The best open source alternative to Truecaller is SpamBlocker. If that doesn't suit you, our users have ranked more than 25 alternatives to Truecaller and five of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Truecaller are Yet Another Call Blocker, NoPhoneSpam, Silence: Block Unknown Callers and CallerPy.
Efficiently blocks unwanted calls and SMS on Android without replacing your default app. Utilizes regex rules, contact filtering, STIR attestation, repeated call checks, dialed number, recently used apps, and a time schedule for precise, customizable protection.
A free and open source application that can block unwanted calls or warn about probable intentions of callers using a third-party crowdsourced phone number database (from some other proprietary app).
YACB is just a call blocker, it's nowhere near Truecaller. YACB doesn't tell you any details about the caller.
Block calls from annoying or private numbers on your Android device. By bitfire.
Truecaller Name Retriever. The simplest method for accessing truecaller's database is through CallerPy's online service.
TrueCaller main function is identification (name ad)