4gCAPTCHA

4gcaptcha is a captcha server based on the one used in 4get

Setup

Copy .env.template to .env and configure the variables accordingly

FONT_PATH is a path to a .ttf file
The default font is RedHat Mono Bold licensed under OFL-1.1
CAPTCHA_DIR is a path to a directory of captcha images in the following format:

captcha/
  birds/
    1.png
    2.png
    3.png
 anime/
    1.png
    2.png

uv sync
uv run server.py

Generates a new CAPTCHA

{
  "token": "<uuid>",
  "image": "data:image/jpeg;base64,...",
  "expires_in": 90
}

Check user submitted answers for the provided token. A token expires on failure

The image grid is by default 4x4 mapped from 0 -> 15

0,1,2,3
4,5,6,7
8,9,10,11
12,13,14,15

{ "token": "<uuid>", "answers": [0, 3, 9] }