BlueChips - finances for people with shared expenses
BlueChips is a simple finance tracking application designed for small groups of people with shared expenses. It was designed and developed by groups of students who got tired of the headaches of managing lots of little payments between roommates.
If you want to try out BlueChips, you can go to http://demo.bluechi.ps
- Larry lives with Curly and Moe.
- Larry gets the utility bill, and enters it as an expenditure on their BlueChips site. Everyone shares the utilities, so it’s just an even split.
- A week later, Moe pays the rent. Curly has a smaller room, so he pays a smaller fraction of the rent.
- At any time, any user can visit the BlueChips site and see who needs to pay who how much in order to settle the books.
- After a few months, Moe has paid for a disproportionate amount of stuff, so the other roommates each make a transfer to Moe, and enter the amounts in BlueChips.
- Support for negative expenses
- Uses any authentication mechanism which can set the REMOTE_USER environment variable, including authentication modules supported by Apache, nginx, lighttpd, and others.
- Email notifications of changes (optional)
- 100% test coverage
Installation and Setup
Install BlueChips using easy_install:
Make a config file as follows:
paster make-config BlueChips config.ini
Tweak the config file as appropriate and then setup the application:
paster setup-app config.ini
Host the application behind an authentication layer which sets REMOTE_USER.
The recommended deployment platform for BlueChips is Apache, mod_wsgi, and any Apache module which provides authentication. Here is an example vhost configuration:
<VirtualHost bluechips.example.com:80> ServerName bluechips.example.com WSGIScriptAlias / /var/www/bluechips.wsgi <Directory /var/www> Order deny,allow Allow from all </Directory> <Location /> AuthType Basic AuthName "Example BlueChips Site" AuthUserFile /etc/apache2/passwords Require valid-user </Location> </VirtualHost>
The bluechips.wsgi wrapper script looks just like:
from paste.deploy import loadapp application = loadapp('config:/var/www/ssl/config.ini')
BlueChips is the latest in a long line of software to make managing group finances easier, and would not be possible without the intellectual inspiration of those predecessors.
CUTCAT’s accounting software started the trend of software-based accounting mechanisms. It inspired a re-implementation as a curses script by Nelson Elhage, which introduced the notion of “pushing expenditures” to simplify transfers. The algorithm used in BlueChips for settling the books is directly cargo-culted from Nelson’s implementation.