LNURL implementation for Python

A collection of helpers for building [LNURL][lnurl] support into wallets and services.

LUDS support

Check out the LUDS repository: luds

• LUD-01
• LUD-02
• LUD-03
• LUD-04
• LUD-05
• LUD-06
• LUD-07
• LUD-08
• LUD-09
• LUD-10
• LUD-11
• LUD-12
• LUD-13
• LUD-14
• LUD-15
• LUD-16
• LUD-17
• LUD-18
• LUD-19
• LUD-20
• LUD-21

Configuration

Developers can force strict RFC3986 validation for the URLs that the library encodes/decodes, using this env var:

LNURL_STRICT_RFC3986 = "0" by default (False)

Basic usage

>>> import lnurl
>>> lnurl.encode('https://service.io/?q=3fc3645b439ce8e7')
Lnurl('LNURL1DP68GURN8GHJ7UM9WFMXJCM99E5K7TELWY7NXENRXVMRGDTZXSENJCM98PJNWXQ96S9', bech32=Bech32('LNURL1DP68GURN8GHJ7UM9WFMXJCM99E5K7TELWY7NXENRXVMRGDTZXSENJCM98PJNWXQ96S9', hrp='lnurl', data=[13, 1, 26, 7, 8, 28, 3, 19, 7, 8, 23, 18, 30, 28, 27, 5, 14, 9, 27, 6, 18, 24, 27, 5, 5, 25, 20, 22, 30, 11, 25, 31, 14, 4, 30, 19, 6, 25, 19, 3, 6, 12, 27, 3, 8, 13, 11, 2, 6, 16, 25, 19, 18, 24, 27, 5, 7, 1, 18, 19, 14]), url=WebUrl('https://service.io/?q=3fc3645b439ce8e7', scheme='https', host='service.io', tld='io', host_type='domain', path='/', query='q=3fc3645b439ce8e7'))
>>> lnurl.decode('LNURL1DP68GURN8GHJ7UM9WFMXJCM99E5K7TELWY7NXENRXVMRGDTZXSENJCM98PJNWXQ96S9')
WebUrl('https://service.io/?q=3fc3645b439ce8e7', scheme='https', host='service.io', tld='io', host_type='domain', path='/', query='q=3fc3645b439ce8e7')

The Lnurl object wraps a bech32 LNURL to provide some extra utilities.

from lnurl import Lnurl

lnurl = Lnurl("LNURL1DP68GURN8GHJ7UM9WFMXJCM99E5K7TELWY7NXENRXVMRGDTZXSENJCM98PJNWXQ96S9")
lnurl.bech32  # "LNURL1DP68GURN8GHJ7UM9WFMXJCM99E5K7TELWY7NXENRXVMRGDTZXSENJCM98PJNWXQ96S9"
lnurl.bech32.hrp  # "lnurl"
lnurl.url  # "https://service.io/?q=3fc3645b439ce8e7"
lnurl.url.host  # "service.io"
lnurl.url.base  # "https://service.io/"
lnurl.url.query  # "q=3fc3645b439ce8e7"
lnurl.url.query_params  # {"q": "3fc3645b439ce8e7"}

Parsing LNURL responses

You can use a LnurlResponse to wrap responses you get from a LNURL. The different types of responses defined in the [LNURL spec][lnurl-spec] have a different model with different properties (see models.py):

import httpx

from lnurl import Lnurl, LnurlResponse

lnurl = Lnurl('LNURL1DP68GURN8GHJ7MRWW4EXCTNZD9NHXATW9EU8J730D3H82UNV94MKJARGV3EXZAELWDJHXUMFDAHR6WFHXQERSVPCA649RV')
try:
  async with httpx.AsyncClient() as client:
    r = await client.get(lnurl.url)
    res = LnurlResponse.from_dict(r.json())  # LnurlPayResponse
    res.ok  # bool
    res.max_sendable  # int
    res.max_sats  # int
    res.callback.base  # str
    res.callback.query_params # dict
    res.metadata  # str
    res.metadata.list()  # list
    res.metadata.text  # str
    res.metadata.images  # list
r = requests.get(lnurl.url)

If you have already httpx installed, you can also use the .handle() function directly. It will return the appropriate response for a LNURL.

>>> import lnurl
>>> lnurl.handle('lightning:LNURL1DP68GURN8GHJ7MRWW4EXCTNZD9NHXATW9EU8J730D3H82UNV94CXZ7FLWDJHXUMFDAHR6V33XCUNSVE38QV6UF')
LnurlPayResponse(tag='payRequest', callback=WebUrl('https://lnurl.bigsun.xyz/lnurl-pay/callback/2169831', scheme='https', host='lnurl.bigsun.xyz', tld='xyz', host_type='domain', path='/lnurl-pay/callback/2169831'), min_sendable=10000, max_sendable=10000, metadata=LnurlPayMetadata('[["text/plain","NgHaEyaZNDnW iI DsFYdkI"],["image/png;base64","iVBOR...uQmCC"]]'))

You can execute and LNURL with either payRequest, withdrawRequest or login tag using the execute function.

>>> import lnurl
>>> lnurl.execute('lightning:LNURL1DP68GURN8GHJ7MRWW4EXCTNZD9NHXATW9EU8J730D3H82UNV94CXZ7FLWDJHXUMFDAHR6V33XCUNSVE38QV6UF', 100000)

Building your own LNURL responses

For LNURL services, the lnurl package can be used to build valid responses.

from lnurl import LnurlWithdrawResponse

res = LnurlWithdrawResponse(
    callback="https://lnurl.bigsun.xyz/lnurl-withdraw/callback/9702808",
    k1="38d304051c1b76dcd8c5ee17ee15ff0ebc02090c0afbc6c98100adfa3f920874",
    min_withdrawable=551000,
    max_withdrawable=551000,
    default_description="sample withdraw",
)
res.json()  # str
res.dict()  # dict

All responses are [pydantic][pydantic] models, so the information you provide will be validated and you have access to .json() and .dict() methods to export the data.

Data is exported using 🐫 camelCase keys by default, as per spec. You can also use camelCases when you parse the data, and it will be converted to snake_case to make your Python code nicer.

If you want to export the data using 🐍 snake_case (in your Python code, for example), you can change the by_alias parameter: res.dict(by_alias=False) (it is True by default).

CLI

$ poetry run lnurl
Usage: lnurl [OPTIONS] COMMAND [ARGS]...

  Python CLI for LNURL decode and encode lnurls

Options:
  --help  Show this message and exit.

Commands:
  decode           decode a LNURL
  encode           encode a URL
  handle           handle a LNURL
  execute          execute a LNURL