Tyk - request body is forwarded without being transformed

There is an issue with your API definition file. The extended_paths section should be a child of Default. For example

{
	"version_data": {
		"not_versioned": true,
		"versions": {
			"Default": {
				"name": "Default",
				"use_extended_paths": true,
				"extended_paths": {
					"transform": [
						{
							"path": "/widgets",
							"method": "POST",
							"template_data": {
								"template_mode": "file",
								"template_source": "./templates/transform_test.tmpl"
							}
						}
					]
				}
			}
		}
	}
}

Try again and let us know if it works now