Qwen3.8-Flash-Next MLX Mixed 2-bit/4-bit

This is a reproducible MLX conversion of Qwen/Qwen3.8-Flash-Next at immutable revision f5d08274bafd880402bd16f5e3e6c514136ec06c.

The 48 base routed-expert banks use MLX affine Q2/group-128, the 160-wide n-gram table and remaining eligible core/MTP matrices use Q4, while token/output embeddings, QSA indexers, routers, vision, and MTP fusion heads remain BF16. This is the 128 GB Mac profile.

Artifact payload: 68.08 GiB
Quantized Q2 modules: 144
Quantized Q4/group-32 modules: 128
Quantized Q4/group-64 modules: 682
Source: 180B parameters including 125B main, 51B n-gram embedding, and 4B MTP
Native model context: 262,144 tokens; see the v0.45.0 runtime limit below.

Run locally with mere.run

Native support is available as of mere.run v0.45.0. The instructions below use its Apple Silicon Swift/MLX runtime. No Python environment, local quantization, or separate MTP-model download is needed.

Requirements and current limits

Apple Silicon Mac, macOS 15 or later, with 128 GB unified memory recommended.
Enough free disk space for the approximately 68.08 GiB checkpoint; a fresh v0.45.0 pull budgets about 82 GiB including safety headroom. Leave memory available for macOS and runtime buffers.
In v0.45.0, text generation is qualified; image input is not yet qualified, despite the model's upstream multimodal architecture and vision-chat ID.
Prompt plus requested output must fit within 2,048 tokens, including chat template/system tokens. The upstream 262,144-token context is not yet available in this runtime: long-context QSA selection is still being integrated. Requests above the current budget are rejected. Set --max-tokens explicitly; the generic 2,048-token output default leaves no room for a prompt.

1. Install or update mere.run

Download mere.run v0.45.0 or newer from the mere.run releases page, install MereRun in Applications, then open the app's Settings and choose Install CLI. Existing installations can use MereRun > Check for Updates… and reinstall the CLI from Settings if needed.

mere.run --version

This should report 0.45.0 or later. See the getting-started guide for installation details.

2. Pull this pre-quantized checkpoint

After reviewing the Qwen Community License 1.0:

mere.run model pull vision-chat-q38-flash-next-mixed \
  --accept-license-terms

Use this managed model ID, not the Hugging Face repository name, with the commands below. It resolves to this Sawfwair mixed Q2/Q4 distribution and includes the bundled MTP head. The repository is public and ungated; the acceptance flag records acknowledgement of the model's terms, not a request for gated access.

For an external SSD, add --cache-dir /Volumes/Models/huggingface-cache to the pull command, substituting your mounted drive's path. Keep that drive mounted while using the model. To inspect support and download requirements without downloading, add --preflight --json to the pull command.

3. Generate text with verified MTP

mere.run text chat \
  --model vision-chat-q38-flash-next-mixed \
  --context-size 2048 \
  --max-tokens 256 \
  --temperature 0 \
  --no-thinking \
  --stream \
  --stats \
  --prompt "Explain sparse attention in three short sentences."

--temperature 0 selects greedy decoding, which uses the bundled MTP draft head by default for eligible requests. Proposed tokens are verified by the full target model. No opt-in flag or extra checkpoint is required. --stats reports local generation timing; --no-thinking keeps this short example focused on the answer.

For a target-only comparison or to avoid loading the draft head, prefix the same command with MERERUN_Q35_MTP_SPECULATION=0.

4. Serve a local OpenAI-compatible API

After the pull completes, start the server:

mere.run api serve \
  --engine text-chat-q36 \
  --model vision-chat-q38-flash-next-mixed \
  --context-size 2048 \
  --host 127.0.0.1 \
  --port 8080

text-chat-q36 is the shared Qwen-family serving engine; it also dispatches this Qwen3.8-Flash-Next model. Startup loads and warms the target and MTP graphs before the server begins listening, so allow the initial warmup to finish.

From another terminal:

curl http://127.0.0.1:8080/health

curl http://127.0.0.1:8080/v1/chat/completions \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "vision-chat-q38-flash-next-mixed",
    "messages": [{"role": "user", "content": "Explain sparse attention in three short sentences."}],
    "max_tokens": 256,
    "temperature": 0
  }'

The example binds to localhost only. If you have configured MERERUN_API_KEY, include its bearer token in requests. See the API guide for authentication and client setup.

Runtime status

The tensor inventory, source hashes, MLX packing, fused-expert split, convolution layout, and zero-centered RMSNorm conversion are validated by the bundled MERERUN_CONVERSION.json. A Qwen4Exp-aware MLX runtime is required; do not expect an older mlx-lm or mlx-vlm release to dispatch this new architecture.

License

This redistribution retains the upstream Qwen Community License 1.0 in LICENSE. Review it before use. In particular, it contains attribution/display requirements for very large commercial products and separate-license conditions for certain commercial Model-as-a-Service and AI Work Assistant uses. The model is not gated; downloading or using it does not remove those terms.

The upstream model card is preserved as README.upstream.md.

Sawfwair/Qwen3.8-Flash-Next-MLX-Mixed-2bit