General way to get OGP(Open Graph protocol) data is getting page data and retrieve og of meta tags, I think. However, this way has two problem.

1. Necessary data is only meta tags but getting whole page is needed.

And critical problem is:

2. If website denies bots and so on, getting page from program is also denied and can't get OGP data.

I think general API is needed only to get OGP. Or such a way already exists?