Scheduling and contact forms,
behind one clean API.
Give every user a public booking page and an embeddable contact form — backed by typed ConnectRPC, a generated SDK, signed webhooks, and a dashboard you don't have to build.
No credit card · deploys on free tiers · self-host anywhere
Intro Call · 30 min
Pick a time
Inbox
Jane Visitor
Saw your portfolio — can we talk?
Marc Dev
Question about the API pricing
Priya S.
Booking rescheduled to Thursday
POST /SubmitMessage · 200 OK
Built on the tools you already run
Everything a booking link needs, and nothing it doesn't
Two products sharing one identity layer, one API, and one deployable binary.
Scheduling that respects timezones
Weekly availability rules, date overrides, Google and Outlook sync, reschedule and cancel flows — slots are computed server-side so two people never book the same minute.
Weekly rules
Next bookings
Spam-proof by default
Honeypot fields, per-IP rate limiting, and a spam score on every submission.
Emails that don't look templated
Five built-in themes plus custom HTML, with live preview before you send.
Typed end to end
Protobuf definitions generate both the Go server and the TypeScript SDK, so a renamed field breaks the build instead of production.
const halo = new HaloMail({ apiUrl: process.env.API_URL });
await halo.contact.submitMessage({
formSlug: "portfolio",
senderName: "Jane Visitor",
senderEmail: "jane@example.com",
data: { message: "Let's talk." },
});One dashboard for meetings and messages.
Every booking, every form submission, every API key and webhook delivery in a single place — with an audit log that records who changed what.
- Read, search, and mark submissions without leaving the app
- Rotate scoped API keys and replay failed webhooks
- Per-form target addresses and redirect URLs
This week
Bookings
34
Messages
128
Show rate
92%
Run as many forms as you have pages.
One form per page, per campaign, per client. Each gets its own slug, target address, field schema, and redirect — and shares the same two-line embed.
See the embed guideLive on your site in three steps
Create a form or event type
From the dashboard or one API call. You get a slug and a public booking handle.
Paste two lines into your site
A script tag and a data-halomail attribute on the form you already designed.
Watch messages and bookings land
Stored, forwarded to your inbox, and pushed to your endpoints as signed webhooks.
Two lines of HTML, or the raw API
The widget is progressive enhancement over a form you already have. Prefer to own the request? It's plain JSON over POST.
<script src="https://api.halomail.app/widget.js" defer></script>
<form data-halomail="portfolio">
<input name="name" required>
<input name="email" type="email" required>
<textarea name="message" required></textarea>
<input name="_hl_hp" tabindex="-1" style="display:none">
<button type="submit">Send</button>
</form>curl https://api.halomail.app/halomail.scheduling.v1.BookingService/CreateBooking \
-H 'Content-Type: application/json' \
-d '{
"eventTypeId": "evt_01a01b8f",
"inviteeName": "Grace Hopper",
"inviteeEmail": "grace@example.com",
"start": "2026-06-15T09:00:00Z"
}'6
services, one binary
~15 MB
container image
$0
to run on free tiers
MIT
licensed, forever
Have a question? We've got answers.
Confused or curious? The docs cover the whole surface — from the first embed to self-hosting the stack on your own infrastructure.
Read the docsWhat is HaloMail?
An open-source platform that gives every user a public booking page and an embeddable contact form, behind one typed API. Run it as a hosted service or self-host the whole thing as a single container.
How do I start using HaloMail?
Create an account, make a form or event type, then paste a script tag into your site. The integration guide walks through both, with copy-paste snippets for plain HTML and React.
Do I need a database?
PostgreSQL, yes — a free Neon project is plenty to start. Redis is optional: without it, rate limiting falls back to an in-memory limiter, which is correct for a single instance.
Can I use my own domain for emails?
Yes. Verify a domain with your email provider, then point EMAIL_FROM at an address on it. Without a verified domain, delivery is limited to your own account address.
Is it really free to run?
In monolith mode it fits inside the free tiers of a container host and a managed Postgres. Scale a single service out to its own deployment later without touching code.
How do I keep the API off the public internet?
Every write endpoint except form submission and booking requires a bearer token. Deploy the gateway behind your own proxy if you want the rest locked down further.
Ship scheduling and contact in an afternoon.
Self-host the whole platform as one container, or run each service on its own. Same API either way.