Introduction
What CustomDomain is, the connect → secure → serve → monitor loop, and where to go next.
Custom-domain onboarding for multi-tenant SaaS — DNS auto-configuration, automatic SSL, and a reverse proxy, in one fully-managed platform. Let your customers point their own domain at your product in minutes, with a drop-in widget and a REST API.
What it does
- Connect — a customer enters their domain; the engine detects their DNS provider and applies the records through the best available rail — OAuth into the provider, provider-hosted one-click setup, a scoped API token, or guided-manual — then watches propagation.
- Secure — the edge issues a TLS certificate on demand during the
handshake, but only for hostnames a live/propagating connection has authorized.
(Certificates come from Let's Encrypt staging — not browser-trusted — until
the edge is run with
EDGE_ACME_PROD=1.) - Serve — the edge reverse-proxies the custom domain to your origin.
- Monitor — webhooks, a developer console, usage metering, and DNS-drift detection keep you informed after go-live.
The two planes
Two independent planes share one database and talk over HTTP:
- Connect plane (the control-plane) — the
/v1REST API, the connect rails, the propagation poller, quotas/metering, and webhooks. - Edge plane — on-demand TLS termination + reverse proxy, gated by a single
internal
askcall to the control-plane.
See Concepts for the full model.
Start here
| If you want to… | Read |
|---|---|
| Find your path (console · API · widget · MCP) and the truths they share | Which path are you on? |
| Point your own domain at your app, no code | Console |
| Provision domains from your server | API |
| Let your customers connect their domains in your UI | Widget |
| Drive it from an agent | MCP |
| Run the stack yourself | Self-hosted quickstart |
| Understand connections, rails, and status | Concepts |
| Authenticate API calls and the widget | Authentication |
| Embed the connect modal | The widget SDK |
| Add email records / merge SPF safely | Email DNS |
| Call the API | API Reference |
| React to events | Webhooks |
| See which DNS providers auto-configure | DNS providers |
| Buy a brand-new domain | Buying a domain |
| Understand the security model | Security |
| Configure plans and quotas | Plans & quotas |
| Look up enums, env vars, error codes | Reference |
| Fix a stuck connection | Troubleshooting |
| Let an AI agent act on your domains | Agent access |
For AI agents
A machine-readable index of this documentation is at
/docs/llms.txt: every page, with its title, URL and
description, so an agent can fetch exactly the page it needs. A site-root copy is
served at /llms.txt. There is no
full-text bundle and no per-page raw-Markdown route today; earlier revisions of
this page advertised /docs/llms-full.txt and /llms/<page-slug>, and both
return 404.
Agents can also drive the product directly through the hosted
MCP server at https://mcp.customdomain.ai/mcp — twelve
tools for searching, buying, and connecting domains. A human owner can also
delegate scoped, revocable access to an agent via OAuth; see
Agent access — not yet enabled on the hosted
service.