Class: TinyGemini

Inherits:
Object
  • Object
show all
Defined in:
lib/tiny_gemini.rb

Overview

tiny, not very robust, HTTP client the Google Gemini API see also: ai.google.dev/api/rest

Instance Method Summary collapse

Constructor Details

#initialize(model: 'gemini-1.5-flash', host: 'generativelanguage.googleapis.com', path: '/v1beta/models', action: 'generateContent', api_key: ENV['TINY_GEMINI_KEY'], system_instruction: nil) ⇒ TinyGemini

a good rule of thumb would be to have a .tiny_gemini.yml config in your project, to parse that as YAML, and pass the parsed reulst into here.



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# File 'lib/tiny_gemini.rb', line 9

def initialize(
  model: 'gemini-1.5-flash',
  host: 'generativelanguage.googleapis.com',
  path: '/v1beta/models',
  action: 'generateContent',
  api_key: ENV['TINY_GEMINI_KEY'],
  system_instruction: nil
)

  @model = model
  @host = host
  @path = path
  @action = action
  @api_key = api_key
  @system_instruction = system_instruction
end

Instance Method Details

#prompt(messages) ⇒ Object

sends a request to POST generateContent

messages: an array of hashes in the following format: [

{
    "parts": [
        {
            "text": "hi, how are you?"
        }
    ],
    "role": "user"
},
{
    "parts": [
        {
            "text": "I am an AI language model, so I don't have feelings or experiences like humans do. However, I am here to assist you with any questions or tasks you may have! How can I help you today??"
        }
    ],
    "role": "model"
},
{
    "parts": [
        {
            "text": "oh, you don't have feelings? I guess I didn't realize that - you seem so ... real!"
        }
    ],
    "role": "user"
},

]

NOTE: if you want the model to impersonate a character (i.e. a talking cat) you need to have set the ‘system_instruction` parameter when initializing this class to make that work

Raises:



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# File 'lib/tiny_gemini.rb', line 59

def prompt(messages)
  body = { contents: messages }
  body.merge!(system_instruction: { parts: { text: @system_instruction } }) if @system_instruction

  request_body = body.to_json

  uri = URI("https://#{@host}#{@path}/#{@model}:#{@action}?key=#{@api_key}")
  headers = { 'Content-Type' => 'application/json; charset=UTF-8' }
  response = Net::HTTP.post(uri, request_body, headers)

  # Handle potential errors (e.g., non-200 responses)
  unless response.is_a?(Net::HTTPSuccess)
    raise TinyGeminiModelError, "Gemini API Error: #{response.code}\n#{JSON.pretty_generate(response.body)}"
  end

  # response and error handling
  parsed_response = JSON.parse(response.body)
  raise(TinyGeminiModelError, "No condidates in Gemini response") unless parsed_response['candidates']

  first_candidate_response = parsed_response['candidates'].first
  raise(TinyGeminiModelError, "No first candidate response in Gemini response") unless first_candidate_response

  text_response = first_candidate_response&.dig('content', 'parts')&.first&.dig('text')&.strip
  raise(TinyGeminiModelError, "Text response is nil or empty: `#{text_response.inspect}`") if text_response.nil? || text_response.length == 0

  text_response
end