new file mode 100644
index 0000000..770de69
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/Alert.cs
@@ -0,0 +1,15 @@
+namespace NexusRMM.Core.Models;
+
+public class Alert
+{
+    public long Id { get; set; }
+    public int RuleId { get; set; }
+    public Guid AgentId { get; set; }
+    public string Message { get; set; } = string.Empty;
+    public AlertSeverity Severity { get; set; }
+    public bool Acknowledged { get; set; }
+    public DateTime CreatedAt { get; set; }
+
+    public AlertRule Rule { get; set; } = null!;
+    public Agent Agent { get; set; } = null!;
+}
diff --git a/Backend/src/NexusRMM.Core/Models/AlertRule.cs b/Backend/src/NexusRMM.Core/Models/AlertRule.cs
new file mode 100644
index 0000000..372b819
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/AlertRule.cs
@@ -0,0 +1,14 @@
+namespace NexusRMM.Core.Models;
+
+public class AlertRule
+{
+    public int Id { get; set; }
+    public string Name { get; set; } = string.Empty;
+    public string MetricPath { get; set; } = string.Empty;
+    public string Operator { get; set; } = ">";
+    public double Threshold { get; set; }
+    public AlertSeverity Severity { get; set; }
+    public bool Enabled { get; set; } = true;
+
+    public ICollection<Alert> Alerts { get; set; } = [];
+}
diff --git a/Backend/src/NexusRMM.Core/Models/Enums.cs b/Backend/src/NexusRMM.Core/Models/Enums.cs
new file mode 100644
index 0000000..bd0549e
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/Enums.cs
@@ -0,0 +1,9 @@
+namespace NexusRMM.Core.Models;
+
+public enum AgentStatus { Online, Offline, Degraded, Pending }
+public enum OsType { Windows, Linux }
+public enum TaskStatus { Pending, InProgress, Completed, Failed, Cancelled }
+public enum TaskType { Shell, InstallSoftware, UninstallSoftware, UpdateAgent, NetworkScan }
+public enum TicketStatus { Open, InProgress, Resolved, Closed }
+public enum TicketPriority { Low, Medium, High, Critical }
+public enum AlertSeverity { Info, Warning, Critical }
diff --git a/Backend/src/NexusRMM.Core/Models/TaskItem.cs b/Backend/src/NexusRMM.Core/Models/TaskItem.cs
new file mode 100644
index 0000000..f5aff71
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/TaskItem.cs
@@ -0,0 +1,17 @@
+using System.Text.Json;
+
+namespace NexusRMM.Core.Models;
+
+public class TaskItem
+{
+    public Guid Id { get; set; }
+    public Guid AgentId { get; set; }
+    public TaskType Type { get; set; }
+    public JsonElement? Payload { get; set; }
+    public TaskStatus Status { get; set; } = TaskStatus.Pending;
+    public JsonElement? Result { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+
+    public Agent Agent { get; set; } = null!;
+}
diff --git a/Backend/src/NexusRMM.Core/Models/Ticket.cs b/Backend/src/NexusRMM.Core/Models/Ticket.cs
new file mode 100644
index 0000000..c7afcf5
--- /dev/null
+++ b/Backend/src/NexusRMM.Core/Models/Ticket.cs
@@ -0,0 +1,15 @@
+namespace NexusRMM.Core.Models;
+
+public class Ticket
+{
+    public int Id { get; set; }
+    public string Title { get; set; } = string.Empty;
+    public string Description { get; set; } = string.Empty;
+    public TicketStatus Status { get; set; } = TicketStatus.Open;
+    public TicketPriority Priority { get; set; } = TicketPriority.Medium;
+    public Guid? AgentId { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+
+    public Agent? Agent { get; set; }
+}
diff --git a/Backend/src/NexusRMM.Infrastructure/Data/RmmDbContext.cs b/Backend/src/NexusRMM.Infrastructure/Data/RmmDbContext.cs
new file mode 100644
index 0000000..447c698
--- /dev/null
+++ b/Backend/src/NexusRMM.Infrastructure/Data/RmmDbContext.cs
@@ -0,0 +1,62 @@
+using Microsoft.EntityFrameworkCore;
+using NexusRMM.Core.Models;
+
+namespace NexusRMM.Infrastructure.Data;
+
+public class RmmDbContext : DbContext
+{
+    public RmmDbContext(DbContextOptions<RmmDbContext> options) : base(options) { }
+
+    public DbSet<Agent> Agents => Set<Agent>();
+    public DbSet<AgentMetric> AgentMetrics => Set<AgentMetric>();
+    public DbSet<TaskItem> Tasks => Set<TaskItem>();
+    public DbSet<Ticket> Tickets => Set<Ticket>();
+    public DbSet<AlertRule> AlertRules => Set<AlertRule>();
+    public DbSet<Alert> Alerts => Set<Alert>();
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        modelBuilder.Entity<Agent>(e =>
+        {
+            e.HasKey(a => a.Id);
+            e.Property(a => a.Tags).HasColumnType("jsonb");
+            e.HasIndex(a => a.Hostname);
+            e.HasIndex(a => a.MacAddress);
+        });
+
+        modelBuilder.Entity<AgentMetric>(e =>
+        {
+            e.HasKey(m => m.Id);
+            e.Property(m => m.Metrics).HasColumnType("jsonb");
+            e.HasIndex(m => m.Timestamp);
+            e.HasOne(m => m.Agent).WithMany(a => a.Metrics).HasForeignKey(m => m.AgentId);
+        });
+
+        modelBuilder.Entity<TaskItem>(e =>
+        {
+            e.HasKey(t => t.Id);
+            e.Property(t => t.Payload).HasColumnType("jsonb");
+            e.Property(t => t.Result).HasColumnType("jsonb");
+            e.HasOne(t => t.Agent).WithMany(a => a.Tasks).HasForeignKey(t => t.AgentId);
+        });
+
+        modelBuilder.Entity<Ticket>(e =>
+        {
+            e.HasKey(t => t.Id);
+            e.HasOne(t => t.Agent).WithMany(a => a.Tickets).HasForeignKey(t => t.AgentId);
+        });
+
+        modelBuilder.Entity<AlertRule>(e =>
+        {
+            e.HasKey(r => r.Id);
+        });
+
+        modelBuilder.Entity<Alert>(e =>
+        {
+            e.HasKey(a => a.Id);
+            e.HasIndex(a => a.CreatedAt);
+            e.HasOne(a => a.Rule).WithMany(r => r.Alerts).HasForeignKey(a => a.RuleId);
+            e.HasOne(a => a.Agent).WithMany(a => a.Alerts).HasForeignKey(a => a.AgentId);
+        });
+    }
+}