Step 5 — API
Provide RPC and explorer details to Ledger. Use rpc-explorer-config.ts:
- RPC_ENDPOINTS — Public HTTPS and WSS URLs for Chain 138.
- EXPLORER — Blockscout at https://explorer.d-bis.org (EIP3091); optional apiUrl for indexer.
- BLOCK_AVG_TIME_SEC — ~2s for Chain 138 (Besu QBFT).
Ledger may run their own indexer or proxy; they will specify. Have these values ready for their config or env (e.g. API_DEFI_ORACLE_META_NODE).