Anissa  Barrows

Anissa Barrows


DropboxApi: Ruby Client Library for Dropbox API V2


Library for communicating with Dropbox API v2.


Add this line to your application's Gemfile:

gem 'dropbox_api'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dropbox_api


Please, refer to this gem's custom Dropbox API documentation. Most of the time you'll be checking the available endpoints.

Unfortunately, the documentation at is disrecommended because it lacks some nice features that have been added with YARD plugins:

  • Each endpoint includes its tests right below the description, this works as an example of its usage.
  • All endpoints are shown as methods of the Client class, just as you will use them.

Basic set up

Authorize your application

Dropbox uses OAuth, in order to use this library from your application you'll have to get an authorization code.

Once you have it, just pass it on client initialization:"VofXAX8D...")
#=> #<DropboxApi::Client ...>

Or set it as an ENV variable called DROPBOX_OAUTH_BEARER, for example:

#=> #<DropboxApi::Client ...>

The official documentation on the process to get an authorization code is here, it describes the two options listed below.

Option A: Get your access token from the website

For a quick test, you can obtain an access token from the App Console in Dropbox's website. Select from My apps your application, you may need to create one if you haven't done so yet. Under your application settings, find section OAuth 2, there is a button to generate an access token.

Option B: OAuth2 Code Flow

This is typically what you will use in production, you can obtain an authorization code with a 3-step process:

# 1. Get an authorization URL.
authenticator =, CLIENT_SECRET)
authenticator.auth_code.authorize_url #=> ""

# 2. Log into Dropbox and authorize your app. You need to open the
# authorization URL in your browser.

# 3. Exchange the authorization code for a reusable access token (not visible
#    to the user).
access_token = authenticator.auth_code.get_token(CODE) #=> #<OAuth2::AccessToken ...>`
access_token.token #=> "VofXAX8D..."

# Keep this token, you'll need it to initialize a `DropboxApi::Client` object:
client = access_token)

# For backwards compatibility, the following also works:
client =

Integration with Rails

If you have a Rails application, you might be interested in this setup guide.

Using refresh tokens

Access tokens are short-lived by default (as of September 30th, 2021), applications that require long-lived access to the API without additional interaction with the user should use refresh tokens.

The process is similar but a token refresh might seamlessly occur as you perform API calls. When this happens you'll need to store the new token hash if you want to continue using this session, you can use the on_token_refreshed callback to do this.

# 1. Get an authorization URL, requesting offline access type.
authenticator =, CLIENT_SECRET)
authenticator.auth_code.authorize_url(token_access_type: 'offline')

# 2. Log into Dropbox and authorize your app. You need to open the
#    authorization URL in your browser.

# 3. Exchange the authorization code for a reusable access token
access_token = authenticator.auth_code.get_token(CODE) #=> #<OAuth2::AccessToken ...>`

# You can now use the access token to initialize a DropboxApi::Client, you
# should also provide a callback function to store the updated access token
# whenever it's refreshed.
client =
  access_token: access_token,
  on_token_refreshed: lambda { |new_token_hash|
    # token_hash is a serializable Hash, something like this:
    # {
    #   "uid"=>"440",
    #   "token_type"=>"bearer",
    #   "scope"=>" account_info.write...",
    #   "account_id"=>"dbid:AABOLtA1rT6rRK4vajKZ...",
    #   :access_token=>"sl.A5Ez_CBsqJILhDawHlmXSoZEhLZ4nuLFVRs6AJ...",
    #   :refresh_token=>"iMg4Me_oKYUAAAAAAAAAAapQixCgwfXOxuubCuK_...",
    #   :expires_at=>1632948328
    # }

Once you've gone through the process above, you can skip the steps that require user interaction in subsequent initializations of DropboxApi::Client. For example:

# 1. Initialize an authenticator
authenticator =, CLIENT_SECRET)

# 2. Retrieve the token hash you previously stored somewhere safe, you can use
#    it to build a new access token.
access_token = OAuth2::AccessToken.from_hash(authenticator, token_hash)

# 3. You now have an access token, so you can initialize a client like you
#    would normally:
client =
  access_token: access_token,
  on_token_refreshed: lambda { |new_token_hash|

Performing API calls

Once you've initialized a client, for example:

client ="VofXAX8D...")
#=> #<DropboxApi::Client ...>

You can perform an API call like this:

result = client.list_folder "/sample_folder"
#=> #<DropboxApi::Results::ListFolderResult>
#=> [#<DropboxApi::Metadata::Folder>, #<DropboxApi::Metadata::File>]
#=> false

The instance of Client we've initialized is the one you'll be using to perform API calls. You can check the class' documentation to find all available endpoints.

Large file uploads

If you need to upload files larger than 150MB the default #upload endpoint won't work. Instead, you need to start a upload session and upload the file in small chunks.

To make this easier, the method upload_by_chunks will handle this for you, example:

client ="VofXAX8D...")
#=> #<DropboxApi::Client ...>"large_file.avi") do |f|
  client.upload_by_chunks "/remote_path.txt", f

Check out the method documentation to find out all available options.

Accessing Team Folders

In order to access your team scope you need to add the namespace_id to you request headers. This can be done using the middlewere layer as per the below:

client ="VofXAX8D...")
#=> #<DropboxApi::Client ...>
client.namespace_id = client.get_current_account.root_info.root_namespace_id

#=> Now returns the team folders

You could unset the namespace ID at any point afterwards with just:

client.namespace_id = nil


This gem depends on oauth2 and faraday.

It has official support for Ruby versions 2.x.


After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment.


I recommend you to use a test account other than your main one.

We use VCR to record the HTTP calls to Dropbox, however we sometimes need to regenerate the cassettes. Let's take list_folder as an example to show what would be the procedure to do so:

Manually delete the existing cassettes in spec/fixtures/vcr_cassettes/list_folder/*.yml.

Run the task to build the scaffolding in your Dropbox account so the tests will pass. If it doesn't exist you may need to write it yourself, check the DropboxScaffoldBuilder class to find all existing scaffold builders.

DROPBOX_OAUTH_BEARER=YOUR_AUTH_BEARER rake test:build_scaffold[list_folder]

Note that you'll have to type rake test:build_scaffold\[list_folder\] if you use zsh.

You can build all available scaffolds with just rake test:build_scaffold.

Run the tests and the cassettes will be written:

DROPBOX_OAUTH_BEARER=YOUR_AUTH_BEARER rspec spec/endpoints/files/list_folder_spec.rb

The OAuth bearer shouldn't have been recorded in the cassette and it should've been filtered. However, you may want to double check before pushing your updates to Github.

Tip: you can simply run export DROPBOX_OAUTH_BEARER=YOUR_AUTH_BEARER at the beginning of your work session so you don't need to prefix it in every command line.


Any help will be much appreciated. The easiest way to help is to implement one or more of the endpoints that are still pending. To see how the endpoints are implemented, check out the lib/dropbox_api/endpoints folder.

Author: Jesus
Source code:
License: MIT license


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DropboxApi: Ruby Client Library for Dropbox API V2

Top 10 API Security Threats Every API Team Should Know

As more and more data is exposed via APIs either as API-first companies or for the explosion of single page apps/JAMStack, API security can no longer be an afterthought. The hard part about APIs is that it provides direct access to large amounts of data while bypassing browser precautions. Instead of worrying about SQL injection and XSS issues, you should be concerned about the bad actor who was able to paginate through all your customer records and their data.

Typical prevention mechanisms like Captchas and browser fingerprinting won’t work since APIs by design need to handle a very large number of API accesses even by a single customer. So where do you start? The first thing is to put yourself in the shoes of a hacker and then instrument your APIs to detect and block common attacks along with unknown unknowns for zero-day exploits. Some of these are on the OWASP Security API list, but not all.

Insecure pagination and resource limits

Most APIs provide access to resources that are lists of entities such as /users or /widgets. A client such as a browser would typically filter and paginate through this list to limit the number items returned to a client like so:

First Call: GET /items?skip=0&take=10 
Second Call: GET /items?skip=10&take=10

However, if that entity has any PII or other information, then a hacker could scrape that endpoint to get a dump of all entities in your database. This could be most dangerous if those entities accidently exposed PII or other sensitive information, but could also be dangerous in providing competitors or others with adoption and usage stats for your business or provide scammers with a way to get large email lists. See how Venmo data was scraped

A naive protection mechanism would be to check the take count and throw an error if greater than 100 or 1000. The problem with this is two-fold:

  1. For data APIs, legitimate customers may need to fetch and sync a large number of records such as via cron jobs. Artificially small pagination limits can force your API to be very chatty decreasing overall throughput. Max limits are to ensure memory and scalability requirements are met (and prevent certain DDoS attacks), not to guarantee security.
  2. This offers zero protection to a hacker that writes a simple script that sleeps a random delay between repeated accesses.
skip = 0
while True:    response ='' + skip),                      headers={'Authorization': 'Bearer' + ' ' + sys.argv[1]})    print("Fetched 10 items")    sleep(randint(100,1000))    skip += 10

How to secure against pagination attacks

To secure against pagination attacks, you should track how many items of a single resource are accessed within a certain time period for each user or API key rather than just at the request level. By tracking API resource access at the user level, you can block a user or API key once they hit a threshold such as “touched 1,000,000 items in a one hour period”. This is dependent on your API use case and can even be dependent on their subscription with you. Like a Captcha, this can slow down the speed that a hacker can exploit your API, like a Captcha if they have to create a new user account manually to create a new API key.

Insecure API key generation

Most APIs are protected by some sort of API key or JWT (JSON Web Token). This provides a natural way to track and protect your API as API security tools can detect abnormal API behavior and block access to an API key automatically. However, hackers will want to outsmart these mechanisms by generating and using a large pool of API keys from a large number of users just like a web hacker would use a large pool of IP addresses to circumvent DDoS protection.

How to secure against API key pools

The easiest way to secure against these types of attacks is by requiring a human to sign up for your service and generate API keys. Bot traffic can be prevented with things like Captcha and 2-Factor Authentication. Unless there is a legitimate business case, new users who sign up for your service should not have the ability to generate API keys programmatically. Instead, only trusted customers should have the ability to generate API keys programmatically. Go one step further and ensure any anomaly detection for abnormal behavior is done at the user and account level, not just for each API key.

Accidental key exposure

APIs are used in a way that increases the probability credentials are leaked:

  1. APIs are expected to be accessed over indefinite time periods, which increases the probability that a hacker obtains a valid API key that’s not expired. You save that API key in a server environment variable and forget about it. This is a drastic contrast to a user logging into an interactive website where the session expires after a short duration.
  2. The consumer of an API has direct access to the credentials such as when debugging via Postman or CURL. It only takes a single developer to accidently copy/pastes the CURL command containing the API key into a public forum like in GitHub Issues or Stack Overflow.
  3. API keys are usually bearer tokens without requiring any other identifying information. APIs cannot leverage things like one-time use tokens or 2-factor authentication.

If a key is exposed due to user error, one may think you as the API provider has any blame. However, security is all about reducing surface area and risk. Treat your customer data as if it’s your own and help them by adding guards that prevent accidental key exposure.

How to prevent accidental key exposure

The easiest way to prevent key exposure is by leveraging two tokens rather than one. A refresh token is stored as an environment variable and can only be used to generate short lived access tokens. Unlike the refresh token, these short lived tokens can access the resources, but are time limited such as in hours or days.

The customer will store the refresh token with other API keys. Then your SDK will generate access tokens on SDK init or when the last access token expires. If a CURL command gets pasted into a GitHub issue, then a hacker would need to use it within hours reducing the attack vector (unless it was the actual refresh token which is low probability)

Exposure to DDoS attacks

APIs open up entirely new business models where customers can access your API platform programmatically. However, this can make DDoS protection tricky. Most DDoS protection is designed to absorb and reject a large number of requests from bad actors during DDoS attacks but still need to let the good ones through. This requires fingerprinting the HTTP requests to check against what looks like bot traffic. This is much harder for API products as all traffic looks like bot traffic and is not coming from a browser where things like cookies are present.

Stopping DDoS attacks

The magical part about APIs is almost every access requires an API Key. If a request doesn’t have an API key, you can automatically reject it which is lightweight on your servers (Ensure authentication is short circuited very early before later middleware like request JSON parsing). So then how do you handle authenticated requests? The easiest is to leverage rate limit counters for each API key such as to handle X requests per minute and reject those above the threshold with a 429 HTTP response. There are a variety of algorithms to do this such as leaky bucket and fixed window counters.

Incorrect server security

APIs are no different than web servers when it comes to good server hygiene. Data can be leaked due to misconfigured SSL certificate or allowing non-HTTPS traffic. For modern applications, there is very little reason to accept non-HTTPS requests, but a customer could mistakenly issue a non HTTP request from their application or CURL exposing the API key. APIs do not have the protection of a browser so things like HSTS or redirect to HTTPS offer no protection.

How to ensure proper SSL

Test your SSL implementation over at Qualys SSL Test or similar tool. You should also block all non-HTTP requests which can be done within your load balancer. You should also remove any HTTP headers scrub any error messages that leak implementation details. If your API is used only by your own apps or can only be accessed server-side, then review Authoritative guide to Cross-Origin Resource Sharing for REST APIs

Incorrect caching headers

APIs provide access to dynamic data that’s scoped to each API key. Any caching implementation should have the ability to scope to an API key to prevent cross-pollution. Even if you don’t cache anything in your infrastructure, you could expose your customers to security holes. If a customer with a proxy server was using multiple API keys such as one for development and one for production, then they could see cross-pollinated data.

#api management #api security #api best practices #api providers #security analytics #api management policies #api access tokens #api access #api security risks #api access keys

Autumn  Blick

Autumn Blick


Public ASX100 APIs: The Essential List

We’ve conducted some initial research into the public APIs of the ASX100 because we regularly have conversations about what others are doing with their APIs and what best practices look like. Being able to point to good local examples and explain what is happening in Australia is a key part of this conversation.


The method used for this initial research was to obtain a list of the ASX100 (as of 18 September 2020). Then work through each company looking at the following:

  1. Whether the company had a public API: this was found by googling “[company name] API” and “[company name] API developer” and “[company name] developer portal”. Sometimes the company’s website was navigated or searched.
  2. Some data points about the API were noted, such as the URL of the portal/documentation and the method they used to publish the API (portal, documentation, web page).
  3. Observations were recorded that piqued the interest of the researchers (you will find these below).
  4. Other notes were made to support future research.
  5. You will find a summary of the data in the infographic below.


With regards to how the APIs are shared:

#api #api-development #api-analytics #apis #api-integration #api-testing #api-security #api-gateway

An API-First Approach For Designing Restful APIs | Hacker Noon

I’ve been working with Restful APIs for some time now and one thing that I love to do is to talk about APIs.

So, today I will show you how to build an API using the API-First approach and Design First with OpenAPI Specification.

First thing first, if you don’t know what’s an API-First approach means, it would be nice you stop reading this and check the blog post that I wrote to the Farfetchs blog where I explain everything that you need to know to start an API using API-First.

Preparing the ground

Before you get your hands dirty, let’s prepare the ground and understand the use case that will be developed.


If you desire to reproduce the examples that will be shown here, you will need some of those items below.

  • NodeJS
  • OpenAPI Specification
  • Text Editor (I’ll use VSCode)
  • Command Line

Use Case

To keep easy to understand, let’s use the Todo List App, it is a very common concept beyond the software development community.

#api #rest-api #openai #api-first-development #api-design #apis #restful-apis #restful-api

Marcelle  Smith

Marcelle Smith


What Are Good Traits That Make Great API Product Managers

As more companies realize the benefits of an API-first mindset and treating their APIs as products, there is a growing need for good API product management practices to make a company’s API strategy a reality. However, API product management is a relatively new field with little established knowledge on what is API product management and what a PM should be doing to ensure their API platform is successful.

Many of the current practices of API product management have carried over from other products and platforms like web and mobile, but API products have their own unique set of challenges due to the way they are marketed and used by customers. While it would be rare for a consumer mobile app to have detailed developer docs and a developer relations team, you’ll find these items common among API product-focused companies. A second unique challenge is that APIs are very developer-centric and many times API PMs are engineers themselves. Yet, this can cause an API or developer program to lose empathy for what their customers actually want if good processes are not in place. Just because you’re an engineer, don’t assume your customers will want the same features and use cases that you want.

This guide lays out what is API product management and some of the things you should be doing to be a good product manager.

#api #analytics #apis #product management #api best practices #api platform #api adoption #product managers #api product #api metrics

Autumn  Blick

Autumn Blick


54% of Developers Cite Lack of Documentation as the Top Obstacle to Consuming APIs

Recently, I worked with my team at Postman to field the 2020 State of the API survey and report. We’re insanely grateful to the folks who participated—more than 13,500 developers and other professionals took the survey, helping make this the largest and most comprehensive survey in the industry. (Seriously folks, thank you!) Curious what we learned? Here are a few insights in areas that you might find interesting:

API Reliability

Whether internal, external, or partner, APIs are perceived as reliable—more than half of respondents stated that APIs do not break, stop working, or materially change specification often enough to matter. Respondents choosing the “not often enough to matter” option here came in at 55.8% for internal APIs, 60.4% for external APIs, and 61.2% for partner APIs.

Obstacles to Producing APIs

When asked about the biggest obstacles to producing APIs, lack of time is by far the leading obstacle, with 52.3% of respondents listing it. Lack of knowledge (36.4%) and people (35.1%) were the next highest.

#api #rest-api #apis #api-first-development #api-report #api-documentation #api-reliability #hackernoon-top-story