diff --git a/.rubocop.yml b/.rubocop.yml
index bfef2d0..8d1fdd3 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.4
+  TargetRubyVersion: 2.7
 
 Style/StringLiterals:
   Enabled: true
diff --git a/lib/uid2.rb b/lib/uid2.rb
index c0bf4be..335ca83 100644
--- a/lib/uid2.rb
+++ b/lib/uid2.rb
@@ -1,8 +1,4 @@
 # frozen_string_literal: true
 
 require_relative "uid2/version"
-
-module Uid2
-  class Error < StandardError; end
-  # Your code goes here...
-end
+require_relative "uid2/client"
diff --git a/lib/uid2/client.rb b/lib/uid2/client.rb
index e69de29..1fb74cf 100644
--- a/lib/uid2/client.rb
+++ b/lib/uid2/client.rb
@@ -0,0 +1,104 @@
+# frozen_string_literal: true
+
+require "net/http/persistent"
+require "faraday"
+require "faraday_middleware"
+require "time"
+
+module Uid2
+  class Client
+    attr_accessor :bearer_token, :base_url
+
+    def initialize(_options = {})
+      yield(self) if block_given?
+
+      self.base_url ||= "https://integ.uidapi.com/v1/"
+    end
+
+    def generate_token(email: nil, email_hash: nil)
+      raise ArgumentError, "Either email or email_hash needs to be provided" if email.nil? && email_hash.nil?
+
+      # As stated in doc, if email and email_hash are both supplied in the same request,
+      # only the email will return a mapping response.
+      params = if email.empty?
+                 { email_hash: email_hash }
+               else
+                 { email: email }
+               end
+      http.get("token/generate", params).body
+    end
+
+    def validate_token(token:, email: nil, email_hash: nil)
+      raise ArgumentError, "Either email or email_hash needs to be provided" if email.nil? && email_hash.nil?
+
+      params = if email.empty?
+                 { email_hash: email_hash }
+               else
+                 { email: email }
+               end
+
+      http.get("token/validate", params.merge(token: token)).body
+    end
+
+    def refresh_token(refresh_token:)
+      http.get("token/refresh", { refresh_token: refresh_token }).body
+    end
+
+    def get_salt_buckets(since: Time.now)
+      # By default, Ruby's iso8601 generates timezone parts (`T`)
+      # which needs to be removed for UID2 APIs
+      http.get("identity/buckets", since_timestamp: since.utc.iso8601[0..-2]).body
+    end
+
+    def generate_identifier(email: nil, email_hash: nil)
+      raise ArgumentError, "Either email or email_hash needs to be provided" if email.nil? && email_hash.nil?
+
+      # As stated in doc, if email and email_hash are both supplied in the same request,
+      # only the email will return a mapping response.
+      params = if email.empty?
+                 { email_hash: email_hash }
+               else
+                 { email: email }
+               end
+
+      http.get("identity/map", params).body
+    end
+
+    def batch_generate_identifier(email: nil, email_hash: nil)
+      raise ArgumentError, "Either email or email_hash needs to be provided" if email.nil? && email_hash.nil?
+
+      # As stated in doc, if email and email_hash are both supplied in the same request,
+      # only the email will return a mapping response.
+      params = if email.empty?
+                 { email_hash: Array(email_hash) }
+               else
+                 { email: Array(email) }
+               end
+
+      http.post("identity/map", params).body
+    end
+
+    private
+
+    def credentials
+      {
+        "Authorization" => "Bearer #{bearer_token}"
+      }
+    end
+
+    def http
+      @http ||= Faraday.new(
+        url: base_url,
+        headers: credentials
+      ) do |f|
+        f.request :json
+
+        f.response :raise_error
+        f.response :mashify
+        f.response :json
+
+        f.adapter :net_http_persistent
+      end
+    end
+  end
+end
diff --git a/uid2.gemspec b/uid2.gemspec
index 6d59628..c30fc5b 100644
--- a/uid2.gemspec
+++ b/uid2.gemspec
@@ -8,30 +8,25 @@ Gem::Specification.new do |spec|
   spec.authors       = ["Richard Lee"]
   spec.email         = ["14349+dlackty@users.noreply.github.com"]
 
-  spec.summary       = "TODO: Write a short summary, because RubyGems requires one."
-  spec.description   = "TODO: Write a longer description or delete this line."
-  spec.homepage      = "TODO: Put your gem's website or public repo URL here."
+  spec.summary       = "Ruby API client for Unified ID 2.0"
+  spec.description   = spec.summary
+  spec.homepage      = "https://github.com/polydice/uid2"
   spec.license       = "MIT"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.4.0")
-
-  spec.metadata["allowed_push_host"] = "TODO: Set to 'http://mygemserver.com'"
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.7.0")
 
   spec.metadata["homepage_uri"] = spec.homepage
-  spec.metadata["source_code_uri"] = "TODO: Put your gem's public repo URL here."
-  spec.metadata["changelog_uri"] = "TODO: Put your gem's CHANGELOG.md URL here."
+  spec.metadata["source_code_uri"] = spec.homepage
+  spec.metadata["changelog_uri"] = "https://github.com/polydice/uid2/blob/master/CHANGELOG.md"
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
   spec.files = Dir.chdir(File.expand_path(__dir__)) do
-    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{\A(?:test|spec|features)/}) }
+    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{\A(?:spec|features)/}) }
   end
-  spec.bindir        = "exe"
-  spec.executables   = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  # Uncomment to register a new dependency of your gem
-  # spec.add_dependency "example-gem", "~> 1.0"
-
-  # For more information and examples about making a new gem, checkout our
-  # guide at: https://bundler.io/guides/creating_gem.html
+  spec.add_dependency "faraday", ">= 1"
+  spec.add_dependency "faraday_middleware", ">= 1"
+  spec.add_dependency "hashie", ">= 4"
+  spec.add_dependency "net-http-persistent", ">= 4"
 end