---
title: The HF Knight
emoji: 🛡️
colorFrom: yellow
colorTo: red
sdk: gradio
sdk_version: 6.18.0
app_file: app.py
pinned: true
license: apache-2.0
models:
- build-small-hackathon/HF-Knight-Qwen2.5-1.5B-Instruct-GGUF
tags:
- track:wood
- achievement:offgrid
- achievement:welltuned
- achievement:offbrand
- achievement:llama
- achievement:sharing
---

# 🛡️ The Adventures of the HF Knight

A medieval text RPG that teaches open-source / Hugging Face concepts — and the whole thing is
driven by a **fine-tuned 1.5B model running locally in this Space**, with **no inference API**.

You are a knight in the **Thousand Token Wood**. A Herald-Mentor tells each trial as a short
medieval story woven around a question. Answer well and rise in rank — Squire → Grandmaster.
Three failed attempts end the quest.

📺 **Demo video & write-up:** [LinkedIn post](https://www.linkedin.com/posts/activity-7472436169834921984-Zs8y)

## Why we built it

To show that a *small* model, fine-tuned for one job and run on a laptop, can carry a whole
interactive experience — no giant model, no paid API. The knight's in-world cause — freeing
knowledge from the towers of the few and giving it to all, *democratizing AI* — is also the
point of the build: the entire app fits on a laptop.

## The model

[**build-small-hackathon/HF-Knight-Qwen2.5-1.5B-Instruct-GGUF**](https://huggingface.co/build-small-hackathon/HF-Knight-Qwen2.5-1.5B-Instruct-GGUF)
— Qwen2.5-1.5B-Instruct, fine-tuned, served in-process with `llama-cpp-python`. It **narrates**
each trial and **calls a `validate_answer` tool** to grade the player and advance the game. The
un-tuned base never calls the tool — it just chats back — so the game would never progress.

## How it was built (field notes)

- **The questions** (6 stages of open-source / HF concepts) were generated with **Google Gemini**.
- **The training traces** (the medieval narration + tool calls) were **hand-authored with Claude**.
  We first tried to generate them with a 7B dev model, but it could not produce reliable
  `<tool_call>` traces — so we wrote them by hand instead.
- **Train ≠ game, by design.** The 90 questions used to *train* and the 60 questions in the
  *live game* are **disjoint — zero overlap**. The model never sees a real game question during
  training — so the disjoint sets test whether it has learned the *skill* (narrate any trial,
  call the tool) rather than just memorized the narration of its training questions.
- **What made the fine-tune work — `assistant_only_loss`:** we train the model only on what the
  *narrator* should say (its replies), not on the long persona we feed it. So it learns to *react
  to* that persona instead of memorizing and reciting it — fixing an early bug where the model
  parroted wording from its own instructions straight back into the story. QLoRA, `r=8`, 3 epochs; held-out eval loss 1.91 → 1.42, no overfit.

## Tech

- **Local-first:** model and game run entirely inside the Space — no external inference service.
- **llama.cpp** (`llama-cpp-python`) loads a q8_0 GGUF; the app is pure Python + Gradio.
- The runtime stack is tiny — `gradio`, `llama-cpp-python`, `huggingface_hub`. The heavy training
  stack lives separately and is not needed to play.

Built for the [Hugging Face Build Small Hackathon](https://huggingface.co/build-small-hackathon)