How to Install and Use atac in Linux for a Terminal API Client

Developing, testing, and debugging REST APIs usually involves graphical tools such as Postman or Insomnia. While feature-rich, graphical API clients are resource-intensive, slow to launch, and impossible to run over headless remote SSH sessions. atac (A Terminal API Client) is an open-source, keyboard-driven API client written in Rust that brings a responsive text-based user interface (TUI) directly to the Linux terminal.

With support for collections, environment variables, multi-part form data, JSON payloads, syntax highlighting, and request history, atac provides developer ergonomics comparable to graphical clients while consuming a fraction of system memory.

Installing atac on Linux

atac is distributed as a lightweight, dependency-free binary across multiple Linux installation channels.

Method 1: Direct Binary Installation (Recommended)

Download the pre-compiled binary release matching your Linux system architecture:

# Download latest release binary
curl -s https://api.github.com/repos/Julien-cpsn/ATAC/releases/latest \
  | grep "browser_download_url.*linux-x86_64.tar.gz" \
  | cut -d : -f 2,3 \
  | tr -d \" \
  | wget -qi -

# Extract and install into PATH
tar -zxvf atac-*-linux-x86_64.tar.gz
sudo mv atac /usr/local/bin/
rm -f atac-*-linux-x86_64.tar.gz

Method 2: Using Cargo (Rust)

If you maintain a local Rust toolchain:

cargo install atac --locked

Method 3: Arch Linux (AUR)

yay -S atac-bin

Verify that atac is installed and ready for execution:

atac --version

Starting atac and Managing Workspaces

Launch the interactive interface by typing the command in any terminal emulator:

atac

By default, atac stores its collections, environments, and configuration files locally under ~/.config/atac/. You can also target project-specific directories by passing a custom directory path:

atac ~/projects/my-api/.atac

Navigating the TUI Layout

The atac interface is divided into functional panels designed for full keyboard navigation:

• Collections Pane (Left): Organises your API requests into folders, collections, and individual HTTP endpoints.
• Request Configuration Pane (Top Right): Allows editing of HTTP methods (GET, POST, PUT, DELETE), URLs, query parameters, auth headers, and body payloads.
• Response Viewer Pane (Bottom Right): Renders HTTP response codes, timing metrics, response headers, and formatted JSON bodies.

Essential Keyboard Shortcuts

• Tab: Cycle focus sequentially between the Collections, Request, and Response panels.
• j / k or Up / Down Arrows: Navigate up and down within active lists and code blocks.
• n: Create a new collection, folder, or request.
• r: Rename the currently selected request or folder.
• d: Delete the selected item.
• Space or Enter: Send the active HTTP request.
• q: Exit atac.

Configuring and Sending an API Request

Creating and executing a request follows standard REST conventions:

1. Focus the Collections pane and press n to create a new request named Get Users.
2. Press Tab to move focus to the URL input field in the Request pane.
3. Enter your endpoint URL (for example, https://jsonplaceholder.typicode.com/users).
4. Use arrow keys to cycle through HTTP methods and select GET.
5. Navigate down to the Headers tab to define custom headers (such as Authorization: Bearer token123 or Content-Type: application/json).
6. Press Enter to dispatch the request.
7. The response streams into the lower viewer, displaying status 200 OK, response latency in milliseconds, and the syntax-highlighted JSON body.

Managing Environments and Dynamic Variables

To avoid hardcoding base URLs or API keys across hundreds of endpoints, atac supports environment files:

1. Press e within the interface to open the Environment Manager.
2. Create environments such as Development and Production.
3. Define key-value pairs (e.g., baseUrl = https://api.dev.example.com and apiKey = sec_xyz987).
4. Reference variables directly within request URLs and headers using double curly brackets:

   {{baseUrl}}/v1/orders

5. Switch active environments instantly to test different backends without modifying endpoints.