diff --git a/.gitignore b/.gitignore
index 3ff4fada..ba5c552f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 
 # Ignore environemnt variables
 .env
+coverage
diff --git a/lib/channel.rb b/lib/channel.rb
new file mode 100644
index 00000000..48a4be79
--- /dev/null
+++ b/lib/channel.rb
@@ -0,0 +1,37 @@
+require 'httparty'
+require 'prettyprint'
+require 'dotenv'
+
+require_relative 'recipient'
+
+Dotenv.load
+
+class Channel < Recipient
+
+  attr_reader :topic,:member_count
+
+  def initialize(slack_id, name, topic, member_count)
+    super(slack_id, name)
+    @topic = topic
+    @member_count = member_count
+  end
+  def self.list_all
+    channel_url = 'https://slack.com/api/conversations.list'
+    response = self.get(channel_url, query: { token: ENV['SLACK_API_TOKEN']})
+
+    channels = response["channels"]
+
+    list = []
+    channels.each do |channel|
+      list << Channel.new(channel["id"], channel["name"], channel["purpose"]["value"], channel["num_members"])
+    end
+    return list
+  end
+
+  def details
+    return "\n channel name: #{self.name} \n topic: #{self.topic} \n user count: #{self.member_count} \n slack_id: #{self.slack_id}"
+  end
+
+
+end
+
diff --git a/lib/recipient.rb b/lib/recipient.rb
new file mode 100644
index 00000000..3d2e505a
--- /dev/null
+++ b/lib/recipient.rb
@@ -0,0 +1,34 @@
+require 'httparty'
+require 'prettyprint'
+require 'dotenv'
+
+Dotenv.load
+
+class SlackApiError < StandardError; end
+
+class Recipient
+
+  attr_reader :slack_id, :name
+
+  def initialize(slack_id, name)
+    @slack_id = slack_id
+    @name = name
+  end
+
+  def self.get(url, params)
+    return HTTParty.get(url, params)
+  end
+
+  def send_message(message)
+    response = HTTParty.post(
+        "https://slack.com/api/chat.postMessage",
+        body:  {
+            token: ENV['SLACK_API_TOKEN'],
+            text: message,
+            channel: @slack_id
+        })
+    unless response.code == 200 && response.parsed_response["ok"]
+      raise SlackApiError, "Error when posting #{message} to #{@name}, error: #{response.parsed_response["error"]}"
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/slack.rb b/lib/slack.rb
index 8a0b659b..99ece09e 100755
--- a/lib/slack.rb
+++ b/lib/slack.rb
@@ -1,12 +1,110 @@
-#!/usr/bin/env ruby
+
+require 'prettyprint'
+require 'awesome_print'
+require 'httparty'
+require 'dotenv'
+
+Dotenv.load
+
+require_relative 'workspace'
 
 def main
-  puts "Welcome to the Ada Slack CLI!"
+
+  begin
   workspace = Workspace.new
+  rescue SlackApiError => error
+    puts "error occurred: #{error.message}"
+    return
+  end
+
+  puts "\nWelcome to the Ada Slack CLI!"
+  puts "There are #{workspace.users.length} users and #{workspace.channels.length} channels."
+
+  statement = "\nPlease enter one of the following commands:\n• list users\n• list channels\n• select user\n• select channel\n• show details\n• send a message\n• quit\n"
+
+  until false
+
+    puts statement
+    puts "\n"
+    input = gets.chomp.downcase
+
+    begin
+      case input
+      when "list users"
+        puts workspace.list_users
+      when "list channels"
+        puts workspace.list_channels
+
+      when "select channel"
+        puts "Please enter a channel name or ID:"
+        input = gets.chomp
+        workspace.select_channel(input)
 
-  # TODO project
+        until workspace.select_channel(input) != nil
+          puts "Invalid channel #{input}. Please try again."
+          input = gets.chomp
+          workspace.select_channel(input)
+        end
 
-  puts "Thank you for using the Ada Slack CLI"
+        puts "\n Selected channel: #{workspace.selected.name} \n ID: #{workspace.selected.slack_id}"
+        puts " Enter #{"show details"} for more details on #{workspace.selected.name}"
+
+      when "select user"
+        puts "Please enter a username or ID:"
+        input = gets.chomp
+        workspace.select_user(input)
+
+        until workspace.select_user(input) != nil
+          puts "Invalid user #{input}. Please try again."
+          input = gets.chomp
+          workspace.select_user(input)
+        end
+
+        puts "\n Selected user: #{workspace.selected.name} \n ID: #{workspace.selected.slack_id}"
+        puts " Enter #{"show details"} for more details on #{workspace.selected.name}"
+
+      when "show details"
+        if workspace.selected == nil
+          puts "Details for whom? Please enter a user or channel"
+          input = gets.chomp
+          workspace.ask_to_select(input)
+          until workspace.ask_to_select(input) != nil
+            puts "Invalid input #{input}. Please try again."
+            input = gets.chomp
+            workspace.ask_to_select(input)
+          end
+        end
+
+        puts workspace.show_details
+
+      when "send a message"
+        if workspace.selected == nil
+          puts "To whom?"
+          input = gets.chomp
+          workspace.ask_to_select(input)
+          until workspace.ask_to_select(input) != nil
+            puts "Invalid input #{input}. Please try again."
+            input = gets.chomp
+            workspace.ask_to_select(input)
+          end
+        end
+
+        puts "What message would you like to send?"
+        message = gets.chomp.to_s
+        puts workspace.send_message(message)
+        puts "message #{message} sent successfully!"
+
+      when "quit"
+        puts "Thank you for using the Ada Slack CLI"
+        break
+      else
+        puts "Invalid input #{input}"
+      end
+    rescue SlackApiError => error
+      puts "error occurred: #{error.message}"
+    end
+  end
 end
 
-main if __FILE__ == $PROGRAM_NAME
\ No newline at end of file
+
+main if __FILE__ == $PROGRAM_NAME
diff --git a/lib/user.rb b/lib/user.rb
new file mode 100644
index 00000000..de246ab6
--- /dev/null
+++ b/lib/user.rb
@@ -0,0 +1,39 @@
+require 'httparty'
+require 'prettyprint'
+require 'dotenv'
+
+require_relative 'recipient'
+
+Dotenv.load
+
+class User < Recipient
+
+  attr_reader :real_name, :status_text, :status_emoji
+
+  def initialize(slack_id, name, real_name, status_text, status_emoji)
+    super(slack_id, name)
+    @real_name = real_name
+    @status_text = status_text
+    @status_emoji = status_emoji
+  end
+
+  def self.list_all
+    user_url = 'https://slack.com/api/users.list'
+    response = self.get(user_url, query: { token: ENV['SLACK_API_TOKEN']})
+
+    raise ArgumentError.new("invalid request") if response["ok"] == false
+
+    users = response["members"]
+
+    list = []
+    users.each do |user|
+      list << User.new(user["id"], user["name"], user["profile"]["real_name"], user["profile"]["status_text"], user["profile"]["status_emoji"])
+    end
+    return list
+  end
+
+  def details
+    return "\n username: #{self.name} \n real name: #{self.real_name} \n slack ID: #{self.slack_id} \n status: #{self.status_text} \n emoji: #{self.status_emoji}"
+  end
+
+end
\ No newline at end of file
diff --git a/lib/workspace.rb b/lib/workspace.rb
new file mode 100644
index 00000000..ffa3b28e
--- /dev/null
+++ b/lib/workspace.rb
@@ -0,0 +1,64 @@
+require 'httparty'
+require 'dotenv'
+
+require_relative 'user'
+require_relative 'channel'
+
+Dotenv.load
+
+class Workspace
+
+  attr_reader :users,:channels,:selected
+
+  def initialize
+    @users = User.list_all
+    @channels = Channel.list_all
+    @selected = nil
+  end
+
+  def list_users
+    user_data = []
+    @users.each do |user|
+      user_data << user.details
+    end
+    return user_data
+  end
+
+  def list_channels
+    channel_data = []
+    @channels.each do |channel|
+      channel_data << channel.details
+    end
+    return channel_data
+  end
+
+  def select_channel(input)
+    @selected = @channels.find { |channel| input == channel.name || input == channel.slack_id}
+    return @selected
+  end
+
+  def select_user(input)
+    @selected = @users.find { |user| input == user.name || input == user.slack_id}
+    return @selected
+  end
+
+  def ask_to_select(input)
+    select_channel(input)
+    if @selected == nil
+      select_user(input)
+    end
+    return @selected
+  end
+
+  def show_details
+    raise SlackApiError.new("no user or channel selected") if @selected == nil
+    return @selected.details
+  end
+
+  def send_message(message)
+    raise SlackApiError.new("no user or channel selected") if @selected == nil
+    @selected.send_message(message)
+  end
+end
+
+
diff --git a/test/cassettes/channel_send_not_authed.yml b/test/cassettes/channel_send_not_authed.yml
new file mode 100644
index 00000000..a602e196
--- /dev/null
+++ b/test/cassettes/channel_send_not_authed.yml
@@ -0,0 +1,66 @@
+---
+http_interactions:
+- request:
+    method: post
+    uri: https://slack.com/api/chat.postMessage
+    body:
+      encoding: UTF-8
+      string: token=<SLACK_API_TOKEN>&text=This%20post%20should%20not%20work&channel=C01BTVCEXCN
+    headers:
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+      User-Agent:
+      - Ruby
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Fri, 09 Oct 2020 23:42:38 GMT
+      Server:
+      - Apache
+      X-Slack-Req-Id:
+      - f7906d9bd24d64df60e2678a99967159
+      X-Oauth-Scopes:
+      - identify,channels:read,groups:read,im:read,users:read,chat:write
+      Access-Control-Expose-Headers:
+      - x-slack-req-id, retry-after
+      Access-Control-Allow-Origin:
+      - "*"
+      X-Slack-Backend:
+      - r
+      X-Content-Type-Options:
+      - nosniff
+      Expires:
+      - Mon, 26 Jul 1997 05:00:00 GMT
+      Cache-Control:
+      - private, no-cache, no-store, must-revalidate
+      X-Xss-Protection:
+      - '0'
+      X-Accepted-Oauth-Scopes:
+      - chat:write
+      Access-Control-Allow-Headers:
+      - slack-route, x-slack-version-ts, x-b3-traceid, x-b3-spanid, x-b3-parentspanid,
+        x-b3-sampled, x-b3-flags
+      Vary:
+      - Accept-Encoding
+      Pragma:
+      - no-cache
+      Strict-Transport-Security:
+      - max-age=31536000; includeSubDomains; preload
+      Referrer-Policy:
+      - no-referrer
+      Content-Length:
+      - '337'
+      Content-Type:
+      - application/json; charset=utf-8
+      X-Via:
+      - haproxy-www-wtop,haproxy-edge-iad-gqnl
+    body:
+      encoding: ASCII-8BIT
+      string: '{"ok":false,"error":"not_authed"}'
+  recorded_at: Fri, 09 Oct 2020 23:42:38 GMT
+recorded_with: VCR 6.0.0
diff --git a/test/channel_test.rb b/test/channel_test.rb
new file mode 100644
index 00000000..7d8c17aa
--- /dev/null
+++ b/test/channel_test.rb
@@ -0,0 +1,43 @@
+require_relative 'test_helper'
+require_relative '../lib/slack'
+
+describe "Channel class" do
+  describe "channel list_all" do
+    it "can call the API and receive a response" do
+      VCR.use_cassette("channel_instance") do
+        all_channels = Channel.list_all
+
+        expect(all_channels).must_be_instance_of Array
+
+        all_channels.each do |channel|
+          expect(channel).must_be_instance_of Channel
+        end
+      end
+    end
+  end
+
+  describe "send message" do
+
+    it "can send a message to a channel" do
+      VCR.use_cassette("channel_send_message") do
+        channel = Channel.new("C01BTVCEXCN", "general", "topic", 3)
+        channel.send_message("This post should work")
+      end
+    end
+
+    it "will not send a message for invalid channel ID" do
+      VCR.use_cassette("channel_send_message") do
+        channel = Channel.new(99999, "test_channel", "this is a fake channel", 3)
+        expect { channel.send_message("This post should not work") }.must_raise SlackApiError
+      end
+    end
+
+    it "returns an error for an invalid token" do
+      VCR.use_cassette("channel_send_not_authed") do
+        channel = Channel.new("C01BTVCEXCN", "general", "topic", 3)
+
+        expect { channel.send_message("This post should not work") }.must_raise SlackApiError
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 1fcf2bab..c2c5e1d8 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -3,27 +3,30 @@
   add_filter 'test/'
 end
 
+require 'dotenv'
 require 'minitest'
 require 'minitest/autorun'
 require 'minitest/reporters'
 require 'minitest/skip_dsl'
 require 'vcr'
 
-Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new
+require_relative "../lib/channel"
+require_relative "../lib/user"
+require_relative "../lib/workspace"
 
-VCR.configure do |config|
-  config.cassette_library_dir = "test/cassettes"
-  config.hook_into :webmock
-end
+
+Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new
 
 VCR.configure do |config|
   config.cassette_library_dir = "test/cassettes" # folder where casettes will be located
   config.hook_into :webmock # tie into this other tool called 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
+      :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 token lying around in a cassette file.
-
+  config.filter_sensitive_data("<SLACK_API_TOKEN>") do
+    ENV["SLACK_API_TOKEN"]
+  end
 end
diff --git a/test/user_test.rb b/test/user_test.rb
new file mode 100644
index 00000000..35ae9a56
--- /dev/null
+++ b/test/user_test.rb
@@ -0,0 +1,44 @@
+require_relative 'test_helper'
+require_relative '../lib/slack'
+
+describe "User class" do
+  describe "user list_all" do
+    it "can call the API and receive a response" do
+      VCR.use_cassette("user_instance") do
+        all_users = User.list_all
+
+        expect(all_users).must_be_instance_of Array
+
+        all_users.each do |user|
+          expect(user).must_be_instance_of User
+        end
+      end
+    end
+  end
+
+  describe "send message" do
+
+    it "can send a message to a user" do
+      VCR.use_cassette("user_send_message") do
+        user = User.new("U01CQGU5LKS", "mahaelmais", "mahaelmais", "", "")
+        user.send_message("This post should work")
+      end
+    end
+
+    it "will not send a message for invalid user ID" do
+      VCR.use_cassette("user_send_message") do
+        user = User.new(99999, "test_user", "fake_user", "", "")
+        expect { user.send_message("This post should not work") }.must_raise SlackApiError
+      end
+    end
+
+    it "returns an error for an invalid token" do
+      VCR.use_cassette("user_send_not_authed") do
+        user = User.new("U01CQGU5LKS", "mahaelmais", "mahaelmais", "", "")
+
+        expect { user.send_message("This post should not work") }.must_raise SlackApiError
+      end
+    end
+  end
+
+end
\ No newline at end of file
diff --git a/test/workspace_test.rb b/test/workspace_test.rb
new file mode 100644
index 00000000..9f11c7d8
--- /dev/null
+++ b/test/workspace_test.rb
@@ -0,0 +1,170 @@
+require_relative 'test_helper'
+require_relative '../lib/slack'
+
+describe "Workspace" do
+  describe "can initialize a workspace" do
+    before do
+      VCR.use_cassette("workspace") do
+        @workspace = Workspace.new
+      end
+    end
+
+    it "can initialize a workspace" do
+
+      expect(@workspace).must_be_kind_of Workspace
+      expect(@workspace.users).must_be_kind_of Array
+      expect(@workspace.channels).must_be_kind_of Array
+      expect(@workspace.selected).must_be_nil
+    end
+
+    it "initializes with user and channel objects" do
+
+      expect(@workspace.users.first).must_be_kind_of User
+      expect(@workspace.channels.first).must_be_kind_of Channel
+    end
+  end
+
+  describe "can list users and channels" do
+    before do
+      VCR.use_cassette("workspace_list_all") do
+        @workspace = Workspace.new
+      end
+    end
+
+    it "can list all users" do
+
+      expect(@workspace.list_users).must_be_kind_of Array
+      expect(@workspace.list_users.length).must_equal 6
+      expect(@workspace.list_users.first).must_be_kind_of String
+
+    end
+
+    it "can list all channels" do
+
+      expect(@workspace.list_channels).must_be_kind_of Array
+      expect(@workspace.list_channels.length).must_equal 4
+      expect(@workspace.list_channels.first).must_be_kind_of String
+
+    end
+  end
+
+  describe "can select users or channels" do
+    before do
+      VCR.use_cassette("select_channels") do
+        @workspace = Workspace.new
+      end
+    end
+
+    it "can select a user by name" do
+      user = @workspace.select_user("slackbot")
+      expect(user).must_be_instance_of User
+      expect(user.name).must_equal "slackbot"
+
+      user = @workspace.select_user("mahaelmais")
+      expect(user).must_be_instance_of User
+      expect(user.name).must_equal "mahaelmais"
+      expect(user.slack_id).must_equal "U01CQGU5LKS"
+    end
+
+    it "can select a user by ID" do
+      user = @workspace.select_user("U01BXJZPYAH")
+      expect(user).must_be_instance_of User
+      expect(user.name).must_equal "sophie.e.messing"
+      expect(user.slack_id).must_equal "U01BXJZPYAH"
+
+      user = @workspace.select_user("U01CQHU8WBS")
+      expect(user).must_be_instance_of User
+      expect(user.name).must_equal "earth_mahaelmais_api_"
+      expect(user.slack_id).must_equal "U01CQHU8WBS"
+    end
+
+    it "can select a channel by name" do
+      channel = @workspace.select_channel("random")
+      expect(channel).must_be_instance_of Channel
+      expect(channel.name).must_equal "random"
+      expect(channel.slack_id).must_equal "C01C0TJK6G3"
+
+    end
+
+    it "can select a channel by ID" do
+      channel = @workspace.select_channel("C01BXNGFDTP")
+      expect(channel).must_be_instance_of Channel
+      expect(channel.name).must_equal "test-channel"
+      expect(channel.slack_id).must_equal "C01BXNGFDTP"
+
+    end
+
+    it "will return nil for invalid user input" do
+      user = @workspace.select_user("xxx")
+      expect(user).must_be_nil
+    end
+
+    it "will return nil for invalid channel input" do
+      user = @workspace.select_user("00001111")
+      expect(user).must_be_nil
+    end
+
+    it "can show details for selected user" do
+      user = @workspace.select_user("mahaelmais")
+      user_details = @workspace.show_details
+
+      expect(user_details).must_be_kind_of String
+      expect(user_details).must_include "U01CQGU5LKS"
+    end
+
+    it "can show details for selected channel" do
+      channel = @workspace.select_channel("general")
+      channel_details = @workspace.show_details
+
+      expect(channel_details).must_be_kind_of String
+      expect(channel_details).must_include "C01BTVCEXCN"
+    end
+  end
+
+  describe "send_message" do
+    before do
+      VCR.use_cassette("send_message") do
+        @workspace = Workspace.new
+      end
+    end
+
+    it "can send a message" do
+      VCR.use_cassette("send_message") do
+        @workspace.select_user("sophie.e.messing")
+        @workspace.send_message("This post should work")
+      end
+    end
+
+    it "will raise an error if we send a message with no channel or user" do
+      expect { @workspace.send_message("This post should not work") }.must_raise SlackApiError
+    end
+  end
+
+  describe "ask_to_select" do
+    it"can select a user" do
+      VCR.use_cassette("ask_to_select") do
+        @workspace = Workspace.new
+      end
+      expect(@workspace.ask_to_select("sophie.e.messing")).wont_be_nil
+    end
+
+    it"can select a channel" do
+      VCR.use_cassette("ask_to_select") do
+        @workspace = Workspace.new
+      end
+      expect(@workspace.ask_to_select("general")).wont_be_nil
+    end
+
+    it"can't select invalid input" do
+      VCR.use_cassette("ask_to_select") do
+        @workspace = Workspace.new
+      end
+      expect(@workspace.ask_to_select("xxxxxxxxxx")).must_be_nil
+    end
+
+  end
+end
+
+
+
+