What is MIME type "application/sparql-results+xml"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

application/sparql-results+xml is a MIME type that marks an XML document carrying results from a SPARQL query.
It tells software that the file contains structured query data using the SPARQL protocol for RDF data access.
Files with the extension SRX use this format.

Data Interchange: It standardizes the way query results are shared between systems.
Integration: Multiple applications can exchange and process RDF query outputs.
Compatibility: Many SPARQL endpoints deliver responses in this XML format.
Parsing: XML tools and libraries easily process and analyze these results.

For additional technical details, refer to the SPARQL Query Results XML Format specification.

Associated file extensions

.srx

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/sparql-results+xml

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/sparql-results+xml">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/sparql-results+xml');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.srx

FAQs

What is application/sparql-results+xml used for?

This MIME type is used to return the results of a SPARQL SELECT or ASK query formatted as XML. Unlike application/rdf+xml, which returns a graph (triples), this format structures the data into a table of variable bindings or a boolean result, as defined by the W3C SPARQL Query Results XML Format.

How do I configure Apache to serve .srx files correctly?

To ensure your Apache server sends the correct Content-Type headers for .srx files, add the following line to your .htaccess file or httpd.conf: AddType application/sparql-results+xml .srx. This prevents the server from defaulting to text/xml or text/plain.

How do I request this format from a SPARQL endpoint?

When querying a SPARQL endpoint, you should include the Accept HTTP header to specify your preferred output format. Use Accept: application/sparql-results+xml to tell the server you want the response encoded in the standard XML result format.

Should I use application/sparql-results+xml or application/sparql-results+json?

The choice depends on your client environment. XML is excellent for strict validation and transformation via XSLT, while application/sparql-results+json is generally preferred for web applications because it is native to JavaScript and easier to parse in browsers.

How do I set up Nginx for SPARQL XML results?

Locate your mime.types file (usually in /etc/nginx/) or edit the types block in your server config. Add the line application/sparql-results+xml srx; to map the file extension to the correct MIME type.

Can I simply use text/xml instead?

While text/xml allows the file to be read as generic XML, it is not recommended for API interactions. Using the specific application/sparql-results+xml subtype allows software to automatically identify the schema and process the variable bindings without manual inspection.

What software can open or parse .srx files?

Since .srx files are plain XML, they can be viewed in any text editor like Notepad++ or VS Code. For programmatic use, Semantic Web libraries like Apache Jena (Java) or rdflib (Python) have built-in parsers to handle this MIME type.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.