Human approval

import { anthropic } from "@ai-sdk/anthropic";
import { generateText, stepCountIs, type ModelMessage, type ToolApprovalResponse } from "ai";
import { createInterface } from "node:readline/promises";
import { getBalances, sendUsdt } from "./tools.ts";

const model = anthropic("claude-sonnet-5-5");
const tools = { getBalances, sendUsdt };
const APPROVAL_ABOVE_USDT = 0.5; // Payments above this wait for a person

const system = [
  "You manage a USDT wallet on BOT Chain testnet.",
  "Check the balance before you send. Only send to addresses the user gives you.",
  "If a tool returns an error or a payment is not approved, explain why and do not retry it.",
  "After a payment, give the amount, the recipient and the BOTScan link.",
].join("\n");

const terminal = createInterface({ input: process.stdin, output: process.stdout });
const messages: ModelMessage[] = [{ role: "user", content: process.argv[2] ?? "What's my balance?" }];

while (true) {
  const result = await generateText({
    model,
    system,
    tools,
    messages,
    stopWhen: stepCountIs(8),
    toolApproval: {
      // Small payments run straight away. Larger ones stop and ask.
      sendUsdt: ({ amount }) =>
        Number(amount) > APPROVAL_ABOVE_USDT
          ? { type: "user-approval", reason: `Payment above ${APPROVAL_ABOVE_USDT} USDT` }
          : "not-applicable",
    },
  });
  messages.push(...result.responseMessages);

  const requests = result.content.filter((part) => part.type === "tool-approval-request" && !part.isAutomatic);
  if (requests.length === 0) {
    console.log(result.text);
    break;
  }

  // Ask a person about each paused call, then hand the answers back to the model.
  const responses: ToolApprovalResponse[] = [];
  for (const request of requests) {
    if (request.type !== "tool-approval-request") continue;
    const answer = await terminal.question(`Approve ${request.toolCall.toolName} ${JSON.stringify(request.toolCall.input)}? (y/n) `);
    const approved = answer.trim().toLowerCase() === "y";
    responses.push({ type: "tool-approval-response", approvalId: request.approvalId, approved, reason: approved ? undefined : "Declined by the owner" });
  }
  messages.push({ role: "tool", content: responses });
}
terminal.close();