---
language:
- en
license: apache-2.0
base_model:
- EphAsad/Atem-8B
tags:
- qwen3
- unsloth
- lora
- reasoning
- agentic
- conversational
- text-generation
- tool-use
pipeline_tag: text-generation
datasets:
- open-thoughts/OpenThoughts-Agent-v1-SFT
- kelexine/fable-5-sft-traces
- Glint-Research/Fable-5-traces
- armand0e/claude-fable-5-claude-code
---

# Midas-FableAgent

*Plan. Act. Observe. Complete.*

An agentic specialisation of [Atem-8B](https://huggingface.co/EphAsad/Atem-8B) — sequential fine-tuned for multi-step task execution, structured action emission, and observation-grounded iteration. Uses Fable agent traces.

[![Base Model](https://img.shields.io/badge/Base-Atem--8B-blue)](https://huggingface.co/EphAsad/Atem-8B)
[![Method](https://img.shields.io/badge/Method-Sequential%20Agentic%20SFT-purple)](https://img.shields.io/badge/Method-Sequential%20Agentic%20SFT-purple)
[![Parameters](https://img.shields.io/badge/Parameters-8B-orange)](https://img.shields.io/badge/Parameters-8B-orange)
[![License](https://img.shields.io/badge/License-Apache%202.0-green)](https://www.apache.org/licenses/LICENSE-2.0)

[![Midas-FableAgent Logo](https://huggingface.co/EphAsad/Midas-FableAgent/resolve/main/Logo.png)](https://huggingface.co/EphAsad/Midas-FableAgent/resolve/main/Logo.png)

---

## Overview

Midas-FableAgent is a sequential fine-tune of [Atem-8B](https://huggingface.co/EphAsad/Atem-8B) toward agentic task execution. Where Atem-8B is a general-purpose reasoning model, Midas-FableAgent is trained to operate in execution loops: receiving a task, reasoning about the current state, emitting structured actions, observing results, and iterating until completion.

Training used two complementary data streams:

- **Stream A** — 10,000 multi-turn agentic execution trajectories from [OpenThoughts-Agent-v1-SFT](https://huggingface.co/datasets/open-thoughts/OpenThoughts-Agent-v1-SFT). Each trajectory is a full ReAct-style loop: task → JSON action → environment observation → JSON action → ... → `task_complete: true`. The model trains on every assistant turn in every trajectory, grounding its actions in real terminal output.

- **Stream B** — 4,665 planning and CoT reasoning examples from [kelexine/fable-5-sft-traces](https://huggingface.co/datasets/kelexine/fable-5-sft-traces). Single or multi-turn examples with full `<think>` traces, covering high-level task decomposition before any execution loop begins.

Together these streams teach the model to *plan before acting* and *execute through observation* — the two capabilities that define reliable agentic behaviour.

**Design note:** This is v2 of Midas-FableAgent. The primary known limitation is that approximately 69% of training examples were removed post-formatting because response tokens fell outside the context window after truncation — effectively training on ~4,100 examples rather than the full 14,665. A v3 using trajectory splitting (each assistant turn as an independent training example) is planned and will substantially increase effective training data. The current model demonstrates correct agentic format and reasoning patterns; it is undertrained relative to what the data should deliver.

---

## Atem Ecosystem

Midas-FableAgent is a task-specialised derivative of the Atem series, not a numbered Atem release.

| Model | Type | Capability |
|---|---|---|
| [Atem-0.6B](https://huggingface.co/EphAsad/Atem-0.6B) | Qwen3 SFT | Compact reasoning |
| [Atem-1.7B](https://huggingface.co/EphAsad/Atem-1.7B) | Qwen3 SFT | Efficient reasoning |
| [Atem-4B](https://huggingface.co/EphAsad/Atem-4B) | Qwen3 SFT | Balanced reasoning |
| [Atem-8B](https://huggingface.co/EphAsad/Atem-8B) | Qwen3 SFT | General-purpose reasoning |
| [Atem-14B](https://huggingface.co/EphAsad/Atem-14B) | Qwen3 SFT | High-capability reasoning |
| **Midas-FableAgent** | Atem-8B → Agentic SFT | Multi-step task execution |

---

## Model Details

| Property | Value |
|---|---|
| **Base model** | EphAsad/Atem-8B |
| **Training method** | Sequential LoRA SFT — attention-only targets |
| **LoRA config** | r=32, alpha=64, dropout=0.05 |
| **Target modules** | q_proj, k_proj, v_proj, o_proj (no MLP) |
| **Parameters** | ~8.22B |
| **Trainable parameters** | 30,670,848 (0.37%) |
| **Effective training examples** | ~4,121 (post all-masked removal) |
| **Training steps** | 130 |
| **Epochs** | 2 |
| **Final val loss** | 0.4525 |
| **Final train loss** | 0.8590 |
| **Learning rate** | 4e-5 (cosine schedule) |
| **Effective batch size** | 64 (4 × 16 grad accum) |
| **Hardware** | NVIDIA A100-SXM4-80GB |
| **Max sequence length** | 12,288 tokens |
| **Precision** | bfloat16 |
| **License** | Apache 2.0 |

**Why attention-only LoRA:** Midas-FableAgent is sequentially trained on top of Atem-8B, not a raw base. Skipping MLP projections and using a lower rank (r=32 vs Atem-8B's training rank) and lower LR (4e-5 vs 1e-4) are deliberate forgetting-prevention measures. The goal is to shift the model's output distribution toward agentic formats without eroding the general reasoning capability established during Atem-8B's training.

---

## Output Format

Midas-FableAgent produces two output formats depending on the task type.

### Agentic execution (Stream A format)

When operating as an execution agent — given a task and environment state — the model responds with a JSON action block, optionally preceded by a `<think>` reasoning trace:

```
<think>
[Reasoning about current state, what commands are needed, potential failure modes]
</think>
{
  "analysis": "Current state assessment grounded in the provided terminal output.",
  "plan": "Concrete sequence of steps to advance toward task completion.",
  "commands": [
    {"keystrokes": "find . -type f -size +100M\n", "duration": 0.5},
    {"keystrokes": "sort -rh\n", "duration": 0.1}
  ],
  "task_complete": false
}
```

On completion:
```json
{
  "analysis": "Task verified complete. All required outputs confirmed.",
  "plan": "No further steps needed.",
  "commands": [],
  "task_complete": true
}
```

### Planning / CoT (Stream B format)

When reasoning through open-ended planning problems without an execution context, the model produces a `<think>` trace followed by structured prose:

```
<think>
[Full reasoning trace — constraint identification, option analysis, decision rationale]
</think>
[Structured, actionable plan or analysis]
```

---

## Training Data

| Dataset | Count | Format | Focus |
|---|---|---|---|
| [open-thoughts/OpenThoughts-Agent-v1-SFT](https://huggingface.co/datasets/open-thoughts/OpenThoughts-Agent-v1-SFT) | 10,000 (streamed) | Multi-turn trajectories | Agentic execution loops |
| [kelexine/fable-5-sft-traces](https://huggingface.co/datasets/kelexine/fable-5-sft-traces) | 4,665 (full) | Single/multi-turn CoT | Planning and reasoning |

**Stream A processing:** Conversations loaded from the `conversations` column. Role names normalised (`human` → `user`, `gpt` → `assistant`). Structural validation: must have at least one user and one assistant turn, must start with a user turn and end with an assistant turn. 100% yield — the OpenThoughts-Agent format is structurally clean.

**Stream B processing:** Loaded directly from parquet (the `messages` column serialises as a numpy array of per-turn JSON strings, bypassing schema parsing). Assistant response reconstructed from the `context` (user prompt), `thinking` (CoT trace → injected as `<think>...</think>`), and `response` (final answer) columns, rather than from the noisy `messages` column which contained `/model` slash-command noise and `<local-command-stdout>` artefacts. 100% yield after column-based reconstruction.

**Loss curve (v2, MAX_SEQ_LENGTH=12288):**

| Step | Train Loss | Val Loss |
|---|---|---|
| 50 | 0.8055 | 0.4942 |
| 100 | 0.7631 | 0.4558 |
| 130 (final) | **0.8196** | **0.4525** |

Validation loss descends monotonically throughout the run. Early stopping did not trigger — the model had not plateaued at the 2-epoch ceiling.

---

## Evaluation

No standard benchmark evaluation (ARC, GSM8K, HellaSwag) was run for this release. Midas-FableAgent's capability is agentic rather than multiple-choice or mathematical, and lm-evaluation-harness metrics are not the appropriate measure. A qualitative evaluation was conducted using six agentic execution prompts (terminal tasks) and five planning prompts.

**Observed strengths:**
- Correctly produces the JSON action format (`analysis` / `plan` / `commands` / `task_complete`) on all execution prompts
- `analysis` fields are grounded in the provided context rather than hallucinated
- `task_complete: false` consistently set on first-step responses where the task is not yet done
- Observation-grounded reasoning: on service health check tasks, correctly reasoned to wait for command output before deciding next action
- Planning traces show genuine constraint identification — the database migration example correctly identified concurrent connection limits, DDL blocking risk, and transfer bandwidth as distinct constraints before structuring the plan
- `<think>` tags present in all agentic outputs despite not being explicitly enforced on data

**Known limitations:**
- Empty or very short think blocks on simpler queries (model short-circuits reasoning on straightforward tasks)

---

## Usage

### Inference note

Qwen3's `apply_chat_template` with `add_generation_prompt=True` appends a `<think>` special token to prime the thinking mode. When decoding, use `skip_special_tokens=False` to preserve think tags in the output, then strip EOS/PAD tokens manually:

```python
raw = tokenizer.decode(generated, skip_special_tokens=False)
raw = raw.replace(tokenizer.eos_token, '').strip()
```

### Transformers

```python
from transformers import AutoModelForCausalLM, AutoTokenizer
import torch

model_name = "EphAsad/Midas-FableAgent"

tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    torch_dtype=torch.bfloat16,
    device_map="auto"
)

# Agentic execution — use a task-specific system prompt
AGENT_SYSTEM = (
    "You are an AI assistant tasked with solving command-line tasks in a "
    "Linux environment. Format your response as JSON with the structure: "
    "{\"analysis\": \"...\", \"plan\": \"...\", \"commands\": [{\"keystrokes\": \"...\", "
    "\"duration\": 0.1}], \"task_complete\": false}"
)

messages = [
    {"role": "system", "content": AGENT_SYSTEM},
    {"role": "user", "content": "Find all files larger than 100MB under /home and list them sorted by size.\n\nCurrent terminal state:\nroot@host:/home#"},
]

inputs = tokenizer.apply_chat_template(
    messages,
    tokenize=True,
    add_generation_prompt=True,
    return_tensors="pt"
).to(model.device)

with torch.no_grad():
    output = model.generate(
        input_ids=inputs,
        max_new_tokens=900,
        temperature=0.2,
        do_sample=True,
        repetition_penalty=1.1,
    )

response = tokenizer.decode(
    output[0][inputs.shape[1]:],
    skip_special_tokens=False
).replace(tokenizer.eos_token, '').strip()
print(response)
```

### Unsloth (faster inference)

```python
from unsloth import FastLanguageModel
import torch

model, tokenizer = FastLanguageModel.from_pretrained(
    model_name="EphAsad/Midas-FableAgent",
    max_seq_length=12288,
    dtype=torch.bfloat16,
    load_in_4bit=False,
)
FastLanguageModel.for_inference(model)

# Planning / CoT mode — uses Midas-FableAgent default identity
messages = [
    {"role": "user", "content": "Plan a zero-downtime migration of a 200GB PostgreSQL database to AWS RDS."},
]

inputs = tokenizer.apply_chat_template(
    messages,
    tokenize=True,
    add_generation_prompt=True,
    return_tensors="pt"
).to("cuda")

with torch.no_grad():
    output = model.generate(
        input_ids=inputs,
        max_new_tokens=1400,
        temperature=0.6,
        do_sample=True,
        repetition_penalty=1.1,
    )

response = tokenizer.decode(
    output[0][inputs.shape[1]:],
    skip_special_tokens=False
).replace(tokenizer.eos_token, '').strip()
print(response)
```

### Ollama

```bash
# Recommended — best speed/quality balance
ollama run hf.co/EphAsad/Midas-FableAgent:Q4_K_M

# Higher quality
ollama run hf.co/EphAsad/Midas-FableAgent:Q5_K_M

# Near-lossless
ollama run hf.co/EphAsad/Midas-FableAgent:Q8_0
```

### llama.cpp

```bash
llama-server -hf EphAsad/Midas-FableAgent:Q4_K_M
```

### Available Files

| File | Size | Description |
|---|---|---|
| `model-0000{1-4}-of-00004.safetensors` | ~16.4 GB | Full bfloat16 weights (4 shards) |
| `Midas-FableAgent.Q4_K_M.gguf` | ~5.0 GB | 4-bit — recommended |
| `Midas-FableAgent.Q5_K_M.gguf` | ~5.9 GB | 5-bit |
| `Midas-FableAgent.Q8_0.gguf` | ~8.7 GB | 8-bit — near-lossless |

### System Prompt

Midas-FableAgent's identity is baked into the chat template and activates without an explicit system message. For agentic execution tasks, override the system prompt with a task-specific instruction that specifies the JSON output format (see usage examples above). To use the default identity directly:

```
You are Midas-FableAgent, an advanced agentic reasoning assistant built on
the Atem foundation. You excel at multi-step task execution — decomposing
complex goals into concrete actions, reasoning carefully about observations,
and iterating reliably toward task completion. You produce structured,
actionable outputs and maintain clear reasoning traces throughout execution.
```

---

## Roadmap

| Version | Status | Change |
|---|---|---|
| v1 (MAX_SEQ=8192) | ✅ Released | Initial training run — 128 steps, ~4,084 effective examples |
| **v2 (MAX_SEQ=12288)** | ✅ **This model** | Increased context — 130 steps, ~4,121 effective examples |
| v3 (trajectory splitting) | 🔄 Planned | Each assistant turn as independent training example — eliminates all-masked removal, ~3× effective data |

---

## Citation

```bibtex
@misc{midas_fableagent_2026,
  author       = {Asad, Zain},
  title        = {Midas-FableAgent: Sequential Agentic SFT on Atem-8B},
  year         = {2026},
  publisher    = {HuggingFace},
  howpublished = {\url{https://huggingface.co/EphAsad/Midas-FableAgent}},
}
```

---

## License

Released under the [Apache 2.0 License](https://www.apache.org/licenses/LICENSE-2.0), consistent with the base model chain (Midas-FableAgent → Atem-8B → Qwen3-8B).

---

Built independently by [EphAsad](https://huggingface.co/EphAsad)