How to calculate MRR from the Lemon Squeezy API

Does Lemon Squeezy return MRR?

No. You compute it from /v1/subscriptions, and the first obstacle is not the maths.

JSON:API, and where the data actually is

Lemon Squeezy serves JSON:API. That means the fields you want are not on the object, they are on attributes, and the relationships you want are references rather than embedded objects.

{
  "data": [
    {
      "type": "subscriptions",
      "id": "123",
      "attributes": { "status": "active", "variant_id": 456 },
      "relationships": { ... }
    }
  ]
}

Code written against a normal REST API reads sub.status and gets undefined, every time, silently. It is sub.attributes.status.

Set the headers or you get nothing useful back:

Accept: application/vnd.api+json
Content-Type: application/vnd.api+json
Authorization: Bearer <api key>

The price is not on the subscription

This is the part that makes Lemon Squeezy MRR more work than it looks. A subscription carries a variant_id, and the price lives on the variant, not on the subscription.

So the calculation is two passes. Collect the distinct variant ids from your active subscriptions, fetch each one's price once, then sum.

const PER_MONTH = { day: 365 / 12, week: 52 / 12, month: 1, year: 1 / 12 };

async function mrr(key, storeId) {
  const subs = await list(
    key,
    `/v1/subscriptions?filter[store_id]=${storeId}&filter[status]=active`,
  );

  // Fetch each price once, not once per subscriber.
  const variantIds = [...new Set(subs.map((s) => s.attributes.variant_id))];
  const prices = new Map();
  for (const id of variantIds) {
    const price = await fetchPriceForVariant(key, id);
    prices.set(id, price);
  }

  let total = 0;
  for (const sub of subs) {
    const price = prices.get(sub.attributes.variant_id);
    if (!price) continue;

    const per = PER_MONTH[price.renewal_interval_unit] ?? 0;
    total += (price.unit_price * per) / (price.renewal_interval_quantity ?? 1);
  }

  return Math.round(total);
}

Deduplicating the variant lookups matters. A thousand subscribers across six plans is six price calls, not a thousand, and the difference is whether you stay inside the rate limit.

renewal_interval_quantity

Same trap as everywhere else. A price renewing every six months has renewal_interval_unit of month and renewal_interval_quantity of 6, so its monthly value is the amount divided by six.

Annual plans have a quantity of one and look correct without it, which is why the bug survives until somebody sells a six-monthly plan.

Statuses, and the trial question

Lemon Squeezy subscriptions can be on_trial, active, paused, past_due, unpaid, cancelled or expired.

Filtering on active excludes trials, which is the honest basis for MRR. Note that this differs from Lemon Squeezy's own active subscriber count, which counts trials in. Two reasonable definitions, and you have to pick which one you are reporting and say so.

cancelled is worth a second look: a cancelled Lemon Squeezy subscription keeps running until ends_at, so it is still being paid for. Whether it belongs in MRR depends on whether you are measuring money arriving or the book you expect to keep.

Pagination

page[size] up to 100, and links.next to continue. Page until there is no next link.

Or read it off the notch

Notch Metrics computes Lemon Squeezy MRR this way, caching the variant prices, and shows it in the MacBook notch alongside revenue, active subscribers, refunds and a feed of recent orders.

Everything Lemon Squeezy reports, or download Notch Metrics.