For developping and testing, the JIRA REST Browser is a great help. Unfortunately, this product has an annoying bug that prevents it from working correctly with non-JIRA add-ons.

JIRA REST Browser

You can find this free add-on here: https://marketplace.atlassian.com/plugins/com.atlassian.labs.rest-api-browser.

The JIRA REST Browser provides a GUI that shows the parameters and allows to run and test REST services:

Some more information can be found here: https://developer.atlassian.com/docs/atlassian-platform-common-components/rest-api-development/developing-a-rest-service-plugin

Patch the JIRA REST Browser

Atlassian has added hard-coded information on the REST services that can be displayed via the JIRA REST Browser, so that, contary to the documentation, services of other add-ons are not displayed.

You can work around this bug with the following patch:

# download plugin (https://marketplace.atlassian.com/plugins/com.atlassian.labs.rest-api-browser): 
# extract files (js) 
 
unzip rest-api-browser-3.0.x.jar  assets/rab/rest-api-browser.min.js assets/rab/services/rest_resources_service.js 
 
# add icbiz in: assets/rab/rest-api-browser.min.js 
var JIRA_PUBLIC_APIS=["^json-rpc/","^api/2","^auth/","^activities/","^icbiz/"] 
 
# add icbiz in: assets/rab/services/rest_resources_service.js 
var JIRA_PUBLIC_APIS = [ 
                '^json-rpc/', 
                '^api/2', 
                '^auth/', 
                '^activities/', 
                '^icbiz' 
            ]; 
 
 
# update Jar-file
jar -uf rest-api-browser-3.0.x.jar assets/rab/rest-api-browser.min.js assets/rab/services/rest_resources_service.js

(replace 3.0.x by the version you are using)

Using the JIRA REST Browser

JIRA REST Browser

Patch the JIRA REST Browser