Schemas - Vela

Every event name you ingest must have a registered schema. The schema defines the expected fields and their types — events are validated against it at ingest time.

Schemas are app-scoped. Use client.forApp('my-app').schemas to access them.

List schemas

const schemas = await appRes.schemas.list();

Get by event name

const schema = await appRes.schemas.getByEventName('order.placed');

Create a schema

const schema = await appRes.schemas.create({
  eventName: 'order.placed',
  description: 'Emitted when a checkout completes',
  fields: [
    {
      id: 'fld-order-id',
      name: 'orderId',
      type: 'string',
      required: true,
      validation: { min: 1, max: 128 },
    },
    {
      id: 'fld-amount',
      name: 'amountCents',
      type: 'number',
      required: true,
    },
    {
      id: 'fld-currency',
      name: 'currency',
      type: 'enum',
      required: true,
      enumValues: ['USD', 'EUR', 'GBP'],
    },
    {
      id: 'fld-items',
      name: 'itemCount',
      type: 'number',
      required: false,
      defaultValue: 1,
    },
  ],
  metadataFields: [
    {
      id: 'meta-env',
      name: 'environment',
      type: 'string',
      description: 'e.g. production, staging',
    },
  ],
});

Update a schema

const updated = await appRes.schemas.update(schema.id, {
  description: 'Updated description',
  fields: [...],
});

Field types

Type	Description	Validation options
`string`	Text value	`min`, `max` (length), `pattern` (regex)
`number`	Numeric value	`min`, `max`
`boolean`	`true` or `false`	—
`date`	ISO-8601 date string	—
`enum`	Fixed set of strings	Provide `enumValues` array
`object`	Nested JSON object	—

Schema field interface

interface SchemaField {
  id: string;
  name: string;
  type: 'string' | 'number' | 'boolean' | 'date' | 'enum' | 'object';
  required: boolean;
  defaultValue?: unknown;
  description?: string;
  enumValues?: string[];
  validation?: {
    min?: number;
    max?: number;
    pattern?: string;
  };
}

You can also manage schemas as code using the Vela CLI — define schemas in JSON files and push them with vela push.