Certain pre-processors can be specified globally anywhere in the template that run as soon as the template is loaded to achieve things like random ids generated for each template run.

randstr

Generates a random ID for a template on each nuclei run. This can be used anywhere in the template and will always contain the same value. randstr can be suffixed by a number, and new random ids will be created for those names too. Ex. {{randstr_1}} which will remain same across the template.

randstr is also supported within matchers and can be used to match the inputs.

For example:-

http:
  - method: POST
    path:
      - "{{BaseURL}}/level1/application/"
    headers:
      cmd: echo '{{randstr}}'

    matchers:
      - type: word
        words:
          - '{{randstr}}'