Templates Module Specification

1. Purpose & Overview

templates

2. Responsibilities

• Maintain

  Template

  and

  TemplateComponent

  domain models.
• Track Meta approval states (

  APPROVED

  ,

  PENDING

  ,

  REJECTED

  ).
• Provide variable binding services for campaign message generation.

3. Directory Structure

services/api/templates/
├── admin.py
├── apps.py
├── migrations/
├── models.py
├── serializers.py
└── views.py

4. Models & Database Schemas

class TemplateStatus(models.TextChoices):
    PENDING = 'PENDING', 'Pending'
    APPROVED = 'APPROVED', 'Approved'
    REJECTED = 'REJECTED', 'Rejected'

class Template(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4)
    tenant = models.ForeignKey('tenants.Tenant', on_delete=models.CASCADE)
    name = models.CharField(max_length=255)
    category = models.CharField(max_length=50) # 'MARKETING', 'UTILITY'
    language = models.CharField(max_length=10, default='en_US')
    components = models.JSONField(default=list) # HEADER, BODY, FOOTER, BUTTONS
    status = models.CharField(max_length=20, choices=TemplateStatus.choices, default=TemplateStatus.PENDING)

5. Services & Business Logic

• Template.render_body(variables_dict)

  : Replaces

  {{1}}

  ,

  {{2}}

  placeholders with customer variable data.

6. Serializers & Data Transfer Objects

• TemplateSerializer

  : Validates structure of header, body, footer, and button components.

7. Views & API Endpoints

• GET /api/templates/

  : List approved templates.

• POST /api/templates/

  : Submit new template for Meta approval.

8. Permissions & Role Rules

• TENANT_ADMIN

  &

  TENANT_USER

  : Access templates within active tenant.

9. Signals & Event Listeners

• post_save

  : Notifies team when a pending template is approved by Meta.

10. Background Tasks & Celery Jobs

• Periodic task syncs template statuses from Meta Graph API.

11. Data Flow & External Dependencies

• Integrates with Meta WhatsApp Graph API (

  v22.0

  ) for template creation & status sync.

12. Business Rules & Validations

• Template names must contain only lowercase alphanumeric characters and underscores.
• Body components must contain valid numbered placeholders (

  {{1}}

  ).

13. Sequence Diagram (Mermaid)

14. Known Limitations & Technical Debt

• Local edits to templates must be synced back with Meta's developer portal.

15. Future Improvements

• Add interactive Drag-and-Drop WhatsApp Template Builder in Next.js UI.