lishunyang
69bcc6416d
Adds Lance (bytedance-research/Lance), a 3B unified AR+diffusion multimodal model on a Qwen2.5-VL backbone. Lance is BAGEL-lineage: it reuses vLLM-Omni's BAGEL Mixture-of-Transformers core verbatim and specializes only the ViT (Qwen2.5-VL vision), the VAE (Wan2.2) and the checkpoint layout. All six single-stage Lance modalities verified end-to-end on 1x B300: t2i, t2v, image_edit, video_edit, x2t_image (image understanding) and x2t_video (video understanding). 3-D mRoPE is wired through BagelRotaryEmbedding for the x2t / video / edit paths. Includes the upstream gap-analysis quality fixes (task-specific system prompts, full Qwen chat template, upstream inference defaults and aspect-ratio buckets). Ships an offline example (examples/offline_inference/lance/), an OpenAI-compatible online-serving example (examples/online_serving/lance/) and an e2e test (tests/e2e/online_serving/test_lance.py). See LANCE_PR.md for the architecture rationale, per-modality status and the two remaining follow-ups (two-stage AR+DiT, video_edit polish). Closes #3697. Signed-off-by: lishunyang <lishunyang03@gmail.com>
41 lines
1.2 KiB
Markdown
41 lines
1.2 KiB
Markdown
# Lance — online serving
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OpenAI-compatible chat completions API for Lance, served by `vllm-omni`.
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## Start the server
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```bash
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bash examples/online_serving/lance/run_server.sh
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# or, with overrides
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MODEL=bytedance-research/Lance \
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DEPLOY_CONFIG=vllm_omni/deploy/lance.yaml \
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PORT=8091 \
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bash examples/online_serving/lance/run_server.sh
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```
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The default deploy config is the single-stage `lance.yaml`; for `video_edit`
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or `text2video` workloads, point ``DEPLOY_CONFIG`` at a video-checkpoint
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config (or pass ``--model bytedance-research/Lance/Lance_3B_Video`` to
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`run_server.sh`).
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## Send a request
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```bash
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# text-to-image
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python examples/online_serving/lance/openai_chat_client.py \
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--prompt "A cute corgi astronaut on the moon, cinematic" \
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--modality text2img \
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--output corgi.png
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# image edit
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python examples/online_serving/lance/openai_chat_client.py \
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--prompt "Convert this into a vibrant cartoon-style illustration" \
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--modality img2img \
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--image-url path/to/photo.png \
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--output edited.png
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```
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The client is shared with BAGEL — same OpenAI message format, same
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``modalities`` and ``num_inference_steps`` / ``seed`` / ``height`` /
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``width`` knobs.
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