Volt API Client

A lightweight, local-first REST API client built for Visual Studio Code.

Volt API Client lets you create, organize, send, and inspect HTTP requests without leaving your editor. Its interface follows VS Code themes and interaction patterns, so API testing feels like part of your development workflow instead of a separate application.

Why Volt API Client?

Beautiful, native-feeling VS Code experience

Volt API Client is designed to blend into VS Code. It adapts to your active color theme, supports native editor tabs, and provides a compact interface that stays out of the way while you work.

Lightweight by design

No heavyweight desktop application and no unnecessary background services. Volt API Client focuses on the essentials of everyday API development with a fast, focused workflow.

Local-first and account-free

No sign-up, login, or cloud workspace is required. Your collections, requests, and environments remain under your control.

You can store project data in a local JSON file such as:.volt/collections.json

Commit it to Git, review changes with your team, or share the file directly with another developer.

Security note: Request data can include headers, API keys, bearer tokens, and passwords. Review and redact .volt/collections.json before committing or sharing it. Volt API Client stores these values as request data; it does not move them into an operating-system keychain.

Features

Organize requests your way

• Create multiple collections
• Group requests into folders
• Collapse and expand collections and folders
• Drag and drop collections, folders, and requests to reorder or move them
• Open requests in native VS Code editor tabs
• Rename and delete resources from contextual menus

Build HTTP requests

• Common HTTP methods including GET, POST, PUT, PATCH, DELETE, and more
• Query parameters and request headers
• JSON, text, multipart form data, and URL-encoded request bodies
• Automatic Content-Type synchronization for supported body types
• JSON validation, syntax highlighting, and formatting

Authentication

• No authentication
• Basic authentication
• Bearer tokens with a configurable token prefix
• API keys added to request headers or query parameters

Environments and variables

Create multiple environments and switch values without editing every request. Global variables are always available, while an optional active environment can override them.

Reference variables anywhere in a request using double braces:{{host}}/api/users

Variables can be used in URLs, parameters, headers, request bodies, and authentication fields. Hover over a variable to see its resolved value and source environment.

Inspect responses

• Status code and request duration
• Response headers
• Formatted and syntax-highlighted JSON responses
• Responsive request and response panes
• Side-by-side or stacked layouts with adjustable pane sizes

Local Data and Git

Volt API Client supports two storage modes:

• Global State keeps data inside VS Code for a simple personal setup.
• File stores shareable request and environment data in a JSON file inside your workspace.

To keep data with your project, add the following settings to your VS Code configuration:

{
  "voltClient.storageMode": "file",
  "voltClient.storageFile": ".volt/collections.json"
}

The collections file contains shareable business data only. Local interaction state, such as the active environment and most recently opened request, is kept separately by VS Code and is not written into the shared file.

Getting Started

1. Open the Volt API Client icon in the Activity Bar.
2. Create a collection.
3. Add a request directly to the collection or create a folder first.
4. Enter a URL, configure the request, and select Send.
5. Optionally open Env to define reusable variables for different environments.

You can also run Volt Client: Open from the Command Palette.

Privacy

Volt API Client does not require an account and does not include telemetry or analytics. Request collections and environment data are stored locally according to your selected storage mode. Requests are sent directly from the VS Code extension host to the destination you specify.

Authentication values and other secrets are stored with their request data. In file storage mode, they may be written to the configured JSON file. Do not commit or share that file until you have checked it for sensitive values.

License

Volt API Client is proprietary software. Copyright (c) 2026 LIANG WEN TAO. All rights reserved.

Personal use and internal business use are permitted under the Volt Client End User License Agreement. Modification, redistribution, resale, and unauthorized commercial exploitation are prohibited.