DeepSeek-V4-Flash-Vision-BF16

[!TIP] Looking for the newer DeepSeek V4 Flash 0731 backbone? Use the 0731 BF16 vision package.

DeepSeek V4 Flash Vision (BF16 source overlay)

DeepSeek V4 Flash with sight. This source overlay connects DeepSeek's reasoning and agentic model to the MoonViT vision encoder from Kimi-K2.6 through WebBrain's trained, routing-aware PatchMerger projector.

The text backbone and vision tower remain frozen. The only newly trained parameters are the 40,119,040-parameter projector that merges each 2x2 group of MoonViT patches and maps the resulting 4608-dimensional representation into DeepSeek's 4096-dimensional token space. Original text routing IDs are preserved; image positions receive deterministic routing IDs from a fixed 64-ID palette.

Why vision at WebBrain

At WebBrain, we build browser agents that need to understand the visual state of the web—not just extracted text. Screenshots, charts, dashboards, rich editors, and the location and appearance of controls are part of real browser work, so vision is a practical product requirement.

In our American–Chinese open-model frontier benchmark, DeepSeek V4 Flash stood out as a very strong and cost-efficient model, but the upstream checkpoint is text-only. This project adds a MoonViT vision bridge while keeping both the language backbone and vision tower frozen.

[!IMPORTANT] This repository is a BF16 vision source overlay, not a complete 291B BF16 checkpoint. It contains the genuine BF16 MoonViT tower, trained BF16 projector, processor, routing bridge, and SGLang integration source. It does not contain or claim a full-BF16 conversion of the DeepSeek text backbone. When paired with NVIDIA's NVFP4 text backbone, the documented pinned B200 runtime has passed full shard loading, server startup, and two live image-response smoke tests. Other text checkpoints and production use remain unvalidated.

Build status

• Pin the official DeepSeek V4 Flash text reference.
• Extract and fingerprint-verify the frozen BF16 MoonViT tower.
• Pass real BF16 H200 forward/backward, overfit, and calibration gates.
• Materialize and cache the 100,000-example MoonViT training set.
• Finish the 100,000-example MoonViT projector run.
• Package the BF16 tower, final projector, routing bridge, and serving glue.
• Pass reference BF16 image inference and KV-cache/full-prefix token parity.
• Pass a full-model loader/startup gate and two live image-response smoke tests with the pinned NVFP4 text backbone and B200 SGLang build.
• Run a fresh full-model loader and smoke test for every other chosen text checkpoint, hardware target, or SGLang build.

Included BF16 artifacts

Machine-readable provenance is in VISION_ADAPTER_MANIFEST.json.

Provenance

• Text reference: deepseek-ai/DeepSeek-V4-Flash at immutable revision 60d8d70770c6776ff598c94bb586a859a38244f1.
• Vision source: moonshotai/Kimi-K2.6 at revision 7eb5002f6aadc958aed6a9177b7ed26bb94011bb, extracted from the frozen vision_tower. namespace without changing tensor dtype.
• Projector: the final WebBrain MoonViT projector trained in BF16 on the frozen tower and a frozen BF16 reconstruction used for gradient-compatible reference training.
• Packaging source: verified vision artifacts and serving glue from webbrain-one/DeepSeek-V4-Flash-Vision-NVFP4. No NVFP4 text shard is included here.

Usage

The repository includes a staging script rather than pretending to be a standalone Transformers checkpoint:

# MODEL_DIR must already contain a compatible DeepSeek V4 text checkpoint,
# including config.json and model.safetensors.index.json.
cp vision_tower.safetensors mm_projector.safetensors "$MODEL_DIR/"
python scripts/prepare_sglang_model_repo.py "$MODEL_DIR" --source-root "$PWD"

Then use the custom SGLang launch wrapper documented in docs/SGLANG_DEPLOYMENT.md. Stock SGLang does not know how to inject MoonViT embeddings into DeepSeek V4 routing. The integration requires the checked-in external model/processor package and a narrow, version-pinned SGLang source patch.

For the documented NVFP4-on-B200 startup profile:

export DEEPSEEK_VISION_MODEL_PATH="$MODEL_DIR"
export DEEPSEEK_VISION_PYTHONPATH="$MODEL_DIR/sglang_ext"
export DEEPSEEK_VISION_KERNEL_PROFILE=blackwell-native
export DEEPSEEK_VISION_TP=4
scripts/launch_sglang_moonvit.sh

That profile selects the native flashinfer_trtllm dense backend and flashinfer_trtllm_routed MoE backend. The BF16 overlay does not select a quantized kernel profile by default because it does not include a text checkpoint.

The first supported correctness endpoint is native /generate with one literal <image> marker. OpenAI /v1/chat/completions image parts are not yet supported by this source package.

Status and limitations

• The two published component files are genuine BF16 tensors and have been hash-checked.
• Reference BF16 multimodal inference and KV-cache/full-prefix parity passed during the original training run.
• The complete DeepSeek text backbone is not included and is not represented as BF16.
• The custom SGLang package is a deployment integration, not upstream stock support.
• The pinned NVFP4-on-B200 combination has passed full loader/startup gates and two consecutive live image-response smoke tests.
• Every other text-checkpoint, hardware, or SGLang combination still requires a fresh full-model loader and smoke test.

Method credit

The overall construction and model-card approach was inspired by Baseten's GLM-5.2-Vision-NVFP4: keep the text backbone and MoonViT tower frozen, train a compact PatchMerger projector between them, and publish provenance and hardware constraints explicitly. Credit to the Baseten team for demonstrating this practical recipe.

This project adds a DeepSeek-specific routing bridge so mixed text/image embeddings preserve hash-routed text behavior. It does not reuse Baseten model weights, benchmark results, or deployment artifacts.

Licenses

The DeepSeek text reference is covered by LICENSE_DEEPSEEK_V4_FLASH. The extracted MoonViT tower is covered by LICENSE_KIMI_K2.6. The newly trained projector and integration source are provided under LICENSE; downstream users remain responsible for complying with both upstream licenses.

Acknowledgements

Built on DeepSeek AI's DeepSeek V4 Flash and Moonshot AI's Kimi-K2.6, with the vision-attachment method inspired by Baseten's GLM-5.2-Vision-NVFP4. These teams were not involved in this development checkpoint; please do not direct issues with this repository to them.

Want this model on your inference provider?

Ask your inference provider—such as OpenRouter or another managed inference service—to deploy this overlay together with a compatible DeepSeek V4 Flash text checkpoint and the included multimodal serving plugin. Deploying only the upstream text model will not enable image input.

Experimental status, roadmap, and get involved

[!CAUTION] Experimental vision adapter. This is a working experimental adapter with basic end-to-end SGLang image generation verified on NVIDIA B200. That bounded smoke test is not a broad quality benchmark: fine-grained OCR, small-object or control identification, GUI grounding, and hallucination calibration remain limited. If community interest warrants further investment, the roadmap is larger and more diverse datasets, higher-resolution OCR/UI examples, and broader parameter-efficient tuning. Do not use this model as the sole decision source for safety-critical automation. Interested in contributing evaluation or training data, sponsoring compute, or working with us as a design partner? Tell us here.