SMS Privacy now provides anonymous voicemail

One of the use cases that inspired me to create SMS Privacy is signing up for accounts for online services without having to link that to a real-world identity. Unfortunately, it turned out that my API provider is blocking the verification codes that many of these services send, in an effort to prevent people from abusing their API to automate the bulk creation of accounts.

Today I added voicemail support to SMS Privacy. It now dynamically gives the API provider a VoiceXML document that says "Leave a message" and then records everything the caller says after that, up to a maximum of 5 minutes. After the caller has hung up, or the 5 minutes are up, an mp3 recording is uploaded to the SMS Privacy server, which is made available in the user interface using the HTML5 audio tag.

This is great for interacting with people who don't know you can only send SMS: if they attempt to call the number, they can now leave a message rather than being unable to get through.

This is also great for signing up to some online services anonymously. While the API provider blocks some of the SMS verification codes, the voice calls still get through, so it now works for signing up to services that can send verification codes over a voice call.

This is good.