Wrapper for Lightning Network Daemon (lnd) ⚡
It provides separate accounts for end users. Live deployment at ln.getalby.com. API documentation
LndHub compatible API implemented in Go using relational database backends
- Using a relational database (PostgreSQL)
- Focussing only on Lightning (no onchain functionality)
- No runtime dependencies (simple Go executable)
- Extensible to add more features
All required configuration is done with environment variables and a .env file can be used.
Check the .env_example for an example.
cp .env_example .env
vim .env # edit your configDATABASE_URI: The URI for the database. (eg.postgresql://user:password@localhost:5432/lndhub?sslmode=disable)JWT_SECRET: We use JWT for access tokens. Configure your secret hereJWT_ACCESS_EXPIRY: How long the access tokens should be valid (in seconds, default 2 days)JWT_REFRESH_EXPIRY: How long the refresh tokens should be valid (in seconds, default 7 days)LND_ADDRESS: LND gRPC address (with port) (e.g.localhost:10009)LND_MACAROON_HEX: LND macaroon (hex-encoded contents ofadmin.macaroonorlndhub.macaroon, see below)LND_MACAROON_FILE: LND macaroon (provided as path on a filesystem)LND_CERT_HEX: LND certificate (hex-encoded contents oftls.cert)LND_CERT_FILE: LND certificate (provided as path on a filesystem)CUSTOM_NAME: Name used to overwrite the node alias in the getInfo callLOG_FILE_PATH: (optional) By default all logs are written to STDOUT. If you want to log to a file provide the log file path hereSENTRY_DSN: (optional) Sentry DSN for exception trackingHOST: (default: "localhost:3000") Host the app should listen onPORT: (default: 3000) Port the app should listen onDEFAULT_RATE_LIMIT: (default: 10) Requests per second rate limitSTRICT_RATE_LIMIT: (default: 10) Requests per second rate limit for resource-intensive APIs (e.g. sending a payment)BURST_RATE_LIMIT: (default: 1) Specifies the maximum number of requests that can pass at the same momentENABLE_PROMETHEUS: (default: false) Enable Prometheus metrics to be exposedPROMETHEUS_PORT: (default: 9092) Prometheus port (path:/metrics)WEBHOOK_URL: Optional. Callback URL for incoming and outgoing payment events, see below.FEE_RESERVE: (default: false) Keep fee reserve for each userALLOW_ACCOUNT_CREATION: (default: true) Enable creation of new accountsADMIN_TOKEN: Only allow account creation requests if they have the headerAuthorization: Bearer ADMIN_TOKEN. Also required for endpoint for updating users login, password and (de)activation status.MIN_PASSWORD_ENTROPY: (default: 0 = disable check) Minimum entropy (bits) of a password to be accepted during account creationMAX_RECEIVE_AMOUNT: (default: 0 = no limit) Set maximum amount (in satoshi) for which an invoice can be createdMAX_SEND_AMOUNT: (default: 0 = no limit) Set maximum amount (in satoshi) of an invoice that can be paidMAX_ACCOUNT_BALANCE: (default: 0 = no limit) Set maximum balance (in satoshi) for each accountMAX_SEND_VOLUME: (default: 0 = no limit) Set maximum volume (in satoshi) for sending for each accountMAX_RECEIVE_VOLUME: (default: 0 = no limit) Set maximum volume (in satoshi) for receiving for each accountMAX_VOLUME_PERIOD: (default: 2592000 = 1 month) Rolling period over which the volume should be calculated in secondsSERVICE_FEE: (default: 0 = no service fee) Set the service fee for each outgoing transaction in 1/1000 (e.g. 1 means a fee of 1sat for 1000sats - rounded up to the next bigger integer)NO_SERVICE_FEE_UP_TO_AMOUNT(default: 0 = no free transactions) the amount in sats up to which no service fee should be charged
There are two ways how to obtain hex-encoded macaroon needed for LND_MACAROON_HEX.
Either you hex-encode the admin.macaroon:
xxd -p -c 1000 ~/.lnd/data/chain/bitcoin/mainnet/admin.macaroon
Or you bake a new macaroon with the following permissions and use that instead:
lncli bakemacaroon info:read invoices:read invoices:write offchain:read offchain:write
If you want to use a macaroon stored on a filesystem, you either set LND_MACAROON_FILE to a path pointing to admin.macaroon
or use the following command to generate the lndhub.macaroon and setting the variable to path of that file.
lncli bakemacaroon --save_to=lndhub.macaroon info:read invoices:read invoices:write offchain:read offchain:write
To run the server
go run cmd/server/main.goTo build an lndhub executable, run the following commands:
makeTo run your own local lightning network and LND you can use Lightning Polar which helps you to spin up local LND instances.
LndHub.go requires a PostgreSQL database backend.
Prometheus metrics can be optionally exposed through the ENABLE_PROMETHEUS environment variable.
For an example dashboard, see https://grafana.com/grafana/dashboards/10913.
If WEBHOOK_URL is specified, a http POST request will be dispatched at that location when an incoming payment is settled, or an outgoing payment is completed. Example payload:
{
"id": 721,
"type": "incoming", //incoming, outgoing
"user_id": 299,
"amount": 1000,
"fee": 0,
"memo": "fill wallet",
"description_hash": "",
"payment_request": "lnbcrt10u1p38p4ehpp5xp07pda02vk40wxd9gyrene8qzheucz7ast435u9jwxejs6f0v5sdqjve5kcmpqwaskcmr9wscqzpgxqyz5vqsp56nyve3v5fw306j74nmewv7t5ey3aer2khjrrwznh4k2vuw44unzq9qyyssqv2wq9hn7a39x8cvz9fvpzul87u4kc4edf0t6jukzvmx8v5swl3jqg8p3sh6czkepczcjkm523q9x8yswsastctnsns3q9d26szu703gpwh7a09",
"destination_pubkey_hex": "0376442c750766d5d127512609a5618d9aa82db2d06aae226084da92a3e133acda",
"custom_records": {
"5482373484": "YWY4MDhlZDUxZjNmY2YxNWMxYWI3MmM3ODVhNWI1MDE="
}, //only set when keysend=true
"r_hash": "305fe0b7af532d57b8cd2a083ccf2700af9e605eec1758d385938d9943497b29",
"preimage": "3735363531303032626332356439376136643461326434336335626434653035",
"keysend": false,
"state": "settled",
"created_at": "2022-05-03T09:18:15.15774+02:00",
"expires_at": "2022-05-04T09:18:15.157597+02:00",
"updated_at": "2022-05-03T09:18:19.837567+02:00",
"settled_at": "2022-05-03T09:18:19+02:00"
}
Both incoming and outgoing keysend payments are supported. For outgoing keysend payments, check out the API documentation.
For incoming keysend payments, we are using a custom TLV record with type 696969, which should contain the hex-encoded login of the receiving user's account. TLV records are stored as json blobs with the invoices and are returned by the /getuserinvoices endpoint.
The V2 API has an endpoint to make multiple keysend payments with 1 request, which can be useful for splitting value4value payments.
- Using low level database constraints to prevent data inconsistencies
- Follow double-entry bookkeeping ideas (Every transaction is a debit of one account and a credit to another one)
┌─────────────┐
│ User │
└─────────────┘
│
┌─────────────────┬───────┴─────────┬─────────────────┐
▼ ▼ ▼ ▼
Accounts: ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐
│ Incoming │ │ Current │ │ Outgoing │ │ Fees │
Every user has └──────────────┘ └──────────────┘ └──────────────┘ └──────────────┘
four accounts
Every Transaction Entry is associated to one debit account and one
credit account
┌────────────────────────┐
│Transaction Entry │
│ │
│+ user_id │
┌────────────┐ │+ invoice_id │
│ Invoice │────────────────▶+ debit_account_id │
└────────────┘ │+ credit_account_id │
│+ amount │
Invoice holds the │+ ... │
lightning related │ │
data └────────────────────────┘