Federated Search Developer Guide: Connect External Search Providers to Salesforce

Federated Search connects the Salesforce federated search connector to the external search provider so that data from external repositories can be searched and returned within Salesforce. External search providers have partnered with Salesforce to provide a search service that conforms to the API found in the Salesforce Federated Search Developer Guide.
Available in:

Professional, Enterprise, Unlimited, and Developer Editions

The Federated Search Developer Guide follows the OpenSearch specification with more Salesforce extensions. External search providers who conform to this API remain fully compliant to the OpenSearch specification and can be queried by any OpenSearch client at the same URL endpoint.