# Database & ORM (/Nyx/server/database)



Database & ORM [#database--orm]

Nyx utilizes PostgreSQL for its persistent data store, accessed exclusively through **Drizzle ORM** for end-to-end type safety.

Database Design [#database-design]

The database schema is defined in `server/src/platform/db/schema/index.ts`. Drizzle handles schema creation and migrations natively.

Core Tables [#core-tables]

1. **`users`**: Contains wallet addresses, display names, and profile pictures. No passwords or email addresses are stored.
2. **`conversations`**: Represents both 1:1 Direct Messages and Group Chats.
3. **`conversation_members`**: The join table associating users with conversations. Defines roles (admin, user) and tracks when a user was added or removed.
4. **`messages`**: Stores the end-to-end encrypted ciphertexts. The server cannot read the `ciphertext` column.
5. **`message_deliveries`**: Tracks the individual status (sent, delivered, read) of a message for every recipient in a conversation.

Drizzle ORM [#drizzle-orm]

Drizzle was chosen for its zero-dependency runtime and native PostgreSQL support, resulting in high performance and excellent TypeScript integration.

Migrations [#migrations]

Migrations are generated locally using `drizzle-kit` and applied during the application boot process or via a CI pipeline using `drizzle-orm/postgres-js/migrator`.

<Mermaid
  chart="`graph LR
  Schema[schema.ts] -->|drizzle-kit generate| Migrations[0000_init.sql]
  Migrations -->|drizzle-orm migrate| Postgres[(PostgreSQL)]`"
/>

Connection Pooling [#connection-pooling]

The server utilizes a standard Postgres connection pool configured for high concurrency, appropriate for a heavily asynchronous WebSockets environment.