Using URL path parameters with Custom REST endpoints in Splunk

restmap.conf

[script:url_path]
match                 = /api/v1/url_path
script                = url_path_handler.py
scripttype            = persist
handler               = url_path_handler.UrlPathHandler
requireAuthentication = true
output_modes          = json
passPayload           = false

url_path_handler.py

import json

from splunk.persistconn.application import PersistentServerConnectionApplication

class UrlPathHandler(PersistentServerConnectionApplication):
    def __init__(self, command_line, command_arg):
        PersistentServerConnectionApplication.__init__(self)

    def handle(self, in_string):
        request = json.loads(in_string)
        return {'payload': {'url_parameter': request['path_info']},
                'status': 200
                }

web.conf

[expose:url_path]
methods = GET
pattern = /api/v1/url_path/*

After deploying this handler, you can pass parameters to the REST endpoint inside of the URL path, e.g. for passing 325039 use:
http://localhost:8000/en-US/splunkd/__raw/servicesNS/-/{appName}/api/v1/url_path/325039

Note: The *.conf files need to be in the default folder and the .py script in the bin folder