Start here

CallerAPI tells your app who is calling. It returns a business name for a phone number, and it tells you whether a number is a known spam caller.

The server never learns which number you looked up. Your app sends a hash prefix that matches many numbers at once, downloads that whole group, and finds the match on the device.

Pick your path

There are two things you can build. They take very different amounts of time. Read this before you start, so you pick the right one.

Path 1: look up numbers inside your app

Your app asks for a name, and shows it in your own screens. A recent call list, a contact card, or a search box.

This takes about 10 minutes on every platform. Go to Quickstart.

Path 2: name and block calls as the phone rings

The name appears on the system call screen, before the user answers. The phone can also reject known spam by itself.

The operating system controls this screen, so most of the work happens in Xcode and Android Studio, not in your code.

Android takes about 30 minutes. The user must grant one permission.

iOS takes about half a day. Apple must approve your app first.

Go to Call screening.

What you need before either path

An account on callerapi.com.

Three credentials from the dashboard. Get your keys shows you where they are.

A real phone for testing. Simulators cannot receive calls.

Which version these docs describe

Version 1.4.0. Every platform shares one version number, so the Android, iOS, Flutter, and React Native packages always release together.

Where to go when something breaks

Troubleshooting lists the failures that happen most, and what each one means. Read it before you open a support ticket. Several failures are silent, so the page is organized by what you see, not by cause.

Get started

Start here#

Pick your path#

Path 1: look up numbers inside your app#

Path 2: name and block calls as the phone rings#

What you need before either path#

Which version these docs describe#