Process Stroke Data

Process handwriting stroke coordinates directly, without needing to generate an image first. Supports the same options as image processing but with lower latency.

Send stroke data

Strokes are represented as arrays of x and y coordinates, where each sub-array is one continuous stroke.

info

The request body has a double-nested strokes key: the outer strokes is the API parameter name, and the inner strokes contains the coordinate data (x and y arrays).

cURL
Python
TypeScript
Go
Java

curl -X POST https://api.mathpix.com/v3/strokes \
-H 'app_id: APP_ID' \
-H 'app_key: APP_KEY' \
-H 'Content-Type: application/json' \
--data '{ "strokes": {"strokes": {
  "x": [[131,131,130,130,131,133,136,146,151,158,161,162,162,162,162,159,155,147,142,137,136,138,143,160,171,190,197,202,202,202,201,194,189,177,170,158,153,150,148],[231,231,233,235,239,248,252,260,264,273,277,280,282,283],[273,272,271,270,267,262,257,249,243,240,237,235,234,234,233,233],[296,296,297,299,300,301,301,302,303,304,305,306,306,305,304,298,294,286,283,281,281,282,284,284,285,287,290,293,294,299,301,308,309,314,315,316]],
  "y": [[213,213,212,211,210,208,207,206,206,209,212,217,220,227,230,234,236,238,239,239,239,239,239,239,241,247,252,259,261,264,266,269,270,271,271,271,270,269,268],[231,231,232,235,238,246,249,257,261,267,270,272,273,274],[230,230,230,231,234,240,246,258,268,273,277,281,281,283,283,284],[192,192,191,189,188,187,187,187,188,188,190,193,195,198,200,205,208,213,215,215,215,214,214,214,214,216,218,220,221,223,223,223,223,221,221,220]]
  }}}'

import requests, json
strokes_data = {
    "strokes": {
        "x": [
            [131,131,130,130,131,133,136,146,151,158,161,162,162,162,162,159,155,147,142,137,136,138,143,160,171,190,197,202,202,202,201,194,189,177,170,158,153,150,148],
            [231,231,233,235,239,248,252,260,264,273,277,280,282,283],
            [273,272,271,270,267,262,257,249,243,240,237,235,234,234,233,233],
            [296,296,297,299,300,301,301,302,303,304,305,306,306,305,304,298,294,286,283,281,281,282,284,284,285,287,290,293,294,299,301,308,309,314,315,316]
        ],
        "y": [
            [213,213,212,211,210,208,207,206,206,209,212,217,220,227,230,234,236,238,239,239,239,239,239,239,241,247,252,259,261,264,266,269,270,271,271,271,270,269,268],
            [231,231,232,235,238,246,249,257,261,267,270,272,273,274],
            [230,230,230,231,234,240,246,258,268,273,277,281,281,283,283,284],
            [192,192,191,189,188,187,187,187,188,188,190,193,195,198,200,205,208,213,215,215,215,214,214,214,214,216,218,220,221,223,223,223,223,221,221,220]
        ]
    }
}
r = requests.post("https://api.mathpix.com/v3/strokes",
    json={"strokes": strokes_data},
    headers={
        "app_id": "APP_ID",
        "app_key": "APP_KEY",
        "Content-type": "application/json"
    }
)
print(json.dumps(r.json(), indent=4, sort_keys=True))

const response = await fetch("https://api.mathpix.com/v3/strokes", {
  method: "POST",
  headers: {
    app_id: "APP_ID",
    app_key: "APP_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    strokes: {
      strokes: {
        x: [
          [131,131,130,130,131,133,136,146,151,158,161,162,162,162,162,159,155,147,142,137,136,138,143,160,171,190,197,202,202,202,201,194,189,177,170,158,153,150,148],
          [231,231,233,235,239,248,252,260,264,273,277,280,282,283],
          [273,272,271,270,267,262,257,249,243,240,237,235,234,234,233,233],
          [296,296,297,299,300,301,301,302,303,304,305,306,306,305,304,298,294,286,283,281,281,282,284,284,285,287,290,293,294,299,301,308,309,314,315,316],
        ],
        y: [
          [213,213,212,211,210,208,207,206,206,209,212,217,220,227,230,234,236,238,239,239,239,239,239,239,241,247,252,259,261,264,266,269,270,271,271,271,270,269,268],
          [231,231,232,235,238,246,249,257,261,267,270,272,273,274],
          [230,230,230,231,234,240,246,258,268,273,277,281,281,283,283,284],
          [192,192,191,189,188,187,187,187,188,188,190,193,195,198,200,205,208,213,215,215,215,214,214,214,214,216,218,220,221,223,223,223,223,221,221,220],
        ],
      },
    },
  }),
});
const result = await response.json();
console.log(JSON.stringify(result, null, 2));

body := bytes.NewBufferString(`{
    "strokes": {"strokes": {
        "x": [[131,131,130,130,131,133,136,146,151,158,161,162,162,162,162,159,155,147,142,137,136,138,143,160,171,190,197,202,202,202,201,194,189,177,170,158,153,150,148],[231,231,233,235,239,248,252,260,264,273,277,280,282,283],[273,272,271,270,267,262,257,249,243,240,237,235,234,234,233,233],[296,296,297,299,300,301,301,302,303,304,305,306,306,305,304,298,294,286,283,281,281,282,284,284,285,287,290,293,294,299,301,308,309,314,315,316]],
        "y": [[213,213,212,211,210,208,207,206,206,209,212,217,220,227,230,234,236,238,239,239,239,239,239,239,241,247,252,259,261,264,266,269,270,271,271,271,270,269,268],[231,231,232,235,238,246,249,257,261,267,270,272,273,274],[230,230,230,231,234,240,246,258,268,273,277,281,281,283,283,284],[192,192,191,189,188,187,187,187,188,188,190,193,195,198,200,205,208,213,215,215,215,214,214,214,214,216,218,220,221,223,223,223,223,221,221,220]]
    }}
}`)
req, _ := http.NewRequest("POST", "https://api.mathpix.com/v3/strokes", body)
req.Header.Set("app_id", "APP_ID")
req.Header.Set("app_key", "APP_KEY")
req.Header.Set("Content-Type", "application/json")
resp, _ := http.DefaultClient.Do(req)
defer resp.Body.Close()
result, _ := io.ReadAll(resp.Body)
fmt.Println(string(result))

HttpClient client = HttpClient.newHttpClient();
String body = """
    {
      "strokes": { "strokes": {
        "x": [[131,131,130,130,131,133,136,146,151,158,161,162,162,162,162,159,155,147,142,137,136,138,143,160,171,190,197,202,202,202,201,194,189,177,170,158,153,150,148],[231,231,233,235,239,248,252,260,264,273,277,280,282,283],[273,272,271,270,267,262,257,249,243,240,237,235,234,234,233,233],[296,296,297,299,300,301,301,302,303,304,305,306,306,305,304,298,294,286,283,281,281,282,284,284,285,287,290,293,294,299,301,308,309,314,315,316]],
        "y": [[213,213,212,211,210,208,207,206,206,209,212,217,220,227,230,234,236,238,239,239,239,239,239,239,241,247,252,259,261,264,266,269,270,271,271,271,270,269,268],[231,231,232,235,238,246,249,257,261,267,270,272,273,274],[230,230,230,231,234,240,246,258,268,273,277,281,281,283,283,284],[192,192,191,189,188,187,187,187,188,188,190,193,195,198,200,205,208,213,215,215,215,214,214,214,214,216,218,220,221,223,223,223,223,221,221,220]]
      }}
    }
    """;
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.mathpix.com/v3/strokes"))
    .header("app_id", "APP_ID")
    .header("app_key", "APP_KEY")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString(body))
    .build();
HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Response:

{
  "request_id": "cea6b8e4-0ab4-550a-c467-ce2eb00430be",
  "is_printed": false,
  "is_handwritten": true,
  "auto_rotate_confidence": 0.0020149118193977245,
  "auto_rotate_degrees": 0,
  "confidence": 1,
  "confidence_rate": 1,
  "latex_styled": "3 x^{2}",
  "text": "\\( 3 x^{2} \\)",
  "version": "SuperNet-109p4"
}

Live stroke sessions

For live digital ink with updating results (e.g., in a mobile app), use app tokens with stroke sessions:

Get an app_token with strokes_session_id from your server:

POST /v3/app-tokens
{
  "include_strokes_session_id": true,
  "expires": 300
}

Use the app_token and strokes_session_id in client requests to v3/strokes.

Live stroke sessions are billed differently from standalone requests — see pricing. You are billed the first time strokes are sent for a session, not when requesting the token.

Next steps

POST v3/strokes reference — Full request parameters and response schema
Authentication — App tokens for client-side stroke sessions

Send stroke data​

Live stroke sessions​

Next steps​

Send stroke data

Live stroke sessions

Next steps