Попробуйте API пакета get:
GET /packages/:subject/:repo/:package[?attribute_values=1]
{
"name": "my-package",
"repo": "repo",
"owner": "user",
"desc": "This package...",
"labels": ["persistence", "database"],
"attribute_names": ["licenses", "vcs", "github", ...], (hidden when using 'attribute_values=1' )
"licenses": ["Apache-2.0"],
"custom_licenses": ["my-license-1", "my-license-2"], (only for Premium Account)
"followers_count": 82,
"created": "ISO8601 (yyyy-MM-dd'T'HH:mm:ss.SSSZ)",
"website_url": "http://jfrog.com",
"rating": 8,
"issue_tracker_url": "https://github.com/bintray/bintray-client-java/issues",
"linked_to_repos": [],
"github_repo": "", (publishers only)
"github_release_notes_file": "", (publishers only)
"public_download_numbers": false, (publishers only)
"public_stats": true, (publishers only)
"permissions": [],
"versions": ["0.9", "1.0", "1.0.1", ...],
"latest_version": "1.2.5",
"rating_count": 8,
"system_ids" : [],
"updated": "ISO8601 (yyyy-MM-dd'T'HH:mm:ss.SSSZ)",
"vcs_url": "https://github.com/bintray/bintray-client-java.git",
"attributes": "{"attr1_name":["attr1_value"], "attr2_name":["attr2_value"]}" (only when 'attribute_values=1')
}
https://bintray.com/docs/api/#_get_packages
Вы можете увидеть раздел версий получившегося JSON.