Templates Worker¶

The templates worker provides email template management with Jinja2 rendering, version history, HTML + plaintext dual rendering, and usage analytics. It is a FastAPI service backed by MySQL, built and enabled in every deployment.

Features¶

Template CRUD: Create, read, update, delete email templates, scoped per organization
Jinja2 rendering: {{ first_name }}-style variable substitution, rendered on demand via the render endpoint
Version history: Every update records a version; history is queryable per template
Dual rendering: HTML and plaintext bodies rendered together
Template library: Pre-built templates for common use cases
Duplication: Clone an existing template as a starting point
Usage stats: Per-template render/usage statistics

Architecture¶

flowchart LR
    API["API Gateway"] --> Templates["Templates Worker\n:8089"]
    Templates --> MySQL[(MySQL)]

API Endpoints¶

Copied from the route decorators in worker/templates/app.py:

Text Only

POST   /templates                        -- Create a template
GET    /templates?org_id=                -- List templates for an org
GET    /templates/library                -- Pre-built template library
GET    /templates/{template_id}          -- Get a template with content
PUT    /templates/{template_id}          -- Update a template (records a version)
DELETE /templates/{template_id}          -- Delete a template
POST   /templates/{template_id}/render   -- Render with supplied variables
POST   /templates/{template_id}/duplicate -- Duplicate a template
GET    /templates/{template_id}/versions -- Version history
GET    /templates/{template_id}/stats    -- Usage statistics
GET    /health                           -- Health check
GET    /metrics                          -- Prometheus metrics

Configuration¶

Variable	Default	Description
`PORT`	`8089`	Bind port
`DB_HOST`	`mysql`	MySQL host
`DB_PORT`	`3306`	MySQL port
`DB_NAME`	`mailserver`	Database name
`DB_USER`	`mailuser`	Database user
`DB_PASSWORD`	--	Database password

Docker Configuration¶

YAML

templates:
  build: ./worker/templates
  container_name: templates
  ports:
    - "8095:8089"
  volumes:
    - ./shared:/app/shared

The ./shared mount is required: the build: ./worker/templates shorthand scopes the build context to that subdirectory, so the image never contains the repo-root shared/ modules at build time. In production (docker-compose.prod.yml) the host port is bound to 127.0.0.1 only.