Fingerprint Generator

A fast browser data generator that mimics actual traffic patterns in the wild. With extensive data coverage.

Created by daijro. Data provided by Scrapfly.

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Features

• Uses a Bayesian generative network to mimic real-world web traffic patterns
• Extensive data coverage for nearly all known browser data points
• Creates complete fingerprints in a few milliseconds ⚡
• Easily specify custom criteria for any data point (e.g. "only Windows + Chrome, with Intel GPUs")
• Simple for humans to use 🚀

Demo Video

Here is a demonstration of what fpgen generates & its ability to filter data points:

demo.mp4

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Installation

Install the package using pip:

pip install fpgen

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Downloading the model

Fetch the latest model:

fpgen fetch

This will be ran automatically on the first import, or every 5 weeks.

To decompress the model for faster generation (up to 10-50x faster!), run:

fpgen decompress

Note: This action will use an additional 100mb+ of storage.

CLI Usage

Usage: python -m fpgen [OPTIONS] COMMAND [ARGS]...

Options:
  --help  Show this message and exit.

Commands:
  decompress  Decompress model files for speed efficiency (will take 100mb+)
  fetch       Fetch the latest model from GitHub
  recompress  Compress model files after running decompress
  remove      Remove all downloaded and/or extracted model files

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Usage

Generate a fingerprint

Simple usage:

>>> import fpgen
>>> fpgen.generate(browser='Chrome', os='Windows')

Or use the Generator object to pass filters downward:

>>> gen = fpgen.Generator(browser='Chrome')  # Filter by Chrome
>>> gen.generate(os='Windows')  # Generate Windows & Chrome fingerprints

Parameters list

Initializes the Generator with the given options.
Values passed to the Generator object will be inherited when calling Generator.generate()

Parameters:
    conditions (dict, optional): Conditions for the generated fingerprint.
    window_bounds (WindowBounds, optional): Constrain the output window size.
    strict (bool, optional): Whether to raise an exception if the conditions are too strict.
    flatten (bool, optional): Whether to flatten the output dictionary
    target (Optional[Union[str, StrContainer]]): Only generate specific value(s)
    **conditions_kwargs: Conditions for the generated fingerprint (passed as kwargs)

See example output.

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Filtering the output

Setting fingerprint criteria

You can narrow down generated fingerprints by specifying filters for any data field.

# Only generate fingerprints with Windows, Chrome, and Intel GPU:
>>> fpgen.generate(
...     os='Windows',
...     browser='Chrome',
...     gpu={'vendor': 'Google Inc. (Intel)'}
... )

This can also be passed as a dictionary.

>>> fpgen.generate({
...     'os': 'Windows',
...     'browser': 'Chrome',
...     'gpu': {'vendor': 'Google Inc. (Intel)'},
... })

Multiple constraints

Pass in multiple constraints for the generator to select from using a tuple.

>>> fpgen.generate({
...     'os': ('Windows', 'MacOS'),
...     'browser': ('Firefox', 'Chrome'),
... })

If you are passing many nested constraints, run fpgen decompress to improve model performance.

Custom filters

Data can be filtered by passing in callable functions.

Examples

Set the minimum browser version:

# Constrain client:
>>> fpgen.generate(client={'browser': {'major': lambda ver: int(ver) >= 130}})
# Or, just pass a dot seperated path to client.browser.major:
>>> fpgen.generate({'client.browser.major': lambda ver: int(ver) >= 130})

Only allow NVIDIA GPUs:

# Note: Strings are lowercased before they're passed.
>>> fpgen.generate(gpu={'vendor': lambda vdr: 'nvidia' in vdr})

Limit the maximum/minimum window size:

# Set allowed ranges for outerWidth & outerHeight:
>>> fpgen.generate(
...   window={
...     'outerWidth': lambda width: 1000 <= width <= 2000,
...     'outerHeight': lambda height: 500 <= height <= 1500
...   }
... )

Or, filter the window dictionary directly.

def window_filter(window):
    if not (1000 <= window['outerWidth'] <= 2000):
        return False
    if not (500 <= window['outerHeight'] <= 1500):
        return False
    return True

fpgen.generate(window=window_filter)

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Only generate specific data

To generate specific data fields, use the target parameter with a string or a list of strings.

Examples

Only generate HTTP headers:

>>> fpgen.generate(target='headers')
{'accept': '*/*', 'accept-encoding': 'gzip, deflate, br, zstd', 'accept-language': 'en-US,en;q=0.9', 'priority': 'u=1, i', 'sec-ch-ua': '"Google Chrome";v="131", "Chromium";v="131", "Not_A Brand";v="24"', 'sec-ch-ua-mobile': None, 'sec-ch-ua-platform': '"Windows"', 'sec-fetch-dest': 'empty', 'sec-fetch-mode': 'cors', 'sec-fetch-site': 'same-site', 'sec-gpc': None, 'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36'}

Or, by using the generate_target shortcut.

>>> fpgen.generate_target('headers')
{'accept': '*/*', 'accept-encoding': 'gzip, deflate, br, zstd', 'accept-language': 'en-GB,en;q=0.9,en-US;q=0.8,sk;q=0.7', 'priority': 'u=1, i', 'sec-ch-ua': '"Google Chrome";v="131", "Chromium";v="131", "Not_A Brand";v="24"', 'sec-ch-ua-mobile': None, 'sec-ch-ua-platform': '"Windows"', 'sec-fetch-dest': 'empty', 'sec-fetch-mode': 'cors', 'sec-fetch-site': 'same-site', 'sec-gpc': None, 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36'}

Generate a User-Agent for Windows & Chrome:

>>> fpgen.generate(
...     os='Windows',
...     browser='Chrome',
...     # Nested targets must be seperated by dots:
...     target='headers.user-agent'
... )
'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:134.0) Gecko/20100101 Firefox/134.0'

Generate a Firefox TLS fingerprint:

>>> fpgen.generate(
...     browser='Firefox',
...     target='network.tls.scrapfly_fp'
... )
{'version': '772', 'ch_ciphers': '4865-4867-4866-49195-49199-52393-52392-49196-49200-49162-49161-49171-49172-156-157-47-53', 'ch_extensions': '0-5-10-11-13-16-23-27-28-34-35-43-45-51-65037-65281', 'groups': '4588-29-23-24-25-256-257', 'points': '0', 'compression': '0', 'supported_versions': '772-771', 'supported_protocols': 'h2-http11', 'key_shares': '4588-29-23', 'psk': '1', 'signature_algs': '1027-1283-1539-2052-2053-2054-1025-1281-1537-515-513', 'early_data': '0'}

You can provide multiple targets as a list.

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Get the probabilities of a target

Calculate the probability distribution of a target given any filter:

>>> fpgen.trace(target='browser', os='Windows')
[<Chrome: 71.29276%>, <Edge: 12.96372%>, <Firefox: 12.64484%>, <Opera: 2.12217%>, <Yandex Browser: 0.94575%>, <Whale: 0.03076%>]

Multiple targets can be passed as a list/tuple. Here is an example of tracking the probability of browser & OS given a GPU vendor:

>>> fpgen.trace(
...   target=('browser', 'os'),
...   gpu={'vendor': 'Google Inc. (Intel)'}
... )
{'browser': [<Chrome: 76.46641%>, <Edge: 13.02665%>, <Firefox: 8.48189%>, <Opera: 1.36188%>, <Yandex Browser: 0.65133%>, <Whale: 0.01184%>],
 'os': [<Windows: 84.08380%>, <Linux: 8.07652%>, <MacOS: 7.46072%>, <ChromeOS: 0.37896%>]}

This also works in the Generator object:

>>> gen = fpgen.Generator(os='ChromeOS')
>>> gen.trace(target='browser')
[<Chrome: 100.00000%>]

Parameters for trace

Compute the probability distribution(s) of a target variable given conditions.

Parameters:
    target (str): The target variable name.
    conditions (Dict[str, Any], optional): A dictionary mapping variable names
    flatten (bool, optional): If True, return a flattened dictionary.
    **conditions_kwargs: Additional conditions to apply

Returns:
    A dictionary mapping probabilities to the target's possible values.

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Reading TraceResult

To read the output TraceResult object:

>>> chrome = fpgen.trace(target='browser', os='ChromeOS')[0]
>>> chrome.probability
1.0
>>> chrome.value
'Chrome'

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Query possible values

You can get a list of a target's possible values by passing it into fpgen.query:

List all possible browsers:

>>> fpgen.query('browser')
['Chrome', 'Edge', 'Firefox', 'Opera', 'Safari', 'Samsung Internet', 'Yandex Browser']

Passing a nested target:

>>> fpgen.query('navigator.maxTouchPoints') # Dot seperated path
[0, 1, 2, 5, 6, 9, 10, 17, 20, 40, 256]

Parameters for query

Query a list of possibilities given a target.

Parameters:
    target (str): Target node to query possible values for
    flatten (bool, optional): Whether to flatten the output dictionary
    sort (bool, optional): Whether to sort the output arrays

Note

Since fpgen is trained on live data, queries may occasionally return invalid or anomalous values. Values lower than a 0.001% probability will not appear in traces or generated fingerprints.

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Generated data

Here is a rough list of the data fpgen can generate:

• Browser data:
  • All navigator data
  • All mimetype data: Audio, video, media source, play types, PDF, etc
  • All window viewport data (position, inner/outer viewport sizes, toolbar & scrollbar sizes, etc)
  • All screen data
  • Supported & unsupported DRM modules
  • Memory heap limit

• System data:
  • GPU data (vendor, renderer, WebGL/WebGL2, extensions, context attributes, parameters, shader precision formats, etc)
  • Battery data (charging, charging time, discharging time, level)
  • Screen size, color depth, taskbar size, etc.
  • Full fonts list
  • Cast receiver data

• Network data:
  • HTTP headers
  • TLS fingerprint data
  • HTTP/2 fingerprint & frames
  • RTC video & audio capabilities, codecs, clock rates, mimetypes, header extensions, etc

• Audio data:
  • Audio signal
  • All Audio API constants (AnalyserNode, BiquadFilterNode, DynamicsCompressorNode, OscillatorNode, etc)

• Internationalization data:
  • Regional internationalization (Locale, calendar, numbering system, timezone, date format, etc)
  • Voices

• And much more!

For a more complete list, see the full example output.

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