# @dgb-wallet/rpc

JSON-RPC client for DigiByte Core, calling only the read-only + broadcast methods a wallet needs. Companion to [`ops/setup.sh`](../../ops/setup.sh), which provisions the matching pruned VPS backend.

## API

- `new RpcClient({ url, username, password, timeoutMs })`
- `getBlockchainInfo(client)` — chain tip, sync progress, prune status
- `scanTxOutSet(client, descriptors)` — walk UTXO set for descriptors/xpubs; returns matching UTXOs
- `sendRawTransaction(client, hex)` — broadcast; returns txid or throws
- `estimateSmartFee(client, confTarget)` — DGB/kB fee estimate
- `descriptorForAccount(purpose, xpub, change, rangeEnd)` — build BIP44/49/84/86 descriptors with checksums
- `descriptorChecksum(desc)`, `withChecksum(desc)` — BIP380 checksum helpers

## Demo — real recovery scan via your VPS

Provision the backend once with [`../../ops/setup.sh`](../../ops/setup.sh) (turnkey for a fresh Ubuntu/Debian VPS). Then:

```bash
cd "D:\Dev\SilentCode\Digibyte"
npm install                        # first time only
npm run build -w @dgb-wallet/core

export DGB_RPC_URL=https://your-domain.example.com/
export DGB_RPC_USER=dgb_...
export DGB_RPC_PASSWORD=...
npm run demo -w @dgb-wallet/rpc
# or with a specific seed:
npm run demo -w @dgb-wallet/rpc -- "word1 word2 ... word12"
```

Scans 3 accounts × 4 descriptor paths × 2 change/receive × 101 addresses each = **2,424 addresses in one RPC call**, typically 5–15 seconds on a synced pruned node. Prints every UTXO found with its descriptor path, ready to feed into `@dgb-wallet/psbt` for spending.

## Descriptor checksums

DGB Core requires descriptors passed to `scantxoutset` to carry a BIP380 checksum. `withChecksum(desc)` and `descriptorForAccount(...)` compute it locally so we don't need a round-trip to `getdescriptorinfo`.

## Notes

- Uses `fetch` — Node 18+, React Native, and browser extensions all work.
- Future: swap `fetch` for `@dgb-wallet/net`'s `NetProvider` so requests can go through Tor by default (per RESEARCH.md §10.7b).
- Wallet-side is stateless; the VPS holds the chain state. Client keys never leave the wallet.