Integration: Hugging Face
Use Models on Hugging Face with Haystack
Table of Contents
Haystack 2.0
You can use models on Hugging Face in your Haystack 2.0 pipelines with Generators, Embedders, Rankers and Readers!
Installation
pip install haystack-ai
Usage
You can use models on Hugging Face in various ways:
Embedding Models
You can leverage embedding models from Hugging Face through two components: SentenceTransformersTextEmbedder and SentenceTransformersDocumentEmbedder.
To create semantic embeddings for documents, use SentenceTransformersDocumentEmbedder in your indexing pipeline. For generating embeddings for queries, use SentenceTransformersTextEmbedder. Once you’ve selected the suitable component for your specific use case, initialize the component with the desired model name.
Below is the example indexing pipeline with InMemoryDocumentStore, DocumentWriter and SentenceTransformersDocumentEmbedder:
from haystack import Document
from haystack import Pipeline
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.components.embedders import SentenceTransformersDocumentEmbedder
from haystack.components.writers import DocumentWriter
document_store = InMemoryDocumentStore(embedding_similarity_function="cosine")
documents = [Document(content="My name is Wolfgang and I live in Berlin"),
Document(content="I saw a black horse running"),
Document(content="Germany has many big cities")]
indexing_pipeline = Pipeline()
indexing_pipeline.add_component("embedder", SentenceTransformersDocumentEmbedder(model="sentence-transformers/all-MiniLM-L6-v2"))
indexing_pipeline.add_component("writer", DocumentWriter(document_store=document_store))
indexing_pipeline.connect("embedder", "writer")
indexing_pipeline.run({
"embedder":{"documents":documents}
})
Generative Models (LLMs)
You can leverage text generation models from Hugging Face through three components: HuggingFaceLocalGenerator, HuggingFaceTGIGenerator and HuggingFaceTGIChatGenerator.
Depending on the model type (chat or text completion) and hosting option (TGI, Inference Endpoint, locally hosted), select the suitable Hugging Face Generator component and initialize it with the model name
Below is the example query pipeline that uses mistralai/Mistral-7B-v0.1 hosted on Hugging Face Inference endpoints with HuggingFaceTGIGenerator:
from haystack import Pipeline
from haystack.utils import Secret
from haystack.components.retrievers.in_memory import InMemoryBM25Retriever
from haystack.components.builders.prompt_builder import PromptBuilder
from haystack.components.generators import HuggingFaceTGIGenerator
template = """
Given the following information, answer the question.
Context:
{% for document in documents %}
{{ document.text }}
{% endfor %}
Question: What's the official language of {{ country }}?
"""
pipe = Pipeline()
pipe.add_component("retriever", InMemoryBM25Retriever(document_store=docstore))
pipe.add_component("prompt_builder", PromptBuilder(template=template))
pipe.add_component("llm", HuggingFaceTGIGenerator(model="mistralai/Mistral-7B-v0.1", token=Secret.from_token("YOUR_HF_API_TOKEN")))
pipe.connect("retriever", "prompt_builder.documents")
pipe.connect("prompt_builder", "llm")
pipe.run({
"prompt_builder": {
"country": "France"
}
})
Ranker Models
To use cross encoder models on Hugging Face, initialize a SentenceTransformersRanker with the model name. You can then use this SentenceTransformersRanker to sort documents based on their relevancy to the query.
Below is the example of document retrieval pipeline with InMemoryBM25Retriever and SentenceTransformersRanker:
from haystack import Document, Pipeline
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.components.retrievers.in_memory import InMemoryBM25Retriever
from haystack.components.rankers import TransformersSimilarityRanker
docs = [Document(content="Paris is in France"),
Document(content="Berlin is in Germany"),
Document(content="Lyon is in France")]
document_store = InMemoryDocumentStore()
document_store.write_documents(docs)
retriever = InMemoryBM25Retriever(document_store = document_store)
ranker = TransformersSimilarityRanker(model="cross-encoder/ms-marco-MiniLM-L-6-v2")
document_ranker_pipeline = Pipeline()
document_ranker_pipeline.add_component(instance=retriever, name="retriever")
document_ranker_pipeline.add_component(instance=ranker, name="ranker")
document_ranker_pipeline.connect("retriever.documents", "ranker.documents")
query = "Cities in France"
document_ranker_pipeline.run(data={"retriever": {"query": query, "top_k": 3},
"ranker": {"query": query, "top_k": 2}})
Reader Models
To use question answering models on Hugging Face, initialize a ExtractiveReader with the model name. You can then use this ExtractiveReader to extract answers from the relevant context.
Below is the example of extractive question answering pipeline with InMemoryBM25Retriever and ExtractiveReader:
from haystack import Document, Pipeline
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.components.retrievers.in_memory import InMemoryBM25Retriever
from haystack.components.readers import ExtractiveReader
docs = [Document(content="Paris is the capital of France."),
Document(content="Berlin is the capital of Germany."),
Document(content="Rome is the capital of Italy."),
Document(content="Madrid is the capital of Spain.")]
document_store = InMemoryDocumentStore()
document_store.write_documents(docs)
retriever = InMemoryBM25Retriever(document_store = document_store)
reader = ExtractiveReader(model="deepset/roberta-base-squad2-distilled")
extractive_qa_pipeline = Pipeline()
extractive_qa_pipeline.add_component(instance=retriever, name="retriever")
extractive_qa_pipeline.add_component(instance=reader, name="reader")
extractive_qa_pipeline.connect("retriever.documents", "reader.documents")
query = "What is the capital of France?"
extractive_qa_pipeline.run(data={"retriever": {"query": query, "top_k": 3},
"reader": {"query": query, "top_k": 2}})
Haystack 1.x
You can use models on Hugging Face in your Haystack 1.x pipelines with the PromptNode, EmbeddingRetriever, Ranker, Reader and more!
Installation (1.x)
pip install farm-haystack
Usage (1.x)
You can use models on Hugging Face in various ways:
Embedding Models
To use embedding models on Hugging Face, initialize an EmbeddingRetriever with the model name. You can then use this EmbeddingRetriever in an indexing pipeline to create semantic embeddings for documents and index them to a document store.
Below is the example indexing pipeline with PreProcessor, InMemoryDocumentStore and EmbeddingRetriever:
from haystack.nodes import EmbeddingRetriever
from haystack.document_stores import InMemoryDocumentStore
from haystack.pipelines import Pipeline
from haystack.schema import Document
document_store = InMemoryDocumentStore(embedding_dim=384)
preprocessor = PreProcessor()
retriever = EmbeddingRetriever(
embedding_model="sentence-transformers/all-MiniLM-L6-v2", document_store=document_store
)
indexing_pipeline = Pipeline()
indexing_pipeline.add_node(component=preprocessor, name="Preprocessor", inputs=["File"])
indexing_pipeline.add_node(component=retriever, name="Retriever", inputs=["Preprocessor"])
indexing_pipeline.add_node(component=document_store, name="document_store", inputs=["Retriever"])
indexing_pipeline.run(documents=[Document("This is my document")])
Generative Models (LLMs)
To use text generation models on Hugging Face, initialize a PromptNode with the model name and the prompt template. You can then use this PromptNode to generate questions from the given context.
Below is the example of question generation pipeline using RAG with EmbeddingRetriever and PromptNode:
from haystack import Pipeline
from haystack.nodes import BM25Retriever, PromptNode
retriever = EmbeddingRetriever(
embedding_model="sentence-transformers/all-MiniLM-L6-v2", document_store=document_store
)
prompt_node = PromptNode(model_name_or_path = "mistralai/Mistral-7B-Instruct-v0.1",
api_key = "HF_API_KEY",
default_prompt_template = "deepset/question-generation")
query_pipeline = Pipeline()
query_pipeline.add_node(component=retriever, name="Retriever", inputs=["Query"])
query_pipeline.add_node(component=prompt_node, name="PromptNode", inputs=["Retriever"])
query_pipeline.run(query = "Berlin")
If you would like to use the Inference API, you need pass your Hugging Face token to PromptNode.
Ranker Models
To use cross encoder models on Hugging Face, initialize a SentenceTransformersRanker with the model name. You can then use this SentenceTransformersRanker to sort documents based on their relevancy to the query.
Below is the example of document retrieval pipeline with BM25Retriever and SentenceTransformersRanker:
from haystack.nodes import SentenceTransformersRanker, BM25Retriever
from haystack.pipelines import Pipeline
retriever = BM25Retriever(document_store=document_store)
ranker = SentenceTransformersRanker(model_name_or_path="cross-encoder/ms-marco-MiniLM-L-6-v2")
document_retrieval_pipeline = Pipeline()
document_retrieval_pipeline.add_node(component=retriever, name="Retriever", inputs=["Query"])
document_retrieval_pipeline.add_node(component=ranker, name="Ranker", inputs=["Retriever"])
document_retrieval_pipeline.run("YOUR_QUERY")
Reader Models
To use question answering models on Hugging Face, initialize a FarmReader with the model name. You can then use this FarmReader to extract answers from the relevant context.
Below is the example of extractive question answering pipeline with BM25Retriever and FARMReader:
from haystack.nodes import BM25Retriever, FARMReader
from haystack.pipelines import Pipeline
retriever = BM25Retriever(document_store=document_store)
reader = FARMReader(model_name_or_path="deepset/roberta-base-squad2", use_gpu=True)
querying_pipeline = Pipeline()
querying_pipeline.add_node(component=retriever, name="Retriever", inputs=["Query"])
querying_pipeline.add_node(component=reader, name="Reader", inputs=["Retriever"])
querying_pipeline.run("YOUR_QUERY")