The Domainr Developer API lets you programmatically interact with Domainr, the instant domain autocomplete and search engine, providing Instant domain autocomplete and availability, via HTTP & JSON.
The API has three methods — search, status, and register — each of which responds to a GET request. The API server will respond identically on port 80 (http) and port 443 (https).
Usage of the Domainr API is free at Mashape. For high-volume commercial usage, contact Domanir directly.