Melon-db — offline-first local database

Melon-db schemas use a fixed set of scalar kinds. Adapters map them to SQLite column types; sync sends JSON-compatible payloads.

Scalar kinds (`MelonScalar`)

Kind	TypeScript (app)	SQLite (typical)	Sync over JSON
`string`	`string`	`TEXT`	string
`number`	`number`	`REAL` / `INTEGER`	number
`boolean`	`boolean`	`INTEGER` (0/1)	boolean
`date`	`Date`	`INTEGER` (ms) or `TEXT` (ISO)	ISO string recommended
`json`	object / array	`TEXT` (serialized)	object / array
`bytes`	`Uint8Array`	`BLOB`	base64 or binary transport-specific

Define fields in schema:

fields: {
  id: { kind: 'string' },
  count: { kind: 'number' },
  active: { kind: 'boolean' },
  updatedAt: { kind: 'date' },
  metadata: { kind: 'json', nullable: true },
  thumbnail: { kind: 'bytes', nullable: true },
}

Nullability

nullable: true allows null in storage. Required fields should omit nullable or set nullable: false.

Indexes

Per-field indexed: true for single-column hints.
Composite indexes via indexes: [['status', 'updatedAt']].

Indexes affect query performance only — they do not change the TypeScript kind.

Query operators by type

Operators	Works on
`eq`, `neq`, `in`, `notIn`	all scalars
`gt`, `gte`, `lt`, `lte`	`number`, `date`
`like`, `contains`	`string` (and `contains` on json string fields in limited cases)
`isNull`	any nullable field

Relations are not a type

Foreign keys are stored as ordinary fields (projectId: { kind: 'string' }). Relation metadata drives include and validation only.

Sync payload notes

Dates: serialize as ISO 8601 strings in created / updated arrays unless you standardize on numeric epochs both sides.
JSON: must be JSON-serializable — no Date, Map, or undefined inside json fields on the wire.
Bytes: prefer base64 in JSON APIs; adapters may store raw BLOB locally.
Deletes: push/pull use string primary keys in the deleted array.

Unsupported / deferred

Feature	Status
Auto-increment integer ids	use string ids or assign in app code
Enums as first-class schema kind	use `string` + app-level constants
Full-text search	use `like` or raw SQL migrations
Partial / filtered indexes	declare via `sql` migration step

Schema — field definitions
Backend — wire format for SyncChanges
FAQ — common type mistakes

Supported data types