YaCy

YaCy is an open-source, self-hosted search engine application. It consists of a server that hosts a search index, a web application for the user interface, and a web crawler with a scheduler to maintain index freshness. The software is deployed as a server and accessed via a web browser, allowing users to maintain their own index of the web or a private network.

Users can deploy YaCy in a variety of environments, including personal hardware or intranet settings. It includes a network scanner to discover HTTP, FTP, and SMB servers within a local network, which makes it suitable for internal enterprise search needs. The application can be installed by compiling from git sources, using a Windows installer, or running as a Docker container on intel-based environments.

Key features

• Peer-to-peer network for exchanging search indexes between installations
• Integrated web crawler with a scheduling system
• Local index operation mode for privacy-focused searches
• Network scanner for discovering HTTP, FTP, and SMB servers
• HTTP/XML and HTTP/JSON APIs for software integration
• Web-based administration interface for configuration and account management
• Ability to embed customized search pages into other web applications

The system is built using Java 11 or later and utilizes a decentralized architecture. By default, YaCy peers connect to a large-scale search cluster operated by other users, which allows new installations to access a wide range of results immediately. However, users can opt-out of the cluster operation through the web interface to ensure that search results are computed from the local index only. This architecture ensures that the search process remains under the control of the person hosting the server.

For developers, the software provides multiple interfaces for integration. In addition to the XML and JSON APIs, YaCy includes shell scripts in the bin subdirectory that call the web interface, enabling the creation of custom API access methods. This allows the search functionality to be attached to other software projects or integrated into existing web applications via customized search pages.

YaCy is designed for users who prioritize privacy and those requiring a decentralized search solution for public or private networks.