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Routing

RGB v0.11 line (rgb-cmd 0.11.1)

This describes the RGB Lightning Node (RLN) and its rust-lightning fork, which is alpha software. Read RGB on Lightning first. See Two RGB lines.

An RGB payment can cross several channels, as long as every hop has a channel with the same asset and enough liquidity in it. Alice → Bob → Carol works when Alice–Bob and Bob–Carol both hold contract C. Each hop forwards the asset amount, and at least 3,000 sats along with it.

What the fork (RGB-Tools/rust-lightning, branch rgb, commit of 2026-08-07) changes:

  • Payment: a route carries one (contract ID, amount) pair end to end (RouteParameters.rgb_payment, lightning/src/routing/router.rs). The onion and the HTLC messages carry the same pair. No state proofs travel along the route. Channel peers exchange RGB data for their own commitment updates.
  • Gossip: channel announcements and updates add the channel's contract_id and htlc_maximum_rgb (lightning/src/routing/gossip.rs). The router uses them to skip channels with the wrong asset or not enough of it. Route hints in invoices carry htlc_maximum_rgb too.
  • Fees are paid in msat only, set per channel with fee_base_msat and fee_proportional_millionths. Routing fees in the asset don't exist.
  • One path: RLN builds routes with max_path_count: 1 (src/utils.rs), so there is no multi-path payment. There is no trampoline routing either.
  • No cross-asset payments in one route. To exchange one asset for another, or for BTC, use RLN's maker/taker swaps: the maker calls POST /makerinit and gets a swap string, the taker accepts it with POST /taker, and the maker completes it with POST /makerexecute. Each swap runs as Lightning payments between the two nodes.

Privacy is as in Lightning: onion routing hides the sender and recipient from intermediate hops. Every hop learns the asset (contract ID) and the amount it forwards, and public channels announce their asset in gossip.

Paying​

There is no route query endpoint. Routing happens inside the payment calls:

# pay a BOLT11 invoice that carries RGB fields
curl -X POST -H "Content-type: application/json" \
  -d '{"invoice": "<lnbcrt…>"}' http://localhost:3001/sendpayment
# spontaneous payment to a node pubkey
curl -X POST -H "Content-type: application/json" \
  -d '{"dest_pubkey": "<pubkey>", "amt_msat": 3000000, "asset_id": "<asset_id>", "asset_amount": 10}' \
  http://localhost:3001/keysend

GET /listpayments and POST /getpayment show the result. GET /networkinfo returns the network and the block height, and GET /nodeinfo returns the counts of known nodes and channels.