Skip to main content

Combining SimLN with Scaling Lightning

· 2 min read
Max Edwards

SimLN is a new tool to generate payment activity between lightning nodes. In this post I give a walkthough of running it against a Scaling Lightning cluster.

Scaling Lightning setup

To start off let's create a local cluster with 2 nodes: Alice(CLN) and Bob(LND).

- name: scalinglightning
- name: bitcoind
namespace: sl
chart: scalinglightning/bitcoind
- name: alice
namespace: sl
chart: scalinglightning/cln
- gRPCEntryPoint: endpoint1
- name: bob
namespace: sl
chart: scalinglightning/lnd
- gRPCEntryPoint: endpoint2

Start the network. The scaling-lightning binary can be downloaded from Please read the README for prerequisites such as helm and installing traefik on your cluster.

scaling-lightning start -f network.yaml

{eer up Alice and Carol and open a channel and send some initial funds that can be sent back and forth.

scaling-lightning send -f bitcoind -t alice -a 1000000
scaling-lightning connectpeer -f alice -t bob
scaling-lightning openchannel -f alice -t bob -a 100000
scaling-lightning createinvoice -n bob -a 50000
scaling-lightning payinvoice -n alice -i <bolt11 invoice>

Scaling Lightning cluster should be running with Alice and Bob having a channel between them.

SimLN setup

SimLN also requires a config file.

git clone
cd sim-ln

Then create config file for SimLN to give it the identity of nodes in the Scaling Lightning cluster.

"nodes": [
"LND": {
"id": "0248efcfe94e3c451f4995b471ef0707163f279d4681af23727279c9c696004b42",
"address": "https://localhost:28102",
"macaroon": "/Users/max/source/sim-ln/auth/bob/admin.macaroon",
"cert": "/Users/max/source/sim-ln/auth/bob/tls.cert"
"CLN": {
"id": "0221b76f4cce7ab42538127022bac6245e999804ab5901813d9337d5cadd6428df",
"address": "https://localhost:28101",
"ca_cert": "/Users/max/source/sim-ln/auth/alice/ca.pem",
"client_cert": "/Users/max/source/sim-ln/auth/alice/client.pem",
"client_key": "/Users/max/source/sim-ln/auth/alice/client-key.pem"
"activity": [
"source": "0248efcfe94e3c451f4995b471ef0707163f279d4681af23727279c9c696004b42",
"destination": "0221b76f4cce7ab42538127022bac6245e999804ab5901813d9337d5cadd6428de",
"interval_secs": 1,
"amount_msat": 2000
"source": "0221b76f4cce7ab42538127022bac6245e999804ab5901813d9337d5cadd6428de",
"destination": "0248efcfe94e3c451f4995b471ef0707163f279d4681af23727279c9c696004b42",
"interval_secs": 1,
"amount_msat": 2000

To create your version of this config file you need three things: pubkey, address+port of GRPC api and auth files. Scaling Lightning has three commands for that.

scaling-lightning writeauthfiles -o ~/source/sim-ln/auth --all
scaling-lightning pubkey -n alice
scaling-lightning pubkey -n bob
scaling-lightning connectiondetails --all

Finally to run SimLN

cargo install --path sim-cli/
sim-cli --log-level debug --config config.json

We will be following the development of SimLN closely. Scaling Lightning will need it's own activity generator and perhaps that could be SimLN?