Invoking a service through REST API

Hi Developers,

I'm working on a scenario where a user with a reference in the composer should be able to invoke a service in a thing through URL alone.

http://Administrator:admin@123@localhost/Thingworx/Things/Test123/Properties/temp?Accept=application/json

Through the above URL i was able to fetch the JSON response of the property. But the drawback is for the first time even with the user credentials passed in the URL, i got the Thingworx User Credentials prompt window coming up. After cancelling it out and trying again with the same session i got the expected result.  

So is this a normal behavior or do we have any work around for it.

For invoking a service how to pass the input params in the same way as above.

The whole point is to invoke a Thingworx service from a third party server by passing the user creds in the URL.

(we would prefer the credentials being passed instead of the Application key).

Thanks and Regards,

Saran.