  This paper presents the latest progress of GPTutor: a ChatGPT-powered
programming tool extension in Visual Studio Code. The emergence of Large
Language Models (LLMs) has improved software development efficiency, but their
performance can be hindered by training data limitations and prompt design
issues. Existing LLM development tools often operate as black boxes, with users
unable to view the prompts used and unable to improve performance by correcting
prompts when errors occur. To address the aforementioned issues, GPTutor was
introduced as an open-source AI pair programming tool, offering an alternative
to Copilot. GPTutor empowers users to customize prompts for various programming
languages and scenarios, with support for 120+ human languages and 50+
programming languages. Users can fine-tune prompts to correct the errors from
LLM for precision and efficient code generation. At the end of the paper, we
underscore GPTutor's potential through examples, including demonstrating its
proficiency in interpreting and generating Sui-Move, a newly introduced smart
contract language, using prompt engineering.
