oddadmix/Emhotob-50M-GRPO-Arabic-Final

Emhotob-50M-GRPO — Arabic Tool-Calling (RL-tuned)

A ~51.8M-parameter Arabic tool-calling / function-calling model, tuned with GRPO (Group Relative Policy Optimization) reinforcement learning on top of a distilled SFT checkpoint. It is a proof-of-concept for agentic Arabic behavior at tiny scale — deciding when to call a tool vs. when to decline, entirely from a model small enough to run on a CPU.

This checkpoint corresponds to the GRPO-v12 run in the training repo: it is tuned for robust abstention — it declines out-of-scope requests reliably instead of forcing a tool call.

• Base model: oddadmix/50M-2048-Emhotob — Llama-architecture, pre-trained from scratch on ~20B Arabic tokens, 2048 ctx.
• Architecture & recipe: derived from SupraLabs/Supra-50M-Base; a POC for training Arabic tiny models from scratch.
• Format: ChatML + Hermes-style <tool_call>{...}</tool_call>.

الملخص بالعربية: نموذج عربي صغير (~51.8 مليون معامل) لاستدعاء الأدوات (Tool/Function Calling)، مبني على معمارية Llama ومدرَّب من الصفر، ثم ضُبط باستخدام التعلّم المعزّز GRPO. هذه النسخة مُحسَّنة للامتناع عن استدعاء أداة عند عدم توفّر أداة مناسبة، بدلًا من اختلاق استدعاء خاطئ. نموذج تجريبي (POC) لسلوك عربي «وكيلي» على نطاق صغير جدًا.

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Model details

Parameters	~51.8M
Architecture	Llama (LlamaForCausalLM)
Hidden size	512 · Layers 12 · Heads 8 (GQA, 4 KV) · head_dim 64
Vocab size	32002 (32000 base + 2 ChatML control tokens)
Context length	2048
Chat format	ChatML (`<
Precision	bfloat16
License	Apache-2.0 (matches the base architecture)

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How it was trained

The model is the end of a base → SFT → distillation → RL pipeline, all in pure 🤗 Transformers (no TRL — the GRPO loop is from scratch):

1. Base: oddadmix/50M-2048-Emhotob, pre-trained from scratch on ~20B Arabic tokens (2048 ctx), architecture and training scripts derived from SupraLabs/Supra-50M-Base.
2. SFT: supervised fine-tuning on Arabic tool-calling data (ChatML + Hermes <tool_call> format).
3. Sequence-level distillation (Kim & Rush, 2016): a 1.2B tool-specialized teacher (LiquidAI/LFM2-1.2B-Tool) generated targets — including fluent Arabic abstentions and hard-negative (no-matching-tool) examples — that the student learned to imitate. This is the variant that reliably declines out-of-scope requests.
4. GRPO (Shao et al., 2024 — DeepSeekMath): on-policy RL with a verifiable reward (the tool-eval scorer itself — no reward model, no LLM judge). For each prompt the policy samples a group of completions; a group-relative advantage plus a KL leash to the reference model shapes the call/abstain decision. This checkpoint uses a balanced 1:1 call/abstain batch with a gentle learning rate, which holds the high-abstention behavior while keeping JSON/tool-selection intact.

What the experiment found (the POC result): at 50M parameters there is a genuine precision ↔ recall frontier on the call decision — you can maximize valid calls or maximize correct refusals, but not both. GRPO with a perfect verifiable reward moves along this frontier rather than beyond it; this checkpoint deliberately sits at the robust-abstention corner. (A separately-tested 2.5× larger student tied these metrics, corroborating that the ceiling is capacity, not the training signal.)

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Evaluation

Numbers are reported honestly for this exact checkpoint against the sibling SFT/RL checkpoints (see the training repo for the full trial log).

Dialect eval (18 items, Egyptian-dialect prompts):

metric	this model	note
strict success	12/18	headline
decision (call/answer correct)	16/18
abstention	4/4 ✅	robustly declines out-of-scope requests

MSA eval v2 (126 items, higher-resolution): strict 11/68, decision 49/68, abstain 27/46 — the high-abstention end of the decision↔abstain frontier. Tool-selection (33%) and argument-exactness (18%) are the capacity-bound bottlenecks shared across all checkpoints at this scale.

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Usage

The tokenizer uses the TokenizersBackend class, which requires transformers>=5.12. Build the ChatML prompt manually and pass the tool schema in the system message:

import json, torch
from transformers import AutoModelForCausalLM, AutoTokenizer

model_id = "oddadmix/Emhotob-50M-GPRO-Arabic-Final"
tok = AutoTokenizer.from_pretrained(model_id)
model = AutoModelForCausalLM.from_pretrained(model_id, torch_dtype=torch.bfloat16)

tools = [{
    "name": "get_weather",
    "description": "Get the current weather for a city",
    "parameters": {"type": "object",
        "properties": {"location": {"type": "string"}},
        "required": ["location"]},
}]

system = (
    "أنت مساعد يستطيع استدعاء الأدوات. الأدوات المتاحة:\n"
    + json.dumps(tools, ensure_ascii=False)
    + "\nإذا لم تكن هناك أداة مناسبة، اعتذر ولا تختلق استدعاءً."
)
user = "ما حالة الطقس في القاهرة؟"

prompt = (
    f"<|im_start|>system\n{system}<|im_end|>\n"
    f"<|im_start|>user\n{user}<|im_end|>\n"
    f"<|im_start|>assistant\n"
)
ids = tok(prompt, return_tensors="pt").to(model.device)
out = model.generate(
    **ids, max_new_tokens=256, do_sample=False,
    repetition_penalty=1.2,
    eos_token_id=tok.convert_tokens_to_ids("<|im_end|>"),
)
print(tok.decode(out[0][ids.input_ids.shape[1]:], skip_special_tokens=True))
# Expected: <tool_call>{"name": "get_weather", "arguments": {"location": "القاهرة"}}</tool_call>

For an out-of-scope request with no matching tool, the model is tuned to refuse in Arabic rather than hallucinate a call.

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Intended use & limitations

Intended use. Research and demonstration of Arabic tool-calling / agentic behavior at tiny scale; a CPU-friendly baseline for from-scratch Arabic SLM experiments.

Limitations. At 50M parameters this is a proof of concept. Tool-selection with several confusable tools (33% correct) and exact argument extraction (~18%) are the capacity-bound weak spots — validate any tool call before executing it. Training was predominantly Modern Standard Arabic; dialect prompts are harder. Not for production agents without a validation/guardrail layer.

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Citation & credits

• Method: GRPO — Shao et al., 2024 (DeepSeekMath); sequence-level KD — Kim & Rush, 2016.
• Teacher: LiquidAI/LFM2-1.2B-Tool.
• Base architecture & training scripts: SupraLabs/Supra-50M-Base (Apache-2.0).
• Base Arabic model: oddadmix/50M-2048-Emhotob — from-scratch, ~20B Arabic tokens, 2048 ctx.