Here is the description of the various API

Note: you must sign to get an API key

measure/add

To submit a new cell measurement: http://www.opencellid.org/measure/add?key=myapikey&mnc=1&mcc=2&lac=200&cellid=234&lat=3.42&lon=3.12 Where:
key: The apikey
mcc: mobile country code
mnc: mobile network code
lac: locale area code
cellid: value of the cell id
lat:latitude when the measure has been taken
lon:longitude when the measure has been taken
Return:
ok or nok

cell/get

Get the position of a specific cell http://www.opencellid.org/cell/get?mnc=1&mcc=2&lac=200&cellid=234
Where:
mcc: mobile country code
mnc: mobile network code
lac: locale area code
cellid: value of the cell id
lac can be ommitted
If cellid is not present or if cellid i unkown, a defaut return will be based on lac information, but with a much lower accuracy. In that case, cellid return will be -1.
The postion will be retourned in xml format by default in the following form
Example: http://www.opencellid.org/cell/get?mcc=250&mnc=99&cellid=29513&lac=0

cell/getMeasures

Get the raw measures used to compute the position of a cell http://www.opencellid.org/cell/getMeasures?mnc=1&mcc=2&lac=200&cellid=234
The positions will be retourned in xml format by default... Example:
http://www.opencellid.org/cell/getMeasures?mcc=250&mnc=99&cellid=29513&lac=0