Django API creation with signed requests utilizing forms for validation.

django, formapi, api, rpc, signed, request, form, validation
pip install django-formapi==0.2.0



Create JSON API:s with HMAC authentication and Django form-validation.


Install django-formapi in your python environment

$ pip install django-formapi

Add formapi to your INSTALLED_APPS setting.


Add formapi.urls to your

urlpatterns = patterns('',
    url(r'^api/', include('formapi.urls')),


Go ahead and create a

class DivisionCall(calls.APICall):
    Returns the quotient of two integers
    dividend = forms.FloatField()
    divisor = forms.FloatField()

    def action(self, test):
        dividend = self.cleaned_data.get('dividend')
        divisor = self.cleaned_data.get('divisor')
        return dividend / divisor

API.register(DivisionCall, 'math', 'divide', version='v1.0.0')

Just create a class like your regular Django Forms but inheriting from APICall. Define the fields that your API-call should receive. The action method is called when your fields have been validated and what is returned will be JSON-encoded as a response to the API-caller. The API.register call takes your APICall-class as first argument, the second argument is the namespace the API-call should reside in, the third argument is the name of your call and the fourth the version. This will result in an url in the form of api/[version]/[namespace]/[call_name]/ so we would get /api/v1.0.0/math/divide/.

A valid call with the parameters {'dividend': 5, 'divisor': 2} would result in this response:

{"errors": {}, "data": 5, "success": true}

An invalid call with the parameters {'dividend': "five", 'divisor': 2} would result in this response:

{"errors": {"dividend": ["Enter a number."]}, "data": false, "success": false}


By default APICalls have HMAC-authentication turned on. Disable it by setting signed_requests = False on your APICall.

If not disabled users of the API will have to sign their calls. To do this they need a secret generate, create a APIKey through the django admin interface. On save a personal secret and key will be generated for the API-user.

To build a call signature for the DivisonCall create a querystring of the calls parameters sorted by the keys dividend=5&divisor=2. Create a HMAC using SHA1 hash function. Example in python:

import hmac
from hashlib import sha1
hmac_sign =, urllib2.quote('dividend=5&divisor=2'), sha1).hexdigest()

A signed request against DivisionCall would have the parameters {'dividend': 5, 'divisor': 2, 'key': generated_key, 'sign': hmac_sign}


Visit /api/discover for a brief documentation of the registered API-calls.