Paying a demo invoice locally (fiber-node-payer)

This is a contributor/testing tool, not something a merchant or integrator needs — it exists so you can actually pay a demo storefront invoice end-to-end without a separate real wallet/node handy.

Runs as a 4th service, fiber-node-payer, right in root docker-compose.yml — local-testing-only, gated behind profiles: [payer] so a plain docker compose up -d never starts it; only docker compose up -d fiber-node-payer / pnpm docker:payer does. It's a second nervos/fiber node on the same fibergate-net network as fiber-node — lets you actually pay a demo invoice by opening a direct channel between the two, entirely over plain TCP inside that network. No TLS/WSS setup needed (that's only required for a browser-based wallet).

This only needs fiber-node itself running — e.g. via pnpm docker:dev — it never touches postgres/fibergate-core.

Generate a CKB testnet key for the payer — separate from fiber-node's own key (this is a throwaway test wallet, not the merchant's identity):

bash

mkdir -p docker/fiber-node-payer/ckb
ckb-cli account export --lock-arg <lock_arg> --extended-privkey-path ./exported-key
head -n 1 ./exported-key > docker/fiber-node-payer/ckb/key
rm ./exported-key
chmod 600 docker/fiber-node-payer/ckb/key

Set FIBER_PAYER_SECRET_KEY_PASSWORD in root .env to the passphrase you want to encrypt that key with.

Fund the payer's wallet via https://faucet.nervos.org — get its CKB address from ckb-cli (the same key/lock-arg from step 1), fund with enough to cover a channel (recommend ~250 CKB: the 99 CKB reserve + a modest funding amount + fees).

Start fiber-node if it isn't already running, then the payer:

bash

pnpm docker:dev    # postgres + fiber-node, if not already running
pnpm docker:payer  # fiber-node-payer only — reads root .env, same as fiber-node
docker compose ps  # wait for fiber-node-payer to report "healthy"

Get fiber-node's pubkey, then convert it to the multiaddr fiber-node-payer needs for connect_peer:

bash

curl -s -X POST http://localhost:8227 -H 'Content-Type: application/json' \
  --data '{"id":1,"jsonrpc":"2.0","method":"node_info","params":[]}' | jq -r '.result.pubkey'

cd apps/demo-storefront
pnpm payer:multiaddr <pubkey from above>
# → /ip4/172.28.0.10/tcp/8228/p2p/<peer id>

Connect the payer to fiber-node and open a channel (both against the payer's own RPC, port 8237):

bash

curl -s -X POST http://localhost:8237 -H 'Content-Type: application/json' \
  --data '{"id":1,"jsonrpc":"2.0","method":"connect_peer","params":[{"address":"<multiaddr from step 4>"}]}'

curl -s -X POST http://localhost:8237 -H 'Content-Type: application/json' \
  --data '{"id":1,"jsonrpc":"2.0","method":"open_channel","params":[{"pubkey":"<fiber-node pubkey>","funding_amount":"0x4a817c800"}]}'
# 0x4a817c800 = 200 CKB in shannons — must be >= fiber-node's own
# open_channel_auto_accept_min_ckb_funding_amount (check via node_info on
# :8227; defaults to 100 CKB = 0x2540be400) or the channel needs a manual
# accept_channel from fiber-node's side.

Poll until ready (no gossip-sync wait needed — this is a direct channel, not a multi-hop route):

bash

curl -s -X POST http://localhost:8237 -H 'Content-Type: application/json' \
  --data '{"id":1,"jsonrpc":"2.0","method":"list_channels","params":[{}]}' | jq '.result.channels[].state.state_name'
# wait for "ChannelReady"

Pay the invoice — grab invoice_address from the demo storefront's QR/text, then:
bash
```
curl -s -X POST http://localhost:8237 -H 'Content-Type: application/json' \
  --data '{"id":1,"jsonrpc":"2.0","method":"send_payment","params":[{"invoice":"<invoice_address>"}]}'
```
fibergate-core's real-time listener picks up the Paid status within seconds (30s poller as fallback), fires the webhook, and the demo storefront's page updates automatically via SSE.

Something not working? See Troubleshooting.

Paying a demo invoice locally (fiber-node-payer) ​

Paying a demo invoice locally (fiber-node-payer)