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 six 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, CallBlocker and Silence: Block Unknown Callers.
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.
A call blocker for Android that rejects calls from numbers that match or do not match a given regular expression. Also supports excluding known contacts or blocking unknown numbers. Does not contain trackers, ads or doesn't need internet access if the optional update feature...
Truecaller Name Retriever. The simplest method for accessing truecaller's database is through CallerPy's online service.
TrueCaller main function is identification (name ad)