A free HTTP client for VS Code — collections, environment variables, and Postman import, without leaving your editor. It's the API Tester tool from Kernel DevTools (our browser extension), ported to run standalone.
Features
Full method support — GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS, and QUERY (the newer IETF-drafted method for safe requests that need a body), with custom headers and a JSON or raw body
Environment variables — define {{variableName}} once and reuse it across any URL, header, or body; toggle variables on/off without deleting them
Collections — save requests into named groups, picked from a dropdown of your existing collections or created fresh, right from the Save dialog
Postman v2.1 import — paste a Postman Collection export (or Kernel's own JSON format) and it's parsed into collections automatically
Export to file — export a single collection or all of them to a .json file via VS Code's native save dialog, for backup or sharing
Save example responses — optionally attach the last response (status, headers, body, timing) to a saved request, so reloading it later shows a worked example without re-sending
Getting started
Open the Kernel API Tester icon in the Activity Bar (far-left icon strip)
Enter a URL, pick a method, and click Send
Click 💾 Save to add it to a collection for later
State (collections, environment variables) persists in VS Code's own storage — nothing is sent to any external server, and no account is required.
Good to know
This extension does not block requests to localhost or private IP addresses. That's a deliberate difference from the Kernel DevTools browser extension, which blocks those requests as a security measure against a malicious webpage abusing the extension's permissions — a threat that doesn't apply here, since every request is one you typed yourself. Testing your own local dev server is a primary use case for this extension.
