The Truecaller API: Phone Directory via Crowd-source

This guest post comes from Andreas Krohn, API Specialist and consultant at Dopter. He blogs about APIs at Swedish) and organises API events at Nordic APIs.

The 600 million numbers that Truecaller has in its directory have been collected via crowd-sourcing. Truecaller’s users can share their contacts and in return they get access to search in the collaborative database. Thanks to this collaborative data solution, the directory is growing and being updated continuously. It also contains numbers that no other directories have, e.g. pre-paid phones.

The API allows for reverse number lookup, which means that you can input a number and get a name back. It also returns a Spam score to indicate if the number is a likely spammer (telesales or robocalls) and a True score to indicate how popular the number is.

How can the API be used?

There are many scenarios where the Truecaller API can add significant value. For example it could be a global call centre that wants to know the names of the people that call in for support, or a bank that needs to confirm that a phone number on a loan application actually belongs to the applicant.

The API itself has two methods where you send in a phone number and get back some data in JSON format. The trueScore method returns just True score for the number, indicating how popular it is. The search method returns True score, Spam score as well as the name attached to the number.

Try it yourself by replacing {NUMBER} in the link below with your own phone number (including your country code):{NUMBER}

For more details about the how the API works go to the Truecaller API documentation.

Avoiding Telephone Spam

Since Truecaller directory is built by its user base, the success of the company is tied to keeping their users happy. This means that Truecaller needs to be vigilant against making their directory available to parties that might use it for nefarious purposes, like to spam users with sales calls. In the mobile apps this is taken care of by letting users control who sees their data. In the API this is done mainly by not allowing name lookup, just number lookup. That limits the API to just allowing users find the names of the owners of a phone number, not the other way around.

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