require('gp').setup { 
  -- your config
}

-- Monkey patch the dispatcher after setup
local dispatcher = require 'gp.dispatcher'
local original_prepare_payload = dispatcher.prepare_payload
dispatcher.prepare_payload = function(messages, model, provider)
  local output = original_prepare_payload(messages, model, provider)
  if provider == 'openai' and model.model:sub(1, 2) == 'o3' then
    for i = #messages, 1, -1 do
      if messages[i].role == 'system' then
        table.remove(messages, i)
      end
    end
    output.max_tokens = nil
    output.temperature = nil
    output.top_p = nil
    output.stream = true
  end
  return output
end