Custom Component Template

A template repository for creating custom Haystack components and publishing them as standalone Python packages.

For more details, see the Haystack documentation on creating custom components and creating custom document stores.

How to use this template

1. Click Use this template to create a new repository.

2. Rename the package directory from src/haystack_integrations/components/example/ to match your integration. See Namespace convention below for the correct path.

3. Update pyproject.toml — search for TODO comments and replace:

   • name: your package name, following the <technology>-haystack convention (e.g. opensearch-haystack)
   • description, authors, keywords, project.urls
   • dependencies: add your integration-specific dependencies
   • tool.hatch.version.raw-options: if you renamed directories, the version path is still derived from git tags so no change is needed here

4. Add your component code in the renamed directory and export your classes from __init__.py.

5. Add tests in tests/ — see the skeleton in tests/test_example.py.

6. Search for all TODO comments across the project and address them.

Namespace convention

Haystack integrations use the haystack_integrations namespace package. The directory structure under src/ determines the import path for your component.

Components (converters, embedders, generators, rankers, etc.) use:

src/haystack_integrations/components/<type>/<name>/

Import path: from haystack_integrations.components.<type>.<name> import MyComponent

Common component types: converters, embedders, generators, rankers, retrievers, connectors, tools, websearch

Document stores use a separate namespace:

src/haystack_integrations/document_stores/<name>/

Import path: from haystack_integrations.document_stores.<name> import MyDocumentStore

Development

This project uses Hatch for build and environment management.

# Install Hatch
pip install hatch

# Format and lint
hatch run fmt        # auto-fix
hatch run fmt-check  # check only

# Run tests
hatch run test:unit         # unit tests only
hatch run test:integration  # integration tests only
hatch run test:all          # all tests
hatch run test:cov          # with coverage

Publishing to PyPI

This template includes a GitHub Actions workflow that publishes your package to PyPI when you push a version tag.

1. Add a PYPI_API_TOKEN secret to your repository settings (Settings > Secrets and variables > Actions).

2. Create a version tag and push it:

   git tag v0.1.0
   git push origin v0.1.0
   

The release workflow will build and publish the package automatically.

License

Apache-2.0 - See LICENSE for details.