diff --git a/backend/src/types.ts b/backend/src/types.ts
new file mode 100644
index 0000000..7e855af
--- /dev/null
+++ b/backend/src/types.ts
@@ -0,0 +1,60 @@
+export type Plan = 'free' | 'pro' | 'team';
+export type FileStatus = 'uploaded' | 'deleted' | 'expired';
+
+export interface UserRecord {
+  id: string;
+  email: string;
+  passwordHash: string;
+  plan: Plan;
+  verified: boolean;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface FileRecord {
+  id: string;
+  linkId: string;
+  /** Google Drive file ID, used to construct download/view/delete URLs */
+  gdriveId: string;
+  /** Session cookie value of the uploader — scopes dashboard/delete access */
+  sessionId: string;
+  /** @deprecated legacy rclone path — only present on old records */
+  gdrivePath?: string;
+  originalName: string;
+  mimeType: string;
+  sizeBytes: number;
+  status: FileStatus;
+  uploader: string;
+  expiresAt: string;
+  deletedAt?: string;
+  createdAt: string;
+  views: number;
+  downloads: number;
+}
+
+export interface RefreshTokenRecord {
+  id: string;
+  userId: string;
+  tokenHash: string;
+  expiresAt: string;
+  revokedAt?: string;
+  createdAt: string;
+}
+
+export interface EventRecord {
+  id: string;
+  linkId: string;
+  type: 'view' | 'download';
+  createdAt: string;
+  ip?: string;
+  userAgent?: string;
+  referrer?: string;
+}
+
+export interface DatabaseShape {
+  users: UserRecord[];
+  refreshTokens: RefreshTokenRecord[];
+  files: FileRecord[];
+  events: EventRecord[];
+}
+