Returns a list of tests for a test run
https://www.gurock.com/testrail/docs/api/reference/tests#gettests
There is an API from Test Rail, it will return a list test case from one test run (id)
This is a limitation, only return up to 250 entities in once.
How can I get more than 400 or 500 case from a run?
Maximum and default value of limit parameter is 250, you can't get more than 250 with one request. But they have offset parameter for that, so you can set the start position of the next chunk.
And also you can use "next link" from the response, here is the example:
"_links": { "next": "/api/v2/get_tests/1&limit=250&offset=250", "prev": null }