Simple Technical Guide for RGB++ Development

RGB++ Code Examples

CKB Scripts (Contracts)
- CKB Bitcoin SPV Type Script: A type script for Bitcoin SPV clients which synchronize Bitcoin state into CKB
- RgbppLockScript and BtcTimeLockScript
The RGB++ SDK repository offers utilities for Bitcoin and RGB++ asset integration:
- @rgbpp-sdk/btc: Bitcoin part of the SDK
- @rgbpp-sdk/ckb: Nervos CKB part of the SDK
- @rgbpp-sdk/service: Wrapped interfaces of Bitcoin/RGB++ Assets Service
Bitcoin/RGB++ Assets Service offers various features for interacting with Bitcoin and RGB++ assets:
- Retrieve Blockchain Information including Bitcoin chain info, blocks, headers, transactions, addresses, and RGB++ assets
- Handle transactions by posting to /bitcoin/v1/transaction or /rgbpp/v1/transaction/ckb-tx
- Generate Bitcoin transaction Proof via /rgbpp/v1/btc-spv/proof through Bitcoin SPV Service on CKB
- Simplify RGB++ assets workflows with RGB++ CKB transaction Queue and cron jobs
- More detailed API documentation can be found on Testnet and Mainnet

Creation of rgbpp_ckb_tx_virtual using @rgbpp-sdk/ckb
1. BTC → BTC
2. BTC → CKB
3. CKB → BTC (isomorphic rgbpp_btc_tx is not required in this workflow)

Important

It's recommended to store the rgbpp_ckb_tx_virtual locally in case you need it in the future.

Creation of rgbpp_btc_tx through @rgbpp-sdk/btc
1. construct isomorphic rgbpp_btc_tx based on rgbpp_ckb_tx_virtual and rgbpp commitment
2. sign and broadcast rgbpp_btc_tx to obtain rgbpp_btc_txid
JoyID or dApp sends rgbpp_btc_txid and rgbpp_ckb_tx_virtual to RGB++ CKB transaction Queue (API Endpoint: /rgbpp/v1/transaction/ckb-tx)
RGB++ CKB transaction Queue will process the following things:
1. verify the received requests
2. continuously fetch request from the queue through a cron job
3. check whether the confirmations of req.rgbpp_btc_txid is sufficient
4. generate the witnesses for RgbppLocks in the rgbpp_ckb_tx_virtual
5. add a paymaster cell into rgbpp_ckb_tx_virtual.inputs if the CKB capacity is insufficient
  1. need to verify the existence of paymaster UTXO in the rgbpp_btc_tx
  2. sign the paymaster cell and the entire transaction if needed
6. finalize the rgbpp_ckb_tx_virtual to a rgbpp_ckb_tx
7. broadcast rgbpp_ckb_tx and mark the job as completed upon tx-confirmation

The RGB++ CKB transaction Queue is designed to streamline the transaction workflow. Developers have the option to implement its features by themselves without limitation.

btc_time_lock → target_ckb_address automation for the BTC → CKB workflow
- every 10 minutes, a cron job queries mature btc_time_lock cells, which means the related btc_txid in btc_time_lock.args has 6+ confirmations
- construct a transaction converting the mature btc_time_lock cells to the target_ckb_addresses