Below is my wiremock mock json. I would like to create a random uuid and assign it in a variable and use the same value in headers and body of the response section. Is it possible ?

{
    "request": {
        "method": "POST",
        "urlPattern": {{url_match_pattern}}
    },
    "response": {
        "status": 200,
        "headers": {
            "Content-Type": "application/json",
            "request-id" : "{{#assign 'ID'}}{{randomValue type='UUID'}}{{/assign}}{{ID}}"
        },
        "jsonBody": {
            "request_id": "{{ID}}"
        }
    }
}

I might be wrong but I have a feeling that the context of the handlebars assign doesn't span the headers and the body. I couldn't get that to work in the tests I ran anyway. The solution could be the state extension as per our conversation here - https://wiremock-community.slack.com/archives/C03NAEH5LVA/p1709682557284889

ok.. got it

sorry for the late reply. I'm not too familiar with WireMock internals in that area. From what understand from an extension point of view, you can assume that for every template, this is parsed individually. You can't assume that this is one scope they are executed in. The response template gets the model for the request passed in. From what I see, if you have two lines like your

request_id

line in there, they will be executed in isolation. If you want to use the same ID mutiple times, you need to built a whole JSON with handlebars (different use case, but maybe it transports the idea: https://github.com/wiremock/wiremock-state-extension/blob/develop/src/test/resourc[…]mplateHelperProviderExtensionTest/list_with_filled_default.json ) .

Thanks @Dirk Bolte

You might also write your own: there’s a hook to extend the model that is passed in. Haven’t tried it though: https://wiremock.org/docs/extensibility/adding-template-model-data/