ATAC - Terminal API Client Cheatsheet

ATAC - Terminal API Client Cheatsheet

ATAC (Arguably a Terminal API Client) is a Postman/Insomnia-style API client that lives entirely in your terminal. Its philosophy is free, account-less, and offline — request collections are stored as plain JSON/YAML files you can commit to Git, there is no cloud or login, and it runs as a single Rust binary. It supports the usual HTTP methods, authentication schemes, environments/variables, and pre-/post-request scripts, and can import existing Postman and Insomnia collections.

Installation

Platform	Command
Cargo (all platforms)	cargo install atac
macOS (Homebrew)	brew install atac
Arch Linux (AUR)	yay -S atac
Binary	download from the GitHub Releases page
Verify	atac --version

Launching

Command	Description
atac	Open with the default collections directory
atac -d ~/api-collections	Use a specific directory for collections
atac --help	Full option list
Import Postman	point ATAC at a Postman export; it converts it

Layout & Navigation

Key	Action
Tab / Shift+Tab	Move between panes
↑ / ↓ or j / k	Move within a list
Enter	Open/select
q	Quit
? / h	Help
Ctrl+c	Cancel / quit

Collections & Requests

Action	How
New collection	Create from the collections pane
New request	Add a request under a collection
Rename/delete	Manage items in the tree
Storage	Everything saved as files (JSON/YAML) → Git-friendly

Building a Request

Field	Notes
Method	GET, POST, PUT, PATCH, DELETE, …
URL	Supports {{variable}} interpolation
Query params	Editable key/value table
Headers	Key/value table
Body	Raw, JSON, form, multipart
Auth	Basic, Bearer token, and more

Sending & Response

Key	Action
Send request	Run the current request (async)
View response	Status, time, size, headers, body
Pretty view	JSON/response formatting
Copy	Copy response body

Environments & Variables

Concept	Use
Environment files	Define {{base_url}}, tokens, etc.
Variable interpolation	{{var}} in URL, headers, body
Switch environments	Dev/staging/prod without editing requests

Scripting

Hook	Purpose
Pre-request script	Set up variables/auth before sending
Post-request script	Extract values from the response (e.g. a token)

Common Workflows

# Keep API collections in a repo and open them in the terminal
atac -d ./api-tests    # edit requests, they save as files you can commit

# Import an existing Postman collection, then run it account-free
atac                   # import the Postman export, send requests

# Chain requests: capture a token in a post-request script, reuse via {{token}}

ATAC vs Other API Clients

Aspect	ATAC	Postman	Yaak	Bruno
Interface	Terminal TUI	Desktop GUI	Desktop GUI	Desktop GUI
Account	None	Optional/cloud	None	None
Storage	Plain files (Git)	Cloud/local	Files (Git)	Files (Git)
Best for	Terminal-first, SSH, CI	Teams, cloud sync	GUI + Git	GUI + Git

Resources

• GitHub Repository
• Wiki / Documentation
• Terminal Trove Page