Selfsend

Selfsend is a self-hosted, Resend-compatible email API that sends through your own SMTP server. It is meant for hobbyists that want to keep using Resend-style SDK calls while routing delivery through infrastructure they control.

Note

THIS DOES NOT IMPLEMENT ALL OF THE RESEND API

The most common features, namely the sending of emails is implemented tho

The app includes:

• A Resend-compatible send API for single and batch email sends.
• Project-scoped ss_ API keys.
• A small web UI for projects, default senders, API keys, and send history.
• SMTP delivery through Nodemailer.
• SQLite persistence with Drizzle.
• email/password, OIDC sign-in, and optional sender allowlists.

API Usage

Point Resend-compatible clients at your Selfsend base URL and use a project API key from the dashboard.

curl http://localhost:3000/emails \
  -H "Authorization: Bearer ss_your_project_key" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Selfsend <[email protected]>",
    "to": "[email protected]",
    "subject": "Hello",
    "html": "<p>Sent through Selfsend.</p>"
  }'

With the official Resend Node SDK, set the SDK base URL before initializing the client:

RESEND_BASE_URL=http://localhost:3000

import { Resend } from "resend";

const resend = new Resend("re_your_project_key");

await resend.emails.send({
  from: "[email protected]",
  to: "[email protected]",
  subject: "Hello",
  html: "<p>Sent through Selfsend.</p>",
});

Implemented Resend-compatible routes include POST /emails, POST /emails/batch, GET /emails, GET /emails/:id, attachment retrieval, and basic API key listing/creation/deletion. Features that SMTP cannot provide, such as hosted domains, broadcasts, inbound routing, and webhooks, are not implemented.

Configuration

Environment variables:

Variable	Description
DB_FILE_NAME	libSQL/SQLite URL. Docker examples use file:/data/selfsend.db.
BETTER_AUTH_URL	Public base URL of the app, for auth redirects and callbacks.
BETTER_AUTH_SECRET	Random production secret, at least 32 characters.
DISABLE_PASSWORD_SIGNIN	Set to true to disable email/password sign-in.
SMTP_HOST	SMTP host used for delivery.
SMTP_PORT	SMTP port, usually 587, 465, or 1025 for MailCatcher.
SMTP_SECURE	true for implicit TLS, otherwise false.
SMTP_USER / SMTP_PASSWORD	Optional SMTP credentials.
SMTP_FROM	Optional fallback sender when a project/request omits from.
ALLOWED_SENDERS	Optional comma-separated sender allowlist.
OIDC_*	Optional generic OIDC provider settings.
API_KEY_RATE_LIMIT_ENABLED	Wheter to rate limit the API

OIDC callback URL:

https://your-selfsend-host.example.com/api/auth/oauth2/callback/oidc

Set OIDC_PROVIDER_ID to something other than oidc if you want a different callback suffix.

Sender Restrictions

Set ALLOWED_SENDERS to restrict which from addresses Selfsend can use. Leave it empty to allow any sender.

Patterns are comma-separated and matched case-insensitively:

• [email protected] allows one exact address.
• @example.com allows any sender at that domain.
• *[email protected] allows matching addresses such as [email protected].
• *@example.com is also valid, but @example.com is the simpler domain form.

Docker

The published image is:

ghcr.io/gametec-live/selfsend:latest

Run the production-style example:

mkdir -p data
chmod 777 data
docker compose up

The default compose.yml uses ./data:/data and stores SQLite at /data/selfsend.db. Replace the placeholder auth, SMTP, and OIDC values before production use. It is also recommended to use a volume to store the database instead of a bind mound with broad permissions.

Test Stack

The test stack runs Selfsend with MailCatcher:

mkdir -p test-data
chmod 777 test-data
docker compose -f compose.test.yml up --build

MailCatcher endpoints:

• SMTP: localhost:1025
• UI: http://localhost:1080

Selfsend runs at http://localhost:3000.

If startup fails with Unable to open connection to local database /data/selfsend.db: 14, the bind-mounted directory is not writable by the container user. Fix the host directory permissions and recreate the stack:

Development

bun install
bun run dev

Useful scripts:

bun run lint
bun run typecheck
bun run build
bun run db:generate
bun run db:migrate
bun run db:push

The app uses SQLite through Drizzle/libSQL. Generated migrations live in drizzle/, and startup migrations run automatically.

Publishing

The GitHub Actions workflow at .github/workflows/docker.yml builds Docker images for pull requests and publishes to GHCR on pushes to main or v* tags.

Published tags:

• latest for the default branch.
• sha-<commit> for pushed commits.
• Git tag names for v* releases.