Weaviate is a multi-purpose vector DB that can store both embeddings and data objects, making it a good choice for multi-modality.

The WeaviateDocumentStore can connect to any Weaviate instance, whether it's running on Weaviate Cloud Services, Kubernetes, or a local Docker container.

Installation

You can simply install the Weaviate Haystack integration with:

pip install weaviate-haystack

Initialization

Weaviate Embedded

To use WeaviateDocumentStore as a temporary instance, initialize it as "Embedded":

from haystack_integrations.document_stores.weaviate import WeaviateDocumentStore
from weaviate.embedded import EmbeddedOptions

document_store = WeaviateDocumentStore(embedded_options=EmbeddedOptions())

Docker

You can use WeaviateDocumentStore in a local Docker container. This is what a minimal docker-compose.yml could look like:

---
version: '3.4'
services:
  weaviate:
    command:
    - --host
    - 0.0.0.0
    - --port
    - '8080'
    - --scheme
    - http
    image: semitechnologies/weaviate:1.24.5
    ports:
    - 8080:8080
    - 50051:50051
    volumes:
    - weaviate_data:/var/lib/weaviate
    restart: on-failure:0
    environment:
      QUERY_DEFAULTS_LIMIT: 25
      AUTHENTICATION_ANONYMOUS_ACCESS_ENABLED: 'true'
      PERSISTENCE_DATA_PATH: '/var/lib/weaviate'
      DEFAULT_VECTORIZER_MODULE: 'none'
      ENABLE_MODULES: ''
      CLUSTER_HOSTNAME: 'node1'
volumes:
  weaviate_data:
...

🚧

With this example, we explicitly enable access without authentication, so you don't need to set any username, password, or API key to connect to our local instance. That is strongly discouraged for production use. See the authorization section for detailed information.

Start your container with docker compose up -d and then initialize the Document Store with:

from haystack_integrations.document_stores.weaviate.document_store import WeaviateDocumentStore
from haystack import Document

document_store = WeaviateDocumentStore(url="http://localhost:8080")
document_store.write_documents([
    Document(content="This is first"),
    Document(content="This is second")
])
print(document_store.count_documents())

Weaviate Cloud Service

To use the Weaviate managed cloud service, first, create your Weaviate cluster.

Then, initialize the WeaviateDocumentStore using the API Key and URL found in your Weaviate account:

from haystack_integrations.document_stores.weaviate import WeaviateDocumentStore, AuthApiKey
from haystack import Document

import os
os.environ["WEAVIATE_API_KEY"] = "YOUR-API-KEY"

auth_client_secret = AuthApiKey()

document_store = WeaviateDocumentStore(url="YOUR-WEAVIATE-URL",
    auth_client_secret=auth_client_secret)

Authorization

We provide some utility classes in the auth package to handle authorization using different credentials. Every class stores distinct secrets and retrieves them from the environment variables when required.

The default environment variables for the classes are:

• AuthApiKey
  • WEAVIATE_API_KEY
• AuthBearerToken
  • WEAVIATE_ACCESS_TOKEN
  • WEAVIATE_REFRESH_TOKEN
• AuthClientCredentials
  • WEAVIATE_CLIENT_SECRET
  • WEAVIATE_SCOPE
• AuthClientPassword
  • WEAVIATE_USERNAME
  • WEAVIATE_PASSWORD
  • WEAVIATE_SCOPE

You can easily change environment variables if needed. In the following snippet, we instruct AuthApiKey to look for MY_ENV_VAR.

from haystack_integrations.document_stores.weaviate.auth import AuthApiKey
from haystack.utils.auth import Secret

AuthApiKey(api_key=Secret.from_env_var("MY_ENV_VAR"))

Supported Retrievers

WeaviateBM25Retriever: A keyword-based Retriever that fetches documents matching a query from the Document Store.

WeaviateEmbeddingRetriever: Compares the query and document embeddings and fetches the documents most relevant to the query.