Digital Collections Web Service

In March 2013, the National Library of Medicine (NLM) released a search-based Web service that provides access to the metadata and full-text OCR of all resources in the Digital Collections repository in Extensible Markup Language (XML) format. The Digital Collections repository includes more than 9,000 digitized monographs, films, and other resources the from NLM collections. Software developers can use this Web service to incorporate the historical resources into their own applications.

The Web service accepts keyword searches as HTTP requests and returns XML with metadata about and keyword-in-context snippets of relevant resources in ranked order. Each returned record includes up to 13 Dublin Core metadata fields and the full-text snippet. The resource’s permanent URL is included in the "dc:identifier" field. It may be used by the application to link users directly to the resource on the Digital Collections site, where users can view the entire digitized resource via integrated presentation software.

The Web service documentation contains detailed descriptions and examples of the parameters for keyword and fielded search requests as well as the structure of the XML output. The documentation also includes Information about the 13 Dublin Core metadata fields and how to highlight the keyword-in-context search terms.

The Web service is updated weekly. It is free of charge and does not require registration or licensing. The "Acceptable Use Policy" requires that users send no more than 85 requests per minute per IP address.

A complete list of NLM Web services and Application Programming Interfaces (APIs) can be found on the NLM APIs page.