New JSON-compatible APIs available

As part of our ongoing efforts to make our data accessible – we’re planning to release a set of new APIs that support the JSON data format. JSON stands for JavaScript Object Notation and is the standard data format used by most AJAX web applications for getting data to and from a server. In this particular case, the APIs were developed in order to support the development of a few new WordPress plugins (more on that later – they should be available in 2-3 weeks or so). The output of one of these API calls looks something like this:

{
"responseCode": 200,
"response": {
"meanSquareFoot": "1,598",
"cityName": "SUNNYVALE",
"pricePerSquareFoot": "$487",
"state": "CA",
"medianPrice": "$747,137",
"medianSquareFoot": "1,519",
"rollingAverage": "90-day",
"date": "2009-06-19",
"daysOnMarket": "114",
"meanAge": "47",
"medianAbsorbed": "3",
"newlyListed": "4",
"medianLotSize": "6,008",
"inventory": "43",
"zipCode": "94086",
"meanBaths": "1.91",
"residenceType": "Single Family",
"meanBeds": "3.24",
"quartile": "All Quartiles"
},
"apiVersion": 1.0
}

While developing these new APIs, I found two tools that were particularly useful:

• http://www.jsonlint.com/ – A tool to validate and reformat JSON output – makes spotting format errors very easy.
• http://code.google.com/p/google-gson/ – The Google GSON library for transforming Java <–> JSON. There are quite a few Java libraries out there for generating JSON representations of Java objects, and this library was well documented, is actively developed and easy to integrate.

The initial set of APIs supports the following set of transactions:

• Authentication
• Retrieving State/City/ZIP info for charting
• Retrieving county/region/MSA info for charting
• Retrieving the current market stats for a single State/City/ZIP

Once these are rolled out, we’ll be adding more support for JSON across our entire set of APIs. If you’ve got ideas for web-based applications built on Altos Research data and need API access to make it happen, just let us know.