Multi-hop Transfers

TL;DR

Connect your local node to Fiber's public relay nodes, open a channel, and send multi-hop payments through the Testnet. Your local node does not need a public IP.

Public Testnet Node Addresses

node1: /ip4/18.162.235.225/tcp/8119/p2p/QmXen3eUHhywmutEzydCsW4hXBoeVmdET2FJvMX69XJ1Eo
node2: /ip4/18.163.221.211/tcp/8119/p2p/QmbKyzq9qUmymW2Gi8Zq7kKVpPiNA1XUJ6uMvsUC4F3p89

Local Node Setup

Download fnn from the releases page:

mkdir tmp && cd tmp
tar xzvf fnn-latest.tar.gz

macOS Security

xattr -d com.apple.quarantine fnn fnn-cli fnn-migrate

Create account and export private key:

mkdir -p testnet-fnn/nodeA/ckb
./ckb-cli account new           # save the lock_arg
./ckb-cli account export --lock-arg <YOUR_LOCK_ARG> --extended-privkey-path ./exported-key
head -n 1 ./exported-key > testnet-fnn/nodeA/ckb/key
chmod 600 testnet-fnn/nodeA/ckb/key

Copy config and tools:

cp config/testnet/config.yml testnet-fnn/nodeA
cp fnn-cli testnet-fnn/nodeA

HTTP Proxy Issues

export NO_PROXY=127.0.0.1,localhost

Fund nodeA's address with 10,000 CKB and 20 RUSD:
- CKB: https://faucet.nervos.org
- RUSD: https://testnet0815.stablepp.xyz/faucet (claim via JoyID, then transfer to nodeA's address)

Start nodeA:

FIBER_SECRET_KEY_PASSWORD='123' RUST_LOG=info ./fnn -c testnet-fnn/nodeA/config.yml -d testnet-fnn/nodeA > testnet-fnn/nodeA/a.log 2>&1 &

CKB Channel with Public Node 1

CLI amounts are in shannons (1 CKB = 100,000,000). RPC amounts are hex strings (e.g. "0x5f5e100" = 100,000,000).

1. Connect to node1

First get node1's pubkey:

curl -s 'http://18.162.235.225:8227' \
  -H 'Content-Type: application/json' \
  -d '{"id":1,"jsonrpc":"2.0","method":"node_info"}' | grep -o '"pubkey":"[^"]*"'

Then connect:

cd testnet-fnn/nodeA && ./fnn-cli peer connect_peer \
  --address "/ip4/18.162.235.225/tcp/8119/p2p/QmXen3eUHhywmutEzydCsW4hXBoeVmdET2FJvMX69XJ1Eo"

curl -s 'http://127.0.0.1:8227' \
  -H 'Content-Type: application/json' \
  -d '{
    "id": 1, "jsonrpc": "2.0", "method": "connect_peer",
    "params": [{"pubkey": "<node1_pubkey>", "address": "/ip4/18.162.235.225/tcp/8119/p2p/QmXen3eUHhywmutEzydCsW4hXBoeVmdET2FJvMX69XJ1Eo"}]
  }'

CCC support coming soon.

2. Open a CKB Channel (500 CKB minimum)

node1 requires at least 438 CKB funding amount.

cd testnet-fnn/nodeA && ./fnn-cli channel open_channel \
  --pubkey <node1_pubkey> \
  --funding-amount 50000000000 \
  --public true

curl -s 'http://127.0.0.1:8227' \
  -H 'Content-Type: application/json' \
  -d '{
    "id": 2, "jsonrpc": "2.0", "method": "open_channel",
    "params": [{"pubkey": "<node1_pubkey>", "funding_amount": "0xba43b7400", "public": true}]
  }'

CCC support coming soon.

3. Wait for ChannelReady

./fnn-cli channel list_channels

curl -s 'http://127.0.0.1:8227' \
  -H 'Content-Type: application/json' \
  -d '{"id": 3, "jsonrpc": "2.0", "method": "list_channels", "params": [{"peer_pubkey": "<node1_pubkey>"}]}'

CCC support coming soon.

After ChannelReady, wait a few minutes before sending payments — the gossip protocol needs time to sync routing info.

4. Create an Invoice on node2

Generate a preimage: payment_preimage="0x$(openssl rand -hex 32)"

./fnn-cli --url http://18.163.221.211:8227 invoice new_invoice \
  --amount 100000000 \
  --currency Fibt \
  --description "test invoice" \
  --expiry 3600 \
  --payment-preimage $payment_preimage

curl -s 'http://18.163.221.211:8227' \
  -H 'Content-Type: application/json' \
  -d "{
    \"id\": 4, \"jsonrpc\": \"2.0\", \"method\": \"new_invoice\",
    \"params\": [{
      \"amount\": \"0x5f5e100\",
      \"currency\": \"Fibt\",
      \"description\": \"test invoice\",
      \"expiry\": \"0xe10\",
      \"payment_preimage\": \"$payment_preimage\",
      \"hash_algorithm\": \"sha256\"
    }]
  }"

CCC support coming soon.

5. Send Payment (nodeA → node1 → node2)

./fnn-cli payment send_payment --invoice "<invoice_address>"

curl -s 'http://127.0.0.1:8227' \
  -H 'Content-Type: application/json' \
  -d '{"id": 6, "jsonrpc": "2.0", "method": "send_payment", "params": [{"invoice": "<invoice_address>"}]}'

CCC support coming soon.

6. Close the Channel

./fnn-cli channel shutdown_channel \
  --channel-id <channel_id> \
  --close-script '{"code_hash":"0x9bd7e06f3ecf4be0f2fcd2188b23f1b9fcc88e5d4b65a8637b17723bbda3cce8","hash_type":"type","args":"<your_lock_arg>"}'

curl -s 'http://127.0.0.1:8227' \
  -H 'Content-Type: application/json' \
  -d '{
    "id": 9, "jsonrpc": "2.0", "method": "shutdown_channel",
    "params": [{
      "channel_id": "<channel_id>",
      "close_script": {
        "code_hash": "0x9bd7e06f3ecf4be0f2fcd2188b23f1b9fcc88e5d4b65a8637b17723bbda3cce8",
        "hash_type": "type",
        "args": "<your_lock_arg>"
      },
      "fee_rate": "0x3FC"
    }]
  }'

CCC support coming soon.

RUSD Channel with Public Node 1

The steps are identical to the CKB channel above, with two differences:

Open channel — add funding_udt_type_script:

./fnn-cli channel open_channel \
  --pubkey <node1_pubkey> \
  --funding-amount 20 \
  --public true \
  --funding-udt-type-script '{"code_hash":"0x1142755a044bf2ee358cba9f2da187ce928c91cd4dc8692ded0337efa677d21a","hash_type":"type","args":"0x878fcc6f1f08d48e87bb1c3b3d5083f23f8a39c5d5c764f253b55b998526439b"}'

curl -s 'http://127.0.0.1:8227' \
  -H 'Content-Type: application/json' \
  -d '{
    "id": 2, "jsonrpc": "2.0", "method": "open_channel",
    "params": [{
      "pubkey": "<node1_pubkey>",
      "funding_amount": "0x2540be400",
      "public": true,
      "funding_udt_type_script": {
        "code_hash": "0x1142755a044bf2ee358cba9f2da187ce928c91cd4dc8692ded0337efa677d21a",
        "hash_type": "type",
        "args": "0x878fcc6f1f08d48e87bb1c3b3d5083f23f8a39c5d5c764f253b55b998526439b"
      }
    }]
  }'

CCC support coming soon.

Create invoice — add udt_type_script:

./fnn-cli --url http://18.163.221.211:8227 invoice new_invoice \
  --amount 100000000 \
  --currency Fibt \
  --description "test RUSD invoice" \
  --expiry 3600 \
  --udt-type-script '{"code_hash":"0x1142755a044bf2ee358cba9f2da187ce928c91cd4dc8692ded0337efa677d21a","hash_type":"type","args":"0x878fcc6f1f08d48e87bb1c3b3d5083f23f8a39c5d5c764f253b55b998526439b"}'

curl -s 'http://18.163.221.211:8227' \
  -H 'Content-Type: application/json' \
  -d "{
    \"id\": 4, \"jsonrpc\": \"2.0\", \"method\": \"new_invoice\",
    \"params\": [{
      \"amount\": \"0x5f5e100\",
      \"currency\": \"Fibt\",
      \"description\": \"test RUSD invoice\",
      \"expiry\": \"0xe10\",
      \"payment_preimage\": \"$payment_preimage\",
      \"hash_algorithm\": \"sha256\",
      \"udt_type_script\": {
        \"code_hash\": \"0x1142755a044bf2ee358cba9f2da187ce928c91cd4dc8692ded0337efa677d21a\",
        \"hash_type\": \"type\",
        \"args\": \"0x878fcc6f1f08d48e87bb1c3b3d5083f23f8a39c5d5c764f253b55b998526439b\"
      }
    }]
  }"

CCC support coming soon.

node1 requires at least 20 RUSD funding amount. The send_payment call is identical to the CKB flow above.

Multi-hop Transfers

TL;DR

Public Testnet Node Addresses

Local Node Setup

CKB Channel with Public Node 1

1. Connect to node1

2. Open a CKB Channel (500 CKB minimum)

3. Wait for ChannelReady

4. Create an Invoice on node2

5. Send Payment (nodeA → node1 → node2)

6. Close the Channel

RUSD Channel with Public Node 1

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Fiber AI Assistant