diff --git a/src/storage/models.py b/src/storage/models.py
new file mode 100644
index 0000000..0332216
--- /dev/null
+++ b/src/storage/models.py
@@ -0,0 +1,170 @@
+"""Data models for DevTrace."""
+
+from datetime import datetime
+from dataclasses import dataclass, field
+from typing import Optional, Dict, Any
+
+
+@dataclass
+class Session:
+    """Represents a development session."""
+    id: int
+    name: str
+    directory: str
+    start_time: Optional[datetime] = None
+    end_time: Optional[datetime] = None
+    notes: Optional[str] = None
+
+    @property
+    def duration(self) -> Optional[float]:
+        """Calculate session duration in seconds."""
+        if self.start_time and self.end_time:
+            return (self.end_time - self.start_time).total_seconds()
+        return None
+
+
+@dataclass
+class FileEvent:
+    """Represents a file system event."""
+    id: int
+    session_id: int
+    event_type: str
+    file_path: str
+    timestamp: Optional[datetime] = None
+    details: Optional[str] = None
+    content_hash: Optional[str] = None
+
+    @property
+    def filename(self) -> str:
+        """Get just the filename from the path."""
+        return self.file_path.split("/")[-1]
+
+    @property
+    def extension(self) -> str:
+        """Get the file extension."""
+        return self.filename.split(".")[-1] if "." in self.filename else ""
+
+
+@dataclass
+class CommandEvent:
+    """Represents a shell command execution."""
+    id: int
+    session_id: int
+    command: str
+    timestamp: Optional[datetime] = None
+    exit_code: Optional[int] = None
+    working_directory: Optional[str] = None
+    details: Optional[str] = None
+
+    @property
+    def was_successful(self) -> Optional[bool]:
+        """Check if command was successful."""
+        if self.exit_code is None:
+            return None
+        return self.exit_code == 0
+
+    @property
+    def short_command(self) -> str:
+        """Get truncated command for display."""
+        max_len = 50
+        if len(self.command) <= max_len:
+            return self.command
+        return self.command[:max_len] + "..."
+
+
+@dataclass
+class GitEvent:
+    """Represents a git operation."""
+    id: int
+    session_id: int
+    operation: str
+    branch: Optional[str] = None
+    commit_hash: Optional[str] = None
+    timestamp: Optional[datetime] = None
+    details: Optional[str] = None
+    diff: Optional[str] = None
+
+    @property
+    def short_hash(self) -> str:
+        """Get short commit hash."""
+        if self.commit_hash:
+            return self.commit_hash[:7]
+        return ""
+
+
+@dataclass
+class SearchResult:
+    """Represents a search result."""
+    event_type: str
+    event_id: int
+    score: float
+    details: Dict[str, Any]
+    content: str = ""
+
+
+@dataclass
+class TimelineEvent:
+    """Unified event representation for timeline display."""
+    id: int
+    session_id: int
+    event_type: str
+    timestamp: Optional[datetime]
+    details: Dict[str, Any]
+    display_text: str
+    icon: str
+
+    @classmethod
+    def from_file_event(cls, event: FileEvent) -> "TimelineEvent":
+        """Create TimelineEvent from FileEvent."""
+        icons = {
+            "created": "📄",
+            "modified": "✏️",
+            "deleted": "🗑️",
+            "moved": "📁"
+        }
+        return cls(
+            id=event.id,
+            session_id=event.session_id,
+            event_type="file",
+            timestamp=event.timestamp,
+            details={"file_path": event.file_path, "content_hash": event.content_hash},
+            display_text=f"{event.event_type} {event.filename}",
+            icon=icons.get(event.event_type, "📄")
+        )
+
+    @classmethod
+    def from_command_event(cls, event: CommandEvent) -> "TimelineEvent":
+        """Create TimelineEvent from CommandEvent."""
+        status = "✅" if event.was_successful else "❌" if event.was_successful is False else "⏳"
+        return cls(
+            id=event.id,
+            session_id=event.session_id,
+            event_type="command",
+            timestamp=event.timestamp,
+            details={"command": event.command, "exit_code": event.exit_code},
+            display_text=f"{event.short_command}",
+            icon=f"⚡ {status}"
+        )
+
+    @classmethod
+    def from_git_event(cls, event: GitEvent) -> "TimelineEvent":
+        """Create TimelineEvent from GitEvent."""
+        icons = {
+            "commit": "💾",
+            "branch": "🌿",
+            "merge": "🔀",
+            "checkout": "🔀",
+            "push": "📤",
+            "pull": "📥",
+            "rebase": "📜",
+            "reset": "⏪"
+        }
+        return cls(
+            id=event.id,
+            session_id=event.session_id,
+            event_type="git",
+            timestamp=event.timestamp,
+            details={"operation": event.operation, "branch": event.branch, "commit": event.commit_hash},
+            display_text=f"{event.operation} {event.branch or event.short_hash}",
+            icon=icons.get(event.operation, "🔧")
+        )