WebSocket Support is Live in Postmate Client

TL;DR: Postmate Client now supports WebSocket and WSS testing directly inside VS Code. Connect to any endpoint, send messages, watch responses stream in real time, save to your collections — free forever, no login, no telemetry. Install or update from the VS Code Marketplace →

Why this matters

If you build anything real-time — chat, notifications, live dashboards, IoT, market data feeds, multiplayer game state, GraphQL subscriptions — you've probably been forced into one of three uncomfortable options for testing WebSockets:

1. Pay for Postman. WebSocket support is locked behind their account requirement, with cloud sync on by default and telemetry running in the background.
2. Pay for Thunder Client. Their WebSocket support is gated behind a paid tier.
3. Roll your own. A bespoke Node.js script, a browser console with new WebSocket(...), or a one-off CLI tool. Works, but doesn't save, doesn't compare, doesn't fit alongside your REST tests.

None of these are great. Today we're shipping a fourth option: WebSocket testing as a first-class feature in Postmate Client — free, local, and in the same editor you write your code in.

What you can do today

Pop open the New HTTP Request dropdown, choose WebSocket, and you get a full WebSocket client inside your editor:

• Connect to any ws:// or wss:// endpoint. Paste the URL, click Connect, and the connection opens immediately.
• Authenticate with custom headers. Add Authorization tokens, API keys, or any other custom header your server expects through the Headers tab.
• Send messages in TEXT, JSON, XML, or HTML mode. Each mode (except TEXT) comes with inline syntax validation that warns you about errors without blocking you from sending.
• Stream responses in real time. Every message the server pushes shows up in the response panel as it arrives. No buffering, no manual refresh.
• Save WebSocket requests to collections. Press Ctrl+S, name your request, and it lands in the collection of your choice with a ws label so you can tell it apart from REST and GraphQL requests at a glance.
• Mix WebSocket and HTTP requests in the same collection. When you run a folder or collection, WebSocket requests are skipped automatically so they don't block your stateless HTTP run.

It's everything you need to test a WebSocket the way you'd test any other API — without leaving VS Code and without paying for a tier upgrade.

How it compares

	Postmate Client	Postman	Thunder Client
WebSocket support	✅ Free	⚠️ Yes (login required)	💰 Paid tier only
Runs inside VS Code	✅ Native	❌ Desktop app	✅ Native
Works without login	✅ Always	❌ Required	⚠️ For paid features
No telemetry	✅ None	❌ Yes	❌ Yes
Save to collections	✅ Yes	✅ Yes	✅ Yes
Inline message validation	✅ TEXT / JSON / XML / HTML	⚠️ Limited	⚠️ Limited
Price	✅ Free forever	💰 Paid plans	💰 Paid tier

A few honest notes

We want to be straightforward about what's in this release and what's coming:

• Reconnection is manual. If your connection drops, click Connect to reopen it. We considered auto-reconnect but decided against it for v1 — when you're testing a protocol, you generally want to see disconnects, not hide them.
• No separate Auth tab yet. WebSocket auth goes through custom headers. If you'd typically configure Bearer tokens or API keys under "Auth" on an HTTP request, add them via the Headers tab on the WebSocket panel.
• CLI support is on the roadmap. Right now WebSocket requests run only inside VS Code. Collection runs (folder/collection runner) and the CI/CD CLI automatically skip WebSocket entries. CLI support for WebSocket flows is coming — no firm ETA yet.
• No connection or message limits. Send what you need.

How to try it

1. Install Postmate Client (or update if you already have it) from the VS Code Marketplace.
2. Click the Postmate Client icon in the VS Code Activity Bar.
3. Click the dropdown arrow next to New HTTP Request and choose WebSocket.
4. Try the public echo server — paste wss://echo.websocket.org into the URL bar and hit Connect. Send a message in JSON mode and watch it bounce back.

Full walkthrough with screenshots: WebSocket testing in VS Code →

Feedback wanted

WebSocket support is a brand-new addition and we want to know how you're using it. What works? What's missing? What real-time API are you testing?

• Open an issue or feature request on GitHub
• Join the conversation in the discussion forum

If you've been waiting for a free, local, VS Code-native WebSocket client — it's here. Happy testing.