How to Build an SMS Service

Using a Mashup: 411Sync

411Sync (http://www.411sync.com) is a service that provides a web-based API to let you create your own application on top of their SMS functionality. It's a free, easy to use method to implement a lookup-type SMS service. The usage paradigm is straightforward:

• Register a keyword with 411Sync, such as smsbook.

• Provide an URL for 411Sync to call when someone sends them an SMS with that keyword.

• Your URL should return an RSS or Atom feed to 411Sync, which they use to construct a reply SMS.

For example, we registered the keyword smsbook in the process of writing this guide. Its purpose was to allow people to easily add themselves to a mailing list that would inform them when the guide was published.

Here's an example of sending using the service (you can try it yourself).

If you send the following text message to [phone](411Sync's SMS number),

smsbook [e-mail]

You will receive an SMS back from [phone] that reads:

More Info at http://tinyurl.com/2phuke -- [e-mail] added to mailing list -- - Reply back ?? to get alerts

Now, that probably looks a bit confusing. 411Sync adds the header ("More info at http://tinyurl.com/xxxxxx") and footer ("- Reply back ??to get alerts") to your message (and, yes, that comes out of your 160 character allotment).

Advantages and disadvantages

This biggest advantage of 411sync is the cost: free. With no money and very little code, you can run a service that sends and receives text messages. Great, right? ...