Low Stock Alerts

Low Stock Alerts

Overview

Low stock alerts notify you when inventory drops below a threshold so you can reorder before running out. Every major platform has this built in — Shopify, WooCommerce, and BigCommerce all send email notifications when stock falls below a configured level. For more advanced needs like demand-based thresholds, supplier PO automation, or team notifications in Slack, dedicated apps add those capabilities without custom code.

When to Use This Skill

• When products are unexpectedly running out of stock and missing sales
• When the current inventory workflow relies on manual checks rather than automated alerts
• When you want demand-based reorder points rather than fixed thresholds
• When the store has supplier lead times that need to be factored into when to reorder

Core Instructions

Step 1: Determine platform and choose the right tool

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Step 2: Platform-specific setup

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Shopify

Built-in low stock notification:

Shopify sends an email to the store admin when inventory hits zero, but doesn't support configurable thresholds natively.

1. Go to Settings → Notifications → Scroll to Staff order notifications 2. Ensure the admin email is set — Shopify will notify this address when stock reaches 0

Setting per-variant thresholds with Stocky:

1. Install Stocky from the Shopify App Store (free) 2. Open Stocky and go to Products 3. For each product, set the Reorder point (the stock level that triggers an alert) 4. Set the Reorder quantity (how many units to order when the alert fires) 5. Stocky will flag products below their reorder point in the dashboard and can generate draft purchase orders automatically

Customer "back in stock" notifications:

• Install Back In Stock (paid) or Klaviyo from the App Store
• These apps show a "Notify me when available" button on out-of-stock products
• Automatically email opted-in customers when stock is replenished

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WooCommerce

Configure global low-stock threshold:

1. Go to WooCommerce → Settings → Products → Inventory 2. Enter a value in Low stock threshold (e.g., 10) 3. Enter your notification email in Notification recipient(s) — comma-separate multiple emails 4. WooCommerce sends an email when any product drops to or below this threshold

Set per-product thresholds:

1. Go to WooCommerce → Products → [Product] → Inventory tab 2. Enable Manage stock? 3. Enter a Low stock threshold specific to this product (overrides the global setting)

Advanced alerting with ATUM:

1. Install ATUM Inventory Management for WooCommerce (free) 2. ATUM's dashboard shows all products at or below their reorder point in one view 3. Per-product reorder point configuration under ATUM → Product Settings 4. ATUM can also email your supplier directly when a product needs reordering (paid feature)

Demand-based thresholds:

• Install Inventory Planner (Shopify/WooCommerce) for sales velocity-based reorder suggestions
• Inventory Planner analyzes your sales history and suggests reorder points based on lead time × daily velocity + safety stock

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BigCommerce

Set per-product low stock threshold:

1. Go to Products → [Product] → Inventory tab 2. Set the Low stock level field 3. BigCommerce sends an automatic email notification to the store admin when stock crosses this threshold

Configure who receives alerts: 1. Go to Store Setup → Store Settings → Miscellaneous 2. Set Low stock email address to your purchasing team's email

For location-specific alerts:

• Install the Multi-Location Inventory app
• Set thresholds per location — useful when you stock the same SKU at multiple warehouses

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Custom / Headless

For custom platforms, implement a background job that checks inventory levels against configured reorder points:

// jobs/checkStockLevels.ts — run every 15-30 minutes via cron
export async function checkStockLevels() {
  const levels = await db.inventoryLevels.findMany({
    include: { reorderConfig: true, variant: { include: { product: true } }, location: true },
    where: { reorderConfig: { isNot: null } },
  });

  const newAlerts = [];

  for (const level of levels) {
    const config = level.reorderConfig!;
    const available = level.onHand - level.reserved;

    // Dynamic reorder point based on sales velocity and lead time
    let reorderPoint = config.reorderPoint;
    if (config.useDynamicReorderPoint) {
      const velocity = await calculateDailySalesVelocity(level.variantId, 30); // 30-day rolling average
      reorderPoint = Math.ceil(velocity * config.leadTimeDays * 1.2); // 20% safety stock buffer
    }

    const alertType = available === 0 ? 'out_of_stock' : available <= reorderPoint ? 'low_stock' : null;
    if (!alertType) continue;

    // Only create a new alert if the previous one is resolved
    const existingAlert = await db.stockAlerts.findFirst({
      where: { variantId: level.variantId, locationId: level.locationId, alertType, resolvedAt: null },
    });

    if (!existingAlert) {
      newAlerts.push({ level, config, available, reorderPoint, alertType });
      await db.stockAlerts.create({ data: {
        variantId: level.variantId, locationId: level.locationId,
        alertType, triggeredAt: new Date(), availableAtTrigger: available,
      }});
    }
  }

  if (newAlerts.length > 0) await sendAlertNotifications(newAlerts);
}

// Calculate daily sales velocity from order history
async function calculateDailySalesVelocity(variantId: string, windowDays: number) {
  const since = new Date(Date.now() - windowDays * 86400000);
  const result = await db.orderLineItems.aggregate({
    where: { variantId, order: { createdAt: { gte: since }, status: { in: ['completed', 'shipped'] } } },
    _sum: { quantity: true },
  });
  return (result._sum.quantity ?? 0) / windowDays;
}

// Send consolidated alerts — group by supplier to avoid email spam
async function sendAlertNotifications(alerts: Alert[]) {
  const bySupplier: Record<string, Alert[]> = {};
  for (const alert of alerts) {
    const key = alert.config.supplierId ?? 'merchant';
    if (!bySupplier[key]) bySupplier[key] = [];
    bySupplier[key].push(alert);
  }

  for (const [supplierId, supplierAlerts] of Object.entries(bySupplier)) {
    const to = supplierId === 'merchant' ? process.env.MERCHANT_ALERT_EMAIL : (await db.suppliers.findById(supplierId))?.email;
    if (!to) continue;
    await emailService.send({ to, template: 'low-stock-alert', data: { alerts: supplierAlerts } });
  }
}

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Step 3: Calculate dynamic reorder points (optional)

Fixed thresholds (e.g., "alert at 10 units") are simple but can be wrong — a product that sells 50 units per day needs a much higher threshold than one that sells 2 per week.

Formula:

Reorder Point = (Daily Sales Velocity × Lead Time Days) × 1.2 (20% safety buffer)

Example: Product sells 5 units/day, supplier lead time is 7 days

• Demand during lead time: 5 × 7 = 35 units
• Reorder point with safety buffer: 35 × 1.2 = 42 units

For Shopify: Use Inventory Planner app — it computes velocity-based reorder points automatically from your sales history.

For WooCommerce: ATUM Inventory Management can be configured with supplier lead times and suggests reorder points based on sales velocity.

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Step 4: Automate reorder notifications to suppliers

Once an alert fires, you want to notify your purchasing team or supplier automatically.

Shopify + Stocky: Stocky generates draft purchase orders when stock falls below the reorder point. Your team reviews and sends the PO to the supplier from within Stocky.

WooCommerce + ATUM (paid): ATUM can email the configured supplier directly when a product needs reordering, including the suggested quantity.

Email workflow (any platform): Set the low-stock notification email directly to your supplier's ordering inbox — include the SKU, product name, and suggested reorder quantity in the notification template.

Best Practices

• Set reorder points based on lead time and sales velocity — a fixed threshold of 10 units may be fine for slow movers but dangerously low for fast sellers; use the formula above as a starting point
• De-duplicate alerts — platforms and custom solutions should only send one alert per SKU per incident, not an alert on every inventory decrement; resolve old alerts when stock is replenished
• Consolidate supplier emails — one email with 5 low-stock SKUs from the same supplier is far less noisy than 5 separate emails
• Set thresholds at the variant level, not just the product level — a shirt with 3 remaining in XL and 50 in M should alert only for XL
• Review and update thresholds seasonally — a product that sells 2/day normally may sell 20/day during peak season; adjust thresholds before high-demand periods

Common Pitfalls

Related Skills

• @inventory-tracking
• @multi-warehouse
• @catalog-import-export

Inventory Alert System — Core Data Layer

Problem Description

A small e-commerce retailer has been managing stock levels manually, relying on a warehouse manager to scan a spreadsheet every morning and email suppliers when something looks low. This process breaks down over weekends and busy seasons, and the team has lost sales on several occasions because they ran out of a variant before anyone noticed.

The engineering team has been asked to build an automated stock monitoring system. The first milestone is the core data layer: the database models that track per-variant, per-location reorder configuration and the alerts that get fired when a threshold is breached. The second part of the milestone is a background job that scans all inventory levels, compares them against configured thresholds, and creates alert records as needed.

A critical requirement from the ops team is that the system must not spam the same alert for a variant that is already in an alerted state — if a low-stock alert for "Red T-Shirt / Medium / East Warehouse" was created yesterday and hasn't been addressed yet, the next job run should not create a duplicate. The system should only create a new alert once the previous one has been closed out.

Output Specification

Produce the following files:

• schema.js — JavaScript object definitions (or equivalent data model) for the two tables needed: one for storing per-variant reorder configuration and one for tracking stock alerts. Include field names, types, and a brief comment on each field's purpose.
• jobs/checkStockLevels.js — The background job function that: fetches all inventory levels that have a reorder config, determines alert type and severity for each, and creates alert records while preventing duplicates.
• DESIGN.md — A short (1-2 page) design note explaining the deduplication strategy and how the system decides what type of alert to raise.

Demand-Driven Reorder Points for Inventory Management

Problem Description

A fashion retailer has been using fixed reorder points across their entire product catalogue — every variant triggers an alert when stock drops to 10 units regardless of how quickly it sells. This means slow-moving items get reorder alerts constantly while fast-moving variants sometimes run out before an alert fires, because 10 units represents three days of supply for one product but two months for another.

The engineering team has been asked to build a demand forecasting module that replaces fixed thresholds with dynamically calculated reorder points. The core idea is simple: look at recent order history to estimate how many units sell per day, then multiply by the supplier's lead time so the reorder fires with enough runway to receive new stock before running out. The formula also needs to include a buffer for safety stock.

The product team flagged one concern: some of their seasonal lines (swimwear, winter coats) see very skewed velocity during peak months. The solution should address how seasonal products should be handled within this framework.

Output Specification

Produce the following files:

• lib/demandForecasting.js — The demand forecasting module containing the velocity calculation and the reorder point formula as separate exported functions.
• jobs/checkStockLevels.js — A background job that fetches inventory levels with their reorder configs and, for variants with dynamic reorder enabled, calls the forecasting module to compute the threshold before checking stock levels.
• DEMAND_FORECASTING.md — A short technical note explaining the approach, the formula, how the safety stock buffer works, and how seasonal products should be configured.

Stock Alert Notifications and Merchant Dashboard API

Problem Description

A retailer's inventory system can already detect when stock falls below a reorder threshold and creates alert records in the database. The next milestone is to notify the right people and give the ops team a way to manage those alerts through an admin interface.

On the notification side, the retailer works with around a dozen suppliers. When multiple products from the same supplier are running low at the same time (which happens frequently before long weekends), the ops team has complained that their suppliers get bombarded with individual emails — one per SKU — which has led several suppliers to start ignoring them. Notifications need to be consolidated so that a supplier receives a single email listing everything they need to reorder, rather than a flood of individual messages. Merchants also need their own alert email summarising what's happening across the store.

On the API side, the ops team wants a simple dashboard that shows all active (unresolved) stock alerts with the ability to filter by alert type and warehouse location. When a team member has reviewed an alert and decided on a course of action, they should be able to mark it as acknowledged. When a purchase order is received and stock is replenished, the system should automatically close out any open alerts for that variant and location.

Output Specification

Produce the following files:

• lib/alertNotifications.js — The notification module. It should accept a list of alert objects and send emails to merchants and suppliers, handling the consolidation logic.
• api/admin/stock-alerts.js — The admin API handlers: one to retrieve active alerts with query-parameter filtering, and one to mark an alert as acknowledged.
• lib/stockAlerts.js — A helper module containing the function to resolve alerts when stock is replenished.
• API.md — Brief API documentation listing the endpoints, their parameters, and response shapes.