---
language:
- zh
- en
base_model: openbmb/MiniCPM-2B-sft-bf16
pipeline_tag: text-classification
---
## MiniCPM-Reranker

**MiniCPM-Reranker** 是面壁智能与清华大学自然语言处理实验室（THUNLP）共同开发的中英双语言文本重排序模型，有如下特点：
- 出色的中文、英文重排序能力。
- 出色的中英跨语言重排序能力。

MiniCPM-Reranker 基于 [MiniCPM-2B-sft-bf16](https://huggingface.co/openbmb/MiniCPM-2B-sft-bf16) 训练，结构上采取双向注意力。采取多阶段训练方式，共使用包括开源数据、机造数据、闭源数据在内的约 600 万条训练数据。

欢迎关注 RAG 套件系列：

- 检索模型：[MiniCPM-Embedding](https://huggingface.co/openbmb/MiniCPM-Embedding)
- 重排模型：[MiniCPM-Reranker](https://huggingface.co/openbmb/MiniCPM-Reranker)
- 面向 RAG 场景的 LoRA 插件：[MiniCPM3-RAG-LoRA](https://huggingface.co/openbmb/MiniCPM3-RAG-LoRA)

**MiniCPM-Reranker** is a bilingual & cross-lingual text re-ranking model developed by ModelBest Inc. and THUNLP, featuring:

- Exceptional Chinese and English re-ranking capabilities.
- Outstanding cross-lingual re-ranking capabilities between Chinese and English.

MiniCPM-Reranker is trained based on [MiniCPM-2B-sft-bf16](https://huggingface.co/openbmb/MiniCPM-2B-sft-bf16) and incorporates bidirectional attention in its architecture. The model underwent multi-stage training using approximately 6 million training examples, including open-source, synthetic, and proprietary data.

We also invite you to explore the RAG toolkit series:

- Retrieval Model: [MiniCPM-Embedding](https://huggingface.co/openbmb/MiniCPM-Embedding)
- Re-ranking Model: [MiniCPM-Reranker](https://huggingface.co/openbmb/MiniCPM-Reranker)
- LoRA Plugin for RAG scenarios: [MiniCPM3-RAG-LoRA](https://huggingface.co/openbmb/MiniCPM3-RAG-LoRA)

## 模型信息 Model Information

- 模型大小：2.4B
- 最大输入token数：1024

- Model Size: 2.4B
- Max Input Tokens: 1024

## 使用方法 Usage

### 输入格式 Input Format

本模型支持指令，输入格式如下：

MiniCPM-Reranker supports instructions in the following format:

```
<s>Instruction: {{ instruction }} Query: {{ query }}</s>{{ document }}
```

例如：

For example:

```
<s>Instruction: 为这个医学问题检索相关回答。Query: 咽喉癌的成因是什么？</s>（文档省略）
```

```
<s>Instruction: Given a claim about climate change, retrieve documents that support or refute the claim. Query: However the warming trend is slower than most climate models have forecast.</s>(document omitted)
```

也可以不提供指令，即采取如下格式：

MiniCPM-Reranker also works in instruction-free mode in the following format:

```
<s>Query: {{ query }}</s>{{ document }}
```

我们在BEIR与C-MTEB/Retrieval上测试时使用的指令见 `instructions.json`，其他测试不使用指令。

When running evaluation on BEIR and C-MTEB/Retrieval, we use instructions in `instructions.json`. For other evaluations, we do not use instructions. 

### 环境要求 Requirements

```
transformers==4.37.2
flash-attn>2.3.5
```

### 示例脚本 Demo

#### Huggingface Transformers

```python
from transformers import AutoModel, LlamaTokenizer, AutoModelForSequenceClassification
import torch
import numpy as np

# from https://github.com/huggingface/transformers/blob/v4.44.2/src/transformers/models/xlm_roberta/tokenization_xlm_roberta.py
class MiniCPMRerankerLLamaTokenizer(LlamaTokenizer):
    def build_inputs_with_special_tokens(
            self, token_ids_0, token_ids_1 = None
        ):
            """
            - single sequence: `<s> X </s>`
            - pair of sequences: `<s> A </s> B`

            Args:
                token_ids_0 (`List[int]`):
                    List of IDs to which the special tokens will be added.
                token_ids_1 (`List[int]`, *optional*):
                    Optional second list of IDs for sequence pairs.

            Returns:
                `List[int]`: List of [input IDs](../glossary#input-ids) with the appropriate special tokens.
            """

            if token_ids_1 is None:
                return super().build_inputs_with_special_tokens(token_ids_0)
            bos = [self.bos_token_id]
            sep = [self.eos_token_id]
            return bos + token_ids_0 + sep + token_ids_1

model_name = "openbmb/MiniCPM-Reranker"
tokenizer = MiniCPMRerankerLLamaTokenizer.from_pretrained(model_name, trust_remote_code=True)
tokenizer.padding_side = "right"

model = AutoModelForSequenceClassification.from_pretrained(model_name, trust_remote_code=True,attn_implementation="flash_attention_2", torch_dtype=torch.float16).to("cuda")
model.eval()

@torch.no_grad()
def rerank(input_query, input_docs):
    tokenized_inputs = tokenizer([[input_query, input_doc] for input_doc in input_docs], return_tensors="pt", padding=True, truncation=True, max_length=1024) 

    for k in tokenized_inputs:
      tokenized_inputs [k] = tokenized_inputs[k].to("cuda")

    outputs = model(**tokenized_inputs)
    score = outputs.logits
    return score.float().detach().cpu().numpy()

queries = ["中国的首都是哪里？"]
passages = [["beijing", "shanghai"]]

INSTRUCTION = "Query: "
queries = [INSTRUCTION + query for query in queries]

scores = []
for i in range(len(queries)):
    print(queries[i])
    scores.append(rerank(queries[i],passages[i]))

print(np.array(scores))  # [[[-4.7460938][-8.8515625]]]
```

#### Sentence Transformer

```python
from sentence_transformers import CrossEncoder
from transformers import LlamaTokenizer
import torch

# from https://github.com/huggingface/transformers/blob/v4.44.2/src/transformers/models/xlm_roberta/tokenization_xlm_roberta.py
class MiniCPMRerankerLLamaTokenizer(LlamaTokenizer):
    def build_inputs_with_special_tokens(
            self, token_ids_0, token_ids_1 = None
        ):
            """
            - single sequence: `<s> X </s>`
            - pair of sequences: `<s> A </s> B`

            Args:
                token_ids_0 (`List[int]`):
                    List of IDs to which the special tokens will be added.
                token_ids_1 (`List[int]`, *optional*):
                    Optional second list of IDs for sequence pairs.

            Returns:
                `List[int]`: List of [input IDs](../glossary#input-ids) with the appropriate special tokens.
            """

            if token_ids_1 is None:
                return super().build_inputs_with_special_tokens(token_ids_0)
            bos = [self.bos_token_id]
            sep = [self.eos_token_id]
            return bos + token_ids_0 + sep + token_ids_1

model_name = "openbmb/MiniCPM-Reranker"
model = CrossEncoder(model_name,max_length=1024,trust_remote_code=True, automodel_args={"attn_implementation":"flash_attention_2","torch_dtype": torch.float16})
model.tokenizer = MiniCPMRerankerLLamaTokenizer.from_pretrained(model_name, trust_remote_code=True)
model.tokenizer.padding_side = "right"

query = "中国的首都是哪里？"
passages = [["beijing", "shanghai"]]

INSTRUCTION = "Query: "
query = INSTRUCTION + query

sentence_pairs = [[query, doc] for doc in passages]

scores = model.predict(sentence_pairs, convert_to_tensor=True).tolist()
rankings = model.rank(query, passages, return_documents=True, convert_to_tensor=True)

print(scores) # [0.0087432861328125, 0.00020503997802734375]
for ranking in rankings:
    print(f"Score: {ranking['score']:.4f}, Corpus: {ranking['text']}")
  
# ID: 0, Score: 0.0087, Text: beijing
# ID: 1, Score: 0.0002, Text: shanghai
```

## 实验结果 Evaluation Results

### 中文与英文重排序结果 CN/EN Re-ranking Results

中文对`bge-large-zh-v1.5`检索的top-100进行重排，英文对`bge-large-en-v1.5`检索的top-100进行重排。

We re-rank top-100 docments from `bge-large-zh-v1.5` in C-MTEB/Retrieval and from `bge-large-en-v1.5` in BEIR.


| 模型 Model            | C-MTEB/Retrieval (NDCG@10) | BEIR (NDCG@10) |
|----------------------------|-------------------|---------------|
| bge-large-zh-v1.5（Retriever for Chinese）  | 70.46             | -             |
| bge-large-en-v1.5（Retriever for English）  | -                 | 54.29         |
| bge-reranker-v2-m3         | 71.82             | 55.36         |
| bge-reranker-v2-minicpm-28 | 73.51             | 59.86         |
| bge-reranker-v2-gemma      | 71.74             | 60.71         |
| bge-reranker-v2.5-gemma2   | -                 | **63.67**     |
| MiniCPM-Reranker                 | **76.79**         | 61.32        |

### 中英跨语言重排序结果 CN-EN Cross-lingual Re-ranking Results

对bge-m3(Dense)检索的top100进行重排。

We re-rank top-100 documents from `bge-m3` (Dense).

| 模型 Model                      | MKQA En-Zh_CN (Recall@20) | NeuCLIR22 (NDCG@10) | NeuCLIR23 (NDCG@10) |
|------------------------------------|--------------------|--------------------|--------------------|
| bge-m3 (Dense)（Retriever）              | 66.4               | 30.49              | 41.09              |
| jina-reranker-v2-base-multilingual | 69.33              | 36.66              | 50.03              |
| bge-reranker-v2-m3                 | 69.75              | 40.98              | 49.67              |
| gte-multilingual-reranker-base     | 68.51              | 38.74              | 45.3              |
| MiniCPM-Reranker                         | **71.73**          | **43.65**          | **50.59**          |

## 许可证 License

- 本仓库中代码依照 [Apache-2.0 协议](https://github.com/OpenBMB/MiniCPM/blob/main/LICENSE)开源。
- MiniCPM-Reranker 模型权重的使用则需要遵循 [MiniCPM 模型协议](https://github.com/OpenBMB/MiniCPM/blob/main/MiniCPM%20Model%20License.md)。
- MiniCPM-Reranker 模型权重对学术研究完全开放。如需将模型用于商业用途，请填写[此问卷](https://modelbest.feishu.cn/share/base/form/shrcnpV5ZT9EJ6xYjh3Kx0J6v8g)。

* The code in this repo is released under the [Apache-2.0](https://github.com/OpenBMB/MiniCPM/blob/main/LICENSE) License. 
* The usage of MiniCPM-Reranker model weights must strictly follow [MiniCPM Model License.md](https://github.com/OpenBMB/MiniCPM/blob/main/MiniCPM%20Model%20License.md).
* The models and weights of MiniCPM-Reranker are completely free for academic research. After filling out a ["questionnaire"](https://modelbest.feishu.cn/share/base/form/shrcnpV5ZT9EJ6xYjh3Kx0J6v8g) for registration, MiniCPM-Reranker weights are also available for free commercial use.