El Cheapo Withings/Nokia Body integration with FatSecret

This is a cheap web function that accepts a weight measurement from a Withings/Nokia Health Body scale and stuffs it into a predefined profile in FatSecret. The web function accepts JSON over POST in the following form.

{ "weightkg" : 80.0 }

The function connects to the FatSecret API and records the value in the configured user's weight log.

The web function is triggered from IFTTT.

Motivation

• Because I'm lazy and I don't want to update my FatSecret log every day;
• Because I'm annoyed that FatSecret hasn't provided any Withings integration;
• Because modern APIs make this trivial to accomplish, so there's no excuse why FatSecret hasn't done this themselves;
• Because it was an excuse to learn a few new things.

Installation

Prerequisites

• FatSecret user account
• IFTTT user account
• FatSecret Platform API account (free account works)
• A place to run a Flask app under Python3

Dependencies

See requirements.txt:

• Flask to run the server
• pyfatsecret to interact with the FatSecret Platform API
• PyYAML to manage configuration data

Store API keys and user tokens

Note: These values permit access to both the API and your personal user data. Do not put them somewhere where an unauthenticated user may view them. If you're running this web function on a cloud service, security is your problem. By default the web function will look in the working directory for the credential file, so if that's not a good place to keep it you should modify the flask_listener.py file appropriately.

Via script

• Obtain your FatSecret API key and secret from here
• Copy the REST API consumer key and REST API shared secret
• Run store_keys.py with your API keys as arguments
• Follow the link the script prints
• Authorize the app
• Enter the PIN

usage: store_keys.py [-h] [--file FILE] consumer_key consumer_secret

Authorize and store FatSecret user token

positional arguments:
  consumer_key     FatSecret API Consumer Key
  consumer_secret  FatSecret REST API Shared Secret

optional arguments:
  -h, --help       show this help message and exit
  --file FILE      credential storage file

Manually

You'll have to figure out how to get a user token and secret on your own. The store_keys.py script shows one way to do it.

• Copy the file sample_fs_credentials.yml to fs_credentials.yml
• Edit fs_credentials.yml and add your keys as indicated

Configuring web hook

Log in to IFTTT and create a new applet

• "If" trigger is "Body Scale - New measurement" from the Withings service

  • Authorize IFTTT to receive measurements from Withings/Nokia Health

• "Then" action is "Make a web request" from the Web Hooks service

  • URL: wherever you're hosting the Flask app
  • Method: POST
  • Content Type: application/json
  • Body:

{ "weightkg" : {{WeightKg}} }

Run the server

Testing

You can run the Flask dev server for testing:

FLASK_APP=flask_listener.py flask run --host 0.0.0.0

By default this listens on port 5000. Refer to the (Flask docs)[http://flask.pocoo.org/docs/1.0/server/] for more.

Production

Consult your hosting environment documentation.

Limitations & Considerations

• Single user is hard-coded
• POSTs are not authenticated
• No other security, really. Use at your own risk.
• What error checking?
• FatSecret API free tier is limited to 5000 calls/day (not really a problem for a single-user deployment :)

Future Work

• Deploy to AWS Lambda (probably via Zappa)
• Enable multi-user support
• Remove dependency on IFTTT
  • Or build an actual IFTTT service

Contributing

Feel free to fork this repo and send me pull requests.