@backchain/core

Foundation package for the Backchain SDK. Provides the dual provider system, fee calculator, contract ABIs, types, and the BackchainContext interface that all modules depend on.

npm install @backchain/core ethers

When to use Core directly

Use @backchain/core instead of the full @backchain/sdk when you only need 1-2 modules and want a smaller bundle:

import { createContext } from '@backchain/core';
import { StakingModule } from '@backchain/staking';

const ctx = createContext({ operator: '0xYOUR_WALLET' });
await ctx.connect();

const staking = new StakingModule(ctx);
await staking.delegate(ethers.parseEther('100'), 365);

BackchainContext

The decoupling interface. All modules depend on this, not on the full Backchain class:

interface BackchainContext {
    readonly operator: string;
    readonly network: NetworkId;
    readonly provider: ProviderManager;
    readonly addresses: ContractAddresses;

    connect(): Promise<string>;
    connectWithSigner(signer: ethers.Signer): Promise<string>;
    disconnect(): void;
    calculateFee(actionId: string, txValue?: bigint): Promise<bigint>;
    getBkcAllowance(spender: string, owner?: string): Promise<bigint>;
    approveBkc(spender: string, amount: bigint): Promise<TxResult>;
}

Dual Provider

Separates reads from writes to prevent MetaMask rate-limiting:

• Reader (provider.reader): Public RPC for background reads, no wallet popups
• Signer (provider.getWriteContract()): MetaMask/injected wallet for writes

Fee Calculator

Solves the eth_call gasPrice=0 problem. Reads fee config from the Ecosystem contract and computes fees client-side:

import { calculateFee, ACTION_IDS, nftActionId } from '@backchain/core';

const fee = await calculateFee(provider, ecosystemAddress, ACTION_IDS.STAKING_DELEGATE);
const nftFee = await calculateFee(provider, ecosystemAddress, nftActionId('NFT_BUY_T', 0));

Networks

type NetworkId = 'sepolia' | 'opbnb-testnet' | 'opbnb-mainnet';

Exports

• createContext() — Lightweight BackchainContext factory
• ProviderManager — Dual provider system
• getNetworkConfig() — Network configuration
• calculateFee() — Client-side fee calculator
• actionId(), nftActionId(), notaryActionId() — Action ID helpers
• getAddresses(), getPoolAddress() — Contract address lookup
• All contract ABIs (BKC_TOKEN_ABI, ECOSYSTEM_ABI, etc.)
• All TypeScript types and interfaces

License

MIT