From “something broke” to “we fixed it, and it worked”

Hear about problems where you already work

Add a Slack incoming webhook, a Microsoft Teams workflow or your own HTTPS endpoint to any app, and choose what goes there. Alerts are checked every hour and sent once a day at most, so an ongoing problem doesn't post every hour.

When a release went out in the two days before an alert, the message names it. That's often the cause.

Know whether the fix worked

Every issue created from Metrickle records its metric for the seven days before it was opened. Metrickle checks the issue every few hours; seven days after it's closed as done, it measures the same thing again and shows the result on the Fixes page, and in Slack, Teams or your webhook if you choose “Fix results”. Issues closed as not planned aren't measured.

Webhook reference

Generic webhooks receive a JSON POST with the event type in metrickle-event and a unique id in metrickle-delivery. Any 2xx response counts as delivered.

Every request is signed with the secret shown when you added the webhook. metrickle-signature is t=<unix ms>,v1=<hex>, where the hex is an HMAC-SHA256 of the timestamp, a full stop and the raw body. Reject requests more than five minutes old.

content-type: application/json
metrickle-event: feedback.created
metrickle-delivery: evt_…
metrickle-signature: t=1790841234000,v1=5f2c…

{
  "id": "evt_…",
  "type": "feedback.created",
  "createdAt": 1790841234000,
  "app": { "id": "app_…", "name": "Orbit Web" },
  "url": "https://app.metrickle.com/apps/app_…/feedback",
  "data": {
    "category": "accessibility",
    "accessibilityBarrier": true,
    "message": "The pay button can't be reached with Tab",
    "path": "/checkout",
    "a11y": ["keyboard"]
  }
}

import { createHmac, timingSafeEqual } from "node:crypto";

// header: t=<ms>,v1=<hex HMAC-SHA256 of "<t>.<raw body>">
export function verify(rawBody, header, secret) {
  const { t, v1 } = Object.fromEntries(header.split(",").map((p) => p.split("=")));
  if (Math.abs(Date.now() - Number(t)) > 5 * 60_000) return false;
  const expected = createHmac("sha256", secret).update(`${t}.${rawBody}`).digest("hex");
  return v1?.length === expected.length && timingSafeEqual(Buffer.from(expected), Buffer.from(v1));
}