dwollav2 2.3.0

Official Dwolla V2 API client

Dwolla SDK for Python

This repository contains the source code for Dwolla's Python-based SDK, which allows developers to interact with Dwolla's server-side API via a Python API. Any action that can be performed via an HTTP request can be made using this SDK when executed within a server-side environment.

Table of Contents

• Getting Started
  • Installation
  • Initialization
    • Tokens
• Making Requests
  • Low-level Requests
    • Setting Headers
    • Responses
      • Success
      • Error
  • Example App
• Changelog
• Community
• Additional Resources

Getting Started

Installation

To begin using this SDK, you will first need to download it to your machine. We use PyPi to distribute this package from where you can automagically download it via pip.

$ pip install dwollav2

Initialization

Before any API requests can be made, you must first determine which environment you will be using, as well as fetch the application key and secret. To fetch your application key and secret, please visit one of the following links:

• Production: https://dashboard.dwolla.com/applications
• Sandbox: https://dashboard-sandbox.dwolla.com/applications

Finally, you can create an instance of Client with key and secret replaced with the application key and secret that you fetched from one of the aforementioned links, respectively.

client = dwollav2.Client(
  key = os.environ['DWOLLA_APP_KEY'],
  secret = os.environ['DWOLLA_APP_SECRET'],
  environment = 'sandbox', # defaults to 'production'
  requests = {'timeout': 0.001}
)

Configure an on_grant callback (optional)

An on_grant callback is useful for storing new tokens when they are granted. The on_grant callback is called with the Token that was just granted by the server.

client = dwollav2.Client(
  key = os.environ['DWOLLA_APP_KEY'],
  secret = os.environ['DWOLLA_APP_SECRET'],
  on_grant = lambda t: save(t)
)

It is highly recommended that you encrypt any token data you store.

Tokens

Generating New Access Tokens

Application access tokens are used to authenticate against the API on behalf of an application. Application tokens can be used to access resources in the API that either belong to the application itself (webhooks, events, webhook-subscriptions) or the Dwolla Account that owns the application (accounts, customers, funding-sources, etc.). Application tokens are obtained by using the client_credentials OAuth grant type:

application_token = client.Auth.client()

Application access tokens are short-lived: 1 hour. They do not include a refresh_token. When it expires, generate a new one using client.Auth.client().

Initializing Pre-Existing Tokens:

The Dwolla Sandbox Dashboard allows you to generate tokens for your application. A Token can be initialized with the following attributes:

client.Token(access_token = '...',
             expires_in = 123)

Making Requests

Once you've created a Token, currently, you can make low-level HTTP requests.

Low-level Requests

To make low-level HTTP requests, you can use the get(), post(), and delete() methods. These methods will return a Response object.

GET

# GET api.dwolla.com/resource?foo=bar
token.get('resource', foo = 'bar')

# GET requests can also use objects as parameters
# GET api.dwolla.com/resource?foo=bar
token.get('resource', {'foo' = 'bar', 'baz' = 'foo'})

POST

# POST api.dwolla.com/resource {"foo":"bar"}
token.post('resource', foo = 'bar')

# POST api.dwolla.com/resource multipart/form-data foo=...
token.post('resource', foo = ('mclovin.jpg', open('mclovin.jpg', 'rb'), 'image/jpeg'))

DELETE

# DELETE api.dwolla.com/resource
token.delete('resource')

Setting headers

To set additional headers on a request you can pass a dict of headers as the 3rd argument.

For example:

token.post('customers', { 'firstName': 'John', 'lastName': 'Doe', 'email': '[e-mail]' },
                        { 'Idempotency-Key': 'a52fcf63-0730-41c3-96e8-7147b5d1fb01' })

Responses

The following snippets demonstrate successful and errored responses from the Dwolla API.

An errored response is returned when Dwolla's servers respond with a status code that is greater than or equal to 400, whereas a successful response is when Dwolla's servers respond with a 200-level status code.

Success

res = token.get('/')

res.status
# => 200

res.headers
# => {'server'=>'cloudflare-nginx', 'date'=>'Mon, 28 Mar 2016 15:30:23 GMT', 'content-type'=>'application/vnd.dwolla.v1.hal+json; charset=UTF-8', 'content-length'=>'150', 'connection'=>'close', 'set-cookie'=>'__cfduid=d9dcd0f586c166d36cbd45b992bdaa11b1459179023; expires=Tue, 28-Mar-17 15:30:23 GMT; path=/; domain=.dwolla.com; HttpOnly', 'x-request-id'=>'69a4e612-5dae-4c52-a6a0-2f921e34a88a', 'cf-ray'=>'28ac1f81875941e3-MSP'}

res.body['_links']['events']['href']
# => 'https://api-sandbox.dwolla.com/events'

Error

If the server returns an error, a dwollav2.Error (or one of its subclasses) will be raised. dwollav2.Errors are similar to Responses.

try:
  token.get('/not-found')
except dwollav2.NotFoundError as e:
  e.status
  # => 404

  e.headers
  # => {"server"=>"cloudflare-nginx", "date"=>"Mon, 28 Mar 2016 15:35:32 GMT", "content-type"=>"application/vnd.dwolla.v1.hal+json; profile=\"http://nocarrier.co.uk/profiles/vnd.error/\"; charset=UTF-8", "content-length"=>"69", "connection"=>"close", "set-cookie"=>"__cfduid=da1478bfdf3e56275cd8a6a741866ccce1459179332; expires=Tue, 28-Mar-17 15:35:32 GMT; path=/; domain=.dwolla.com; HttpOnly", "access-control-allow-origin"=>"*", "x-request-id"=>"667fca74-b53d-43db-bddd-50426a011881", "cf-ray"=>"28ac270abca64207-MSP"}

  e.body.code
  # => "NotFound"
except dwollav2.Error:
  # ...

dwollav2.Error subclasses:

See https://developers.dwolla.com/api-reference#errors for more info.

• dwollav2.AccessDeniedError
• dwollav2.InvalidCredentialsError
• dwollav2.NotFoundError
• dwollav2.BadRequestError
• dwollav2.InvalidGrantError
• dwollav2.RequestTimeoutError
• dwollav2.ExpiredAccessTokenError
• dwollav2.InvalidRequestError
• dwollav2.ServerError
• dwollav2.ForbiddenError
• dwollav2.InvalidResourceStateError
• dwollav2.TemporarilyUnavailableError
• dwollav2.InvalidAccessTokenError
• dwollav2.InvalidScopeError
• dwollav2.UnauthorizedClientError
• dwollav2.InvalidAccountStatusError
• dwollav2.InvalidScopesError
• dwollav2.UnsupportedGrantTypeError
• dwollav2.InvalidApplicationStatusError
• dwollav2.InvalidVersionError
• dwollav2.UnsupportedResponseTypeError
• dwollav2.InvalidClientError
• dwollav2.MethodNotAllowedError
• dwollav2.ValidationError
• dwollav2.TooManyRequestsError
• dwollav2.ConflictError

Example App

Take a look at the Sample Application for examples on how to use this SDK to call the Dwolla API. Before you can begin using the app, however, you will need to specify a DWOLLA_APP_KEY and DWOLLA_APP_SECRET environment variable.

Changelog

• 2.3.0
  • Remove hidden dependency on simplejson. Replace conditional simplejson import with explicit DecimalEncoder using standard library json module for consistent cross-environment behavior. Fixes #55. (#56 - Thanks @robotadam!)
  • Update test suite from unittest2 to standard library unittest for modern Python compatibility. (#54 - Thanks @robotadam!)
  • Remove unused future dependency for cleaner dependency management. Fixes #52. (#53 Thanks @robotadam!)
  • Add UpdateCredentialsError class for handling credential update scenarios in Open Banking integrations. Developers can now catch specific UpdateCredentialsError exceptions instead of generic Error when exchange sessions need re-authentication. Fixes #50
• 2.2.1
  • Add extra check in URL's to ensure they are clean. #36.
• 2.2.0
  • Update JSON request bodies to serialize via simplejson so datatypes like Decimal still serialize like they did pre 2.0.0
• 2.1.0
  • Do not share requests.session() across instances of dwollav2.Client
• 2.0.0
  • JSON request bodies now contain sorted keys to ensure the same request body for a given set of arguments, no matter the order they are passed to dwolla.post. This ensures the Idempotency-Key header will work as intended without additional effort by developers.
  • NOTE: Because this change alters the formatting of JSON request bodies, we are releasing it as a major new version. The request body of a request made with 1.6.0 will not match the request body of the same request made in 2.0.0. This will nullify the effect of the Idempotency-Key header when upgrading, so please take this into account. If you have any questions please reach out to us! There are no other changes since 1.6.0.
• 1.6.0 Allow configuration of requests options on dwollav2.Client.
• 1.5.0 Add integrations auth functionality
• 1.4.0 Pass kwargs from get, post, and delete methods to underlying requests methods. (Removed in v1.6)
• 1.3.0 Change token URLs, update dependencies.
• 1.2.4 Create a new session for each Token.
• 1.2.3 Check if IOBase when checking to see if something is a file.
• 1.2.2 Strip domain from URLs provided to token.* methods.
• 1.2.1 Update sandbox URLs from uat => sandbox.
• 1.2.0 Refer to Client id as key.
• 1.1.8 Support verified_account and dwolla_landing auth flags
• 1.1.7 Use session over connections for performance improvement (#8 - Thanks @bfeeser!
• 1.1.5 Fix file upload bug when using with Python 2 (#6)
• 1.1.2 Add TooManyRequestsError and ConflictError
• 1.1.1 Add MANIFEST.in
• 1.1.0 Support per-request headers

Community

• If you have any feedback, please reach out to us on our forums or by creating a GitHub issue.
• If you would like to contribute to this library, bug reports and pull requests are always appreciated!
  • After checking out the repo, run pip install -r requirements.txt to install dependencies. Then, run python setup.py test to run the tests.
  • To install this gem onto your local machine, run pip install -e ..

Docker

If you prefer to use Docker to run dwolla-v2-python locally, a Dockerfile is included at the root directory. Follow these instructions from Docker's website to create a Docker image from the Dockerfile, and run it.

Additional Resources

To learn more about Dwolla and how to integrate our product with your application, please consider visiting the following resources and becoming a member of our community!

• Dwolla
• Dwolla Developers
• SDKs and Tools
  • Dwolla SDK for C#
  • Dwolla SDK for Kotlin
  • Dwolla SDK for Node
  • Dwolla SDK for PHP
  • Dwolla SDK for Ruby
• Developer Support Forum