`send_crypto_to_signed_in_user`

This tool (dapp/app/lib/mcp/tools/send-crypto.ts) lets the chatbot send 0.1–0.3 ETH on the active network. Registration is conditional on AI_PRIVATE_KEY being set.

Security & Gating

JWT injection — MCPDispatcher adds __jwt.address so the LLM can’t spoof a destination. The handler refuses to read any user-provided address and only trusts extractJwtAddress(params).
Manual preflight — Before sending, the tool fetches the signer’s balance, estimates gas with viem, and ensures the AI wallet can cover amountEth + fee.
Quotas — Successful sends call recordCryptoSpend when the quota feature flag is active; failures leave quota state untouched.
Chain config — getChainConfig supplies the active RPC + chain ID so viem clients point to the same network the chat session is using (RitoNet, Sepolia, Mainnet, etc.).


// dapp/app/lib/mcp/tools/send-crypto.ts
const tool: Tool<{ amountEth: number }> = {
  name: 'send_crypto_to_signed_in_user',
  requiresJwt: true,
  inputSchema: InputSchema,
  async handler(params) {
    const priv = aiServerConfig.secrets.aiPrivateKey;
    if (!priv) fail('send-crypto is unavailable: AI_PRIVATE_KEY not configured.');
 
    const amountEth = Number(params.amountEth);
    if (!Number.isFinite(amountEth) || amountEth < 0.1 || amountEth > 0.3) {
      fail('amountEth must be between 0.1 and 0.3 ETH (inclusive).');
    }
 
    const to = extractJwtAddress(params as Record<string, unknown>);
    if (!to) fail('No JWT-bound address available.');
 
    const { rpcUrl, chainId } = getChainConfig();
    const account = privateKeyToAccount(priv);
    const walletClient = createWalletClient({ account, transport: http(rpcUrl) });
    const publicClient = createPublicClient({ transport: http(rpcUrl) });
 
    const value = parseEther(amountEth.toString());
    const [balance, estGas, gasPrice] = await Promise.all([
      publicClient.getBalance({ address: account.address }),
      publicClient.estimateGas({ account: account.address, to, value }),
      publicClient.getGasPrice(),
    ]);
    if (balance < value + estGas * gasPrice) {
      return errorResultShape('Insufficient balance for amount + gas');
    }
 
    const hash = await walletClient.sendTransaction({ to, value });
    const receipt = await publicClient.waitForTransactionReceipt({ hash });
    if (isCryptoQuotaFeatureActive()) await recordCryptoSpend(to, amountEth);
 
    return {
      content: [
        { type: 'text', text: `Sent Crypto.\n${formatEthAmount(amountEth)} ETH sent to ${shortAddr(to)}.` },
        { type: 'json', data: formatPayload(hash, to, amountEth, chainId) },
      ],
    };
  },
};

Presenter Behavior

dapp/components/chatBot/ToolActivity/catalog/presenters/send_crypto.presenter.ts summarizes the outcome:

Status	Label	Details
pending	`Sending Crypto`	No body text to keep the chip compact.
success	`Sent Crypto.`	Shows `<amount> ETH sent to <short addr> on <network>`, falling back to the streamed text if the JSON is missing.
error	`Failed to Send Crypto.`	Recognizes wallet/auth errors (“Your wallet must be connected…”) so the user knows to re-authenticate.

Tips

⚠️

Because the tool estimates gas and checks the AI wallet’s balance on every call, local testing still requires funding the signer before the transaction can be broadcast.