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Build with the Unstoppable Domains User API

Build out your custom domaining workflow and stack with our user API.

Hassan Ali

Principal Engineer ·

Hassan is a Principal Engineer at Unstoppable. He works on the infrastructure behind domain and DNS resolution, and writes up the protocol details most guides skip.

UD ships its registrar and marketplace as an API for domainers and indie hackers automating their own portfolios. The User API covers registration, DNS, listings, cart, and webhooks across UD's infrastructure.

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What you can build

  • Custom registration flows — search, availability, and pricing across 150+ TLDs, with full registration and renewal endpoints

  • Custom backordering system — build out a custom backordering system

  • DNS and nameserver management — create, update, delete records programmatically across the portfolio

  • Marketplace listings — create, update, and cancel listings; set BIN, Make Offer, and LTO terms via API

  • Cart and checkout — build custom purchase flows on top of UD's registrar and marketplace

  • Bulk portfolio operations — push, auto-renewal updates, tagging, organizing across hundreds of domains

  • Real-time events — webhooks for registrations, transfers, offers, and transaction completions

Free to use. OAuth 2.0 for user-context calls, API keys for server-to-server. Standard registration, renewal, and marketplace fees apply.

Docs: docs.unstoppabledomains.com/user-api/overview

Check out the Domain Finder

The Domain Finder lets you search for new domains, marketplace, and pending delete, using natural language and filters. unstoppabledomains.com/products/ai-assistant