Testing STOMP websocket with Postman

With Postman v8 you can test Websockets - great! But..

When testing STOMP servers you will encounter a problem:

The body is then followed by the NULL octet.

See https://stomp.github.io/stomp-specification-1.2.html#STOMP_Frames

The only way (on windows) to get the NULL octet into the frame is by using the "binary/Base64" encoding (see screenshot below).

To easily convert the frame you can use Notepad++:

1. Activate "Character Panel"
2. Add "NULL" at the end of the frame (after all headers and body) - make sure to actually click on "NULL"
3. Select complete frame and encode it to Base64

If you found an easier way, please comment!

Comments

[mrichardsonjr]

Mr. Schreiber, I don't use the word "hero" lightly, but you are the greatest hero in American history. (Thank you for saving me hours of beating my head against the wall.)

[benayat]

if you want something easier and user friendly, use apic to test your websocket with stomp. just a chrome extention, it works out of the box: docs.apic.app/tester/test-websocket

[rangoy]

Hi, thank you for your tips.

Inspired by your effort I found a way of adding the NULL char at the end:
It's not beautiful, but less hassle than going through base64 encoding

1. Use a pre-request Script in an other collection (as websocket collections doesn't yet support scripts) set a variable, eg NULL_CHAR. I use the same script to get a token too.

pm.environment.set('NULL_CHAR', '\0');

1. Run a request in the other collection to get the token and set the variables,
2. Use the token and variables in the messages, eg. Make sure you do not add a newline after NULL_CHAR

CONNECT
Authorization:Bearer {{TOKEN}}
accept-version:1.1,1.0
heart-beat:10000,10000

{{NULL_CHAR}}

[[e-mail]]

For linux, setting NULL_CHAR as ^@ worked for me.
pm.globals.set("NULL_CHAR",'^@')

[Aleksandr Putilov]

Setting environment variable didn't work for me. I used global variables
pm.globals.set("NULL_CHAR", '\0');

[Daniel Schreiber]

Nice!

[fmaillard-tbs]

So how to use

pm.globals.set("NULL_CHAR", '\0');

with Websockets ? Somebody succeded it ?