KingPepe SDK

Official JavaScript and TypeScript SDK for communicating with KingPepe Core v31.1.0 through JSON-RPC.

• npm package: https://www.npmjs.com/package/@kingpepe2/sdk
• KingPepe website: https://kingpepe.net
• KingPepe Core: https://github.com/kingpepe2/king-pepe-source-code
• SDK source: https://github.com/kingpepe2/SDK

This SDK does not store coins, private keys, or seed phrases. It is only a JSON-RPC client that sends requests to a KingPepe node/wallet that you run and control. Your keys and funds stay in your node's wallet, never in this library.

Package	@kingpepe2/sdk
Current version	1.0.0
KingPepe Core compatibility	v31.1.0
Symbol	KPEPE
SLIP-0044 coin type	6789

Installation

npm install @kingpepe2/sdk

Requires Node.js >= 18 (for the global fetch and AbortController). Zero runtime dependencies. Ships both ESM and CommonJS builds with TypeScript declarations.

Usage (TypeScript / ESM)

import { KingPepeClient } from "@kingpepe2/sdk";

const client = new KingPepeClient({
  url: "http://127.0.0.1:24027",
  username: process.env.KINGPEPE_RPC_USER,
  password: process.env.KINGPEPE_RPC_PASSWORD,
});

const blockchain = await client.getBlockchainInfo();
console.log(blockchain);

Usage (CommonJS)

const { KingPepeClient } = require("@kingpepe2/sdk");

const client = new KingPepeClient({
  url: "http://127.0.0.1:24027",
  username: process.env.KINGPEPE_RPC_USER,
  password: process.env.KINGPEPE_RPC_PASSWORD,
});

client.getBlockCount().then((height) => console.log("height:", height));

Methods

Every method is asynchronous and returns a Promise. Input-validation problems surface as a rejected promise (never a synchronous throw).

Node & network information

Method	RPC
getNetworkInfo()	getnetworkinfo
getConnectionCount()	getconnectioncount
getMempoolInfo()	getmempoolinfo

Blockchain

Method	RPC
getBlockchainInfo()	getblockchaininfo
getBlockCount()	getblockcount
getBlockHash(height)	getblockhash
getBlock(blockhash, verbosity?)	getblock
getRawTransaction(txid, verbose?, blockhash?)	getrawtransaction

Wallet

Method	RPC
listWallets()	listwallets
getWalletInfo()	getwalletinfo
getBalances()	getbalances
getNewAddress(label?, addressType?)	getnewaddress
listTransactions(label?, count?, skip?, includeWatchOnly?)	listtransactions
sendToAddress(address, amount, comment?) *	sendtoaddress
walletPassphrase(passphrase, timeoutSeconds) *	walletpassphrase
walletLock()	walletlock
backupWallet(destination) *	backupwallet

Mining

Method	RPC
getMiningInfo()	getmininginfo
getNetworkHashPs(nblocks?, height?)	getnetworkhashps
getBlockTemplate(templateRequest?)	getblocktemplate
submitBlock(hexData)	submitblock

Raw transactions

Method	RPC
createRawTransaction(inputs, outputs, locktime?)	createrawtransaction
decodeRawTransaction(hexString)	decoderawtransaction
signRawTransactionWithWallet(hexString) *	signrawtransactionwithwallet
sendRawTransaction(hexString, maxFeeRate?) *	sendrawtransaction

* = guarded (see below). Need an RPC method not wrapped yet? Use the typed escape hatch: await client.call<MyType>("somerpcmethod", [arg1, arg2]).

Wallet writes are off by default

Fund-moving and secret-handling methods (sendToAddress, sendRawTransaction, signRawTransactionWithWallet, walletPassphrase, backupWallet) are disabled unless you explicitly opt in, protecting read-only integrations from accidentally spending funds:

const wallet = new KingPepeClient({
  url: "https://your-node.example:24027/wallet/mywallet",
  username: process.env.KINGPEPE_RPC_USER,
  password: process.env.KINGPEPE_RPC_PASSWORD,
  enableWalletWrites: true, // required for the guarded methods
});

await wallet.walletPassphrase(process.env.KINGPEPE_WALLET_PASSPHRASE, 60);
try {
  const txid = await wallet.sendToAddress("kpepe1q...", 1.25);
  console.log("sent", txid);
} finally {
  await wallet.walletLock();
}

Authentication configuration

Pass RPC credentials explicitly — the SDK never reads config files or environment variables on its own:

new KingPepeClient({
  url: "https://your-node.example:24027/",
  username: process.env.KINGPEPE_RPC_USER,      // from your environment / secret manager
  password: process.env.KINGPEPE_RPC_PASSWORD,
});

Credentials are sent only in the HTTP Authorization header (HTTP Basic) and are never logged by the SDK.

Timeout configuration

Each request has a per-call timeout (default 30000 ms). A timed-out request is aborted and rejects with KingPepeTimeoutError:

const client = new KingPepeClient({ url: "http://127.0.0.1:24027", timeoutMs: 5000 });

Secure RPC usage

• Prefer HTTPS (or an SSH tunnel / private network). Use client.isSecureEndpoint to confirm your endpoint is HTTPS.
• Provide a custom fetch or extra headers when you need a proxy or bespoke transport.

Error handling

All errors extend KingPepeError:

Class	Meaning
KingPepeRpcError	The node returned a JSON-RPC error (.code, .data).
KingPepeHttpError	Non-2xx HTTP response (.status).
KingPepeTimeoutError	The request exceeded timeoutMs.
KingPepeValidationError	Client-side input validation failed.
KingPepeSecurityError	A guarded method was called without opt-in.
KingPepeTransportError	Network/transport failure.

import { KingPepeRpcError } from "@kingpepe2/sdk";

try {
  await client.getBlock("not-a-hash");
} catch (err) {
  if (err instanceof KingPepeRpcError) console.error("rpc code", err.code);
}

TypeScript types

The package ships full type declarations. Result shapes such as BlockchainInfo, NetworkInfo, MempoolInfo, Block, WalletInfo, Balances, MiningInfo, BlockTemplate, and RawTransaction are exported, along with the client options (KingPepeClientOptions) and every error class.

import type { BlockchainInfo, KingPepeClientOptions } from "@kingpepe2/sdk";

⚠️ Security

• Never expose KingPepe RPC directly to the public internet.
• Never commit RPC credentials.
• Use environment variables or a secure secret manager.
• Restrict RPC access to localhost or a trusted private network.
• Wallet-send methods can transfer real funds.
• The SDK does not store private keys or seed phrases.

Versioning

This package follows Semantic Versioning. Breaking API changes bump the MAJOR version; see CHANGELOG.md.

License

MIT © The KingPepe Core developers