FK Type Inference

When a model declares a typed ID, any FK Record field that references it via @model() automatically inherits the ID type. You don't repeat the type on FK fields — Cerial infers it.

model Author {
  id Record(int) @id
  name String
  books Relation[] @model(Book)
}

model Book {
  id Record @id
  title String
  authorId Record                                  // Just Record — not Record(int)
  author Relation @field(authorId) @model(Author)
}

Cerial sees that authorId points to Author (which has Record(int) @id) and generates the correct types:

// Output type
interface Book {
  id: CerialId<string>;
  authorId: CerialId<number>; // inferred from Author's int ID
}

// Input — connect accepts number
const book = await client.db.Book.create({
  data: {
    title: 'My Book',
    author: { connect: 1 },
  },
});

book.authorId;    // CerialId<number>
book.authorId.id; // 1

// CerialId from a previous query works too
const author = await client.db.Author.create({ data: { id: 1, name: 'Alice' } });
const book2 = await client.db.Book.create({
  data: {
    title: 'Another Book',
    author: { connect: author.id },
  },
});

FK fields must not use Record(Type). The type is always inferred from the target model's @id declaration. Adding Record(int) to a FK field is a validation error — Cerial rejects it to prevent type mismatches.

See also:

Complex Record — Full Record(Type) syntax reference, supported types, and standalone record typing

Record Type Inference

FK Type Inference

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