Update documentation

Author: lalithr95

README.md

@@ -1,8 +1,17 @@
 # APIFuzzer
 
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/API_Fuzzer`. To experiment with that code, run `bin/console` for an interactive prompt.
-
-TODO: Delete this and the text above, and describe your gem
+`API_Fuzzer` gem accepts a API request as input and returns vulnerabilities possible in the API. Following are the main check involved in API_Fuzzer gem
+
+- Cross-site scripting vulnerability
+- SQL injection
+- Blind SQL injection
+- XML External entity vulnerability
+- IDOR (in specific cases)
+- API Rate Limiting
+- Open redirect vulnerabilities
+- Information Disclosure flaws
+- Info leakage through headers
+- Cross-site request forgery vulnerability
 
 ## Installation
 
@@ -22,14 +31,54 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+Run `bin/console`
+
+Lets say you have following endpoint
+
+```
+POST /api/v2/credit_cards/123
+
+Host: test.host.com
+User-Agent: Mozilla Firefox
+Auth: Basic Adnjefnef443nr4jh4h
+{ credit_card: '4242424242424242', expiry: '07/17', cvv: '123', name: 'First name' }
+```
+
+API_Fuzzer module comes with static method `scan` and accepts above request
+```ruby
+require 'API_Fuzzer'
+
+options = {
+  url: 'http://test.host.com/api/v2/credit_cards/123',
+  params: {
+    credit_card: '4242424242424242',
+    expiry: '07/17',
+    cvv: '123',
+    name: 'First name'
+  },
+  method: ['POST'],
+  headers: {
+    'Host' => 'test.host.com',
+    'User-Agent' => 'Mozilla Firefox',
+    'Auth' => 'Basic Adnjefnef443nr4jh4h'
+  }
+}
+vulnerabilities = API_Fuzzer.scan(options)
+```
+`vulnerabilites` is an array of vulnerability, each distinguished with impact type, title and description.
+
+
+Above Ruby code can be painful for writing ruby script for each request. [Fuzzapi](https://github.com/lalithr95/Fuzzapi) is a rails application which integrates and bundles API_Fuzzer and brings UI changes to easily scan API endpoints.
 
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
 
+If you have any issue, we would be happy to help. You can create an issue in repository or contact any of following twitter handles
+@abhijeth, @srini0x00, @lalithr95 
+
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/API_Fuzzer. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.