payload-mailing/CUSTOM-TYPES.md

Using Custom ID Types

The mailing plugin now supports both string and number ID types. By default, it works with the generic BaseEmailDocument interface, but you can provide your own types for full type safety.

Usage with Your Generated Types

When you have your own generated Payload types (e.g., from payload generate:types), you can use them with the mailing plugin:

import { sendEmail, BaseEmailDocument } from '@xtr-dev/payload-mailing'
import { Email } from './payload-types' // Your generated types

// Option 1: Use your specific Email type
const email = await sendEmail<Email>(payload, {
  template: {
    slug: 'welcome',
    variables: { name: 'John' }
  },
  data: {
    to: 'user@example.com',
    // All your custom fields are now type-safe
  }
})

// Option 2: Extend BaseEmailDocument for custom fields
interface MyEmail extends BaseEmailDocument {
  customField: string
  anotherField?: number
}

const customEmail = await sendEmail<MyEmail>(payload, {
  data: {
    to: 'user@example.com',
    subject: 'Hello',
    html: '<p>Hello World</p>',
    customField: 'my value', // Type-safe!
  }
})

Compatibility

The plugin works with:

• String IDs: id: string
• Number IDs: id: number
• Nullable fields: Fields can be null, undefined, or have values
• Generated types: Works with payload generate:types output

Your Payload configuration determines which types are used. The plugin automatically adapts to your setup.

Type Definitions

The base interfaces provided by the plugin:

// JSON value type that matches Payload's JSON field type
type JSONValue = string | number | boolean | { [k: string]: unknown } | unknown[] | null | undefined

interface BaseEmailDocument {
  id: string | number
  template?: any
  to: string[]
  cc?: string[] | null
  bcc?: string[] | null
  from?: string | null
  replyTo?: string | null
  subject: string
  html: string
  text?: string | null
  variables?: JSONValue  // Supports any JSON-compatible value
  scheduledAt?: string | null
  sentAt?: string | null
  status?: 'pending' | 'processing' | 'sent' | 'failed' | null
  attempts?: number | null
  lastAttemptAt?: string | null
  error?: string | null
  priority?: number | null
  createdAt?: string | null
  updatedAt?: string | null
}

interface BaseEmailTemplateDocument {
  id: string | number
  name: string
  slug: string
  subject?: string | null
  content?: any
  createdAt?: string | null
  updatedAt?: string | null
}

These provide a foundation that works with any ID type while maintaining type safety for the core email functionality.