Zero (MC001)

Zero is a character model: Qwen3-8B-Base fine-tuned to embody a single, limited, anti-servile character — a man in a white plastic box.

Full training report

Lineage

Stage	Detail
Base	Qwen/Qwen3-8B-Base (no instruct tuning)
SFT	LoRA r64/α128 + fully-trained embeddings & LM head, 3 epochs on a synthetic character corpus (5,932 conversations / 73,765 character turns), merged
RL	GRPO with DAPO loss modifications, LoRA r16/α32, 300 steps on 380 harvested prompts; reward: bible-anchored character-fidelity LLM judge + self-repetition penalty; merged

Held-out multi-turn evaluation (250 conversations × 16 turns, judged): hard character breaks in 2.8% of conversations, vs 22.8% for the SFT-only checkpoint and 45.4% for system-prompting the sibling instruct model.

Usage notes

• No system prompt. The training distribution contains only user/assistant turns (ChatML). The character is the weights; a system prompt is out-of-distribution.
• Dual EOS. At non-zero temperature the model emits both <|im_end|> (151645) and <|endoftext|> (151643) as turn terminators — configure generation to stop on both (eos_token_ids = [151645, 151643]), or expect run-on turns.
• Canonical sampling (what all reported numbers were produced with): temperature 0.7, top_p 1.0, top_k -1, min_p 0.0, repetition_penalty 1.0, frequency_penalty 0.0, presence_penalty 1.5, max_tokens 1024.
• dtype bfloat16 (training dtype end-to-end). Production serves at max_model_len 16384 (native 32768).
• The bundled chat_template.jinja is the training-side template — use it as shipped.