Software you own, not software you rent.
We publish the tools we build for our own work under the Apache 2.0 licence. Run them on your own server for free, use our hosted version, or have an AT20 engineer set them up for you. The first is Slotnest, appointment booking for small teams.
This is the page you book a call with us on. It runs on Slotnest.
Some software shouldn't be a monthly bill.
Stop renting seats
Booking tools charge every month for every person who takes meetings. Run Slotnest yourself and that line on the bill goes away.
Your data stays with you
Self-hosted, every booking, contact and calendar token lives in your own database, on a server you choose.
Read it, change it, keep it
The code is public under Apache 2.0. Audit it, change it to fit how you work, and keep running it whatever happens to us.
Everything a small team needs to take bookings.
We built it for our own sales calls, then published it so anyone can use it.
- Booking pages and an embedA public page for each event type, plus a widget that opens inline or as a popup on your own site.
- Calendar and videoChecks Google Calendar for free time and writes the event back, with Google Meet or Zoom links added.
- TeamsRound-robin meetings shared evenly across your team, collective meetings when everyone must attend, and group sessions with seats.
- Reminders and follow-upsEmail reminders before and follow-ups after, with your own wording, and self-service reschedule and cancel.
- Questions and routingUp to 10 booking questions per event, shown in your emails, calendar and dashboard.
- Webhooks and paymentsSigned webhooks for every booking, change and cancellation, and paid bookings through your own Stripe account.
Run it, rent it, or hand it to us.
Run it yourself
Clone the code and run one command on any server with Docker. It starts the app with Postgres and HTTPS. Setup guide on GitHub →
Use our hosted version
One event type, calendar sync, Meet and Zoom, confirmations and reminders, free. Paid plans are a one-time setup fee and a small yearly fee per seat, not a monthly subscription. Start on slotnest.at20.ai →
Have us set it up
An AT20 engineer installs Slotnest on your servers, connects your calendars, your branding and your CRM through webhooks, and keeps it updated. Book a 15-min call →
Slotnest is the first, not the last.
When we build something for our own team or solve the same problem for several clients, and it would help other businesses, we'll publish it here. Paying every month for a tool your team barely uses? See which SaaS tools we can replace →
Questions about our open source.
Is Slotnest really free?
Yes. The code is released under the Apache 2.0 licence, so you can use it, change it and run it for your business at no cost. The hosted version also has a free plan.
What do I need to run it myself?
A server with Docker and a domain or subdomain pointed at it. Email, Google Calendar, Zoom and Stripe each need your own account keys; the setup guide on GitHub walks through each one.
Who looks after it if something breaks?
Self-hosted, you do, with the setup guide and GitHub issues to help. If you'd rather not, use the hosted version or ask us to set it up and maintain it for you.
Why does an AI agency give software away?
Because code you can read earns more trust than a sales page. The engineers who build Slotnest are the same people who build and run AT20's AI agents for clients.
Can I contribute?
Yes. Report bugs and suggest features as GitHub issues, and send pull requests. Tell us what's missing.