I have already tried this some time ago. There are very few bet sites which really offers betting data via api even if you sign up for affiliate.
Getting the data via api could cause a sure bet finding site and bet sites do not want this.
If you google, you will find some sites which offer data from various sites but you have to pay for. Those site have created crawler to get the data without api.
You can usually get odds feeds from the betting sites if you sign up to their affiliate program. Usually you need to send them some new customers now and again, which might be a hassle if this is for private use.