Slumber arrives as a terminal‑based HTTP client aimed at developers who need a fast, interactive way to test REST endpoints. It offers two distinct interfaces: a Terminal User Interface (TUI) that lets users compose requests, inspect headers, and scroll responses, and a Command Line Interface (CLI) for one‑liners or script integration. Both modes share a single configuration format.

Configuration lives in a YAML file called a request collection, letting teams store endpoints, authentication tokens, and payload templates in version‑controlled text. Because the TUI and CLI read the same file, a developer can prototype a call in the interactive view and then drop into a script without rewriting parameters. The design emphasizes ease of sharing across machines.

Users start by following the Getting Started guide, which walks through creating a collection and launching the TUI. Once familiar, the Key Concepts section reveals shortcuts for navigating chapters, searching responses, and toggling help, mirroring familiar editor keystrokes. Slumber therefore provides a lightweight yet powerful alternative to GUI tools for rapid API experimentation.

The project’s open‑source license invites contributions, and its minimal dependencies keep the binary under a megabyte, making it suitable for low‑resource environments.