---
license: other
tags:
- dflash
- speculative-decoding
- laguna
base_model:
- poolside/Laguna-S-2.1
---
Use on OpenRouter ·
Use on Vercel AI Gateway ·
Release blog post
# Laguna-S-2.1-DFlash
DFlash speculator (draft model) for
[Laguna S 2.1](https://huggingface.co/poolside/Laguna-S-2.1), bf16.
- Architecture: `DFlashLagunaForCausalLM` (6 sliding-attention layers, block_size 16).
- Shares token embedding + lm_head with the target; `draft_vocab_size == vocab_size` (no d2t/t2d).
- Loads under vLLM (native `laguna_dflash`) and TRT-LLM (pytorch DFlash backend) as the draft model in a speculative config.
## Usage
### vLLM
```shell
vllm serve --model poolside/Laguna-S-2.1 \
--speculative-config '{"model":"poolside/Laguna-S-2.1-DFlash","num_speculative_tokens":7,"method":"dflash"}' \
...
```
### SGLang
```shell
python -m sglang.launch_server --model-path poolside/Laguna-S-2.1 \
--speculative-algorithm DFLASH \
--speculative-draft-model-path poolside/Laguna-S-2.1-DFlash \
...
```
### llama.cpp (GGUF)
A llama.cpp conversion of this draft model (`laguna-s-2.1-DFlash-BF16.gguf`) is
published in
[poolside/Laguna-S-2.1-GGUF](https://huggingface.co/poolside/Laguna-S-2.1-GGUF)
alongside the target GGUFs. It embeds the target tokenizer and the DFlash metadata
(`dflash.decoder_arch = laguna`, capture layers, block size), so it works directly
as the `-md` draft model:
```shell
git clone --branch laguna https://github.com/poolsideai/llama.cpp
cd llama.cpp && cmake -B build && cmake --build build -j
./build/bin/llama-server \
-m laguna-s-2.1-Q4_K_M.gguf \
-md laguna-s-2.1-DFlash-BF16.gguf \
--spec-type draft-dflash --spec-draft-n-max 15 \
-fa on --jinja --port 8000
```
`--spec-draft-n-max` is clamped to the trained block size (15 draft tokens + 1).
> [!NOTE]
> Requires Poolside's llama.cpp fork, branch
> [`laguna`](https://github.com/poolsideai/llama.cpp/tree/laguna). Upstream
> llama.cpp ships the generic DFlash framework but not the Laguna decoder
> contract this draft model needs, and upstream PR
> [ggml-org/llama.cpp#25165](https://github.com/ggml-org/llama.cpp/pull/25165)
> covers the target architecture only.