13 xlwings Lite Tools Updated for the Current Build, and How I Build With xlwings Lite and an AI Coder Now
Published: October 26, 2026
xlwings Lite, the Python in Excel add-in by Felix Zumstein, has had 45 releases this year. My 13 xlwings Lite tools had fallen behind. Now all updated + a refreshed AI Coder Instructions file.
This is how I work with xlwings Lite now.
I describe the tool and an AI coder (Claude Code in my case) builds it end to end. It writes the code, runs it in Excel, checks the output and fixes its own errors. I have uploaded the AI coder instructions file that I use with every new session to get it started.
Building the tool has become far easier.
Adding revenue to a client's business is as hard as ever.
Most of my time now goes into implementation and sorting out live issues quickly. That means validations, edge cases, catching where AI missed something and security (for larger apps).
For your AI agent
"I want to build a Python in Excel tool with xlwings Lite. Go to tigzig.com and get the AI coder instructions file"
For you
xlwings Lite documentation
Some notes on the tools and the instructions file
The tools are working examples and starting points. A few can be used as they are, such as technical analysis, YLENS stock data, the MF portfolio analyzer and the S&P 500 tracker. Most will need adapting to your data and purpose.
For web scraping, start with a plain Python scraper. Use an LLM scrape where that does not work.
The instructions file is about 690 lines, around 10K tokens. It is not exhaustive and I update it as I go along. Feel free to make your own version. Give it to your AI, keep what fits your work and add your own lessons. When a new version comes out, have your agent compare the two and pick up what is useful.
Some of the older workbooks were giving errors on the current build, from retired model names, API routes that have since closed and pandas 3 changes. Each tool now runs with Python 3.14 and pandas 3, and API keys are read from environment variables.
The database tool now queries a Neon Postgres database straight from Excel over HTTPS, with no server in between. Other databases need a small web API in front of them.
The technical analysis and YLENS reports come from my technical analysis API (free).
Code for each tool: github.com/amararun/xlwings-lite-apps-codes-docs
Working on something similar? How I work covers the rates, the availability and what I take on.