curl_cffi

Documentation

Python binding for curl-impersonate fork via cffi.

Unlike other pure python http clients like httpx or requests, curl_cffi can impersonate browsers' TLS/JA3 and HTTP/2 fingerprints. If you are blocked by some website for no obvious reason, you can give curl_cffi a try.

Only Python 3.8 and above are supported. Python 3.7 has reached its end of life.

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ScrapeNinja is a web scraping API with two engines: fast, with high performance and TLS fingerprint; and slower with a real browser under the hood.

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Features

• Supports JA3/TLS and http2 fingerprints impersonation, including recent browsers and custome fingerprints.
• Much faster than requests/httpx, on par with aiohttp/pycurl, see benchmarks.
• Mimics requests API, no need to learn another one.
• Pre-compiled, so you don't have to compile on your machine.
• Supports asyncio with proxy rotation on each request.
• Supports http 2.0, which requests does not.
• Supports websocket.

	requests	aiohttp	httpx	pycurl	curl_cffi
http2	❌	❌	✅	✅	✅
sync	✅	❌	✅	✅	✅
async	❌	✅	✅	❌	✅
websocket	❌	✅	❌	❌	✅
fingerprints	❌	❌	❌	❌	✅
speed	🐇	🐇🐇	🐇	🐇🐇	🐇🐇

Install

pip install curl_cffi --upgrade

This should work on Linux, macOS and Windows out of the box. If it does not work on you platform, you may need to compile and install curl-impersonate first and set some environment variables like LD_LIBRARY_PATH.

To install beta releases:

pip install curl_cffi --upgrade --pre

To install unstable version from GitHub:

git clone https://github.com/lexiforest/curl_cffi/
cd curl_cffi
make preprocess
pip install .

Usage

curl_cffi comes with a low-level curl API and a high-level requests-like API.

requests-like

from curl_cffi import requests

# Notice the impersonate parameter
r = requests.get("https://tools.scrapfly.io/api/fp/ja3", impersonate="chrome")

print(r.json())
# output: {..., "ja3n_hash": "aa56c057ad164ec4fdcb7a5a283be9fc", ...}
# the js3n fingerprint should be the same as target browser

# To keep using the latest browser version as `curl_cffi` updates,
# simply set impersonate="chrome" without specifying a version.
# Other similar values are: "safari" and "safari_ios"
r = requests.get("https://tools.scrapfly.io/api/fp/ja3", impersonate="chrome")

# To pin a specific version, use version numbers together.
r = requests.get("https://tools.scrapfly.io/api/fp/ja3", impersonate="chrome124")

# To impersonate other than browsers, bring your own ja3/akamai strings
# See examples directory for details.
r = requests.get("https://tls.browserleaks.com/json", ja3=..., akamai=...)

# http/socks proxies are supported
proxies = {"https": "http://localhost:3128"}
r = requests.get("https://tools.scrapfly.io/api/fp/ja3", impersonate="chrome", proxies=proxies)

proxies = {"https": "socks://localhost:3128"}
r = requests.get("https://tools.scrapfly.io/api/fp/ja3", impersonate="chrome", proxies=proxies)

Sessions

s = requests.Session()

# httpbin is a http test website, this endpoint makes the server set cookies
s.get("https://httpbin.org/cookies/set/foo/bar")
print(s.cookies)
# <Cookies[<Cookie foo=bar for httpbin.org />]>

# retrieve cookies again to verify
r = s.get("https://httpbin.org/cookies")
print(r.json())
# {'cookies': {'foo': 'bar'}}

curl_cffi supports the same browser versions as supported by my fork of curl-impersonate:

However, only WebKit-based browsers are supported. Firefox support is tracked in #59.

Browser versions will be added only when their fingerprints change. If you see a version, e.g. chrome122, were skipped, you can simply impersonate it with your own headers and the previous version.

If you are trying to impersonate a target other than a browser, use ja3=... and akamai=... to specify your own customized fingerprints. See the docs on impersonatation for details.

• chrome99
• chrome100
• chrome101
• chrome104
• chrome107
• chrome110
• chrome116 ^[1]
• chrome119 ^[1]
• chrome120 ^[1]
• chrome123 ^[3]
• chrome124 ^[3]
• chrome131 ^[4]
• chrome99_android
• chrome131_android ^[4]
• edge99
• edge101
• safari15_3 ^[2]
• safari15_5 ^[2]
• safari17_0 ^[1]
• safari17_2_ios ^[1]
• safari18_0 ^[4]
• safari18_0_ios ^[4]

Notes:

1. Added in version 0.6.0.
2. Fixed in version 0.6.0, previous http2 fingerprints were not correct.
3. Added in version 0.7.0.
4. Added in version 0.8.0.

asyncio

from curl_cffi.requests import AsyncSession

async with AsyncSession() as s:
    r = await s.get("https://example.com")

More concurrency:

import asyncio
from curl_cffi.requests import AsyncSession

urls = [
    "https://google.com/",
    "https://facebook.com/",
    "https://twitter.com/",
]

async with AsyncSession() as s:
    tasks = []
    for url in urls:
        task = s.get(url)
        tasks.append(task)
    results = await asyncio.gather(*tasks)

WebSockets

from curl_cffi.requests import WebSocket

def on_message(ws: WebSocket, message: str | bytes):
    print(message)

ws = WebSocket(on_message=on_message)
ws.run_forever("wss://api.gemini.com/v1/marketdata/BTCUSD")

For low-level APIs, Scrapy integration and other advanced topics, see the docs for more details.

asyncio WebSockets

import asyncio
from curl_cffi.requests import AsyncSession

async with AsyncSession() as s:
    ws = await s.ws_connect("wss://echo.websocket.org")
    await asyncio.gather(*[ws.send_str("Hello, World!") for _ in range(10)])
    async for message in ws:
        print(message)

Acknowledgement

• Originally forked from multippt/python_curl_cffi, which is under the MIT license.
• Headers/Cookies files are copied from httpx, which is under the BSD license.
• Asyncio support is inspired by Tornado's curl http client.
• The synchronous WebSocket API is inspired by websocket_client.
• The asynchronous WebSocket API is inspired by aiohttp.

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