I use https://qcxxx.xxx.com:443/qcbin/rest/domains/{domain}/projects/{project}/defects but I can only get 100 defects. Actually there are many more than 100 defects. Why is this?
You can pass some paramethers to "fix" it.
/defects?page-size=X&start-index=Y
X is the number of how many defects you can see at same page. Y is the number of how many defects you will "skip".
There are some limits that are setted in QC configuration.