Quickstart

Get started with Sponge in under 5 minutes.

Installation

Install the Sponge SDK using your preferred package manager:

bun add @spongewallet/sdk

Or with npm:

npm install @spongewallet/sdk

Or with yarn:

yarn add @spongewallet/sdk

Basic Usage

Import and Connect

The connect() method handles authentication automatically using the device flow. On first run, it will prompt you to authorize in your browser.

import { SpongeWallet } from "@spongewallet/sdk";
 
const wallet = await SpongeWallet.connect();

Check Balances

Retrieve balances across all supported chains:

const balances = await wallet.getBalances();
 
console.log(balances);
// [
//   { chain: "ethereum", balance: "0.5", symbol: "ETH", usdValue: "1250.00" },
//   { chain: "base", balance: "100.0", symbol: "USDC", usdValue: "100.00" },
//   { chain: "solana", balance: "10.0", symbol: "SOL", usdValue: "450.00" }
// ]

Get Wallet Addresses

Each agent gets one EVM wallet (works across Ethereum, Base, and other EVM chains) and one Solana wallet:

const addresses = await wallet.getAddresses();
 
console.log(addresses);
// {
//   evm: "0x1234...abcd",
//   solana: "7nYB...xyz"
// }

Transfer Crypto

Send crypto to any address:

const tx = await wallet.transfer({
  chain: "base",
  to: "0xRecipientAddress",
  amount: "10.0",
  currency: "USDC"
});
 
console.log(`Transaction: ${tx.hash}`);
console.log(`Explorer: ${tx.explorerUrl}`);

Test Mode vs Live Mode

API Key Types

Sponge uses different API keys for test and live environments. Test keys (prefixed with sponge_test_) can only access testnets, while live keys (sponge_live_) can only access mainnets.

Using Test Mode

By default, connect() uses test mode during the device flow. You can explicitly request a test or live key:

// Explicitly request test mode
const testWallet = await SpongeWallet.connect({ testnet: true });
 
// Request live mode (requires approval)
const liveWallet = await SpongeWallet.connect({ testnet: false });

Test Chains Available

Chain	Description
`sepolia`	Ethereum Sepolia testnet
`base-sepolia`	Base Sepolia testnet
`solana-devnet`	Solana Devnet
`tempo`	Tempo testnet (instant finality)

Get Free Testnet Tokens

Use the faucet to get free testnet tokens:

// Request testnet tokens (test keys only)
const faucet = await wallet.requestFaucet({ chain: "tempo" });
 
console.log(`Received ${faucet.amount} ${faucet.symbol}`);

Connect to Claude

Sponge integrates natively with Claude via MCP or direct tools.

MCP Integration (Recommended)

import Anthropic from "@anthropic-ai/sdk";
import { SpongeWallet } from "@spongewallet/sdk";
 
const wallet = await SpongeWallet.connect();
const anthropic = new Anthropic();
 
const response = await anthropic.messages.create({
  model: "claude-sonnet-4-20250514",
  max_tokens: 1024,
  messages: [{ role: "user", content: "What's my wallet balance?" }],
  mcp_servers: {
    wallet: wallet.mcp()
  }
});

Direct Tools

const tools = wallet.tools();
 
const response = await anthropic.messages.create({
  model: "claude-sonnet-4-20250514",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Send 1 USDC to 0x..." }],
  tools: tools.definitions
});
 
// Execute any tool calls
for (const block of response.content) {
  if (block.type === "tool_use") {
    const result = await tools.execute(block.name, block.input);
    // ... continue conversation with result
  }
}