Model	Description	Backbone	Backbone Type	Hidden Size	#Layers
DMRetriever-33M	Base 33M variant	MiniLM	Encoder-only	384	12
DMRetriever-33M-PT	Pre-trained version of 33M	MiniLM	Encoder-only	384	12
DMRetriever-109M	Base 109M variant	BERT-base-uncased	Encoder-only	768	12
DMRetriever-109M-PT	Pre-trained version of 109M	BERT-base-uncased	Encoder-only	768	12
DMRetriever-335M	Base 335M variant	BERT-large-uncased-WWM	Encoder-only	1024	24
DMRetriever-335M-PT	Pre-trained version of 335M	BERT-large-uncased-WWM	Encoder-only	1024	24
DMRetriever-596M	Base 596M variant	Qwen3-0.6B	Decoder-only	1024	28
DMRetriever-596M-PT	Pre-trained version of 596M	Qwen3-0.6B	Decoder-only	1024	28
DMRetriever-4B	Base 4B variant	Qwen3-4B	Decoder-only	2560	36
DMRetriever-4B-PT	Pre-trained version of 4B	Qwen3-4B	Decoder-only	2560	36
DMRetriever-7.6B	Base 7.6B variant	Qwen3-8B	Decoder-only	4096	36
DMRetriever-7.6B-PT	Pre-trained version of 7.6B	Qwen3-8B	Decoder-only	4096	36

Usage

Using HuggingFace Transformers:

python

import numpy as np
import torch
import torch.nn.functional as F
from transformers import AutoTokenizer, AutoModel

MODEL_NAME = "DMIR01/DMRetriever-335M"

# Load model/tokenizer
device = "cuda" if torch.cuda.is_available() else "cpu"
dtype = torch.float16 if device == "cuda" else torch.float32
tokenizer = AutoTokenizer.from_pretrained(MODEL_NAME, use_fast=True)
# Some decoder-only models have no pad token; fall back to EOS if needed
if tokenizer.pad_token is None and tokenizer.eos_token is not None:
    tokenizer.pad_token = tokenizer.eos_token
model = AutoModel.from_pretrained(MODEL_NAME, torch_dtype=dtype).to(device)
model.eval()

# Mean pooling over valid tokens (mask==1)
def mean_pool(last_hidden_state: torch.Tensor, attention_mask: torch.Tensor) -> torch.Tensor:
    mask = attention_mask.unsqueeze(-1).type_as(last_hidden_state)  # [B, T, 1]
    summed = (last_hidden_state * mask).sum(dim=1)                  # [B, H]
    counts = mask.sum(dim=1).clamp(min=1e-9)                        # [B, 1]
    return summed / counts                                          # [B, H]

# Optional task prefixes (use for queries; keep corpus plain)
TASK2PREFIX = {
    "FactCheck": "Given the claim, retrieve most relevant document that supports or refutes the claim",
    "NLI":       "Given the premise, retrieve most relevant hypothesis that is entailed by the premise",
    "QA":        "Given the question, retrieve most relevant passage that best answers the question",
    "QAdoc":     "Given the question, retrieve the most relevant document that answers the question",
    "STS":       "Given the sentence, retrieve the sentence with the same meaning",
    "Twitter":   "Given the user query, retrieve the most relevant Twitter text that meets the request",
}
def with_prefix(task: str, text: str) -> str:
    p = TASK2PREFIX.get(task, "")
    return f"{p}: {text}" if p else text

# Batch encode with L2 normalization (recommended for cosine/inner-product search)
@torch.inference_mode()
def encode_texts(texts, batch_size: int = 32, max_length: int = 512, normalize: bool = True):
    all_embs = []
    for i in range(0, len(texts), batch_size):
        batch = texts[i:i + batch_size]
        toks = tokenizer(
            batch,
            padding=True,
            truncation=True,
            max_length=max_length,
            return_tensors="pt",
        )
        toks = {k: v.to(device) for k, v in toks.items()}
        out = model(**toks, return_dict=True)
        emb = mean_pool(out.last_hidden_state, toks["attention_mask"])
        if normalize:
            emb = F.normalize(emb, p=2, dim=1)
        all_embs.append(emb.cpu().numpy())
    return np.vstack(all_embs) if all_embs else np.empty((0, model.config.hidden_size), dtype=np.float32)

# ---- Example: plain sentences ----
sentences = [
    "A cat sits on the mat.",
    "The feline is resting on the rug.",
    "Quantum mechanics studies matter and light.",
]
embs = encode_texts(sentences)  # shape: [N, hidden_size]
print("Embeddings shape:", embs.shape)

# Cosine similarity (embeddings are L2-normalized)
sims = embs @ embs.T
print("Cosine similarity matrix:\n", np.round(sims, 3))

# ---- Example: query with task prefix (QA) ----
qa_queries = [
    with_prefix("QA", "Who wrote 'Pride and Prejudice'?"),
    with_prefix("QA", "What is the capital of Japan?"),
]
qa_embs = encode_texts(qa_queries)
print("QA Embeddings shape:", qa_embs.shape)

Citation

If you find this repository helpful, please kindly consider citing the corresponding paper. Thanks!

@article{yin2025dmretriever,
  title={DMRetriever: A Family of Models for Improved Text Retrieval in Disaster Management},
  author={Yin, Kai and Dong, Xiangjue and Liu, Chengkai and Lin, Allen and Shi, Lingfeng and Mostafavi, Ali and Caverlee, James},
  journal={arXiv preprint arXiv:2510.15087},
  year={2025}
}