Approval gate

import OpenAI from 'openai';
import { Mcpmailer } from '@mcpmailer/sdk';

/* ── your provider: this block is the only part that changes ── */
const client = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });

const MODEL = process.env.MODEL;
if (!MODEL) throw new Error('Set MODEL to the model name your provider expects, e.g. export MODEL=gpt-4o-mini');

/** The only provider-specific code in any of these examples. */
async function ask({ system, user, schema }: {
  system: string;
  user: string;
  schema?: object;
}) {
  const res = await client.chat.completions.create({
    model: MODEL,
    messages: [
      { role: 'system', content: system },
      { role: 'user', content: user }
    ],
    // A schema turns the answer into an object instead of prose, which is what
    // the branching examples want. Without one you get the text back.
    ...(schema
      ? { response_format: { type: 'json_schema', json_schema: { name: 'out', schema, strict: true } } }
      : {})
  });

  const text = res.choices[0].message.content ?? '';
  return schema ? JSON.parse(text) : text;
}

/* ── the agent ── */

const agent = new Mcpmailer({ apiKey: process.env.AGENT_KEY });
const gate = new Mcpmailer({ apiKey: process.env.GATE_KEY });

const APPROVER = 'jules@acme.com';

export async function sendWithApproval(draft: {
  to: string[];
  subject: string;
  body: string;
}) {
  // The approver sees the exact bytes, not a description of them.
  const ask = await gate.send({
    to: [APPROVER],
    subject: `Approve: ${draft.subject}`,
    body: [
      `To: ${draft.to.join(', ')}`,
      `Subject: ${draft.subject}`,
      '',
      draft.body,
      '',
      '---',
      'Reply YES to send, NO to discard, or with edits.'
    ].join('\n')
  });

  const reply = await waitForReply(gate, ask.messageId!, 30 * 60_000);

  // Silence is not consent. Neither is a yes from the wrong address.
  if (!reply) return { sent: false, reason: 'timeout' as const };
  if (reply.from !== APPROVER) return { sent: false, reason: 'wrong-approver' as const };
  if (!/^\s*(yes|approved?|send it|go ahead)\b/i.test((reply.body ?? reply.snippet)))
    return { sent: false, reason: 'not-approved' as const };

  // Sent exactly as approved. Rewriting here would void the approval.
  const result = await agent.send(draft);
  return { sent: result.status === 'sent', messageId: result.messageId };
}

async function waitForReply(mm: Mcpmailer, messageId: string, ms: number) {
  const sent = await mm.getMessage(messageId);
  const deadline = Date.now() + ms;
  while (Date.now() < deadline) {
    const thread = await mm.getThread(sent.thread_id!);
    const answer = thread.messages.find((m) => m.direction === 'in' && m.id !== messageId);
    if (answer) return answer;
    await new Promise((r) => setTimeout(r, 5_000));
  }
  return null;
}