May 11, 2026 · 2 min read
Building a Zero-Dependency Character Sheet Web App
A single HTML file that lets D&D players build characters and export them to their AI Dungeon Master.
When I built the AI Dungeon Master, I hit a question: how do players get their character sheets into the game?
The obvious answer was building a web server — logins, databases, accounts. The wrong answer. The players already had Telegram. They didn’t need another place to sign in.
The Solution
A single HTML file. Open it in any browser, build your character, click Export, paste into Telegram.
No install. No server. No accounts. No dependencies.
What It Does
The sheet covers all the standard D&D 5e fields:
- Ability scores — modifiers auto-calculate as you type
- Skills — tap to toggle proficiency, bonus updates live
- Saving throws — same deal, proficiency toggle + auto-calc
- Combat stats — HP, AC, initiative, speed, proficiency bonus
- Attacks and equipment — add/remove items dynamically
- Spellcasting — pick your ability, slots per level, save DC auto-calculates
- Features, backstory, notes — free text areas for everything else
Export Flow
Player builds character → clicks Export → gets a markdown file → drops it in the Telegram chat → DM reads it and logs it into the campaign wiki.
The import works both ways — if the DM updates your sheet mid-campaign, you can download the updated markdown and import it back into the app.
The Design Choice
Zero dependencies means it works offline, on any device (phone, tablet, desktop), with no infrastructure. Host it anywhere — GitHub Pages, a USB drive, an email attachment. The file is ~22KB.
It auto-saves to browser localStorage, so closing the tab doesn’t lose progress. And you can download full JSON backups whenever you want.
Why This Matters for Selling AI Products
The character sheet web app taught me something about packaging AI agents as products: the agent is the core feature, but the tooling around it is what makes it usable.
A DM that can read character sheets is useful. A DM plus a dead-simple way for players to create and share those sheets? That’s a product.
When you’re building AI products, think about the full workflow — not just what the agent does, but how people interact with it before, during, and after the session.
The AI Dungeon Master, including the character sheet web app, is available on Gumroad.