Validation

Mondel uses Zod under the hood to perform rigorous runtime validation. This ensures the data entering your database strictly adheres to your TypeScript definitions.

Zod Integration

Every schema definition you create with defineSchema is compiled into a Zod schema internally. When you perform create or update operations, Mondel automatically validates the input against this schema.

Runtime vs Compile-Time

• Compile-Time: TypeScript catches most errors before you run your code. E.g., passing a string where a number is expected.
• Runtime: Zod catches data that is dynamically invalid. E.g., an email string that doesn't actually look like an email.

Validation Modes

You can control how strict Mondel should be when validating data. This is configured when creating the client.

const client = createClient({
  schemas: [users],

  // "strict" | "loose" | "off"
  validation: "strict",
});

• strict (Default): Throws a ZodError immediately if validation fails. This guarantees 100% data integrity but has a slight performance cost.
• loose: Logs a warning to the console if validation fails, but proceeds with the operation. Useful for gradual migrations or development.
• off: Disables runtime validation completely. rely solely on TypeScript. Good for maximum performance in trusted environments.

Performance Considerations

Validation adds a small overhead to write operations. Read operations (find, findOne) generally do not undergo validation, assuming the data in the database is already correct. This keeps read performance extremely high.

If you need to validate data coming out of the database (e.g., from a legacy system), you can manually use the schema's Zod validator, though this is rarely needed in a greenfield Mondel application.