FlagEmbedding

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FlagEmbedding focus on retrieval-augmented LLMs, consisting of following projects currently:

Long-Context LLM: Activation Beacon
Fine-tuning of LM : LM-Cocktail
Dense Retrieval: BGE-M3, LLM Embedder, BGE Embedding
Reranker Model: BGE Reranker
Benchmark: C-MTEB

News

1/30/2024: Release BGE-M3, a new member to BGE model series! M3 stands for Multi-linguality (100+ languages), Multi-granularities (input length up to 8192), Multi-Functionality (unification of dense, lexical, multi-vec retrieval). It is the first embedding model which supports all three retrieval methods, which achieves new SOTA on multi-lingual (MIRACL) and cross-lingual (MKQA) benchmarks Technical Report and Code. 🔥
1/9/2024: Release Activation-Beacon, an effective, efficient, compatible, and low-cost (training) method to extend the context length of LLM. Technical Report 🔥
12/24/2023: Release LLaRA, a LLaMA-7B based dense retriever, leading to state-of-the-art performances on MS MARCO and BEIR. Model and code will be open-sourced. Please stay tuned. Technical Report 🔥
11/23/2023: Release LM-Cocktail, a method to maintain general capabilities during fine-tuning by merging multiple language models. Technical Report 🔥
10/12/2023: Release LLM-Embedder, a unified embedding model to support diverse retrieval augmentation needs for LLMs. Technical Report
09/15/2023: The technical report of BGE has been released
09/15/2023: The massive training data of BGE has been released
09/12/2023: New models:
- New reranker model: release cross-encoder models BAAI/bge-reranker-base and BAAI/bge-reranker-large, which are more powerful than embedding model. We recommend to use/fine-tune them to re-rank top-k documents returned by embedding models.
- update embedding model: release bge-*-v1.5 embedding model to alleviate the issue of the similarity distribution, and enhance its retrieval ability without instruction.

09/07/2023: Update fine-tune code: Add script to mine hard negatives and support adding instruction during fine-tuning.
08/09/2023: BGE Models are integrated into Langchain, you can use it like this; C-MTEB leaderboard is available.
08/05/2023: Release base-scale and small-scale models, best performance among the models of the same size 🤗
08/02/2023: Release bge-large-*(short for BAAI General Embedding) Models, rank 1st on MTEB and C-MTEB benchmark! 🎉 🎉
08/01/2023: We release the Chinese Massive Text Embedding Benchmark (C-MTEB), consisting of 31 test dataset.

Projects

BGE-M3(Paper, Code)

In this project, we introduce BGE-M3, the first embedding model which supports multiple retrieval modes、multilingual and multi-granularity retrieval.

Multi-Functionality: It can simultaneously perform the three common retrieval functionalities of embedding model: dense retrieval, multi-vector retrieval, and sparse retrieval.
Multi-Linguality: It can support more than 100 working languages.
Multi-Granularity: It is able to process inputs of different granularities, spanning from short sentences to long documents of up to 8192 tokens.

We propose a novel self-knowledge distillation approach to improve the performance of single retrieval mode. We optimize the batching strategy, enabling a large batch size, which can used simply when fine-tuning with long text or large language model. We also construct a dataset for document retrieval and propose a simple strategy to improve the ability to model long text. The training code and fine-tuning data will be open-sourced in the near future.

Activation Beacon

The utilization of long contexts poses a big challenge for large language models due to their limited context window length. Activation Beacon condenses LLM's raw activations into more compact forms such that it can perceive a much longer context with a limited context window. It is an effective, efficient, compatible, and low-cost (training) method to extend the context length of LLM. More details please refer to our paper and code.

LM-Cocktail

Model merging has been used to improve the performance of single model. We find this method is also useful for large language models and dense embedding model, and design the LM-Cocktail strategy which automatically merges fine-tuned models and base model using a simple function to compute merging weights. LM-Cocktail can be used to improve the performance on target domain without decrease the general capabilities beyond target domain. It also can be used to generate a model for new tasks without fine-tuning. You can use it to merge the LLMs (e.g., Llama) or embedding models. More details please refer to our report: LM-Cocktail and code.

LLM Embedder

LLM Embedder is fine-tuned based on the feedback from LLMs. It can support the retrieval augmentation needs of large language models, including knowledge retrieval, memory retrieval, example retrieval, and tool retrieval. It is fine-tuned over 6 tasks: Question Answering, Conversational Search, Long Conversation, Long-Range Language Modeling, In-Context Learning, and Tool Learning. For more details please refer to report and ./FlagEmbedding/llm_embedder/README.md

BGE Reranker

Cross-encoder will perform full-attention over the input pair, which is more accurate than embedding model (i.e., bi-encoder) but more time-consuming than embedding model. Therefore, it can be used to re-rank the top-k documents returned by embedding model. We train the cross-encoder on a multilingual pair data, The data format is the same as embedding model, so you can fine-tune it easily following our example. For more details please refer to ./FlagEmbedding/reranker/README.md

BGE Embedding

BGE embedding is a general Embedding Model. We pre-train the models using retromae and train them on large-scale pair data using contrastive learning. You can fine-tune the embedding model on your data following our examples. We also provide a pre-train example. Note that the goal of pre-training is to reconstruct the text, and the pre-trained model cannot be used for similarity calculation directly, it needs to be fine-tuned. Refer to our report: c-pack and code for more details.

BGE uses the last hidden state of [cls] as the sentence embedding: sentence_embeddings = model_output[0][:, 0]. If you use mean pooling, there will be a significant decrease in performance.

C-MTEB

A benchmark for chinese text embedding. This benchmark has been merged into MTEB. Refer to our report: c-pack and code for more details.

Model List

bge is short for BAAI general embedding.

Model	Language		Description	query instruction for retrieval
BAAI/bge-m3	Multilingual	Inference Fine-tune	Multi-Functionality(dense retrieval, sparse retrieval, multi-vector(colbert)), Multi-Linguality, and Multi-Granularity(8192 tokens)
LM-Cocktail	English		fine-tuned models (Llama and BGE) which can be used to reproduce the results of LM-Cocktail
BAAI/llm-embedder	English	Inference Fine-tune	a unified embedding model to support diverse retrieval augmentation needs for LLMs	See README
BAAI/bge-reranker-large	Chinese and English	Inference Fine-tune	a cross-encoder model which is more accurate but less efficient
BAAI/bge-reranker-base	Chinese and English	Inference Fine-tune	a cross-encoder model which is more accurate but less efficient
BAAI/bge-large-en-v1.5	English	Inference Fine-tune	version 1.5 with more reasonable similarity distribution	`Represent this sentence for searching relevant passages:`
BAAI/bge-base-en-v1.5	English	Inference Fine-tune	version 1.5 with more reasonable similarity distribution	`Represent this sentence for searching relevant passages:`
BAAI/bge-small-en-v1.5	English	Inference Fine-tune	version 1.5 with more reasonable similarity distribution	`Represent this sentence for searching relevant passages:`
BAAI/bge-large-zh-v1.5	Chinese	Inference Fine-tune	version 1.5 with more reasonable similarity distribution	`为这个句子生成表示以用于检索相关文章：`
BAAI/bge-base-zh-v1.5	Chinese	Inference Fine-tune	version 1.5 with more reasonable similarity distribution	`为这个句子生成表示以用于检索相关文章：`
BAAI/bge-small-zh-v1.5	Chinese	Inference Fine-tune	version 1.5 with more reasonable similarity distribution	`为这个句子生成表示以用于检索相关文章：`
BAAI/bge-large-en	English	Inference Fine-tune	Embedding Model which map text into vector	`Represent this sentence for searching relevant passages:`
BAAI/bge-base-en	English	Inference Fine-tune	a base-scale model but with similar ability to `bge-large-en`	`Represent this sentence for searching relevant passages:`
BAAI/bge-small-en	English	Inference Fine-tune	a small-scale model but with competitive performance	`Represent this sentence for searching relevant passages:`
BAAI/bge-large-zh	Chinese	Inference Fine-tune	Embedding Model which map text into vector	`为这个句子生成表示以用于检索相关文章：`
BAAI/bge-base-zh	Chinese	Inference Fine-tune	a base-scale model but with similar ability to `bge-large-zh`	`为这个句子生成表示以用于检索相关文章：`
BAAI/bge-small-zh	Chinese	Inference Fine-tune	a small-scale model but with competitive performance	`为这个句子生成表示以用于检索相关文章：`

Contributors:

Citation

If you find this repository useful, please consider giving a star ⭐ and citation

@misc{cocktail,
      title={LM-Cocktail: Resilient Tuning of Language Models via Model Merging}, 
      author={Shitao Xiao and Zheng Liu and Peitian Zhang and Xingrun Xing},
      year={2023},
      eprint={2311.13534},
      archivePrefix={arXiv},
      primaryClass={cs.CL}
}

@misc{llm_embedder,
      title={Retrieve Anything To Augment Large Language Models}, 
      author={Peitian Zhang and Shitao Xiao and Zheng Liu and Zhicheng Dou and Jian-Yun Nie},
      year={2023},
      eprint={2310.07554},
      archivePrefix={arXiv},
      primaryClass={cs.IR}
}

@misc{bge_embedding,
      title={C-Pack: Packaged Resources To Advance General Chinese Embedding}, 
      author={Shitao Xiao and Zheng Liu and Peitian Zhang and Niklas Muennighoff},
      year={2023},
      eprint={2309.07597},
      archivePrefix={arXiv},
      primaryClass={cs.CL}
}

License

FlagEmbedding is licensed under the MIT License.

xwild / FlagEmbedding