An AI game master ("Spielleiter") for German-language D&D 5e-style tabletop sessions, powered by NVIDIA NIM — sign up free at build.nvidia.com, no AWS account required. Claude narrates, a deterministic rule engine enforces the mechanics, you roll your own physical dice. The name means "Fable Forge" — where the stories are forged.

• German-only Spielleiter — narrates exclusively in natural modern German, in character, with distinct NPC voices.
• Rules before vibes — a small deterministic rule engine (backend/src/ruleEngine.ts) is the sole authority on ability, level, and resource-slot legality; the LLM narrates outcomes but never decides what's legal.
• Physical dice, always — the app never rolls for you; it asks for your result and narrates from there.
• Spoken narration (optional) — GM narration read aloud in a German voice via NVIDIA NIM Magpie TTS.
• Single-screen play — everyone plays pass-and-play on one browser tab.

cp .env.example .env    # fill in NVIDIA_API_KEY
npm install
npm run dev             # backend on :8787, frontend on :5173

In .env, set:

LLM_PROVIDER=nim
NVIDIA_API_KEY=your-free-key-from-build.nvidia.com

NIM_MODEL defaults to meta/llama-3.3-70b-instruct and rarely needs changing. Open the frontend URL printed by Vite in a browser — that's it.

Already have Anthropic or AWS credentials? Set one of these in .env instead (LLM_PROVIDER picks explicitly; if left unset, Anthropic takes precedence, then Bedrock):

• Anthropic API directly — ANTHROPIC_API_KEY.
• AWS Bedrock — AWS_REGION (needs access to us.anthropic.claude-opus-4-8 in that region).

Set TTS_PROVIDER=nim in .env (reusing the same NVIDIA_API_KEY) to have the GM's narration spoken aloud in German via NVIDIA NIM Magpie TTS. A 🔊/🔇 toggle in play mutes it for the table; each new narration autoplays and every line has a ▶ replay button. Leave TTS_PROVIDER unset for text-only.

Fabelschmiede is built for D&D 5e-style play, not a generic multi-system engine — the campaign prompts, tone, and rule engine are all shaped around it. We're actively deepening this: more D&D-specific mechanics and SRD-grounded content are on the roadmap, moving well past today's lightweight ability/level/resource model.

• Campaign state is persisted to a local SQLite database (data/campaigns.db) — refreshing or restarting the server picks up right where you left off.
• The app never rolls dice — it asks you for the result.