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The Irish grammar checker is available as a web service that other developers can use in their own products. At present this service powers the Gramadóir web interface, a CALL platform named An Scéalaí developed at Trinity College Dublin, as well as command-line clients.

To use the API, simply make a HTTP POST request to the URL with three parameters:

  • teacs: The Irish language text to be checked, as URL-encoded UTF-8
  • teanga: The ISO 639-1 code of the language for the error messages. You can find the list of available languages on the page with the web interface.
  • cliant: A unique identifier for your client so I can track usage of the API. Please send me an email (kscanne at gmail) requesting an identifier if you are building something new. Depending on demand, I may eventually block requests made without a whitelisted unique ID.

The parameters should be sent in the body of the request (not as part of the URL), and the request should specify Content-Type: application/x-www-form-urlencoded.

The response will be a JSON array of grammatical errors. Each error is represented by a hash with the following keys:

  • fromy — the line number within the teacs parameter at which the error starts (counting from 0)
  • fromx — the position within this line at which the error starts (counting from 0)
  • toy — the line number within the teacs parameter at which the error ends (counting from 0)
  • tox — the position within this line at which the error ends (counting from 0)
  • ruleId — the Gramadóir error code
  • msg — user-readable error message, localized into the language specified by the parameter teanga
  • context — the sentence in which the error occurs
  • contextoffset — the position within the context string where the error starts
  • errortext — the text of the error itself
  • errorlength — the length of the errortext string

For example, if the value of the teanga parameter is "en" (English error messages), and the value of the teacs parameter is the following string (containing embedded newlines):

'Achainí agam ort, a Phádraig,
a leanbh,' a deirimse. 'Cuir ar Áit an Puint mé.
Ar hÁit an Phuint.

You should get a response resembling the following:

	"ruleId": "Lingua::GA::Gramadoir/SEIMHIU",
	"toy": "1",
	"fromx": "36",
	"errorlength": "8",
	"errortext": "an Puint",
	"context": "'Cuir ar Áit an Puint mé.",
	"tox": "43",
	"contextoffset": "13",
	"fromy": "1",
	"msg": "Lenition missing"
}, {
	"fromy": "2",
	"msg": "Unnecessary prefix /h/",
	"contextoffset": "3",
	"tox": "6",
	"context": "Ar hÁit an Phuint.",
	"errortext": "hÁit",
	"ruleId": "Lingua::GA::Gramadoir/NIAITCH",
	"toy": "2",
	"fromx": "3",
	"errorlength": "4"


  • The context field encodes all ASCII double quotes, ampersands, and greater-than or less-than signs as HTML entities: ", <, >, &. The contextoffset is counted within the context field with these entities.
  • The web service supports CORS requests.

HTTP Response Codes

  • 200 (OK): Successful request
  • 400 (Bad Request): Missing parameter in request, unsupported language for error messages, empty source text, source text not encoded as UTF-8, etc.
  • 403 (Forbidden): Request from unapproved IP address
  • 405 (Method Not Allowed): Only POST requests permitted
  • 413 (Payload Too Large): Request larger than 16k bytes
  • 500 (Internal Server Error): Translation server failed to process request

Rate Limits

Since these are pretty low-traffic web sites, I am not currently placing any rate limits on requests to the API. Individual requests are capped at 16k bytes. I would appreciate an email (kscanne at gmail) if you build something interesting or useful in any case, and especially so if you expect to be making many requests.