The HarvardMaps API allows you to request data programmatically from HarvardMaps in CSV, JSON, JSONP, serialized PHP, or XML format. The API provides a RESTful interface, which means that you can query it using simple HTTP GET requests.


To report bugs or request features, contact:


Use of this API is governed by a Creative Commons Attribution-Noncommerical 3.0 Unported license, which means that you may use its data for non-commercial purposes so long as you attribute your data to this API, as by including a link to HarvardMaps in your own work. To discuss commercial purposes, contact the author.


All methods support CORS.


To query the HarvardMaps API for buildings, contact the server via URLs in this format:

Supported parameters include:

parameter description


Optional. Comma-separated list of buildings' roots. If omitted, all buildings will be returned. If this parameter is provided, id should not be.


Optional. Comma-separated list of buildings' IDs. If omitted, all buildings will be returned. If this parameter is provided, root should not be.


Required iff output is *jsonp*. Callback function with which response will be padded.


Required. Format for output. Must be csv, json, jsonp, php, or xml.

If any parameters are malformed or any required parameters are omitted, an empty response will be returned along with, possibly, HTTP status code 400 Bad Request.

Harvard is in the process of transitioning "building IDs" (aka bids, aka BL_IDs) to "roots" as unique identifies for buildings. This API supports both for backwards compatibility’s sake. Note that buildings' IDs are not strictly numeric; some are alphanumeric. All roots should be 5-digit values. Some building IDs and some roots include leading zeroes.

Because the HarvardMaps API and the HarvardEnergy API rely on data from different sources on campus, this method’s output may not be identical to the HarvardEnergy API's buildings method.


If you request buildings in CSV format (e.g.,,03365&output=csv), the response will be a series of comma-delimited rows, per the below:

03364,991,"Mather House",42.368270,-71.115270
03365,952,"Matthews Hall",42.374070,-71.118150

Note that the response’s first row defines the CSV file’s fields. Fields' order may change over time, so do not hardcode indices into your own code. Use that first row to determine fields' indices dynamically, per this article on parsing CSV.

Beware opening the CSV file in Excel, as some roots and IDs have leading 0s that Excel likes to remove.


If you request channels in JSON format (e.g.,,03365&output=json), the response wil be an array of objects, per the below:

      "name":"Mather House",
      "name":"Matthews Hall",


If you request channels in JSONP format (e.g.,,03365&output=jsonp&callback=parseResponse), the response will be a padded array of objects, per the below:

parseResponse([{"root":"03364","id":"991","name":"Mather House","lat":"42.368270","lng":"-71.115270"},{"root":"03365","id":"952","name":"Matthews Hall","lat":"42.374070","lng":"-71.118150"}])


If you request channels in serialized PHP format (e.g.,,03365&output=php), the response will be a serialized array of associative arrays, per the below:

a:2:{i:0;a:5:{s:4:"root";s:5:"03364";s:2:"id";s:3:"991";s:4:"name";s:12:"Mather House";s:3:"lat";s:15:"42.368153055571";s:3:"lng";s:16:"-71.115234108143";}i:1;a:5:{s:4:"root";s:5:"03365";s:2:"id";s:3:"952";s:4:"name";s:13:"Matthews Hall";s:3:"lat";s:15:"42.374068817179";s:3:"lng";s:16:"-71.118154165321";}}

Once you unserialize that response, you’ll have the below in memory:

    [0] => Array
            [root] => 03364
            [id] => 991
            [name] => Mather House
            [lat] => 42.368270
            [lng] => -71.115270

    [1] => Array
            [root] => 03365
            [id] => 952
            [name] => Matthews Hall
            [lat] => 42.374070
            [lng] => -71.118150



If you request data in XML format (e.g.,,03365&output=xml), the response will be an XML document whose root element is buildings, each of whose children is a building, per the below:

<?xml version="1.0" encoding="utf-8"?>
    <name>Mather House</name>
    <name>Matthews Hall</name>


  • 1.0

  • 1.1

    • Added support for JSONP * 1.2

    • Added support for root.

    • Added support for XML

  • 1.3

    • Fixed bug in CSV format whereby address header was omitted.