whose-number-is-this

Whose Number Is This is an OSINT skill for investigating a phone number: normalizing it to E.164 with libphonenumber, scanning with phoneinfoga, identifying carrier and line type, detecting VoIP and burner numbers, checking messaging-app registration, and consulting reverse-lookup and caller-ID sources. Its premise is that a phone number is a strong selector — expensive to acquire, hard to change, and used as an account-recovery anchor almost everywhere — but the metadata people quote most (the carrier) is frequently stale, and a large share of numbers now belong to software rather than a SIM. It explicitly forbids calling or texting the subject, since that is contact rather than research.

The workflow starts with writing authorized scope and jurisdiction (reverse lookup is regulated in many places) and deciding whether interactive messaging-app checks are allowed. It then normalizes to E.164 (handling trunk-prefix traps), reads off country code, national destination code, and line type, and classifies carrier data honestly — distinguishing a live HLR query from prefix-to-carrier tables that only name the original allocation block and break under number portability. It flags VoIP as often the highest-signal finding for fraud and sockpuppet work while stressing that VoIP is not proof of bad faith. Reference files cover line types and a messaging-app disclosure matrix (registration, display name, profile photo, about text, last-seen, username, group membership) and the operational-security and privacy costs of interactive checks, including that contact-list sync uploads your address book, that lookups can make your account visible to the subject, and that bulk lookup violates platform terms.

It targets fraud, trust-and-safety, and investigative professionals handling vishing, business email compromise, counterparty verification before payment, and recruitment or marketplace scam checks. This is dual-use investigative tooling that profiles an individual and touches privacy-sensitive, regulated territory; those concerns are the notable considerations, but they are heavily mitigated by mandatory scope-setting, jurisdiction awareness, a no-contact rule, an ethics reference, and disable-model-invocation so the skill is not auto-triggered.