README.md

A knowledge graph querying framework for JavaScript
Flexible SPARQL and GraphQL over decentralized RDF on the Web.

Learn more about Comunica on our website.

Comunica is an open-source project that is used by many other projects, and is being maintained by a group of volunteers. If you would like to support this project, you may consider:

• Contributing directly by writing code or documentation; or
• Contributing indirectly by funding this project via Open Collective.

Supported by

Comunica is a community-driven project, sustained by the Comunica Association. If you are using Comunica, becoming a sponsor or member is a way to make Comunica sustainable in the long-term.

Our top sponsors are shown below!

Query with Comunica

Read one of our guides to get started with querying:

• Querying from the command line
• Updating from the command line
• Querying local files from the command line
• Querying in a JavaScript app
• Updating in a JavaScript app
• Querying in a JavaScript browser app
• Setting up a SPARQL endpoint
• Querying from a Docker container
• Setting up a Web client
• Query using the latest development version

Or jump right into one of the available query engines:

• Comunica SPARQL: SPARQL/GraphQL querying from JavaScript applications or the CLI (Browser-ready via a CDN)

• Source Customisation

  • Comunica SPARQL File: Engine to query over local RDF files
  • Comunica SPARQL RDFJS: Engine to query over in-memory RDFJS-compliant sources.
  • Comunica SPARQL HDT: Library to query over local HDT files

• Solid Customisation

  • Comunica SPARQL Solid: Engine to query over files behind Solid access control.

• Link Traversal Research

  • Comunica SPARQL Link Traversal: Engine to query over multiple files by following links between them.
  • Comunica SPARQL Link Traversal Solid: Engine to query within Solid data vaults by following links between documents.

• Reasoning Support

  • Comunica SPARQL Reasoning: Engine that adds support for reasoning
  • Comunica SPARQL Reasoning File: Engine to query over local RDF files with support for reasoning

Modify or Extending Comunica

Read one of our guides to get started with modifying Comunica, or have a look at some examples:

• Querying with a custom configuration from the command line
• Querying with a custom configuration in a JavaScript app
• Exposing your custom config as an npm package
• Exposing your custom config in a Web client
• Contributing a new query operation actor to the Comunica repository
• Adding a config parameter to an actor

Contribute

Interested in contributing? Have a look at our contribution guide.

Development Setup

(JSDoc: https://comunica.github.io/comunica/)

This repository should be used by Comunica module developers as it contains multiple Comunica modules that can be composed. This repository is managed as a monorepo using Lerna.

If you want to develop new features or use the (potentially unstable) in-development version, you can set up a development environment for Comunica.

Comunica requires Node.JS 8.0 or higher and the Yarn package manager. Comunica is tested on OSX, Linux and Windows.

This project can be setup by cloning and installing it as follows:

$ git clone https://github.com/comunica/comunica.git
$ cd comunica
$ yarn install

Note: npm install is not supported at the moment, as this project makes use of Yarn's workspaces functionality

This will install the dependencies of all modules, and bootstrap the Lerna monorepo. After that, all Comunica packages are available in the packages/ folder and can be used in a development environment, such as querying with Comunica SPARQL (@comunica/query-sparql).

Furthermore, this will add pre-commit hooks to build, lint and test. These hooks can temporarily be disabled at your own risk by adding the -n flag to the commit command.

Benchmarking

If you want to do benchmarking with Comunica in Node.js, make sure to run Node.js in production mode as follows:

> NODE_ENV=production node packages/some-package/bin/some-bin.js

The reason for this is that Comunica extensively generates internal Error objects. In non-production mode, these also produce long stacktraces, which may in some cases impact performance.

Cite

If you are using or extending Comunica as part of a scientific publication, we would appreciate a citation of our article.

@inproceedings{taelman_iswc_resources_comunica_2018,
  author    = {Taelman, Ruben and Van Herwegen, Joachim and Vander Sande, Miel and Verborgh, Ruben},
  title     = {Comunica: a Modular SPARQL Query Engine for the Web},
  booktitle = {Proceedings of the 17th International Semantic Web Conference},
  year      = {2018},
  month     = oct,
  url       = {https://comunica.github.io/Article-ISWC2018-Resource/}
}

License

This code is copyrighted by the Comunica Association and Ghent University – imec and released under the MIT license.