Projects & Folders

​

Overview

Team
└── Project (e.g., "Marketing Site")
    ├── Folder (e.g., "Transactional")
    │   ├── Template: welcome-email
    │   ├── Template: password-reset
    │   └── Template: order-confirmation
    └── Folder (e.g., "Newsletters")
        ├── Template: weekly-digest
        └── Template: product-updates

​

Transactional vs. Marketing Templates

​

Choosing the mode over the API

• "transactional" — the default, used when you omit the field
• "campaign" — a marketing template, the only kind a campaign can pick

curl -X POST https://app.lettr.com/api/templates \
  -H "Authorization: Bearer $LETTR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name": "March newsletter", "html": "<p>Hello {{FIRST_NAME}}</p>", "purpose": "campaign"}'

curl "https://app.lettr.com/api/folders?purpose=campaign" \
  -H "Authorization: Bearer $LETTR_API_KEY"

​

Other behaviors

• Copying to the other mode — Use the Copy to Transactional / Copy to Marketing action on a template to create a copy in the other mode. The copy is named “name (Copy)”, gets a new unique slug, and carries over all versions and merge tags. It lands in your current folder if that folder already belongs to the target mode, otherwise in the project’s default folder for that mode.
• Moving or duplicating into a folder — A moved or duplicated template takes on the mode of the folder it lands in, not the mode of the original.
• Returning to the list — The ← Emails link on an email’s detail page takes you back to the list with your folder and search still applied. Deleting an email from the list keeps you in the same folder, with the same view, search and sort.
• Deleting a folder keeps its templates — Templates in a deleted folder are not deleted with it. Each one is moved to the project’s default folder for its mode.

await lettr.emails.send({
  from: 'you@example.com',
  to: ['recipient@example.com'],
  subject: 'Welcome',
  template_slug: 'welcome-email',
  project_id: 123
});

​

Listing Templates by Project

curl -X GET "https://app.lettr.com/api/templates" \
  -H "Authorization: Bearer lttr_xxxxxxxxxxxx"

{
  "data": [
    {
      "id": 1,
      "name": "Welcome Email",
      "slug": "welcome-email",
      "project_id": 123,
      "folder_id": 3,
      "created_at": "2026-01-10T09:00:00Z",
      "updated_at": "2026-01-15T14:30:00Z"
    },
    {
      "id": 2,
      "name": "Order Confirmation",
      "slug": "order-confirmation",
      "project_id": 123,
      "folder_id": 5,
      "created_at": "2026-01-12T11:00:00Z",
      "updated_at": "2026-01-20T08:15:00Z"
    }
  ]
}

​

Default Project

• Cannot be deleted
• Receives templates when no project is specified
• Is used when API calls don’t include a project_id

​

Best Practices

​

Project Organization

• By Brand: Create separate projects for each brand if you send emails from multiple brands
• By Product: Separate projects for different products or services
• By Environment: Consider separate projects for production vs. staging if testing extensively

​

Folder Organization

• By Email Type: Group transactional, marketing, and notification emails
• By Customer Journey: Organize by lifecycle stage (onboarding, engagement, retention)
• By Frequency: Separate one-time emails from recurring ones

​

Naming Conventions

Projects:
- "Acme SaaS"
- "Acme Enterprise"
- "Internal Communications"

Folders:
- "Transactional"
- "Onboarding Sequence"
- "Product Updates"

Templates (slugs):
- welcome-email
- password-reset
- weekly-digest-v2

​

Related Topics