Documentation on using LNbits API to pay lightning addresses and LNURL

Link to the relevant part of the LNbits API: https://demo.lnbits.com/docs#/Payments/api_payments_pay_lnurl_api_v1_payments_lnurl_post

For testing purposes, you can inspect your LNURL and lightning address and view the expected description_hash using this tool: https://lightninginspector.mysatoshikit.com/

1. Decode LNURL using LNbits API. Skip this if you're paying a lightning address.

   curl -X 'POST'
   https://your-lnbits-endpoint.com/api/v1/payments/decode
   -H "X-Api-Key: <INVOICE KEY>"
   -H "Content-type: application/json"
   -d '{"data": <LNURL>}'
   

   Sample response:

   {
       "domain": "https://decoded-lnurl-domain.com"
   }
   

2. Retrieve callback URL and metadata from lightning address or LNURL.

   cURL for lightning address:

   curl 'https://lightning-wallet-domain.com/.well-known/lnurlp/username'

   OR

   cURL for LNURL:

   curl 'https://decoded-lnurl-domain.com'

   Sample response:

   {
       "status": "OK",
       "tag": "payRequest",
       "commentAllowed": 255,
       "callback": "https://lightning-wallet-domain.com/lnurlp/username/callback",
       "metadata": "[[\"text/identifier\",\"[email protected]\"],[\"text/plain\",\"Payment\"]]",
       "minSendable": 1000,
       "maxSendable": 11000000000,
       "payerData": {
           "name": {
               "mandatory": false
           },
           "email": {
               "mandatory": false
           },
           "pubkey": {
               "mandatory": false
           }
       }
   }
   

3. Process payment using LNbits API:

   curl -X 'POST' 
     'https://your-lnbits-endpoint.com/api/v1/payments/lnurl'
     -H "X-Api-Key: <ADMIN KEY>"
     -H 'Content-Type: application/json' 
     -d '{
       "description_hash": <string>,
       "callback": <string>,
       "amount": <int>,
       "comment": <string>,
       "description": <string>
   }'
   

   WHERE:

   description_hash = the sha256 hash of parsed metadata from decoded LNURL or lightning address

   callback = callback url from decoded LNURL or lightning address

   amount = amount to be paid; specified in millisats (sats to be paid * 1000)

   comment = transaction note that will appear in receiver's lightning wallet (write what you want)

   description = memo that will appear in your LNbits wallet (write what you want)

1. On lightning addresses: https://github.com/andrerfneves/lightning-address/blob/master/README.md
2. On LNURL payRequest: https://github.com/lnurl/luds/blob/luds/06.md
3. Tool to view expected description_hash of parsed metadata from decoded LNURL or lightning address: https://lightninginspector.mysatoshikit.com/