diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 00000000..40c88a7b
Binary files /dev/null and b/.DS_Store differ
diff --git a/.gitignore b/.gitignore
index 8d6a243f..bd0ea0a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 *.rbc
 /.config
 /coverage/
+*/coverage/
 /InstalledFiles
 /pkg/
 /spec/reports/
@@ -11,7 +12,7 @@
 /tmp/
 
 # Used by dotenv library to load environment variables.
-# .env
+.env
 
 ## Specific to RubyMotion:
 .dat*
@@ -54,3 +55,5 @@ build-iPhoneSimulator/
 
 # Ignore cassette files
 /specs/cassettes/
+
+.vscode
\ No newline at end of file
diff --git a/lib/.DS_Store b/lib/.DS_Store
new file mode 100644
index 00000000..c2638d5c
Binary files /dev/null and b/lib/.DS_Store differ
diff --git a/lib/channel.rb b/lib/channel.rb
new file mode 100644
index 00000000..f203188c
--- /dev/null
+++ b/lib/channel.rb
@@ -0,0 +1,49 @@
+require 'dotenv'
+require 'httparty'
+require 'table_print'
+require_relative 'recipient'
+Dotenv.load
+
+module SlackAPI
+  class Channel < Recipient
+        
+  attr_reader :topic, :member_count
+
+  URL = "https://slack.com/api/channels.list"
+  TOKEN = ENV['TOKEN']
+  @@all = []
+
+    def initialize(slack_id:, name:, topic:, member_count:)
+      super(slack_id: slack_id, name: name)
+      @topic = topic
+      @member_count = member_count
+    end
+
+    def details
+    return "Channel name: #{name}
+     Slack ID: #{slack_id}
+     Topic: #{topic}
+     Member count: #{member_count}"
+    end
+
+    def self.list
+      return @@all
+    end
+
+    def self.load
+      query_parameters = {
+        token: TOKEN,
+      }
+      response = HTTParty.get(URL, query: query_parameters)['channels']
+      response.each do |channel|
+        topic = channel['topic']['value']
+        member_count = channel['num_members']
+        slack_id = channel['id']
+        name = channel['name']
+        new_channel = Channel.new(topic: topic, member_count: member_count, slack_id: slack_id, name: name)
+        @@all << new_channel
+      end
+      return @@all
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/recipient.rb b/lib/recipient.rb
new file mode 100644
index 00000000..d62a49f8
--- /dev/null
+++ b/lib/recipient.rb
@@ -0,0 +1,43 @@
+module SlackAPI
+  class Recipient
+
+    attr_reader :slack_id, :name
+    
+    def initialize(slack_id:, name:)
+        @slack_id = slack_id
+        @name = name
+    end
+
+    def send_message(text:)
+      body = {
+        text: text,
+        channel: slack_id,
+        token: ENV["TOKEN"],
+      }
+
+      response = HTTParty.post("https://slack.com/api/chat.postMessage",
+                               body: body,
+                               headers: { "Content-Type" => "application/x-www-form-urlencoded" })
+
+      unless response.code == 200 && response.parsed_response["ok"]
+        raise SlackApiError, "Error when posting #{text} to #{name}, error: #{response.parsed_response["error"]}"
+      end
+
+      return response.code == 200 && response.parsed_response["ok"]
+    end
+
+    def self.load
+      raise NotImplementedError
+    end
+    
+    def details
+      raise NotImplementedError
+    end
+
+    def self.list
+      raise NotImplementedError
+    end
+
+  end
+
+end
\ No newline at end of file
diff --git a/lib/slack.rb b/lib/slack.rb
index 960cf2f7..911b683e 100755
--- a/lib/slack.rb
+++ b/lib/slack.rb
@@ -1,10 +1,85 @@
 #!/usr/bin/env ruby
+require 'dotenv'
+require 'httparty'
+require_relative 'channel'
+require_relative 'recipient'
+require_relative 'user'
+require_relative 'workspace'
+Dotenv.load
+
+token = ENV['TOKEN']
 
 def main
-  puts "Welcome to the Ada Slack CLI!"
+  input = 0
+
+  users = SlackAPI::User.load
+  channels = SlackAPI::Channel.load
+  workspace = SlackAPI::Workspace.new(users: users, channels: channels)
+
+  until input == "G" do
+    puts "Welcome to the Ada Slack CLI!"
+    puts "What would you like to do?"
+    puts "[A] List users"
+    puts "[B] List channels"
+    puts "[C] Select user"
+    puts "[D] Select channel"
+    puts "[E] Show details of selected user / channel"
+    puts "[F] Send message"
+    puts "[G] Quit"
+    input = gets.chomp.upcase
+    valid_input = ["A", "B", "C", "D", "E", "F", "G"]
 
-  # TODO project
+    until valid_input.include?(input)
+      puts "Please try again"
+      input = gets.chomp.upcase
+    end
 
+    case input
+      when "A"
+        tp SlackAPI::User.list
+      when "B"
+        tp SlackAPI::Channel.list
+      when "C"
+        puts "Please supply a slack ID or user name (case sensitive!)"  
+        workspace.selected = nil
+        user_id_or_name = gets.chomp
+        selected = workspace.select_user(id_or_name: user_id_or_name)
+        if selected 
+          puts "Selected user: #{user_id_or_name}"
+        else
+          puts "User not found"
+        end
+      when "D"
+        puts "Please supply a slack ID or channel name (case sensitive!)"
+        workspace.selected = nil
+        chan_id_or_name = gets.chomp.downcase
+        workspace.select_channel(id_or_name: chan_id_or_name)
+        if selected 
+          puts "Selected channel: #{chan_id_or_name}"
+        else
+          puts "Channel not found"
+        end
+        
+      when "E"
+        if workspace.selected
+          puts workspace.show_details
+        else
+          puts "No recipient selected \n\n"
+        end
+      when "F"
+        if workspace.selected
+          puts "Please type the message you want to send"
+          user_text = gets.chomp
+          if user_text != ""
+            workspace.send_message(text: user_text)
+          else
+            "Message cannot be empty"
+          end
+        else
+          puts "No recipient selected \n\n"
+        end
+    end
+  end
   puts "Thank you for using the Ada Slack CLI"
 end
 
diff --git a/lib/user.rb b/lib/user.rb
new file mode 100644
index 00000000..092f0d8d
--- /dev/null
+++ b/lib/user.rb
@@ -0,0 +1,49 @@
+require "dotenv"
+require "httparty"
+require "table_print"
+require_relative "recipient"
+
+Dotenv.load
+
+module SlackAPI
+  class SlackApiError < StandardError; end
+
+  class User < Recipient
+
+    attr_reader :real_name
+
+    BASE_URL = "https://slack.com/api"
+    USERS_LIST_PATH = "/users.list"
+    CHAT_POST_MESSAGE_PATH = "/chat.postMessage"
+    TOKEN = ENV["TOKEN"]
+    @@all = []
+
+    def initialize(real_name:, slack_id:, name:)
+      super(slack_id: slack_id, name: name)
+      @real_name = real_name
+    end
+
+    def details
+      return "Name: #{name}
+     Slack ID: #{slack_id}
+     Real name: #{real_name}"
+    end
+
+    def self.list
+      return @@all
+    end
+    
+    def self.load
+      query_parameters = { token: TOKEN }
+      response = HTTParty.get(BASE_URL << USERS_LIST_PATH, query: query_parameters)
+      response["members"].length.times do |i|
+        real_name = response["members"][i]["real_name"]
+        slack_id = response["members"][i]["id"]
+        name = response["members"][i]["name"]
+        new_user = SlackAPI::User.new(real_name: real_name, slack_id: slack_id, name: name)
+        @@all.push(new_user)
+      end
+      return @@all
+    end
+  end
+end
diff --git a/lib/workspace.rb b/lib/workspace.rb
new file mode 100644
index 00000000..08ee92d4
--- /dev/null
+++ b/lib/workspace.rb
@@ -0,0 +1,48 @@
+require 'dotenv'
+require 'httparty'
+require 'pry'
+Dotenv.load
+
+module SlackAPI
+  class Workspace
+
+  attr_reader :users, :channels
+  attr_accessor :selected
+
+    def initialize(users:, channels:, selected: nil)
+      @users = users
+      @channels = channels
+      @selected = selected
+    end
+
+    def select_channel(id_or_name:)
+      @channels.each do |channel|
+        if channel.name == id_or_name
+          @selected = channel
+        elsif channel.slack_id == id_or_name
+          @selected = channel
+        end
+      end
+      return @selected
+    end 
+
+    def select_user(id_or_name:)
+      @users.each do |user|
+        if user.name == id_or_name
+          @selected = user
+        elsif user.slack_id == id_or_name
+          @selected = user
+        end
+      end
+      return @selected
+    end
+
+    def show_details
+      @selected.details
+    end
+
+    def send_message(text:)
+      @selected.send_message(text: text)
+    end
+  end
+end
\ No newline at end of file
diff --git a/specs/channel_spec.rb b/specs/channel_spec.rb
new file mode 100644
index 00000000..b44bc343
--- /dev/null
+++ b/specs/channel_spec.rb
@@ -0,0 +1,40 @@
+require 'minitest'
+require_relative 'test_helper.rb'
+
+describe "Channel" do
+  before do
+    VCR.use_cassette("channel_list") do
+      @response = SlackAPI::Channel.load
+    end
+  end
+
+  describe "details" do
+
+  end
+
+  describe "self.list" do
+    it "can list details of all the channels" do
+      expect(SlackAPI::Channel.list).must_be_kind_of Array
+    end
+  end
+
+  describe "self.load" do
+    it "can find the list of channels" do
+      expect(@response).must_be_kind_of Array
+      expect(@response[0]).must_be_kind_of SlackAPI::Channel
+      expect(@response[0].name).must_equal "everyone"
+      expect(@response[0].slack_id).must_equal "CH2SBU69Y"
+      expect(@response[0].topic).must_equal "Company-wide announcements and work-based matters"
+      expect(@response[0].member_count).must_equal 2
+    end
+  end
+
+    it "sends a message to selected channel" do
+      VCR.use_cassette("channel_send_message") do
+        channel = SlackAPI::Channel.list[0]
+        test2 = channel.send_message(text: "hello")
+        expect(test2).must_equal true
+       end
+    end
+
+end
\ No newline at end of file
diff --git a/specs/recipient_spec.rb b/specs/recipient_spec.rb
new file mode 100644
index 00000000..74ff73a3
--- /dev/null
+++ b/specs/recipient_spec.rb
@@ -0,0 +1,20 @@
+require 'minitest'
+require_relative 'test_helper.rb'
+
+describe "Recipient" do
+  before do
+
+  end
+
+  describe "self.get" do
+    
+  end
+
+  describe "details" do
+
+  end
+
+  describe "self.list" do
+    
+  end
+end
\ No newline at end of file
diff --git a/specs/test_helper.rb b/specs/test_helper.rb
index 81ccd06b..2d5ca445 100644
--- a/specs/test_helper.rb
+++ b/specs/test_helper.rb
@@ -7,9 +7,23 @@
 require 'minitest/skip_dsl'
 require 'vcr'
 
+require_relative "../lib/user.rb"
+require_relative "../lib/channel.rb"
+require_relative "../lib/workspace.rb"
+require_relative "../lib/recipient.rb"
+require_relative "../lib/slack.rb"
+
 Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new
 
 VCR.configure do |config|
   config.cassette_library_dir = "specs/cassettes"
   config.hook_into :webmock
+  config.default_cassette_options = {
+    record: :new_episodes,    # record new data when we don't have it yet
+    match_requests_on: [:method, :uri, :body] # The http method, URI and body of a request all need to match
+  }
+  # Don't leave our Slack token lying around in a cassette file.
+  config.filter_sensitive_data("<TOKEN>") do
+    ENV["TOKEN"]
+  end
 end
\ No newline at end of file
diff --git a/specs/user_spec.rb b/specs/user_spec.rb
new file mode 100644
index 00000000..f1d25ce2
--- /dev/null
+++ b/specs/user_spec.rb
@@ -0,0 +1,39 @@
+require 'minitest'
+require_relative 'test_helper.rb'
+
+describe "User" do
+  before do 
+    VCR.use_cassette("load_users") do
+      @response = SlackAPI::User.load
+    end
+  end
+
+  describe "self.load" do
+    it "can find the list of users" do
+          expect(@response).must_be_kind_of Array
+          expect(@response[0]).must_be_kind_of SlackAPI::User
+          expect(@response[0].name).must_equal "slackbot"
+          expect(@response[0].real_name).must_equal "Slackbot"
+          expect(@response[0].slack_id).must_equal "USLACKBOT"
+      end
+  end
+
+  describe "self.list" do
+    it "prints out a table of users" do
+          expect(SlackAPI::User.list).must_be_kind_of Array
+    end
+  end
+
+  describe "send message" do
+    it "sends a message to selected user" do
+      VCR.use_cassette("user_send_message") do
+        user = SlackAPI::User.list[0]
+        test = user.send_message(text: "hello")
+        expect(test).must_equal true
+       end
+    end
+
+  end
+end
+
+
diff --git a/specs/workspace_spec.rb b/specs/workspace_spec.rb
new file mode 100644
index 00000000..f0f1a737
--- /dev/null
+++ b/specs/workspace_spec.rb
@@ -0,0 +1,127 @@
+require 'minitest'
+require_relative 'test_helper.rb'
+
+describe "Workspace" do
+  before do
+    VCR.use_cassette("load_workspace") do
+      response = SlackAPI::User.load
+      response2 = SlackAPI::Channel.load
+      @workspace = SlackAPI::Workspace.new(users: response, channels: response2)
+     end
+  end
+
+  describe "select_user" do
+    it "selects a user when name is provided" do
+      @workspace.select_user(id_or_name:"slackbot")
+      expect(@workspace.selected).must_be_kind_of SlackAPI::User
+      expect(@workspace.selected.name).must_equal "slackbot"
+    end
+
+    it "selects a user when id is provided" do
+      @workspace.select_user(id_or_name:"USLACKBOT")
+      expect(@workspace.selected).must_be_kind_of SlackAPI::User
+      expect(@workspace.selected.slack_id).must_equal "USLACKBOT"
+    end
+  end
+
+  describe "select_channel" do
+    it "returns nil if no user / channel is selected" do
+      expect(@workspace.selected).must_be_nil
+    end
+    
+    it "selects a channel when id is provided" do
+      @workspace.select_channel(id_or_name:"CH2SBU69Y")
+      expect(@workspace.selected).must_be_kind_of SlackAPI::Channel
+      expect(@workspace.selected.slack_id).must_equal "CH2SBU69Y"
+    end
+
+    it "selects a channel when name is provided" do
+      @workspace.select_channel(id_or_name:"everyone")
+      expect(@workspace.selected).must_be_kind_of SlackAPI::Channel
+      expect(@workspace.selected.name).must_equal "everyone"
+    end
+
+    it "returns nil if channel is not found" do
+      @workspace.select_channel(id_or_name:"madeup_channel")
+      expect(@workspace.selected).must_be_nil
+    end
+  end
+  
+  describe "show_details" do
+    it "shows details for a selected user" do
+      @workspace.select_user(id_or_name:"slackbot")
+      expect(@workspace.show_details).must_be_kind_of String
+    end
+
+    it "shows details for a selected channel" do
+      @workspace.select_channel(id_or_name:"everyone")
+      expect(@workspace.show_details).must_be_kind_of String
+    end
+    
+  end
+  
+  describe "send_message" do
+
+    it "will raise an error when given an invalid channel" do
+      bad_channel = SlackAPI::Channel.new(slack_id: "123", name: "bad", topic: "bad", member_count: "1")
+      @workspace.channels.push(bad_channel)
+      @workspace.select_channel(id_or_name:"bad")
+      VCR.use_cassette("send_message_bad_channel") do
+        exception = expect {
+          @workspace.send_message(text:"This post should not work")
+        }.must_raise SlackAPI::SlackApiError
+      end
+      @workspace.channels.pop
+    end
+
+    it "will raise an error when given an invalid user" do
+      bad_user = SlackAPI::User.new(real_name: "baddie", slack_id: "123", name: "baddie")
+      @workspace.users.push(bad_user)
+      @workspace.select_user(id_or_name:"baddie")
+      VCR.use_cassette("send_message_bad_user") do
+        exception = expect {
+          @workspace.send_message(text:"This post should not work")
+        }.must_raise SlackAPI::SlackApiError
+      end
+      @workspace.users.pop
+    end
+    
+    it "will send a message to a channel" do
+      channel = @workspace.channels[0].name
+      @workspace.select_channel(id_or_name: channel)
+      VCR.use_cassette("send_message_to_channel") do
+        response = @workspace.send_message(text:"message to channel!")
+        expect(response).must_equal true
+      end
+    end
+
+    it "will send a message to a user" do
+      user = @workspace.users[0].name
+      @workspace.select_user(id_or_name: user)
+      VCR.use_cassette("send_message_to_user") do
+        response = @workspace.send_message(text:"message to user!")
+        expect(response).must_equal true
+      end
+    end
+
+    it "will send rasie an error for empty text" do
+      user = @workspace.users[0].name
+      @workspace.select_user(id_or_name: user)
+      VCR.use_cassette("send_empty_message_user") do
+        exception = expect {
+          @workspace.send_message(text:"")
+        }.must_raise SlackAPI::SlackApiError
+      end
+    end
+
+    it "it sends message with digits for text" do
+      channel = @workspace.channels[0].name
+      @workspace.select_channel(id_or_name: channel)
+      VCR.use_cassette("send_digit_message_to_channel") do
+        response = @workspace.send_message(text: 123)
+        expect(response).must_equal true
+      end
+    end
+
+  end
+end
\ No newline at end of file