In the Bitbucket API documentation it is stated:
GET /repositories/{username}/{repo_slug}/commits/dev?exclude=master
Returns all commits on ref dev, except those that are reachable on master (similar to git log dev ^master).
git log returns expected result, but the API returns only the latest commit from the develop branch.
UPDATE:
It's not an exclude problem if I pass call like "/commits/develop" it returns 1 commit also.