Schema & Config

Which Prisma schema features IndexedDB supports, and what prisma.config.ts contains

This page lists what a Prisma schema can contain when it targets IndexedDB, and what each field in prisma.config.ts does. For a first setup, follow the Quick Start instead.

Scalar types

Prisma type	JavaScript value	Notes
`String`	`string`
`Int`	`number`
`Float`	`number`
`Boolean`	`boolean`	Can't be a key or indexed. See Indexes.
`DateTime`	`Date`	Compared and sorted by time, not by object identity.
`BigInt`	`bigint`	Can't be a key or indexed.
`Decimal`	`string`
`Json`	any JSON value	Can't be a key or indexed.
`Bytes`	`Uint8Array`	Compared and sorted byte by byte.

Add ? to make a field optional. Its value is then null when it isn't set.

Each model becomes an IndexedDB object store. The store is named after the model with its first letter lowercased, so model TodoItem is stored in todoItem. The same name is the model's key on the client: db.orm.todoItem.

Use @@map to choose a different name:

model Todo {
  id    String @id
  title String

  @@map("todos")
}

const todos = await db.orm.todos.all();

Primary keys

Every model needs a primary key.

@id on one field, or @@id([a, b]) for a compound key.
Key fields must be String, Int, Float, DateTime, Decimal or Bytes, the types IndexedDB can use as keys.
In a compound key, order matters: @@id([a, b]) and @@id([b, a]) are different keys. findUnique() and delete() take the values in the order you declared them.
@default(autoincrement()) is supported on a single-field Int key, not on a compound key.

Indexes

Attribute	Creates
`@unique`	A unique index on one field.
`@@unique([a, b])`	A unique compound index.
`@@index([a])`	A non-unique index.
`@@index([a, b])`	A non-unique compound index.

Pass name: to choose an index's name, for example @@index([userId], name: "byUser"). Without one, the name is the field names joined with _, plus _unique for a unique index. A field can't appear twice in one index.

Like keys, indexed fields must be String, Int, Float, DateTime, Decimal or Bytes. IndexedDB silently leaves other values out of an index, so contract emit rejects an index on a Boolean, BigInt or Json field.

Queries use an index automatically for equality filters on an indexed field.

Defaults

Attribute	Sets the field to
`@default("text")`, `@default(0)`, `@default(true)`	That literal value, on create.
`@default(now())`	The current time, on create.
`@default(uuid())`	A random UUID v4, on create. `uuid(7)` gives a UUID v7.
`@default(cuid())`	A CUID2, on create.
`@default(autoincrement())`	The next number, assigned by IndexedDB. Single `Int` keys only.
`@updatedAt`	The current time, on create and on every update.

A default only applies when the field is left out. It also counts as setting the field: a foreign key filled in by a default is checked like one you set yourself.

Relations

Declare relations the usual way, with @relation(fields: [...], references: [...]) on the side that holds the foreign key.

model Todo {
  id     String @id
  userId String
  user   User   @relation(fields: [userId], references: [id], onDelete: Cascade)
}

One-to-many, many-to-one and one-to-one relations are supported. Many-to-many relations aren't; use an explicit join model.
Compound foreign keys are supported: @relation(fields: [orgId, userId], references: [orgId, id]).
onDelete and onUpdate accept Cascade, SetNull, SetDefault, Restrict and NoAction. Both default to Restrict. NoAction behaves like Restrict.

IndexedDB has no foreign keys of its own, so the client enforces them. See Foreign keys and referential actions for exactly what it checks.

Server-only fields and models

When you sync with a server, mark fields and models that must never reach the browser with @idb.exclude (a field) or @@idb.exclude (a model). The browser's contract leaves them out when your config sets projection: "client":

contract: prismaIdbContract("src/prisma/schema.prisma", { projection: "client" }),

Client Contracts explains the rules, including what happens to a relation that points at an excluded model.

Config

prisma.config.ts wraps an orm section built with defineConfig from @prisma-idb/family-idb/config-types. The Quick Start shows a complete file.

Field	Value for IndexedDB	What it does
`family`	`@prisma-idb/family-idb/control`	The database family.
`target`	`@prisma-idb/target-idb/control`	The target within the family. Carries the migration planner.
`adapter`	`@prisma-idb/adapter-idb/control`	Maps Prisma types to how IndexedDB stores them.
`driver`	`@prisma-idb/driver-idb/control`	Required by the framework. No CLI command can reach a browser database, so this is a stub.
`db.connection`	Any string, such as `":memory:"`	Required by the framework, unused. The database name is chosen in the browser, with `dbName`.
`contract`	`prismaIdbContract("path/to/schema.prisma", { projection })`	The schema to read. `contract emit` writes `contract.json` and `contract.d.ts` next to it.
`migrations.dir`	`"migrations"`	Where `prisma-idb migration plan` writes migration packages.

Both prisma and prisma-idb read this file, so neither needs --contract or --migrations-dir flags. Pass --config <path> if the file isn't in the project root.