Mailship

A Nostr email notification server. Receives events pushed from relays via NIP-9a, stores them, and sends daily or weekly digest emails.

Architecture

Flotilla ──HTTP──▶ Mailship (PUT /subscription/email)
  │                   NIP-98 auth
  │                   returns {key, callback}
  │
  └──kind 30390──▶ relay or NPB
                         │
                    event matches filter
                         │
                         ▼
                    POST /notify/:subId ──▶ Mailship
                         {id, relay}         │
                           UUID in path      ├── fetch event from relay
                           is the auth       ├── store in SQLite (dedup)
                                             │
                                        cron fires ──▶ render digest ──▶ SMTP ──▶ email

Configuration

Variable	Required	Description
MAILSHIP_SECRET	✓	A nostr private key hex string for the server's identity
MAILSHIP_NAME	✓	Name of this Mailship instance
MAILSHIP_URL	✓	Public URL of this instance
BASE_URL	✓	Base URL for callback URLs (same as MAILSHIP_URL typically)
SMTP_HOST	✓	SMTP server hostname
SMTP_PORT	✓	SMTP server port
SMTP_USER	✓	SMTP username
SMTP_PASSWORD	✓	SMTP password
SMTP_FROM	✓	From email address for outgoing mail
EVENT_VIEWER_URL		Base URL of the app event links open in (defaults to Flotilla at https://app.flotilla.social, or anything handling the same /spaces/<relay>/<hash> and /<nevent> URL shapes)
BRAND_NAME		Name used in email branding (default: Flotilla)
BRAND_ACCENT		Accent color string used in email branding (default: #7161FF)
BRAND_LOGO		URL of the logo image shown in the email header. Defaults to <EVENT_VIEWER_URL>/logo.png; if empty/unset, a colored brand name is shown instead
DEFAULT_RELAYS	✓	Comma-separated list of default relays
INDEXER_RELAYS	✓	Comma-separated list of indexer relays
SEARCH_RELAYS	✓	Comma-separated list of search relays
PORT		Port to run on (default: 4738)

API

PUT /subscription/email

Idempotently register or update an email subscription. Re-sends the confirmation email only when the subscription is new or the email address changed; a frequency change keeps the existing confirmation. The pubkey is extracted from the NIP-98 Authorization header — the body does not include a pubkey field.

Body: { email, frequency }
Auth: NIP-98 (Nostr <base64> Authorization header)
Response: { key, callback }

GET /subscription/email

Look up an existing subscription for the authenticated pubkey, so clients can avoid re-registering (and re-confirming) when settings haven't changed. Returns 404 if none exists.

Auth: NIP-98 (Nostr <base64> Authorization header)
Response: { key, callback, email, frequency, confirmed }

DELETE /subscription/:key

Unsubscribe. Verifies the NIP-98 auth pubkey matches the subscription owner.

Auth: NIP-98 (Nostr <base64> Authorization header)
Response: { ok: true }

POST /notify/:id

NIP-9a relay push callback. Called by relays or NPB when matching events are found.

Body: { id, relay }
Response: { ok: true, stored: boolean }
Returns 404 if subscription not found or inactive.

When the event is not found at the relay (e.g. it was deleted or never arrived), the endpoint returns { ok: true, stored: false } — the event is silently skipped rather than erroring. The stored field is always present in a 200 response.

GET /confirm?token=...

Confirm email address via link from confirmation email.

GET /unsubscribe?token=...

Unsubscribe via link from digest email.

Development

pnpm install
pnpm run build
pnpm run start

Previewing the digest email

To iterate on the email template, render it with sample data and open the result in your browser:

pnpm run preview:digest
open digest-preview.html

Docker

Quick start

cp .env.template .env
# Fill in your secrets in .env
docker compose up -d

Build and run manually

docker build -t mailship .
docker run -d \
  -p 4738:4738 \
  -v mailship-data:/data \
  --env-file .env \
  mailship

Tests

pnpm test:unit       # Run unit tests (vitest)
pnpm test            # Run integration tests (bash E2E)
pnpm test:server     # Start server for manual testing

Forked from Anchor

Mailship is a fork of Anchor, stripped of push notification support and adapted for NIP-9a relay push event intake.