SageMath is an open-source project to create mathematical software that is a free alternative to proprietary, closed-source packages. One way to access it on the Internet is through the SageMathcell server, where code can be entered and evaluated. It can also be accessed as a web service for situations requiring more interactive access to the data output.

The URL for accessing the web API is https://sagecell.sagemath.org/service. The secure URL is necessary to avoid CORS errors. Appending a trailing slash to this URL produces an additional CORS error when retrieving data. The code to be executed must be URL encoded as a URL component, not a full URL. The encoded string is then POSTed to the server with a prefix code= and a JSON response returned with the result of the interaction.

Here is some simple JavaScript code to send a request to the server:

var xhr = new XMLHttpRequest();

xhr.onload = function() {

  var data = JSON.parse( xhr.response );
  callback( data.stdout );

};

xhr.open( 'POST', 'https://sagecell.sagemath.org/service', true );
xhr.setRequestHeader( 'content-type', 'application/x-www-form-urlencoded' );
xhr.send( 'code=' + encodeURIComponent( codeString ) );

The standard output is processed in the callback function.

Here is a simple interface for viewing the full JSON result returned by the server. Enter SageMath code in the input box and activate the button:

Output will go here

It appears to be necessary to include a print() statement in the code in order for a result to appear in the standard output. The server times out after thirty seconds, returning a success value of false.

If a URL-encoded query string is appended to the location of this page, it will be evaluated automatically as Python and the result will appear here:

Output will go here

Projects and presentations utilizing the SageMath web service:

Uploaded 2016.08.27 — Updated 2019.06.19 analyticphysics.com