extracting YOUR data from the withings smart body analyzer ws-50

The top of line Withings scale smart body analyzer was released in April 2013. However to this day, 8 months later, it is still impossible to extract the CO₂ and temperature data through the API or download these as CSV file. Their customer support just keep tossing the issue under the carpet labeled "forwarded to engineering department", meanwhile they are just busy releasing other botched products.

So I had to figure out a way to get MY data, here is how you can get yours using just firefox:

.with Firefox, log in your account at http://healthmate.withings.com
.select Tools -> Web developer -> Network

.reload the page with F5 or the refresh button

.click "Method" in the network tab
.look at POST rows
.select the last POST row "measure"
.click "Params" in the bottom right panel
the bottom right panel now shows the parameters used
parameter meastype should read "12,35", it means the request grabs both sets of data labeled 12 = room temperature!! and 35 = CO2 concentration!!

These types are yet unaccessible and unreferenced in the API documentation, but we can get to them through the dashboard web interface, we just need to trick that interface to return everything, not just the last 24 hours:
.click on "Headers"
.click the "Resend" button below the Request URL
.in the Request Body change the startdate to a time before your device started logging, let's say 1360000000
.click "Send"
.click "Response"
.copy paste in an empty file the contents of the response: {"status":0,"body":{"series":["type":12,"data:[{"date.....

Congratulations, you finally have your full history of temperature and CO₂ data! The format is json, I will assume that you know how to transform json to whatever format is more convenient for you to run your analysis otherwise look at json2csv or similar tools.

more advanced withings hacks:

spoofing withings servers http://www.prolixium.com/mynews?id=915

http://blog.chris007.de/?p=459

advanced firmware hacking of the WS-30 http://poppopret.org/2013/06/10/summercon-2013-hacking-the-withings-ws-30/