DeepL Haystack Integration

Haystack integration with DeepL translation services provider.

CI/CD
Package

---

Documentation: https://haystack.deepset.ai/integrations/deepl

Source Code: https://github.com/dribia/deepl-haystack

---

Installation

This project resides in the Python Package Index (PyPI), so it can easily be installed with pip:

pip install deepl-haystack

Usage

The DeepL Haystack integration provides two Haystack components: DeepLTextTranslator and DeepLDocumentTranslator. These components can be used to translate text and documents, respectively, using the DeepL API.

Examples

To run these examples you'll need a working DeepL API key. You can get one by signing up at the DeepL API website.

Standalone Text Translation

from haystack.utils import Secret

from deepl_haystack import DeepLTextTranslator

translator = DeepLTextTranslator(
    api_key=Secret.from_token("your_api_key_here"), source_lang="EN", target_lang="ES"
)

translated_text = translator.run("Hello, world!")
print(translated_text)
# {'translation': '¡Hola, mundo!', 'meta': {'source_lang': 'EN', 'target_lang': 'ES'}}

Standalone Document Translation

from haystack.dataclasses import Document
from haystack.utils import Secret

from deepl_haystack import DeepLDocumentTranslator

translator = DeepLDocumentTranslator(
    api_key=Secret.from_token("your_api_key_here"), source_lang="EN", target_lang="ES"
)

documents_to_translate = [
    Document(content="Hello, world!"),
    Document(content="Goodbye, Joe!", meta={"name": "Joe"}),
]

translated_documents = translator.run(documents_to_translate)
print("\n".join([f"{doc.content}, {doc.meta}" for doc in translated_documents]))
# ¡Hola, mundo!, {'source_lang': 'EN', 'target_lang': 'ES'}
# ¡Adiós, Joe!, {'name': 'Joe', 'source_lang': 'EN', 'target_lang': 'ES'}

Haystack Pipeline Integration

from haystack import Pipeline
from haystack.components.converters import TextFileToDocument
from haystack.components.writers import DocumentWriter
from haystack.dataclasses.byte_stream import ByteStream
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.utils import Secret

from deepl_haystack import DeepLDocumentTranslator

document_store = InMemoryDocumentStore()

pipeline = Pipeline()
pipeline.add_component(instance=TextFileToDocument(), name="converter")
pipeline.add_component(
    instance=DeepLDocumentTranslator(
        api_key=Secret.from_token("your_api_key_here"),
        target_lang="ES",
    ),
    name="translator",
)
pipeline.add_component(
    instance=DocumentWriter(document_store=document_store), name="document_store"
)
pipeline.connect("converter", "translator")
pipeline.connect("translator", "document_store")
pipeline.run({"converter": {"sources": [ByteStream.from_string("Hello world!")]}})
print(document_store.filter_documents())
# [Document(id=..., content: '¡Hola, mundo!', meta: {'source_lang': 'EN', 'language': 'ES'})]

Contributing

uv is the best way to interact with this project, to install it, follow the official uv installation guide.

With uv installed, one can install the project dependencies with:

uv sync

Then, to run the project unit tests:

make test-unit

To run the linters (ruff and mypy):

make lint

To apply all code formatting:

make format

And finally, to run the project integration tests (which actually use the DeepL API), you should either have the DEEPL_API_KEY environment variable set, or create a .env file:

DEEPL_API_KEY=your_api_key_here

And run:

make test-integration

License

deepl-haystack is distributed under the terms of the MIT license. Check the LICENSE file for further details.