Where can I find the data types of simvars

Is there a list of simvars with their data types? I’m building a client that
talks with the embedded web server in FSUIIPC It asks for data type when
declaring a simvar to listen to .

 // create the request object
        var request = {
            command: 'offsets.declare',
            name: 'myOffsets',
            offsets: [
    name: 'altitude', address: 0x0570, type: 'int', size: 8 },
    name: 'avionicsMaster', address: 0x2E80, type: 'uint', size: 4 },
    name: 'heading', address: 0x0580, type: 'uint', size: 4 },
    name: 'aircraftName', address: 0x3D00, type: 'string', size: 256 },

        // send to the server as a JSON string
        if (ws) {

Have a look at textsimvars.cs in the SimvarWatcher sample, there are two
string array declarations there, “Names”, containing 1314 items with the
variable names, and “DefaultUnits”, which 1314 items as well, with the Units
names. Other than the fact there are lots of Simvars recognized in the sim but
missing from that list, this should get you started…

Is there any rhyme or reason to these types? There are so many duplicates
.e.g. ‘degree’ or ‘degrees’. Sometimes it doesn’t seem to matter what types
you choose, sometimes it does.

We always had similar names for identical unit numbers, since FSX. They are
just alias so, in that case, you could use either degree or degrees, and they
will be both accepted. Also, all numerical variables always accept the
“number” unit, which will return the value as stored internally.