smoke tests vs cron job for validating/checking 3rd party api

I have a mock server for 3rd party service in my integration tests. Now I want to have some approach which validates specs and assumption of real server, as I want to detect their api changes asap.

Currently I see 2 approaches:

1. Set up a cron job which runs the tests against 'real' api(still it's not a production)

2. Have smoke tests, which runs before all other tests.

   Actually I have no experience with this, and not really sure should I run every time before running my integration tests or ..?

But using smoke test for me looks better. What I am not sure, how to set up, when to run, etc, as I don't want to stop running my tests if there is no internet let's say.

Thanks.