WebSocket

Choose WS in the protocol menu and enter a ws:// or wss:// address. Params, Headers, and Authorization apply to the handshake, the HTTP request that opens the connection.

Exchange messages

Select Connect. When the server accepts the handshake, the log shows Connected and a timer, and the button changes to Send.
In Message, choose JSON, Text, or Binary and type the message. JSON is checked as you type and highlighted.
Select Send. Each message appears in the log with an arrow for its direction, its size, and the time it was sent or received.
Select Disconnect to close the connection.

For Binary, enter the bytes as Base64 or as hex with a 0x prefix, such as 0x48656c6c6f. Received binary messages are shown as Base64.

Catalog example

The Catalog API serves a WebSocket at /ws. It greets each connection, echoes what you send, and streams stock updates after a subscription.

Start the Catalog API and create a WS request to ws://127.0.0.1:8787/ws.
Select Connect. The first message is a welcome that lists the available channels.

Choose JSON and send this message:

{ "type": "subscribe", "channel": "stock" }

The server confirms with subscribed and then sends five stock messages, one for each product.

Any other message comes back as an echo with the text the server received.

Reuse a message

Select Save above the editor to keep the current message with the request. Saved then shows how many messages are kept; open it and pick one to put it back in the editor with its format. A request keeps the six most recently saved messages. Select the cross next to a saved message to remove it.

Read the log

Select Received or Sent to show only one direction. Select it again to show both. The number next to each is the count of messages.
Select the search icon to find messages by text.
Clear the log to start over without closing the connection.

Connection issues

If the connection fails, check the address, the handshake status, and the authorization. A server that requires a subprotocol expects the Sec-WebSocket-Protocol header; add it under Headers.

An open connection does not mean that the server will send anything. Many servers wait for a subscription or a first message, as the Catalog API does. Read the server’s first messages and its documentation to learn what it expects.