Requires Java 11+ (uses java.net.http.HttpClient, no external dependencies).
export CHECKNUMBER_API_KEY="YOUR_API_KEY"
java InstagramChecker.java # reads numbers.txt (one E.164 number per line)Submits to POST /v1/tasks (task_type=instagram), polls POST /v1/gettasks, prints the result URL.
This example keeps JSON/multipart handling dependency-free for readability. In production, use a JSON library (Jackson/Gson) and a multipart helper. Full docs: https://docs.checknumber.ai/instagram-bulk-number-checker