Signing Client (Recommended)

The BitBadgesSigningClient provides a streamlined, wallet-agnostic interface for signing and broadcasting transactions. It handles account info fetching, gas estimation, signing, and broadcasting in a single call.

When to Use

Use BitBadgesSigningClient when:

• You want a simple, all-in-one signing solution

• You don't need fine-grained control over the signing process

• You want automatic gas estimation and sequence management

• You want automatic retry on sequence mismatch errors

Use manual signing (Cosmos / Ethereum) when:

• You need full control over the transaction lifecycle

• You need to customize the signing flow (e.g., custom fee logic)

• You need to handle simulation separately from signing

• You're integrating with existing transaction management infrastructure

Installation

The signing client is included in the main SDK:

npm install bitbadgesjs-sdk

Quick Start

Cosmos Wallet (Keplr, Leap, etc.)

import {
    BitBadgesSigningClient,
    GenericCosmosAdapter,
    MsgTransferTokens,
} from 'bitbadgesjs-sdk';

// Create adapter from browser wallet
const adapter = await GenericCosmosAdapter.fromKeplr('bitbadges-1');
// Or: GenericCosmosAdapter.fromLeap('bitbadges-1')
// Or: GenericCosmosAdapter.fromCosmostation('bitbadges-1')

// Create signing client
const client = new BitBadgesSigningClient({ adapter });

// Create and broadcast transaction
const result = await client.signAndBroadcast([
    MsgTransferTokens.create({
        creator: client.address,
        collectionId: '1',
        transfers: [
            /* ... */
        ],
    }),
]);

if (result.success) {
    console.log('Transaction hash:', result.txHash);
} else {
    console.error('Transaction failed:', result.error);
}

EVM Wallet (MetaMask, etc.)

import {
    BitBadgesSigningClient,
    GenericEvmAdapter,
    MsgTransferTokens,
} from 'bitbadgesjs-sdk';
import { BrowserProvider } from 'ethers';

// Create adapter from ethers.js signer
const provider = new BrowserProvider(window.ethereum);
const signer = await provider.getSigner();
const adapter = await GenericEvmAdapter.fromSigner(signer);

// Or directly from window.ethereum
// const adapter = await GenericEvmAdapter.fromBrowserWallet();

// Create signing client
const client = new BitBadgesSigningClient({ adapter });

// Create and broadcast transaction (uses precompile path automatically)
const result = await client.signAndBroadcast([
    MsgTransferTokens.create({
        creator: client.address,
        collectionId: '1',
        transfers: [
            /* ... */
        ],
    }),
]);

console.log('Transaction hash:', result.txHash);

Server-Side Signing (EVM Path — Recommended)

Building an AI agent or bot? See the AI Agents & Bots section for end-to-end examples, testnet faucet, and MCP tool reference.

Server-side signing uses GenericEvmAdapter which connects to the EVM JSON-RPC endpoint and broadcasts via precompile calls. This is the recommended path for bots, agents, and backend services.

import {
    BitBadgesSigningClient,
    GenericEvmAdapter,
    NETWORK_CONFIGS,
} from 'bitbadgesjs-sdk';

// From mnemonic (secure server-side only!)
const adapter = await GenericEvmAdapter.fromMnemonic(
    'word1 word2 word3 ...', // 12 or 24 word mnemonic
    NETWORK_CONFIGS['mainnet'].evmRpcUrl, // 'https://evm-rpc.bitbadges.io'
);

// Or from private key
const adapter = await GenericEvmAdapter.fromPrivateKey(
    '0x...', // hex private key
    NETWORK_CONFIGS['mainnet'].evmRpcUrl,
);

const client = new BitBadgesSigningClient({ adapter });
const result = await client.signAndBroadcast([
    /* messages */
]);

Server-Side Signing (Cosmos Path)

The Cosmos path uses GenericCosmosAdapter with Cosmos-derived addresses and standard signDirect broadcasting. This produces a different address from the same key (Cosmos derivation vs ETH derivation).

import { BitBadgesSigningClient, GenericCosmosAdapter } from 'bitbadgesjs-sdk';

const adapter = await GenericCosmosAdapter.fromMnemonic(
    'word1 word2 word3 ...', // 12 or 24 word mnemonic
    'bitbadges-1',
);

const client = new BitBadgesSigningClient({ adapter });
const result = await client.signAndBroadcast([
    /* messages */
]);

Note: The same mnemonic/private key produces different addresses depending on which adapter you use. EVM adapter uses keccak256 (ETH-style) with coin type 60 HD path (m/44'/60'/0'/0/0), while Cosmos adapter uses ripemd160/sha256 with coin type 118 HD path (m/44'/118'/0'/0/0). The default for Keplr and the Cosmos chain registry is coin type 118. Make sure you fund the correct address for your chosen adapter.

Client Options

interface SigningClientOptions {
    adapter: WalletAdapter; // Required - the wallet adapter
    network?: NetworkMode; // 'mainnet' | 'testnet' | 'local' (default: 'mainnet')
    apiUrl?: string; // Override API URL from network preset
    nodeUrl?: string; // Override node LCD URL from network preset
    cosmosChainId?: string; // Override Cosmos chain ID from network preset
    evmChainId?: number; // Override EVM chain ID from network preset
    evmRpcUrl?: string; // Override EVM JSON-RPC URL from network preset
    sequenceRetryEnabled?: boolean; // Auto-retry on sequence mismatch (default: true)
    maxSequenceRetries?: number; // Max retry attempts (default: 3)
    gasMultiplier?: number; // Gas estimation multiplier (default: 1.3)
    defaultGasLimit?: number; // Default gas limit (default: 400000)
    evmPrecompileGasLimit?: number; // EVM precompile gas limit (default: 2000000)
    apiKey?: string; // BitBadges API key for authenticated requests
}

Network Presets

The SDK provides built-in network configurations via NETWORK_CONFIGS:

import { NETWORK_CONFIGS, type NetworkMode } from 'bitbadgesjs-sdk';

// Available presets
const mainnet = NETWORK_CONFIGS['mainnet'];
// {
//   apiUrl: 'https://api.bitbadges.io',
//   nodeUrl: 'https://lcd.bitbadges.io',
//   cosmosChainId: 'bitbadges-1',
//   evmChainId: 50024,
//   evmRpcUrl: 'https://evm-rpc.bitbadges.io'
// }

const testnet = NETWORK_CONFIGS['testnet'];
// {
//   apiUrl: 'https://api.bitbadges.io/testnet',
//   nodeUrl: 'https://lcd-testnet.bitbadges.io',
//   cosmosChainId: 'bitbadges-2',
//   evmChainId: 50025,
//   evmRpcUrl: 'https://evm-rpc-testnet.bitbadges.io'
// }

const local = NETWORK_CONFIGS['local'];
// {
//   apiUrl: 'http://localhost:3001',
//   nodeUrl: 'http://localhost:1317',
//   cosmosChainId: 'bitbadges-1',
//   evmChainId: 90123,
//   evmRpcUrl: 'http://localhost:8545'
// }

Use network presets with optional overrides:

// Use mainnet preset (default)
const client = new BitBadgesSigningClient({ adapter });

// Use testnet preset
const client = new BitBadgesSigningClient({
    adapter,
    network: 'testnet',
});

// Use preset with custom override
const client = new BitBadgesSigningClient({
    adapter,
    network: 'mainnet',
    apiUrl: 'https://custom-api.example.com', // overrides preset's apiUrl
});

Sign and Broadcast Options

interface SignAndBroadcastOptions {
    memo?: string; // Transaction memo
    fee?: SigningFee; // Custom fee (overrides auto-calculation)
    simulate?: boolean; // Simulate first for gas estimation (default: true for Cosmos)
    gasMultiplier?: number; // Override gas multiplier for this transaction
}

Broadcast Result

interface BroadcastResult {
    txHash: string; // Transaction hash
    success: boolean; // Whether broadcast succeeded
    error?: string; // Error message if failed
    code: number; // Transaction code (0 = success)
    rawResponse: any; // Raw response from broadcast endpoint
}

Wallet Adapters

GenericCosmosAdapter

For browser wallets (Keplr, Leap, etc.) and server-side Cosmos signing:

// Browser wallets
GenericCosmosAdapter.fromKeplr(chainId: string)
GenericCosmosAdapter.fromLeap(chainId: string)
GenericCosmosAdapter.fromCosmostation(chainId: string)
GenericCosmosAdapter.fromBrowserWallet(wallet: KeplrLike, chainId: string)

// Server-side (Cosmos derivation — different address than EVM adapter)
GenericCosmosAdapter.fromMnemonic(mnemonic: string, chainId: string)
GenericCosmosAdapter.fromPrivateKey(privateKey: string, chainId: string)

GenericEvmAdapter

For browser EVM wallets and server-side signing (recommended for bots/agents):

// Server-side (recommended for bots, agents, backends)
GenericEvmAdapter.fromMnemonic(mnemonic: string, evmRpcUrl: string, options?: EvmAdapterOptions)
GenericEvmAdapter.fromPrivateKey(privateKey: string, evmRpcUrl: string, options?: EvmAdapterOptions)

// Browser wallets
GenericEvmAdapter.fromSigner(signer: EthersSigner, options?: EvmAdapterOptions)
GenericEvmAdapter.fromProvider(provider: EIP1193Provider, options?: EvmAdapterOptions)
GenericEvmAdapter.fromBrowserWallet(options?: EvmAdapterOptions)

EVM adapters only support sendEvmTransaction — they do not support signDirect. The BitBadgesSigningClient handles routing automatically based on the adapter type.

EVM Chain ID Validation

You can validate that the wallet is connected to the correct EVM network:

import { GenericEvmAdapter, NETWORK_CONFIGS } from 'bitbadgesjs-sdk';

// Validate chain ID when creating adapter
const adapter = await GenericEvmAdapter.fromSigner(signer, {
    expectedChainId: NETWORK_CONFIGS['mainnet'].evmChainId, // 50024
});

// Or for local development
const adapter = await GenericEvmAdapter.fromBrowserWallet({
    expectedChainId: NETWORK_CONFIGS['local'].evmChainId, // 90123
});

// Throws error if wallet is on wrong network:
// "Wallet is connected to chain X, but expected chain Y. Please switch your wallet to the correct network."

Network Selection

// Mainnet (default)
const client = new BitBadgesSigningClient({
    adapter,
    network: 'mainnet',
});

// Testnet
const client = new BitBadgesSigningClient({
    adapter,
    network: 'testnet',
});

// Local development
const client = new BitBadgesSigningClient({
    adapter,
    network: 'local',
});

Gas Estimation

By default, the client simulates transactions to estimate gas:

// Auto gas estimation (default)
const result = await client.signAndBroadcast(messages);

// Skip simulation, use default gas
const result = await client.signAndBroadcast(messages, {
    simulate: false,
});

// Custom fee
const result = await client.signAndBroadcast(messages, {
    fee: {
        amount: '10000000',
        denom: 'ubadge',
        gas: '500000',
    },
});

Sequence Management

The client automatically handles account sequence (nonce) management:

const client = new BitBadgesSigningClient({
    adapter,
    sequenceRetryEnabled: true, // Auto-retry on sequence mismatch (default)
    maxSequenceRetries: 3, // Max retries (default)
});

// Cached sequence is incremented after successful transactions
// If sequence mismatch occurs, client will:
// 1. Clear cached account info
// 2. Fetch fresh sequence from chain
// 3. Retry the transaction

Account Info

// Get account info (cached)
const info = await client.getAccountInfo();
console.log(info.address, info.accountNumber, info.sequence);

// Force refresh from chain
const freshInfo = await client.getAccountInfo(true);

// Clear cache manually
client.clearCache();

Multiple Messages

const result = await client.signAndBroadcast(
    [
        MsgTransferTokens.create({
            /* ... */
        }),
        MsgSetTokenMetadata.create({
            /* ... */
        }),
        MsgSetCollectionMetadata.create({
            /* ... */
        }),
    ],
    {
        memo: 'Batch update',
    },
);

Error Handling

try {
    const result = await client.signAndBroadcast(messages);

    if (!result.success) {
        // Transaction was broadcast but failed on-chain
        console.error('Transaction failed:', result.error);
        console.error('Error code:', result.code);
    }
} catch (error) {
    // Pre-broadcast error (wallet rejected, network error, etc.)
    console.error('Signing error:', error.message);
}

Comparison with Manual Signing

Feature	BitBadgesSigningClient	Manual Signing
Complexity	Simple, all-in-one	More setup required
Control	Abstracted	Full control
Account Info	Auto-fetched & cached	Manual fetch
Gas Estimation	Built-in simulation	Manual simulation
Sequence Retry	Automatic	Manual handling
Broadcasting	Built-in	Separate step
Custom Flow	Limited	Fully customizable

See Also

• Signing - Cosmos - Manual Cosmos wallet signing

• Signing - Ethereum - Manual EVM wallet signing

• Transaction Context - Understanding TxContext

• Broadcast to Node - Manual broadcasting