It is possible to write a basic screen scraper to pull account transactions from your Mint.com account. Of course, this means you'll have to have an account set up there and let them to the dirty work for you.
CasperJS is a great tool that makes this fairly trivial, you will need to install both Casper and PhantomJS, the framework it is built on.
var casper = require('casper').create();
casper.start('https://wwws.mint.com/login.event', function() {
this.fill('form#form-login', {
username: 'mintusername',
password: 'mintpassword'
}, true);
}).then(function() {
this.echo('Downloading transaction history...')
this.download('https://wwws.mint.com/transactionDownload.event', '/path/to/save/transactions.csv');
});
casper.run(function() {
this.echo('Done.').exit();
});
This script logs into your Mint account, and downloads your transaction history (as a CSV file) to wherever you specify. From there, you can do what you like with the data. Of course, this script could be expanded significantly to do more advanced things, or to filter the transactions it pulls down, but as a matter of best practice I would advise keeping the screen scraping as simple as possible and add the logic on your program's end.
You can have this script run periodically using launchd for Mac OS X or cron for most Linux flavors.