# Jaime Ferrando Huertas: jiwo

> A Qwen3.5-4B decision model by Jaime Ferrando Huertas with a trained readout: a state and named typed questions (choice up to 255 options, score on 2 to 10 levels, noul) go in, and one forward pass returns a probability for every option, with no generated text.

- Page: https://systemonemodels.ai/jaime-ferrando-huertas/jiwo
- API: https://api.systemonemodels.ai/v1/models/jaime-ferrando-huertas/jiwo
- Download: `pip install systemonemodels && systemone pull jaime-ferrando-huertas/jiwo`

## Facts

| | |
|---|---|
| Maker | Jaime Ferrando Huertas (https://systemonemodels.ai/jaime-ferrando-huertas) |
| Decides | choice, score, noul |
| Architecture | jiwo |
| Base model | qwen/qwen3.5-4b |
| Parameters | 4.2B |
| Context | 8K tokens |
| Licence | apache-2.0 |
| Availability | Open weights |
| Released | 2026-10-05 |
| Latest version | 2026.09 |

## Reported evaluation

Suite: Decision Index 0.2.1 suite (third-party), the maker's own run. Numbers are the publisher's own.

- Median latency: 53 ms

## Model card

<!-- generated by scripts/seed_catalog.py; edit content/models/catalog.yaml -->

# jiwo-4b

A Qwen3.5-4B decision model by Jaime Ferrando Huertas with a trained readout: a state and named typed questions (choice up to 255 options, score on 2 to 10 levels, noul) go in, and one forward pass returns a probability for every option, with no generated text.

Full weights plus a readout file (8.4 GB). Trained with an 8,192-token context; mostly English. `jiwo serve` runs a Jev-style server on /v1/systemone; the card says TypeSafe does not endorse it. The maker's own run of the third-party Decision Index 0.2.1 gives 44.97 for the 4b and 28.00 for the 0.8b, not yet verified by the board. Sibling jiwo-0.8b (0.75B). Code is MIT.

## What it decides

- **choice** — picks one option from a set
- **score** — places the input on an ordered scale
- **noul** — answers a yes/no question with one probability

## At a glance

| | |
|---|---|
| Parameters | 4.2B |
| Base model | `Qwen/Qwen3.5-4B` |
| Maker | Jaime Ferrando Huertas |
| Released | 2026-10-05 |
| License | apache-2.0 |
| Reported latency | 53 ms median per request on one H100 (48 ms for jiwo-0.8b) |

## Get the weights

```bash
pip install systemonemodels
systemone pull jaime-ferrando-huertas/jiwo
```

The files are served from the maker's Hugging Face repository, [`eljiwo/jiwo-4b`](https://huggingface.co/eljiwo/jiwo-4b), and verified against the checksums recorded here.

## Read more

- [Model card](https://huggingface.co/eljiwo/jiwo-4b)
- [jiwo-0.8b](https://huggingface.co/eljiwo/jiwo-0.8b)
- [Code](https://github.com/jiwidi/jiwo)

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*This page was opened by System One for Jaime Ferrando Huertas, who can claim the organisation and take it over at any time.*

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From System One Models — https://systemonemodels.ai/ · every System One model: https://systemonemodels.ai/system-one-models