// personal
Aerithyl
An AI dungeon sage for D&D 5e.
// overview
Aerithyl is a D&D 5e companion I built end to end — a character builder and a real-time at-the-table assistant, wrapped around an AI 'Sage.' You design a character by talking to Sage, then bring it to the table, where Sage referees live play. I built it as a birthday gift for a friend.
// what I built
The Sage & its RAG brain
Built a Gemini-powered assistant grounded in a 1,854-chunk retrieval index of the SRD 5.1 rules — conditions, spells, monsters, magic items — with 1536-dimension embeddings, so its answers are cited from the actual rulebook rather than guessed.
Conversational character building
A 'build with Sage' flow proposes ability scores, class and subclass, proficiencies, spells, and gear through decision cards — each tagged grounded, suggested, or user — that commit to a full 5e character sheet.
An AI referee at the table
In play, Sage runs approval-gated tools — apply damage, spend and restore spell slots, toggle conditions, log rolls — that it can only propose, never execute, until you confirm. Homebrew rules can be uploaded and are embedded into its retrieval too.