---
title: QwenFX
canonical_url: "https://www.modelscope.ai/models/Spartan1925/QwenFX"
md_url: "https://www.modelscope.ai/models/Spartan1925/QwenFX.md"
repository: Spartan1925/QwenFX
last_updated: 2026-11-09
license: apache-2.0
base_model:
  - Qwen/Qwen3.5-4B
base_model_relation: adapter
parameters: 136.6M
tensor_type:
  - U16
  - I64
  - BF16
  - I32
  - U8
library_name:
  - safetensors
downloads: 4
stars: 0
tags:
  - qwenputer
  - risc-v
  - compiled-weights
  - coding-agent
  - fx
---

# QwenFX

> QwenFX - An open-source model by Spartan1925 on ModelScope. Code: GitHub · Mirror: ModelScope Part of Qwenputer, the computer compiled into Qwen3.5's weights.

Spartan1925/QwenFX is a 136.6M-parameter machine learning model on ModelScope. licensed under apache-2.0. derived from Qwen/Qwen3.5-4B.

- **Repository**: Spartan1925/QwenFX
- **License**: apache-2.0
- **Parameters**: 136.6M
- **Base model**: Qwen/Qwen3.5-4B
- **Tags**: qwenputer, risc-v, compiled-weights, coding-agent, fx
- **Downloads**: 4
- **Stars**: 0
- **Last updated**: 2026-11-09

Source: https://www.modelscope.ai/models/Spartan1925/QwenFX

---

<p align="center">
  <img src="qwenfx-banner.svg" alt="QwenFX: a coding agent, running inside the weights of the model it drives." width="100%">
</p>

Code: [GitHub](https://github.com/divagr18/QwenFX) · Mirror: [ModelScope](https://www.modelscope.ai/models/Spartan1925/QwenFX)  
Part of [Qwenputer](https://github.com/divagr18/qwenputer), the computer compiled into Qwen3.5's weights.

**QwenFX runs [fx](https://github.com/vercel-labs/fx), Vercel's coding agent, as its exact compiled
binary on a RISC-V CPU compiled into weights that run beside Qwen3.5-4B, with that same Qwen as fx's
model.** fx solved 15 of 15 small coding tasks, each checked by a hidden test, and opened five pull
requests on GitHub by itself
([#6](https://github.com/divagr18/fxputer-sandbox/pull/6)-[#10](https://github.com/divagr18/fxputer-sandbox/pull/10)).
Every chip token in every run was checked against a reference machine. None was wrong.

This repository holds the chip: the CPU's weights, with fx's boot state in them. Qwen3.5-4B is not
included; use [Qwen/Qwen3.5-4B](https://huggingface.co/Qwen/Qwen3.5-4B) unchanged.

## Files

| file | what | bytes | sha256 |
|---|---|---|---|
| `fx-live-u13-f4096.safetensors` | the chip: 162 layers, 4,096 RAM frames, the 13 hot-code units, fx's boot state | 124,960,497 | `48ddb06c…` |
| `fx-live-u13-f4096-text.safetensors` | the same, plus the text bridge that carries Qwen's text through the circuit (`--text`) | 129,060,613 | `fda824ef…` |
| `fx-fastcopy.elf` | fx's RV32IM+Zba ELF, built from fx's unmodified source at `757bdb9` | 75,606,908 | `282e53d4…` |
| `imports.json` | the ELF's import table | | |

The chip file is a sparse safetensors file: 19.07M nonzero bf16 weights, plus the machine's state
after fx's boot. Executor v4 lifts the circuit from these weights at load. With base Qwen beside it,
a live task peaks at 10-14 GB of GPU memory on an L4.

## Use

```bash
git clone https://github.com/divagr18/QwenFX && cd QwenFX && uv sync --extra hf
uv run python qwenfx.py setup
uv run hf download divagr1925/QwenFX fx-live-u13-f4096.safetensors --local-dir chip
uv run python qwenfx.py task t1_bug
```

`qwenfx.py chip` builds the same file from the Python circuit instead (about 3 minutes, 6.4 GB of
RAM); the arrays are identical. The GitHub README has the issue-to-pull-request flow, what runs on
the chip and what runs on the host, and the checks.

## Not a merged checkpoint

The chip and Qwen are two sets of weights in one process on one GPU. Qwen's own weights are
unchanged. A merged checkpoint is very possible, since the chip uses Qwen3.5's own layer types and
Qwenputer already ships its CPU merged, but at fx's size it would be about 25-37 GB (estimated),
mostly zero padding, against 8.5 GB for base Qwen plus this 125 MB file. So I chose this layout. The host still renders the chat template, tokenizes, parses tool calls, keeps the file
store fx reads and writes, and does the git and GitHub work of a pull request. fx's own code, all of
it, runs on the chip.

## License

Apache-2.0. fx is by Vercel, Apache-2.0: `LICENSE` is fx's license, and `THIRD_PARTY_NOTICES.md` is
fx's, unchanged. The ELF and the chip files' boot state are fx-derived; `NOTICE` in the GitHub
repository's `third_party/fx/` (and here) says how the ELF was built and what else it contains. Qwen3.5-4B is
Apache-2.0 and is not redistributed here.