oob callback logger

Mint a unique callback URL, then drop it into anything you're testing. When a target reaches back — a blind SSRF fetching your URL, a command injection running curl, a SQLi exfiltrating over HTTP — the request is logged here with its full headers, body, and source IP. The Collaborator/interactsh pattern, ephemeral and no-login.

For authorized security testing only. HTTP callbacks only — DNS-interaction logging isn't offered here.