4.0 KiB
base_model, tags, license, language
| base_model | tags | license | language | |||||
|---|---|---|---|---|---|---|---|---|
| unsloth/qwen3-4b-unsloth-bnb-4bit |
|
apache-2.0 |
|
OpenFable-4B
"The US banned Fable 5 outside America. I'm outside America. So I made my own."
OpenFable-4B is a fine-tune of Qwen3-4B designed to replicate the conversational style, reasoning depth, and structured output quality of Claude Fable 5 — built entirely from scratch by a solo developer in Brazil.
This is not a generic instruction-tuned model. It's a deliberate attempt to bring Fable-style responses to the open-source ecosystem, with a custom-built dataset and a personality baked into the chat template.
What makes it different
- Style-first fine-tune — trained to match Claude Fable 5's tone: direct, warm, structured, and non-verbose
- Custom dataset — ~300 hand-curated examples across coding, math, agentic planning, and cybersecurity. No public synthetic datasets that leak CoT preambles
- Custom chat template — default system prompt embedded in
tokenizer_config.json: "You are OpenFable, created by SynastrIA Networks" - GGUF quantized — Q4_K_M, ready for local inference via llama.cpp, LM Studio, PocketPal, or Jan
Benchmarks
MMLU — Zero-shot (no few-shot)
OpenFable-4B was evaluated on MMLU with zero-shot prompting, achieving an overall score of 68.48%.
Strongest in Social Sciences. Weakest in Humanities — expected given the dataset skew toward technical and reasoning tasks.
GSM8K — Comparison with 4B-class models
OpenFable-4B holds its own against the competitive 4B landscape on grade-school math reasoning:
OpenFable matches top-tier 4B models on math reasoning despite being a style fine-tune, not a reasoning-optimized model. The base Qwen3-4B it's built on scores ~76% — OpenFable closes that gap significantly through LoRA training.
Model details
| Property | Value |
|---|---|
| Base model | Qwen/Qwen3-4B |
| Fine-tuning method | LoRA (via Unsloth) |
| Dataset size | ~300 examples |
| Quantization | Q4_K_M (GGUF) |
| Context length | 32768 |
| Language | English |
| License | Apache 2.0 |
Usage
llama.cpp
./llama-cli \
-m OpenFable-4B-Q4_K_M.gguf \
-p "You are OpenFable, created by SynastrIA Networks." \
--ctx-size 4096 \
-i
Python (llama-cpp-python)
from llama_cpp import Llama
llm = Llama(
model_path="OpenFable-4B-Q4_K_M.gguf",
n_ctx=4096,
chat_format="chatml",
)
response = llm.create_chat_completion(
messages=[
{"role": "system", "content": "You are OpenFable, created by SynastrIA Networks."},
{"role": "user", "content": "Explain how LoRA fine-tuning works."},
]
)
print(response["choices"][0]["message"]["content"])
LM Studio / Jan / PocketPal
Download the .gguf file and load it directly. The system prompt is already embedded in the tokenizer config — no manual setup required.
Downloads
| Format | Link |
|---|---|
| GGUF (Q4_K_M) | gustajunq/OpenFable-4B-GGUF |
| Org page | SynastrIA Networks on HuggingFace |
Known limitations
- Humanities performance lags behind other categories (~59.5% MMLU) — reflective of dataset composition
- Style fine-tune, not RLHF-aligned — may occasionally drift on edge-case prompts
- Not optimized for multilingual use — English only
About
Built by Gustavo at SynastrIA Networks — a one-person AI startup from Brazil.
OpenFable is part of the broader SynastrIA ecosystem, which includes Lucian, an AI agent platform for creators.
Follow the build-in-public journey: @synastriadev · @openfable
V2 — June 2026

