signal-cli is an unofficial command-line interface (CLI) for the Signal messenger. It allows users to register, verify, send, and receive messages directly from the terminal. This tool leverages a patched version of libsignal-service-java, derived from the Signal-Android source code, to interact with the Signal protocol. It is primarily designed for server-side use cases, offering JSON-RPC and D-BUS interfaces for automation and administrative tasks.
signal-cli distinguishes itself through its comprehensive support for Signal's core functionalities within a command-line environment. The project provides adaptable configuration options through command-line arguments, enabling tailored interactions. Furthermore, it offers pre-built binaries for various operating systems and experimental native builds using GraalVM, enhancing accessibility. The active development and community support ensures ongoing maintenance and adaptation to Signal server updates.
- Message Sending: Allows sending text messages to registered Signal accounts.
- Number Verification: Supports registering Signal accounts using SMS or voice verification.
- JSON-RPC Interface: Provides a JSON-RPC interface for programmatic interaction with the Signal protocol.
- D-BUS Interface: Offers a D-BUS interface for integration with desktop environments.
- Command-line Arguments: Supports various command-line arguments for configuration and control.
- Cross-Platform Compatibility: Provides binaries for Linux, macOS, and Windows.
- Daemon Mode: Enables background operation for continuous message reception.
signal-cli has been actively developed since 2015, with regular updates focusing on maintaining compatibility with Signal server changes. The project has a significant number of stars and forks, indicating community interest and usage. While occasional updates may be required to adapt to new Signal server versions, the project demonstrates a consistent development pattern and a responsive maintainer. The documentation is relatively complete, covering installation, usage, and troubleshooting.
signal-cli is valuable for system administrators, developers, and power users seeking a command-line interface for managing Signal accounts and automating messaging tasks. It simplifies Signal interactions, particularly for server-side notifications and integrations. It offers a flexible alternative to the official Signal client and facilitates scripting and automation workflows where a user interface is not ideal.