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These endpoints provide word predictions and auto-corrections based on a user tapping on an onscreen virtual keyboard. The process is as follows:

1. Create a keyboard using keyboard/create.
2. Decode a sequence of taps using rec/taps.

Here are some test pages for the endpoints:

• Keyboard tests
• Tap decoding tests

keyboard/create

Create a new keyboard with a specified set of keys. Each key is defined by a center x- and y-coordinate, a width, a height, and at least one character label. Call should be via a POST containing a JSON collection with the name/value pair keys and the optional parameter lang. lang specifies the Language to use (see list) for the language of the keyboard (default is en). The keys value is a list that defines the following about each key:

Notes:

• Normally labels is a list with just a single character.
• For ambiguous keyboards (e.g. T9), labels is a list of all characters assigned to a key. Each character is assumed to be equally likely as far as the keyboard model is concerned.
• The created keyboards are valid for one hour after their last access time (or we have to restart the server for some reason).

Returns JSON containing the following:

Example POST request:

BASE_URL/keyboard/create

{"keys": [
           {"labels": ["a"], "x": 1.23, "y": 4.56, "height": 7.89, "width": 10.11},
           {"labels": ["b"], "x": 3.33, "y": 4.44, "height": 5.55, "width": 6.66},
           {"labels": [" "], "x": 6.66, "y": 7.77, "height": 8.88, "width": 9.99}
         ]}

Example response:

{"id"      : "MY_KEYBOARD_ID",
 "numKeys" : 3,
 "x"       : 3.915000,
 "y"       : 6.412500,
 "width"   : 15.480000,
 "height"  : 11.595000}

keyboard/get

Get details about an existing keyboard.

Returns JSON with the same fields as keyboard/create.

Example GET request:

BASE_URL/keyboard/get?id=MY_KEYBOARD_ID

{"id"      : "MY_KEYBOARD_ID",
 "numKeys" : 3,
 "x"       : 3.915000,
 "y"       : 6.412500,
 "width"   : 15.480000,
 "height"  : 11.595000}

keyboard/transform

Move or scale an existing keyboard.

Returns JSON with the same fields as keyboard/create.

Example GET request:

BASE_URL/keyboard/transform?id=MY_KEYBOARD_ID&x=100&width=31

Example response:

{"id"      : "MY_KEYBOARD_ID",
 "numKeys" : 3,
 "x"       : 100.000000,
 "y"       : 6.412500,
 "width"   : 31.000000,
 "height"  : 11.595000}

rec/taps

Returns the most likely text given a sequence of taps on the specified onscreen keyboard. Caller should first create the keyboard using keyboard/create. Optionally can return word completion predictions based on the observation sequence being the prefix of a word. Call should be via a POST containing JSON with the following key/value pairs:

The taps parameter is a list of the sequence of taps made by the user. Each tap contains the following:

Notes:

• Best recognition hypotheses assume the tap sequence represents all the user's desired word(s).
• Prefix recognition hypotheses assume the end of the tap sequence may only be the prefix of the desired word.
• If list is empty and numPrefix > 0, returns the most probable words given surrounding text.
• If singleWord is true, input is assumed to potentially contain observations from multiple words with or without spaces between them.
• Setting certain to true results in locking the corresponding character during the recognition. This can allow users to avoid auto-correct errors for difficult words.
• time is the time of the observation in seconds from some arbitrary starting reference point (e.g. the start of input).

Example POST request:

BASE_URL/rec/taps

{
    "keyboardId" : "MY_KEYBOARD_ID",
    "left"       : "this is a",
    "right"      : "message",
    "numBest"    : 2,
    "numPrefix"  : 3,
    "vocab"      : "100k",
    "sort"       : "logprob",
    "safe"       : false,
    "singleWord" : true,
    "taps"       : [ { "touches" : [ {"x": 1.2, "y": 3.4, "time": 0.012},
                                     {"x": 1.3, "y": 3.5, "time": 0.022} ],
                       "certain" : false
                     },
                     { "touches" : [ {"x": 4.4, "y": 5.5, "time": 0.031},
                                     {"x": 4.5, "y": 5.4, "time": 0.048},
                                     {"x": 4.7, "y": 5.1, "time": 0.078} ],
                      "certain" : false
                     }
                   ]
}

Example response:

{
    "best"     : [ { "text"    : "te",
                     "logProb" : -2.749233 },
                   { "text"    : "tr",
                     "logProb" : -3.548494 } ],
    "prefix"   : [ { "text"    : "test",
                     "logProb" : -5.54844 },
                   { "text"    : "trait",
                     "logProb" : -8.484444 },
                   { "text"    : "trace",
                     "logProb" : -11.45330 } ]
}