Mailbus

Mailbus is a self-hosted email newsletter that allows:

• A blog visitor to subscribe to the newsletter
• Blog author to send an email to all subscribers
• A subscriber to unsubscribe from the newsletter

API Design

• POST /subscriptions: sign up a new subscriber
• GET /subscriptions/confirm: subscriber consent
• GET /unsubscribe: unsubscribe from the newsletter

Data Schema

CREATE TABLE subscriptions (
    id            INTEGER PRIMARY KEY AUTOINCREMENT,
    email         TEXT NOT NULL UNIQUE,
    subscribed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE subscription_tokens (
    subscription_token TEXT NOT NULL,
    subscriber_id      INTEGER NOT NULL REFERENCES subscriptions (id),

    PRIMARY KEY (subscription_token)
);

Sequence Diagram

sequenceDiagram
    Visitor ->> Blog: Enter an email address
    Blog ->> Blog: Validate email address
    Blog ->> Mailbus: POST /subscriptions
    Mailbus ->> Visitor: Send confirmation email
    Visitor ->> Mailbus: GET /subscriptions/confirm