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A strong Captcha and bot protection system for Flask with many features: rate limiting, special rules for users, web crawler detection, and automatic bot detection.

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tn3w/flask_Captchaify

🤖 𝐟𝐥𝐚𝐬𝐤_𝐂𝐚𝐩𝐭𝐜𝐡𝐚𝐢𝐟𝐲

A strong Captcha and bot protection system for Flask with many features: rate limiting, special rules for users, web crawler detection, and automatic bot detection. Supports Google reCaptcha, hCaptcha, Cloudflare Turnstile, Friendly Captcha, and Altcha, as well as custom image, text, and audio captchas with your own data sets. Can also embed captchas in forms and offers its own Captcha box service called TrueClick.

Github PyPI Libraries.io


from flask import Flask
from flask_Captchaify import Captchaify

app = Flask(__name__)
captchaify = Captchaify(app)

@app.route('/')
def index():
    """
    Extremely well protected route
    """

    return 'Hello human!🖐️'

if __name__ == '__main__':
    app.run(host = 'localhost', port = 9000)

Table of Contents

How does it work?

In situations where it is deemed necessary, a captivating challenge may be presented to either the user or any automated agents, depending on the predetermined level of security required. Upon successful completion of this captivating challenge, a unique token is generated. This token serves as a secure vessel, encapsulating the client's information in an encrypted format. Subsequently, this token is deployed as both a cookie within the client's browser or as a parameter in the URL, denoted as 'captcha'. This mechanism ensures the continual validation of legitimacy with each subsequent request.

Features

  • Captcha Verification: flask_Captchaify can verify captchas from third-party services like Google reCaptcha, hCaptcha, Cloudflare Turnstile, and Friendly Captcha, as well as custom verification options such as images, text or audio captchas.
  • Bot Identification: flask_Captchaify can automatically identify and block known bots using block lists, API`s and similar mechanisms.
  • Rate Limiting: flask_Captchaify allows you to set rate limits for requests to prevent bots from overwhelming your server.
  • Client-Specific Rules: You can set rules specific to individual clients, such as allowing certain IP addresses to bypass the captcha.
  • JavaScript not required: flask_Captchaify does not require JavaScript. All captchas are fully functional without it. (Third party services like Google reCaptcha, hCaptcha, Cloudflare Turnstile, Friendly Captcha, Altcha and Trueclick require JavaScript to work.)
  • Crawler Detection: flask_Captchaify can detect and block web crawlers from accessing your site. Web Crawlers can also be given hints and be shown meta tags.
  • Customizable Dataset: You can customize the captchas by providing your own dataset of images and keywords.
  • Customizable Templates: You can customize the templates used for the captchas and error pages.
  • Customizable Themes: Users can customize the themes used for the captchas and error pages.
  • Multiple Captcha Types: flask_Captchaify supports multiple types of captchas, including one-click captchas, custom captchas, and captchas from third-party services.
  • Personalization: You can customize the behavior of flask_Captchaify by providing your own arguments and values.
  • Error Handling: flask_Captchaify handles errors and displays custom error pages.
  • Fully Open Source: flask_Captchaify is fully open source and free to use. ʕっ•ᴥ•ʔっ

About

Installation

  1. Make sure you have the latest version of Python and Pip installed, you also need git installed.
  2. Install the script with pip pip install flask_Captchaify or manually via git clone https://github.com/tn3w/flask_Captchaify or download the zip.
  3. If you installed it manually, make sure your python script is in the folder where there is a subfolder flask_Captchaify, and make sure you run pip install -r requirements.txt in the flask_Captchaify folder.
  4. Make sure that after:
    app = Flask(__name__)
    You add the line:
    captchaify = Captchaify(app, action = "fight")
    And at the beginning of the file add the import:
    from flask_Captchaify import Captchaify

Speed

flask_Captchaify operates very efficiently, generating a multiclick captcha with 10 images from the AI_Dogs dataset in approximately 80 milliseconds.

Here are additional test results:

Time the program took Total Type of action
60 ms 109 ms Executing Bot Detection and Displaying a Multi-click Captcha with 10 Images.
27 ms 55 ms Verifying captcha using param captcha, store_anonymously is set to True.
3 ms 22 ms Verifying captcha using param captcha, store_anonymously is set to False.
18 ms 63 ms Displaying a rate limit error page.
3~6 ms 56 ms Translating a page after the translations were cached.

Testing was conducted locally on localhost using Postman and internal analysis. The metric 'Total' represents the total duration of data transfer.

Some Screenshots

  • Captcha oneclick: Display
  • Captcha multiclick: Display
  • Captcha using Google reCaptcha: Display
  • Site to change language: Display
  • Site when user is blocked: Display
  • Site when user is rate limited: Display
  • Site when user has javascript disabled and a captcha third party like Google reCaptcha is used: Display

To-Do's

  • Integrate Captchaify Trueclick as captcha type
  • Add location propertys
  • Add is_captcha_valid and show_captcha function to add an way to check in an specific case in an route
  • Add clickable Captcha
  • Captcha data set with emojis

Note for Contributors

If you want to contribute, please read CONTRIBUTING.md


Documentation

Captcha Integration

Google reCaptcha, hCaptcha, Cloudflare Turnstile and Altcha are automatically integrated into captchas if the site_key and secret are given. (site_key and secret are not required for Altcha). Recommendation: Use Altcha, you don't need authorization tokens and the challenges are generated by the server. Altcha uses a Prove of Work system that is future-proof.

Here are all the available captcha third parties:

Third party Description Verify Function
Google reCaptcha Uses Google reCaptcha for verification. Set recaptcha_site_key and recaptcha_secret. is_recaptcha_valid()
hCaptcha Uses hCaptcha for verification. Set hcaptcha_site_key and hcaptcha_secret. is_hcaptcha_valid()
Cloudflare Turnstile Uses Cloudflare Turnstile for verification. Set turnstile_site_key and turnstile_secret. is_turnstile_valid()
Friendly Captcha Uses Friendly Captcha for verification. Set friendly_site_key and friendly_secret. is_friendly_valid()
Altcha Use a Prove-of-Work from Altcha to make spam more difficult. You can set the hardness by supplementing it like this: altcha1 is_altcha_valid()
Trueclick Uses Trueclick for verification. See https://github.com/tn3w/TrueClick for more information. is_trueclick_valid()

Template example:

<!DOCTYPE html>
<html>
   <head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <title>Altcha Example</title>
   </head>
   <body>
      <form method="POST">
         <input name="name" type="text">
         <input name="password" type="password">
         {{ altcha }} <!-- or {{ altcha2 }} -->
         <button type="submit">Submit</button>
      </form>
   </body>
</html>

Use the Flask functions render_template or render_template_string to render the template, if you do not render the template the captcha will not be added.

An example that renders the template and checks the captcha:

from flask import Flask, render_template
from flask_Captchaify import Captchaify

app = Flask(__name__)
captchaify = Captchaify(app)

@app.route('/', methods=['GET', 'POST'])
def index():
   """
   Index page
   """

   if request.method == 'POST':
      if not captchaify.is_altcha_valid():
         return 'Captcha incorrect.'

      return 'Correct.'

   return render_template('example.html')

if __name__ == '__main__':
   app.run()

Special Cases

In some cases or if you like it better, you can use a combination of captchaify.is_captcha_valid() and captchaify.show_captcha() to show a captcha when needed.

An example route that displays a captcha to all clients using proxies:

from flask import Flask
from flask_Captchaify import Captchaify

app = Flask(__name__)
captchaify = Captchaify(app, action = 'allow') # Captchaify is detecting proxies automatically, here this is disabled

# Or use:
# captchaify = Captchaify(app, rules = [{'rule': ['path', 'is', '/login'], 'change': {'action': 'allow'}}])

@app.route('/login') # you can also use an endpoint
def login():
   if not captchaify.is_captcha_valid() and\
      (not captchaify.is_valid_ip or captchaify.is_proxy\
       or captchaify.is_spammer or captchaify.is_tor): # Crawler: `or captchaify.is_crawler`
      return captchaify.show_captcha()

   return 'MY LOGIN TEMPLATE' # the user is not a robot.

if __name__ == '__main__':
   app.run()

Arguments

All args and default value:

args = {
   "app": None, "rules": [],
   "action": 'auto', "captcha_type": 'oneclick',
   "dataset": 'keys', "dataset_size": (20, 100),
   "dataset_dir": DATASETS_DIR, "hardness": 1,
   "verification_age": 3600, "template_dir": TEMPLATE_DIR,
   "without_customisation": False, "without_cookies": False,
   "without_arg_transfer": False, "without_watermark": False,
   "third_parties": ['geoip', 'tor', 'ipapi', 'stopforumspam'],
   "enable_rate_limit": True, "rate_limit": (15, 300),
   "block_crawler": True, "crawler_hints": True,"as_route": False,
   "fixed_route_name": '_captchaify', "theme": 'light',
   "language": 'en', "store_anonymously": True,
   "without_trueclick": False, "error_codes": [],
   "recaptcha_site_key": None, "recaptcha_secret": None,
   "hcaptcha_site_key": None, "hcaptcha_secret": None,
   "turnstile_site_key": None, "turnstile_secret": None,
   "friendly_site_key": None, "friendly_secret": None
}

  1. app Arg

    A Flask() object of a Flask app that is modified by Captchaify so that each request is checked for bots

    Example:

    from flask import Flask
    from flask_Captchaify import Captchaify
    
    app = Flask('MyWebsite')
    captchaify = Captchaify(app)

  1. debug Arg

    If True, the Captchaify app will be in debug mode. This will raise the errors instead of logging them into the log.txt file. Some errors which are normally not logged will now be logged.

    Debug mode can lead to unintended behavior and error raises for errors that are not sever which can lead to Internal Server Error Messages.

    Debug mode should only be used for testing purposes or to find and fix bugs.

    Example on how to use debug mode:

    captchaify = Captchaify(app, debug=True)

  1. rules Arg

    Certain changes based on specific criteria such as IP, proxy, hosting or geo information

    Web page that blocks the localhost Ip:

    captchaify = Captchaify(app, rules=[{"rule": ['ip', 'equals', '127.0.0.1'], "change": {"action": "block"}}])

    Criteria can also be combined, with 'and' meaning that both criteria must be met and 'or' meaning that one of the two criteria must be met:

    rules = [{"rule": ['ip', 'is in', ['127.0.0.1', '10.0.0.1'], 'or', 'proxy', 'is', True]}, "change": {"action": "block"}]

    • Client Info

      The following client info fields can be compared:

      Name of field Type Information Example
      ip str Client's IP address. 169.150.196.74
      user_agent str User agent string of the client's browser. Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:126.0) Gecko/20100101 Firefox/126.0
      invalid_ip bool Boolean indicating if the IP is invalid. False
      continent str Name of the continent. Europe
      continent_code str Continent code. (ISO 3166) EU
      country str Name of the country. The Netherlands
      country_code str Country code. (ISO 3166) NL
      region str Name of the region. North Holland
      region_code str Region code. (ISO 3166) NH
      city str Name of the city. Amsterdam
      district str Name of the district. None
      zip int Postal code. 1012
      lat int Latitude. 52.3759
      lon int Longitude. 4.8975
      timezone str Timezone. Europe/Amsterdam
      offset int Timezone offset. 7200
      currency str Local currency. (ISO 4217) EUR
      isp str Internet Service Provider. Datacamp Limited
      org str Organization name. CSNext
      as str Autonomous system name. Datacamp Limited
      as_code int Autonomous system code. 212238
      reverse str Reverse DNS lookup result. unn-169-150-196-74.datapacket.com
      mobile bool Boolean indicating if the connection is via a mobile network. False
      proxy bool Boolean indicating if the client is using a proxy. True
      tor bool Boolean indicating if the client is using Tor. False
      hosting bool Boolean indicating if the client is using a hosting service. True
      forum_spammer bool Boolean indicating if the client is a known forum spammer. True
      netloc str Network location part of the URL. (includes Port) domain.example.com:80
      hostname str Fully qualified domain name (FQDN) of the server. domain.example.com
      domain str Primary domain name, which is a subset of the hostname. example.com
      path str Path component of the URL, indicates a specific resource. /login
      endpoint str The request.endpoint Endpoint Information. login
      scheme str Protocol used to access the resource. https
      url str Complete URL that combines all the individual components. https://domain.example.com/login

    • Operators

      The following operators are available:

      Name of Operator The same as
      ==, equals, equal, is field == value
      !=, does not equal, does not equals, not equals, not equal, not is field != value
      contains, contain value in field
      does not contain, does not contains, not contain, not contains value not in field
      is in, in field in value
      is not in, not is in, not in field not in value
      greater than, larger than field > value
      less than field < value
      starts with, begins with field.startswith(value)
      ends with, concludes with, finishes with field.endswith(value)

      Where field is the type of data e.g. ip and value is the value it should have e.g. 169.150.196.74.


    • Changes

      All changes that can be made by these rules:

      Name of the change Type Example
      captcha_type str multiclick
      dataset str ai-dogs
      dataset_dir str /path/to/dataset/dir
      action str allow
      hardness int (1-5) 3
      enable_rate_limit bool True
      rate_limit Tuple[int, int] (20, 100)
      template_dir str /path/to/template/dir
      recaptcha_site_key str 6Lfp1PEpAAAAANS3PIXmQ4c7k2p7gqxMopD5Npy3
      recaptcha_secret str 6Lfp1OEyBBBBBDjuZ-xK8H2LMnPVFQR-5nKkTBY9
      hcaptcha_site_key str d4f8bc19-c517-4387-9cb1-826935d73f47
      hcaptcha_secret str ES_e7d43d0818455496a48d22ddc3367d68
      turnstile_site_key str 0x5CCCCCCAp-qCgUJkS4MJa
      turnstile_secret str 0x5BBBBBBBc-vRpT3xZNR1bKfDJKUPGLQPF
      friendly_site_key str WZMSUDMH2PXWVJN9
      friendly_secret str B2YL26SFRPF3C9VOMOOF9HW8R0MX5WESVXO3OZ5TJ2AP62L91B4PCUP5C1J

    • Asterik *

      The asterisk creates the customization options for information comparisons. The asterisk (*) serves as a wildcard, representing any number of characters including zero.

      Example of a rule that all routes that start with /login then have a string and then have /development as route e.g. /login/api/development or /login/2fa/development:

      rules = [{"rule": ['path', 'is', '/login*/development']}, "change": {"action": "block"}]

    Here are all the things that can be changed:

    • Captcha types (captcha_type)

      Name of captcha type Displayed Captchas
      oneclick (Default) The user only needs one click to confirm that he is not a bot
      multiclick The user must select several images that match a motif (harder)
      text The user enters a text combination from an image into an input
      audio The user enters a text combination from an audio into an input
      text&audio The user enters a text and an audio combination into an input
      altcha Use a Prove-of-Work from Altcha to make spam more difficult. (Recommended if you do not want to use our own tools.)
      trueclick TrueClick is an in-house programmed clickable third party captcha. It is built in.
      recaptcha Uses Google Recaptcha for verification. Set recaptcha_site_key and recaptcha_secret.
      hcaptcha Uses HCaptcha for verification. Set hcaptcha_site_key and hcaptcha_secret.
      turnstile Uses Cloudflare Turnstile for verification. Set turnstile_site_key and turnstile_secret.
      friendly Uses Friendly Captcha for verification. Set friendly_site_key and friendly_secret.

      Example of a website that has set its captcha type to "multiclick" for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"captcha_type": "multiclick"}]

    • Datasets (dataset)

      Name of dataset Displayed Captchas
      keys Displays images based on specific keywords of landscapes, objects, and more (default for oneclick)
      animals Displays 50 different animal species (default for multiclick)
      ai-dogs Displays smiling and not smiling dogs

      Example of a website that has set its data set to "keys" for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"dataset": "ai-dogs"}]

    • Dataset Dir (dataset_dir)

      dataset_dir\
            \keys.json
            \animals.json
            \ai-dogs.json
            ...
      

      Example of a website that specifies its own dataset folder for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"dataset_dir": "/path/to/dataset/dir"}]

    • Actions (action)

      Name of action Executing Action
      allow Allows all traffic through, regardless of whether the IP is blocked.
      block Blocks all traffic if it is blocked, without captcha.
      fight Displays a captcha to all traffic, whether suspicious or not.
      auto Default value, shows only suspicious traffic captchas.

      Example of a website that has set its action to "block" for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"action": "block"}]

    • Hardness (hardness)

      The variable hardness must be a number between 1 and 5. The higher the value, the harder the captcha is. (Default: 1)

      Example of a website that has set its hardness to 3 for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"hardness": 3}]

    • Enable Rate Limit (enable_rate_limit)

      To enable or disable rate limits.

      Example of a website that has set its rate limit to false for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"enable_rate_limit": False}]

    • Rate Limits (rate_limit)

      The syntax is a bit different from the others, because two values are specified (rate_limit, max_rate_limit). The variable rate_limit must be a number indicating how many requests per 10 seconds can come from a given ip. max_rate_limit indicates how many requests can come from all ips per 10 seconds, also a int.

      Example of a website that has set its rate limit to (20, 300) for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"rate_limit": (20, 1200)}]

    • Template Dir (template_dir)

      To change the template directory of a particular route use the template_dirs arg.

      A template directory can look like this:

      template_directory\
               \captcha_text_audio.html
               \captcha_oneclick.html
               \captcha_multiclick.html
               \captcha_third_party.html
               \change_language.html
               \blocked.html
               \rate_limited.html
               \nojs.html
               \exception.html
      

      If one of the three templates does not exist in the folder, a 404 error is displayed when calling it. e.g. if you remove the change_language page at apis.

      Example of a website that has set its template dir to "template_directory" for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"template_dir": "/path/to/template/dir"}]

    • Site Keys and Secrets

      To change the site_key and secret of a particular route use the recaptcha_site_key, recaptcha_secret, hcaptcha_site_key, hcaptcha_secret, turnstile_site_key, turnstile_secret, friendly_site_key and friendly_secret args.

      For google reCaptcha you can get this here: https://www.google.com/recaptcha/admin/create, for hCaptcha here: https://dashboard.hcaptcha.com/login, for Cloudflare Turnstile here: https://dash.cloudflare.com/sign-up?to=/:account/turnstile (Important: You must have an domain with Cloudflare) and for Friendly Captcha here: https://friendlycaptcha.com/signup/, after signing up you can create an organization and get your site key under Applications and secret under Api Keys.

      Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

      Example of a website that has set its recaptcha_site_key to "recaptcha_site_key" for specific ips:

      rules = [{"rule": ['ip', 'is in', ('1.1.1.1', '1.0.0.1', '8.8.8.8')]}, "change": {"recaptcha_site_key": "recaptcha_site_key"}]

  1. action Arg

    To specify the default action of all routes or endpoints use the action arg.

    Example of a very paranoid website that has set its action to "fight" for all routes:

    captchaify = Captchaify(app, action="fight")

    All actions:

    Name of action Executing Action
    allow Allows all traffic through, regardless of whether the IP is blocked.
    block Blocks all traffic if it is blocked, without captcha.
    fight Displays a captcha to all traffic, whether suspicious or not.
    auto Default value, shows only suspicious traffic captchas.

  1. captcha_type Arg

    To specify the default captcha type of all routes or endpoints use the captcha_type arg.

    Example of a website that has set its types to "text" (for text bases captchas) for all routes:

    captchaify = Captchaify(app, captcha_type="text")

    All captcha types:

    Name of captcha type Displayed Captchas
    oneclick (Default) The user only needs one click to confirm that he is not a bot
    multiclick The user must select several images that match a motif (harder)
    text The user enters a text combination from an image into an input
    audio The user enters a text combination from an audio into an input
    text&audio The user enters a text and an audio combination into an input
    altcha Use a Prove-of-Work from Altcha to make spam more difficult. (Recommended if you do not want to use our own tools.)
    trueclick TrueClick is an in-house programmed clickable third party captcha. It is built in.
    recaptcha Uses Google Recaptcha for verification. Set recaptcha_site_key and recaptcha_secret.
    hcaptcha Uses HCaptcha for verification. Set hcaptcha_site_key and hcaptcha_secret.
    turnstile Uses Cloudflare Turnstile for verification. Set turnstile_site_key and turnstile_secret.
    friendly Uses Friendly Captcha for verification. Set friendly_site_key and friendly_secret.

  1. dataset Arg

    To specify the default data set of all routes or endpoints use the dataset arg.

    Example of a website that has set its data set to "keys" for all routes:

    captchaify = Captchaify(app, dataset="keys")

    All data sets:

    Name of dataset Displayed Captchas
    keys Displays images based on specific keywords of landscapes, objects, and more (default for oneclick)
    animals Displays 50 different animal species (default for multiclick)
    ai-dogs Displays smiling and not smiling dogs

    (more is in progress ʕっ•ᴥ•ʔっ)


  1. dataset_size Arg

    The size of the data set with e.g. images and keywords that determine how much of a data set is used, if a lot is used this can reduce RAM capacity but also increase security. Either a tuple of 2 numbers where the first indicates how many images per keyword (always the first ones) can be used (recommended around 20, maximum 200 or more depending on the data set) and the second number how many keywords are e.g. (images_per_keyword, number_of_keywords), default setting: (20, 100).

    But can also be a string for prefabricated dimensions:

    value corresponding tuple
    largest (200, 140)
    large (20, 140)
    medium (100, 100)
    normal (default) (20, 100)
    small (20, 36)
    smaller (20, 8)
    little (6, 8)

    The more images per keyword, the more inaccurate the user rate becomes, as images further behind in the image search and in the data set could no longer show the keyword. It is recommended that you generate your own dataset as the default data could be trained, use the script written in https://github.com/tn3w/Captcha_Datasets and put the file in a folder and use the dataset_dir Arg to use it.

    Example of a website that uses 100 images per keyword and 140 keywords:

    captchaify = Captchaify(app, dataset_size=(100, 140))

  1. dataset_dir Arg

    Specifies where the program can find data sets. A dataset should be a json file.

    Example of a website that specifies its own dataset folder:

    captchaify = Captchaify(app, dataset_dir='/path/to/my/dataset')

    A dataset dir can look like this:

    dataset_dir\
           \keys.json
           \animals.json
           \ai-dogs.json
           ...
    

  1. hardness Arg

    Specifies the default hardness of the captcha. The variable hardness must be a number between 1 and 5. The higher the value, the harder the captcha is. (Default: 1)

    Example of a website that has set its default hardness to 3:

    captchaify = Captchaify(app, hardness=3)

  1. verification_age Arg

    Indicates the time in seconds how long a solved captcha is valid (Default: 3600 = 1 hour)

    Website with 3 hours verification_age:

    captchaify = Captchaify(app, verification_age=10800)

  1. template_dir Arg

    To specify the default template_dir of all routes or endpoints use the template_dir arg.

    Example of a web page with custom template_dir:

    captchaify = Captchaify(app, template_dir="/path/to/my/custom/template/directory")

    A template directory can look like this:

    template_directory\
               \captcha_text_audio.html
               \captcha_oneclick.html
               \captcha_multiclick.html
               \captcha_third_party.html
               \change_language.html
               \blocked.html
               \rate_limited.html
               \nojs.html
               \exception.html
               ...
    

  1. without_customisation Arg

    Whether to allow customisation of the captcha site (theme and language) or not. If you want the best possible user experience, allow customization, if you just want protection, activate this option

    Web page where customisation is not allowed:

    captchaify = Captchaify(app, without_customisation = True)

  1. without_cookies Arg

    If True, no cookies are created, and verification is proven via URL args. (Default: False)

    Website with without_cookies enabled:

    captchaify = Captchaify(app, without_cookies=True)

  1. without_arg_transfer Arg

    Whether to allow other args to be passed to sites after the captcha has been solved. (Default: False)

    Web page where this is activated:

    captchaify = Captchaify(app, without_other_args = True)

  1. without_watermark Arg

    Whether to show the Captchaify watermark or not. (Default: False) You don't have to use the Captchaify watermark, if you like the project you can give it a star on GitHub.

    When you use custom templates you can remove the watermark in the template.

    Web page where this is activated and the watermark is not shown:

    captchaify = Captchaify(app, without_watermark = True)

  1. third_parties Arg

    Specifies which third parties are used to check the IP addresses. By default, all 4 third parties are used. (See list)

    Web page that only asks a third party for Tor Ip addresse information:

    captchaify = Captchaify(app, third_parties=["tor"])

    Possible entries would be:

    Abbreviation Who is requested and how does the evaluation mechanism work?
    tor Uses dnspython to check if an IP is a Tor Exit Node. See Stackoverflow #78535126
    reverse socket.gethostbyaddr(client_ip) is used to get the reverse DNS name of the IP address.
    ipapi Ipapi is requested with the Ip and the result of the fields "proxy" and "hosting" is used
    stopforumspam StopForumSpam is requested and the result is used
    ipify (FOR DEBUG ONLY, can possibly leak local IP) The local IP address 127.0.0.1 is converted to your real IP address using ipify.

  1. as_route Arg

    Specifies whether Captchaify pages are displayed as separate routes in order not to confuse the cache between normal pages and Captchaify pages (e.g. for Cloudflare)

    Web page where this is activated:

    captchaify = Captchaify(app, as_route = True)

  1. fixed_route_name Arg

    Specifies the name of the route that is used if Captchaify pages are displayed as separate routes. (Default: _captchaify)

    Web page where this is edited:

    captchaify = Captchaify(app, fixed_route_name = "") # Can be any string and nothing

  1. enable_rate_limit Arg

    Whether to enable rate limiting or not.

    Example of a web page with rate limiting enabled:

    captchaify = Captchaify(app, enable_rate_limit=True)

  1. rate_limit Arg

    To specify the default rate_limit of all routes or endpoints use the rate_limit arg. It is a tuple of 2 values: (rate_limit, max_rate_limit)

    rate_limit is a number indicating how many requests per 10 seconds can come from a given ip. max_rate_limit indicates how many requests can come from all ips 10 seconds, also a int.

    Example of a web page with custom rate_limit:

    captchaify = Captchaify(app, rate_limit=(20, 300))

  1. block_crawler Arg

    If True, crawlers like Googlebot, further are estimated via their user agent as suspicious and not the website, good for websites that should not be crawled (Default: True)

    Web page with block_crawler enabled:

    captchaify = Captchaify(app, block_crawler=True)

  1. crawler_hints Arg

    If True, crawlers like Googlebot, are shown meta tags and the title of a normal web page, while they would have to solve a captcha. (Default: True)

    Web page with crawler_hints disabled:

    captchaify = Captchaify(app, crawler_hints=False)

  1. theme Arg

    To specify the default theme of all routes or endpoints use the theme arg.

    Example of a website that has set its theme to "dark" for all routes:

    captchaify = Captchaify(app, theme="dark")

    All themes:

    Name of theme Description
    light Bright theme with a light background and dark text, ideal for well-lit settings.
    dark Dark theme with a dark background and light text, perfect for low-light environments.

  1. language Arg

    To specify the default language of all routes or endpoints use the language arg.

    Example of a website that has set its language to "de" (German language) for all routes:

    captchaify = Captchaify(app, language="de")

    A list off all languages according to ISO 639-1:

    languages = ['en', 'es', 'zh-cn', 'hi', 'ar', 'fr', 'ru', 'pt', 'de', 'ja', 'bn', 'pa', 'ko', 'it', 'vi', 'zh-tw', 'te', 'mr', 'ta', 'ur', 'tr', 'th', 'gu', 'fa', 'pl', 'uk', 'ro', 'nl', 'hu', 'el', 'cs', 'sv', 'he', 'da', 'fi', 'no', 'sk', 'hr', 'ms', 'id', 'sr', 'lt', 'sl', 'et', 'lv', 'sw', 'bg', 'ka', 'az', 'kk', 'uz', 'hy', 'sq', 'my', 'km', 'mk', 'am', 'ne', 'lo', 'si', 'sd', 'ug', 'mn', 'ky', 'ps', 'ku', 'gl', 'mt', 'so', 'gd', 'cy', 'lb', 'yi', 'ha', 'haw', 'mg', 'yo', 'ny', 'ceb', 'co', 'fy', 'ig', 'is', 'jw', 'la', 'mi', 'su', 'tg', 'tl', 'xh', 'zu', 'af', 'eu', 'be', 'bs', 'ca', 'eo', 'ht', 'iw', 'hmn', 'ga', 'kn', 'ml', 'or', 'sm', 'st', 'sn']

  1. store_anonymously Arg

    Whether to store the captcha data anonymously or not. (Default: True)

    If it is stored anonymously, all cache data is stored hashed and encrypted. This can be slower but more secure for the end user.

    Web page where user data is not stored anonymously:

    captchaify = Captchaify(app, store_anonymously=False)

  1. without_trueclick Arg

    Whether to add an TrueClick route. If you do not use TrueClick at all, activate this option. It removes all routes that are not required for TrueClick. (Default: False)

    Web page with without_trueclick enabled:

    captchaify = Captchaify(app, without_trueclick=True)

  1. error_codes Arg

    Which HTTP status codes or Exception classes should be handled by Captchaify. By default, none HTTP status codes are handled. (See list)

    You can customize the error data in the following way:

    error_codes = [404] # Normal HTTP error message, title and error code
    error_codes = [
       404,
       {
          "code": 500, "code_override": "Oops",
          "title": "Internal Server Error",
          "description": "Something went wrong"
       }
    ] # 404 is normal but 500 is handled with custom data

    Web page where only the status code 418 I'm a teapot is handled:

    captchaify = Captchaify(app, error_codes = [418])

    A list off all HTTP status codes and their descriptions can be found here: https://en.wikipedia.org/wiki/List_of_HTTP_status_codes.

    Use all to enable all these HTTP status codes:

    error_codes = [400, 401, 403, 404, 405, 406, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 422, 423, 424, 428, 429, 431, 451, 500, 501, 502, 503, 504, 505]

  1. recaptcha_site_key Arg

    Is required if Google reCaptcha is used as captcha_type or in an form. For Google reCaptcha you can get this here: https://www.google.com/recaptcha/admin/create Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

    Example: 6Lfp1PEpAAAAANS3PIXmQ4c7k2p7gqxMopD5Npy3

    Web page where this is set:

    captchaify = Captchaify(app, recaptcha_site_key = '<site-key>')

  1. recaptcha_secret Arg

    Is required if Google reCaptcha is used as captcha_type or in an form. For Google reCaptcha you can get this here: https://www.google.com/recaptcha/admin/create Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

    Example: 6Lfp1OEyBBBBBDjuZ-xK8H2LMnPVFQR-5nKkTBY9

    Web page where this is set:

    captchaify = Captchaify(app, recaptcha_secret = '<secret>')

  1. hcaptcha_site_key Arg

    Is required if hCaptcha is used as captcha_type or in an form. For hCaptcha you can get this here: https://dashboard.hcaptcha.com/login Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

    Example: d4f8bc19-c517-4387-9cb1-826935d73f47

    Web page where this is set:

    captchaify = Captchaify(app, hcaptcha_site_key = '<site-key>')

  1. hcaptcha_secret Arg

    Is required if hCaptcha is used as captcha_type or in an form. For hCaptcha you can get this here: https://dashboard.hcaptcha.com/login Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

    Example: ES_e7d43d0818455496a48d22ddc3367d68

    Web page where this is set:

    captchaify = Captchaify(app, hcaptcha_secret = '<secret>')

  1. turnstile_site_key Arg

    Is required if Cloudflare Turnstile is used as captcha_type or in an form. For Cloudflare Turnstile you can get this here: https://dash.cloudflare.com/sign-up?to=/:account/turnstile Important: Here you need a domain. Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

    Example: 0x5CCCCCCAp-qCgUJkS4MJa

    Web page where this is set:

    captchaify = Captchaify(app, turnstile_site_key = '<site-key>')

  1. turnstile_secret Arg

    Is required if Cloudflare Turnstile is used as captcha_type or in an form. For Cloudflare Turnstile you can get this here: https://dash.cloudflare.com/sign-up?to=/:account/turnstile Important: Here you need a domain. Usually site_key and secret are displayed after creating an account or when linking a domain or ip.

    Example: 0x5BBBBBBBc-vRpT3xZNR1bKfDJKUPGLQPF

    Web page where this is set:

    captchaify = Captchaify(app, turnstile_secret = '<secret>')

  1. friendly_site_key Arg

    Is required if Friendly Captcha is used as captcha_type or in an form. For Friendly Captcha you can get this here: https://friendlycaptcha.com/signup/, after signing up you can create an organization and get your site_key under Applications.

    Example: WZMSUDMH2PXWVJN9

    Web page where this is set:

    captchaify = Captchaify(app, friendly_site_key = '<site-key>')

  1. friendly_secret Arg

    Is required if Friendly Captcha is used as captcha_type or in an form. For Friendly Captcha you can get this here: https://friendlycaptcha.com/signup/, after signing up you can create an organization and get your secret under Api Keys.

    Example: B2YL26SFRPF3C9VOMOOF9HW8R0MX5WESVXO3OZ5TJ2AP62L91B4PCUP5C1J

    Web page where this is set:

    captchaify = Captchaify(app, friendly_secret = '<secret>')

Known issues

Exceptions

  • Using log.txt
    All exceptions are logged to the console and the stack trace is written to the log.txt file. You can find the log.txt file in the directory where the package is installed.

    Use the command pip show flask_Captchaify to show information about the package and then copy the location directory value. e.g.: Location: C:\Users\user\anaconda3\Lib\site-packages

    The file is located under COPIED_DIR\flask_Captchaify\log.txt

    If more than one error is stored in the file, you can search for the correct error stack trace by searching for the error ID you saw in the console that is in the console with the error, e.g. [flask_Captchaify Error #ERROR_ID at 2024-07-20 21:49:09]: Error Message

    An error stacktrace in the file looks like this: (real error example)

    ----- Error #ERROR_ID at 2024-01-01 22:24:04 -----
    Traceback (most recent call last):
    File "C:\Users\user\Documents\Code\flask_Captchaify\src\flask_Captchaify\__init__.py", line 2065, in _set_cookies
       print(g.captchaify_no_new_cookies)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "C:\Users\user\Documents\Code\flask_Captchaify\.venv\Lib\site-packages\flask\ctx.py", line 56, in __getattr__
       raise AttributeError(name) from None
    AttributeError: captchaify_no_new_cookies
  • Using debug=True
    If you are using debug mode, all errors are raised instead of being logged.

    Debug mode can lead to unintended behavior and error raises for errors that are not sever which can lead to Internal Server Error Messages. The stability of the package can be altered by using debug mode. Only recommended for testing purposes.

Malformed files

It is possible that some of the files are corrupted or missing. If this happens, you can delete alle files in the data directory or remove the package.

To find the data directory, use the command pip show flask_Captchaify to show information about the package and then copy the location directory value. e.g.: Location: C:\Users\user\anaconda3\Lib\site-packages

The directory is located under COPIED_DIR\flask_Captchaify\data

You can reinstall the package using pip install flask_Captchaify --force-reinstall --upgrade

Requests from localhost

When requested from localhost, Captchaify can not resolve the IP address of the requester or any data.

Add ipify to the third party list. The real IP is automatically resolved.

captchaify = Captchaify(app, third_parties = ['geoip', 'tor', 'ipapi', 'stopforumspam', 'ipify'])

Request exceptions

Captchaify uses free APIs to get information about IP addresses. It also uses own implementations to request the reverse DNS name and if the client is Tor or not. It also requests the newest geoip file. This behaviour can lead to request exceptions.

All third parties can be disabled by setting third_parties = [] in the captchaify = Captchaify(app) line. The default is all 4 third parties.

captchaify = Captchaify(app, third_parties = [])

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A strong Captcha and bot protection system for Flask with many features: rate limiting, special rules for users, web crawler detection, and automatic bot detection.

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