ethers signer

You write ethers. BkcSigner returns an ordinary ethers v6 Signer; Contract, ContractFactory, tx.wait() and queryFilter behave as on any EVM chain.

Create a signer

import { BkcSigner, GasPrice } from "@bkc-network-lib/sdk";

const endpoints = {
  evmRpcUrl: "https://rpc.bkc.network",           // reads
  cosmosRpcUrl: "https://comet-rpc.bkc.network",  // writes are broadcast here
  gasPrice: GasPrice.fromString("5000000bkc"),
};

const signer = await BkcSigner.fromMnemonic(process.env.MNEMONIC!, endpoints);
// or: await BkcSigner.fromSeed(seedBytes, endpoints)       // 32-byte ML-DSA-65 seed
// or: await BkcSigner.fromWallet(offlineDirectSigner, endpoints)

Always pass gasPrice

Without it the SDK falls back to bkcChain.gasPrice, 66,666,666,667 bkc per gas — about 13,000× the chain minimum. Transactions still succeed, but each one costs that much more (a native send ≈ 0.017 BKC instead of ≈ 0.0000013 BKC).

Deploy, write, read

import { ContractFactory, Contract } from "@bkc-network-lib/sdk";

const factory = new ContractFactory(abi, bytecode, signer);
const contract = await factory.deploy();
await contract.waitForDeployment();

await (await contract.set(42)).wait();   // a write: MsgExecuteEvmCall, signed with ML-DSA-65
await contract.get();                    // a read: eth_call, no signing → 42n

Native transfers are writes too:

const tx = await signer.sendTransaction({ to: "0x…", value: 10n ** 18n }); // 1 BKC
await tx.wait();

What works

Measured against the live chain:

Works unchanged	Cannot work (throws with an explanation)
getNetwork, getBlockNumber, getBalance, getBlock	signer.signMessage, signTypedData — secp256k1 only
ContractFactory.deploy(), contract.method(), estimateGas	eth_sendRawTransaction
tx.wait(), getTransaction, receipt log decoding	queryFilter with no block range — the node caps a log query at 10,000 blocks
queryFilter(filter, fromBlock, toBlock)
signer.sendTransaction({ to, value })

ethers nests the explanation one level down, at error.error.message; error.shortMessage only says "could not coalesce error".

Replacements

Instead of	Use	You get
receipt.fee (always 0)	getEvmTransactionCost(hash, restUrl)	the fee actually charged, the Cosmos hash and gas
queryFilter with no range	getLogsPaged(provider, filter, { maxWindows })	logs walked backwards one 10,000-block window at a time
signer.signMessage	signMessage(wallet, text)	an ADR-36 document signed with ML-DSA-65

import { getEvmTransactionCost, getLogsPaged, signMessage, verifyMessage } from "@bkc-network-lib/sdk";

const cost = await getEvmTransactionCost(receipt.hash, "https://api.bkc.network");

// getLogsPaged takes an EIP-1193 provider and a plain { address, topics } filter
import { JsonRpcProvider, id } from "ethers";
const rpc = new JsonRpcProvider("https://rpc.bkc.network");
const eip1193 = { request: ({ method, params }) => rpc.send(method, params ?? []) };

const { logs, reachedBlock } = await getLogsPaged(
  eip1193,
  { address: tokenAddress, topics: [id("Transfer(address,address,uint256)")] },
  { maxWindows: 5 },          // 5 × 10,000 blocks, newest first
);
// reachedBlock: the oldest block searched — continue from there if you need more history

Concurrency

call_nonce is the account's Cosmos sequence, and the chain requires it to match exactly. Two writes sent at once from the same signer would collide; send them one after another (await tx.wait() between) or use separate accounts.

Lower-level pieces

For custom tooling: makeEvmCallMessage, withGasHeadroom, cosmosGasForEvmCall, findEthereumTxHash, toEvmAddress, tryToEvmAddress, and createBkcEip1193Provider() — a raw EIP-1193 provider for libraries that wire their own stack (viem, wallets).