Is scraping job listings illegal? If not how can i do it correctly?

Iv looked everywhere for an answer to this question but all of them are just in general and not particular to job/career industry.

I know that all the big players (Indeed, Beyond, etc) scrapy and also use API's to get their jobs. Even mid players like startwire and other fully rely on scraping.

I really want to make a small job site aggregator and want to make sure i do it correctly.. like how they are.

1. I will redirect all traffic to the rightful site that I got the job from.
2. I will put the company name next to each listing that appears on my site so the user knows its from there.

I would appreciate any tips because I feel like this would be a great project for me to learn some Python and to make a decent website long term!

Thank you!