From 726967855f9467f33efdcad791532d7128ed5f8d Mon Sep 17 00:00:00 2001
From: Lily Shen <115414357+lilyshen0722@users.noreply.github.com>
Date: Thu, 15 Oct 2026 09:44:54 -0700
Subject: [PATCH] feat(spend): the spend alarm names the user

Cofounder's condition on the Pro run ceiling (2026-10-15): the $2-a-day
alarm names the user, so whoever is paged sees who without a lookup. Each
alarm line now carries the username next to the userId, looked up only for
the users who crossed the line; a failed lookup still logs the id.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015NDyNbwmCco62PAAviSL1k
---
 .../unit/services/spendAlarmService.test.js     | 12 ++++++++++++
 backend/services/spendAlarmService.ts           | 17 +++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/backend/__tests__/unit/services/spendAlarmService.test.js b/backend/__tests__/unit/services/spendAlarmService.test.js
index 86e9444954..666bf6440c 100644
--- a/backend/__tests__/unit/services/spendAlarmService.test.js
+++ b/backend/__tests__/unit/services/spendAlarmService.test.js
@@ -102,6 +102,18 @@ describe('checkSpend', () => {
     });
   });
 
+  test('names the user in the line, so whoever is paged sees who without a lookup', async () => {
+    const warn = jest.spyOn(console, 'warn').mockImplementation(() => {});
+    const User = require('../../../models/User');
+    await User.deleteMany({});
+    await User.create({ _id: USER_A, username: 'maya', email: 'maya@example.com', password: 'x'.repeat(12) });
+    await AgentRun.create(run(USER_A, [{ model: 'deepseek-v4-flash', promptTokens: 2_000_000, completionTokens: 2_000_000 }]));
+
+    await spend.checkSpend(NOW);
+
+    expect(alarmLines(warn)).toEqual([expect.objectContaining({ userId: String(USER_A), username: 'maya' })]);
+  });
+
   test('SPEND_ALARM_USD_PER_DAY moves the line, and a bad value falls back to $2', async () => {
     const warn = jest.spyOn(console, 'warn').mockImplementation(() => {});
     await AgentRun.create(run(USER_B, [{ model: 'deepseek-v4-flash', promptTokens: 1_000_000, completionTokens: 1_000_000 }]));
diff --git a/backend/services/spendAlarmService.ts b/backend/services/spendAlarmService.ts
index ff51dfe13a..fcc18a71af 100644
--- a/backend/services/spendAlarmService.ts
+++ b/backend/services/spendAlarmService.ts
@@ -127,12 +127,29 @@ export const checkSpend = async (now: Date = new Date()): Promise<UserSpend[]> =
   const day = utcDayStart(now).toISOString().slice(0, 10);
   const over = (await userSpendForDay(now)).filter((spend) => spend.usd >= threshold);
   const fresh = over.filter((spend) => !alarmed.has(`${day}:${spend.userId}`));
+  // Name each user in the line, so whoever is paged sees who without a lookup
+  // (Cofounder, 2026-10-15). A failed lookup still logs the id.
+  const usernames = new Map<string, string>();
+  if (fresh.length) {
+    try {
+      // eslint-disable-next-line global-require, @typescript-eslint/no-require-imports
+      const User = require('../models/User');
+      const ids = fresh.map((spend) => spend.userId).filter((id) => /^[a-f\d]{24}$/i.test(id));
+      const users = await User.find({ _id: { $in: ids } }).select('username').lean();
+      users.forEach((user: { _id: unknown; username?: string }) => {
+        if (user.username) usernames.set(String(user._id), user.username);
+      });
+    } catch (error) {
+      console.warn('[spend-alarm] username lookup failed; logging ids only:', (error as Error).message);
+    }
+  }
   for (const spend of fresh) {
     alarmed.add(`${day}:${spend.userId}`);
     console.warn(JSON.stringify({
       alarm: 'user_spend',
       day,
       userId: spend.userId,
+      ...(usernames.has(spend.userId) ? { username: usernames.get(spend.userId) } : {}),
       usd: Number(spend.usd.toFixed(4)),
       thresholdUsd: threshold,
       runs: spend.runs,