One of the things I love most about working in technology is finding unexpected ways it can serve other parts of my life. As a deacon, I have weekly responsibilities that require careful preparation—and I recently discovered that Claude skills can help bridge my professional expertise with my theological work.
The Problem: Formatting the Penitential Act
Each week at Mass, I read the Penitential Act (Form C), which includes three invocations that change based on the liturgical season and readings. I format these into a worship aid document that needs to be:
- Large enough to read easily at the ambo
- Properly formatted with red rubrics (the “Deacon:” labels) and black spoken text
- Sized to fit perfectly on a single page
This follows the traditional Catholic principle of “say the black, do the red”—the spoken text appears in black, while the liturgical instructions appear in red.
The meaningful part of my weekly preparation is choosing the right invocations—words that connect with the readings and speak to the congregation. But I was spending too much time on the tedious work of manually adjusting font sizes to get everything to fit just right on one page. I found myself thinking: there has to be a better way.
What is a Claude Skill?
A Claude Skill is a way to extend Claude’s capabilities with custom, reusable functionality. Think of it as a plugin system for AI—you can package up specialized knowledge and tools that Claude can invoke when needed.
What makes skills powerful is the combination of two things:
- Natural language understanding: You interact with Claude conversationally, describing what you need in plain English
- Deterministic code execution: Behind the scenes, the skill runs actual code that produces precise, consistent results
This is different from asking Claude to “just figure it out.” When I ask Claude to format a document without a skill, it’s making educated guesses about spacing, font sizes, and layout. Sometimes it works well, sometimes it doesn’t. But with a skill, the formatting logic is written in code that executes the same way every time. The LLM handles understanding my request and extracting the relevant information; the code handles the precise execution.
You can create your own skills and share them with others, building on each other’s work to extend what Claude can do.
My First Claude Skill
I built a Catholic Liturgy Skills repository that includes a Penitential Act formatting tool. I provide the three invocation texts I’ve chosen for a given Sunday, and it handles all the formatting work—producing a beautifully formatted .docx file with:
- A centered title showing the Sunday, season, and liturgical year
- Proper red/black formatting for rubrics and spoken text
- Automatic font sizing to fit everything on one page
- Professional typography using the Sabon Next LT font
Here’s an example Penitential Act document generated by the skill, so you can see what the output looks like.
How to Use This Skill
Installation
- If you don’t already have an account, sign up at claude.ai
- Visit the Releases page on GitHub
- Download the
.skillfile for the Penitential Act - Upload the skill file to Claude
Example Prompts
Once you have the skill installed, you can use prompts like these:
Basic usage:
Generate a Penitential Act for the 2nd Sunday of Advent, Year A, with these invocations:
- You came to gather the nations into the peace of God’s Kingdom
- You come in word and sacrament to strengthen us in holiness
- You will come in glory with salvation for your people
Specifying the season explicitly:
Create a Penitential Act document for the 15th Sunday of Ordinary Time, Year B. The three invocations are:
- You were sent to heal the contrite of heart
- You came to call sinners
- You are seated at the right hand of the Father to intercede for us
For Easter season:
I need a Penitential Act for the 3rd Sunday of Easter, Year C with these tropes:
- You are the way that leads to the Father
- You are the truth that enlightens the nations
- You are the life that renews the world
The skill handles all the formatting automatically—I just provide the invocation texts and receive a print-ready document.
The Technology Behind This Skill
Under the hood, this skill is TypeScript code that runs in a sandboxed environment. When I ask Claude to create a Penitential Act document, here’s what actually happens:
- Claude parses my request - The LLM extracts the Sunday name, liturgical season, year, and the three invocation texts from my natural language prompt
- The skill code executes - Claude calls my TypeScript function with these extracted parameters
- Deterministic document generation - The code uses the
docxlibrary to build a Word document with precise formatting: exact font sizes, specific RGB color values for the red rubrics, calculated spacing, and proper page margins - Binary file output - The skill produces an actual
.docxfile that I can download and print
The key insight is that the creative, fuzzy work (understanding what I’m asking for) happens in the LLM, while the precise, repeatable work (pixel-perfect document formatting) happens in code. This separation plays to each technology’s strengths.
The code doesn’t use AI to guess at formatting. It calculates exact measurements: if the invocations are longer, the font size decreases according to a formula. The red color is always RGB(192, 0, 0). The margins are always exactly 0.5 inches. This determinism means I get consistent, professional results every time—something that would be hard to achieve with pure LLM generation.
This pattern—LLM as the interface, code as the engine—opens up possibilities for all kinds of specialized tools. Anywhere you need the flexibility of natural language combined with the precision of software, a Claude Skill can bridge that gap.
The Joy of Learning
I spend my days working with AI tools and thinking about developer productivity. Building this skill let me apply that same work to something outside the office. The skill doesn’t choose the words for me—that’s the prayerful, creative work I want to be doing. It just handles the formatting so I can focus on discerning the right invocations rather than wrestling with font sizes.
If you’re a fellow deacon or liturgical minister, I’d encourage you to give this skill a try. The Catholic Liturgy Skills repository is open source under the MIT license, and I’d love to hear how it works for you.
More importantly, I’d love to know what other skills would help you in your liturgical ministry. Do you spend time formatting intercessions, preparing worship aids, or organizing liturgical schedules? Let me know—I’m eager to build more tools that can serve those who serve at the altar.