async-requests-tls 0.1.0

Async HTTP/1.1 client whose TLS handshake is identical to the `requests` library.

async-requests-tls

Async Python HTTP/1.1 client whose TLS ClientHello is byte-for-byte identical to what the requests library sends — same JA3, same JA4. Useful when a site fingerprints the TLS handshake and rejects modern async clients (httpx, niquests, …) while happily accepting plain requests.

The trick: requests builds its ssl.SSLContext through urllib3.util.ssl_.create_urllib3_context(). So do we. The context is then fed into asyncio.open_connection(..., ssl=ctx), so both stacks drive the same OpenSSL build with the same cipher list, options, ALPN, curves, and sigalgs.

Install

pip install async-requests-tls
# or with uv:
uv add async-requests-tls

The PyPI distribution name is async-requests-tls but the Python import name is async_requests_tls.

For development from a clone of this repo:

pip install -e .[dev]
# or:
uv sync --extra dev

Requires Python 3.13+ and urllib3>=2.0.

Quickstart

import asyncio
from async_requests_tls import AsyncSession

async def main():
    async with AsyncSession() as s:
        # GET
        r = await s.get("https://httpbin.org/get", params={"hello": "world"})
        print(r.status_code, r.json())

        # POST with JSON
        r = await s.post("https://httpbin.org/post", json={"x": 1})
        print(r.json())

        # Session-wide base_url, headers, and cookie jar
        async with AsyncSession(
            base_url="https://api.example.com",
            headers={"X-Token": "secret"},
        ) as api:
            await api.get("/users")          # GET https://api.example.com/users
            await api.post("/orders", data={"sku": "abc"})

asyncio.run(main())

AsyncSession supports get / post / put / patch / delete / head / options, with a requests-style API: params, headers, data, json, cookies, allow_redirects. Responses expose status_code, headers, content, text, json(), ok, and cookies.

Caveats

• HTTP/1.1 only. ALPN defaults to ["http/1.1"] so the server never upgrades us to h2. If you pass alpn=alpn_protocols_like_urllib3() (to match the exact ALPN bytes requests sends when urllib3-future is installed) and the server picks h2, the session raises NotImplementedError — the TLS handshake still matched, the wire protocol did not.
• No connection pooling, no proxies, no streaming, no multipart, no HTTP/2. This is a small, focused library.
• JA3 parity ≠ detection-evasion parity. Modern detectors also look at HTTP/2 SETTINGS frames, header order (JA4_H), and Akamai-style timing. This library only matches the TLS layer.

Testing

uv run pytest        # or: pytest

All tests are unit tests — they don't open real sockets. The wire-level tests drive asyncio.StreamReader with canned bytes; the session tests patch _send_once with a fake.

Public API

from async_requests_tls import (
    AsyncSession,
    Response,
    build_ssl_context,            # if you want the SSLContext directly
    alpn_protocols_like_urllib3,  # exact ALPN list urllib3 would send
)

License

MIT — see LICENSE.