Building a Simple Ruby Chatbot with Google's Gemini API

def initialize(token: ENV["GEMINI_API_KEY"], base_uri: BASE_URI, model: "gemini-2.0-flash")
  @token = token
  @base_uri = base_uri
  @model = model
  @conversation_history = []
end

• The class takes in an API key (GEMINI_API_KEY), the base URI, and the model to use (default: gemini-2.0-flash).
• It initializes an empty conversation history to track interactions.

def chat(message)
  @conversation_history << {role: "user", parts: [{text: message}]}
  response = generate_content(
    contents: @conversation_history,
    generationConfig: { candidateCount: 1 }
  )

  gemini_response = response.dig("candidates", 0, "content", "parts", 0, "text")
  @conversation_history << {role: "model", parts: [{text: gemini_response}]}
  gemini_response
end

• The method appends the user's message to the conversation history.
• It sends the full conversation history to the API, ensuring context is maintained. It is important to set candidateCount: 1 in the generationConfig to maintain the history
• The response is extracted using the dig command. The response is stored in the history array, and returned to the user so they can see it.

def post(path, body:, headers: {"content-type": "application/json"})
  url = URI("#{@base_uri}#{@model}:#{path}?key=#{@token}")
  data = JSON.dump(body)
  response = Net::HTTP.post(url, data, headers)
  JSON.parse(response.body)
end

• This private helper method constructs the request to the Gemini API, sends it via Net::HTTP, and parses the response.

if __FILE__ == $0
  gemini = GeminiChat.new
  puts "Starting chat with Gemini (type 'exit' to quit)"
  puts "-" * 50

  loop do
    print "\nYou: "
    input = gets.chomp
    break if input.downcase == "exit"
    response = gemini.chat(input)
    puts "\nGemini: #{response}"
  end

  puts "\nChat ended. Goodbye!"
end

• It starts a chat session and continuously sends user input to Gemini.
• The conversation runs in a loop until the user types "exit".

export export GEMINI_API_KEY=thekeyyougotfromAIStudio 

ruby gemini_chat.rb