Inventory API Overview

The Inventory API is the backbone of your eBay selling operations. It provides 80+ tools to manage inventory items, create offers, publish listings, and handle product variations.

Core Concepts

Inventory Items

Products you have available to sell (SKU-based management)

Offers

Listing configurations (price, quantity, format) for inventory items

Inventory Locations

Physical locations where inventory is stored

Product Compatibility

Specify which vehicles/products your items are compatible with

Inventory Management Workflow

Create Inventory Items

Define products using SKUs:

await mcp.useTool('inventory_createOrReplaceInventoryItem', {
  sku: 'WIDGET-001',
  product: {
    title: 'Premium Widget',
    aspects: { Brand: ['WidgetCo'], Color: ['Blue'] },
    description: 'High-quality widget for all your needs'
  },
  availability: {
    shipToLocationAvailability: {
      quantity: 100
    }
  }
});

Create Offers

Set pricing and format:

await mcp.useTool('inventory_createOffer', {
  sku: 'WIDGET-001',
  marketplace_id: 'EBAY_US',
  format: 'FIXED_PRICE',
  listing_duration: 'GTC',
  pricingSummary: {
    price: { value: '29.99', currency: 'USD' }
  },
  categoryId: '12345'
});

Publish Listings

Make offers live on eBay:

await mcp.useTool('inventory_publishOffer', {
  offer_id: 'offer_id_here'
});

Available Tools

Inventory Item Tools (30+)

Tool Name	Description	Common Use
`inventory_createOrReplaceInventoryItem`	Create/update inventory item	Add new products
`inventory_getInventoryItem`	Get single inventory item	Check product details
`inventory_getInventoryItems`	Get all inventory items	Bulk inventory review
`inventory_deleteInventoryItem`	Delete inventory item	Remove discontinued products
`inventory_bulkCreateOrReplaceInventoryItem`	Batch create/update	Import product catalog
`inventory_bulkUpdatePriceQuantity`	Update price/quantity in bulk	Price adjustments

Offer Tools (25+)

Tool Name	Description	Common Use
`inventory_createOffer`	Create listing offer	List new item
`inventory_getOffer`	Get offer details	Check listing config
`inventory_getOffers`	Get all offers	Review all listings
`inventory_updateOffer`	Modify offer	Update price/quantity
`inventory_deleteOffer`	Remove offer	Delist item
`inventory_publishOffer`	Make offer live	Publish listing
`inventory_publishOfferByInventoryItemGroup`	Publish variation listing	Publish multi-variation
`inventory_withdrawOffer`	End listing	Remove from eBay

Location Tools (10+)

Tool Name	Description	Common Use
`inventory_createInventoryLocation`	Add warehouse location	Setup fulfillment center
`inventory_getInventoryLocation`	Get location details	Check location info
`inventory_getInventoryLocations`	Get all locations	Review warehouses
`inventory_updateInventoryLocation`	Modify location	Update address/hours
`inventory_deleteInventoryLocation`	Remove location	Close warehouse

Product Compatibility Tools

Tool Name	Description	Common Use
`inventory_createOrReplaceProductCompatibility`	Set compatible products	Auto parts compatibility
`inventory_getProductCompatibility`	Get compatibility list	View compatible vehicles
`inventory_deleteProductCompatibility`	Remove compatibility	Update fitment data

Quick Start Examples

Single Item Listing

// Complete flow: item → offer → publish
async function listSingleItem() {
  const sku = 'WIDGET-001';

  // 1. Create inventory item
  await mcp.useTool('inventory_createOrReplaceInventoryItem', {
    sku,
    product: {
      title: 'Premium Blue Widget - Model X',
      description: 'High-quality widget perfect for home and office use',
      aspects: {
        Brand: ['WidgetCo'],
        Color: ['Blue'],
        Model: ['X'],
        Condition: ['New']
      },
      imageUrls: [
        'https://example.com/widget-front.jpg',
        'https://example.com/widget-side.jpg'
      ]
    },
    condition: 'NEW',
    availability: {
      shipToLocationAvailability: {
        quantity: 50
      }
    }
  });

  // 2. Create offer
  const offer = await mcp.useTool('inventory_createOffer', {
    sku,
    marketplace_id: 'EBAY_US',
    format: 'FIXED_PRICE',
    listing_duration: 'GTC', // Good 'Til Cancelled
    available_quantity: 50,
    category_id: '1234', // eBay category ID
    listing_policies: {
      payment_policy_id: 'payment_policy_id',
      return_policy_id: 'return_policy_id',
      fulfillment_policy_id: 'fulfillment_policy_id'
    },
    pricingSummary: {
      price: {
        value: '29.99',
        currency: 'USD'
      }
    }
  });

  // 3. Publish offer
  const listing = await mcp.useTool('inventory_publishOffer', {
    offer_id: offer.offerId
  });

  console.log(`✅ Listed successfully! Listing ID: ${listing.listingId}`);
  return listing;
}

await listSingleItem();

Bulk Inventory Upload

// Upload 100+ items efficiently
async function bulkUploadInventory(products) {
  const requests = products.map(product => ({
    sku: product.sku,
    product: {
      title: product.title,
      description: product.description,
      aspects: product.aspects,
      imageUrls: product.images
    },
    condition: product.condition || 'NEW',
    availability: {
      shipToLocationAvailability: {
        quantity: product.quantity
      }
    }
  }));

  // Upload in batches of 25 (API limit)
  const batchSize = 25;
  const results = [];

  for (let i = 0; i < requests.length; i += batchSize) {
    const batch = requests.slice(i, i + batchSize);

    const response = await mcp.useTool('inventory_bulkCreateOrReplaceInventoryItem', {
      requests: batch
    });

    results.push(...response.responses);
    console.log(`Uploaded batch ${i / batchSize + 1} of ${Math.ceil(requests.length / batchSize)}`);
  }

  const successful = results.filter(r => r.statusCode === 200).length;
  console.log(`✅ Successfully uploaded ${successful}/${products.length} items`);

  return results;
}

Variation Listing (Multiple SKUs)

// Create a variation listing (e.g., T-shirt in multiple sizes/colors)
async function createVariationListing() {
  const baseTitle = 'Premium Cotton T-Shirt';

  // 1. Create inventory items for each variation
  const sizes = ['S', 'M', 'L', 'XL'];
  const colors = ['Red', 'Blue', 'Green'];
  const variations = [];

  for (const size of sizes) {
    for (const color of colors) {
      const sku = `TSHIRT-${color.toUpperCase()}-${size}`;

      await mcp.useTool('inventory_createOrReplaceInventoryItem', {
        sku,
        product: {
          title: `${baseTitle} - ${color} ${size}`,
          aspects: {
            Size: [size],
            Color: [color],
            Brand: ['YourBrand']
          },
          imageUrls: [`https://example.com/tshirt-${color.toLowerCase()}.jpg`]
        },
        condition: 'NEW',
        availability: {
          shipToLocationAvailability: {
            quantity: 25
          }
        }
      });

      variations.push({ sku, size, color });
    }
  }

  // 2. Create inventory item group
  const group = await mcp.useTool('inventory_createOrReplaceInventoryItemGroup', {
    inventory_item_group_key: 'TSHIRT-GROUP',
    title: baseTitle,
    description: 'Premium quality cotton t-shirt available in multiple sizes and colors',
    imageUrls: [
      'https://example.com/tshirt-main.jpg',
      'https://example.com/tshirt-detail.jpg'
    ],
    variesBy: {
      specifications: [
        { name: 'Size', values: sizes },
        { name: 'Color', values: colors }
      ]
    },
    variantSKUs: variations.map(v => v.sku)
  });

  // 3. Create offer for the group
  const offer = await mcp.useTool('inventory_createOffer', {
    sku: variations[0].sku, // Use first variation SKU
    marketplace_id: 'EBAY_US',
    format: 'FIXED_PRICE',
    category_id: '15687', // T-shirts category
    listing_policies: {
      payment_policy_id: 'payment_policy_id',
      return_policy_id: 'return_policy_id',
      fulfillment_policy_id: 'fulfillment_policy_id'
    },
    pricingSummary: {
      price: { value: '19.99', currency: 'USD' }
    }
  });

  // 4. Publish variation listing
  const listing = await mcp.useTool('inventory_publishOfferByInventoryItemGroup', {
    inventory_item_group_key: 'TSHIRT-GROUP',
    marketplace_id: 'EBAY_US'
  });

  console.log(`✅ Variation listing published! ${variations.length} variations`);
  return listing;
}

Best Practices

SKU Management

Use descriptive, consistent SKUs:

✅ Good: TSHIRT-RED-L, WIDGET-PRO-001
❌ Bad: SKU1, TEMP123

SKU naming conventions:

[CATEGORY]-[ATTRIBUTE]-[IDENTIFIER]
Examples:
- SHOE-NIKE-AIR-MAX-10.5
- BOOK-FICTION-THRILLER-001
- ELECTRONICS-PHONE-CASE-IPHONE14

Benefits:

Easy inventory tracking
Quick product identification
Simplified reordering
Better reporting

Inventory Sync & Accuracy

Keep inventory synchronized:

// Update inventory every hour
setInterval(async () => {
  const updates = await getInventoryFromWarehouse();

  await mcp.useTool('inventory_bulkUpdatePriceQuantity', {
    requests: updates.map(item => ({
      sku: item.sku,
      shipToLocationAvailability: {
        quantity: item.quantity
      }
    }))
  });
}, 3600000); // Every hour

Prevent overselling:

Set safety stock levels (reserve 5-10% inventory)
Update quantities immediately after sales
Use inventory management software
Enable out-of-stock control program

Product Descriptions & SEO

Optimize titles for search:

// ✅ Good title (60 characters, keyword-rich)
const title = 'Apple iPhone 14 Pro Max 256GB Unlocked - Deep Purple - NEW';

// ❌ Bad title (vague, no keywords)
const badTitle = 'Great Phone for Sale';

Title structure:

Brand/Manufacturer
Model/Product name
Key features (size, color, capacity)
Condition
Unique selling points

Description best practices:

Use HTML formatting
Include detailed specifications
Add warranty information
List what’s included
Use bullet points for readability

Image Requirements

Image specifications:

Minimum 500px on longest side
Recommended: 1600px or larger
White or light background (preferred)
Product fills 85% of frame
Format: JPG, PNG, GIF
Maximum 12 images per listing

Image order importance:

Main product image (white background)
Product in use/lifestyle shot
Detail shots (features, materials)
Size/scale reference
Package contents
Additional angles

const imageUrls = [
  'https://cdn.example.com/product-main-1600px.jpg',      // Main
  'https://cdn.example.com/product-lifestyle.jpg',        // In use
  'https://cdn.example.com/product-detail-closeup.jpg',   // Details
  'https://cdn.example.com/product-scale.jpg',            // Size reference
  'https://cdn.example.com/product-package.jpg'           // What's included
];

Common Workflows

Daily Inventory Sync

async function syncInventoryDaily() {
  // 1. Get all eBay inventory
  const ebayInventory = await mcp.useTool('inventory_getInventoryItems', {
    limit: 100
  });

  // 2. Get warehouse inventory
  const warehouseInventory = await getWarehouseInventory();

  // 3. Find discrepancies
  const updates = [];

  for (const ebayItem of ebayInventory.inventoryItems) {
    const warehouseItem = warehouseInventory.find(w => w.sku === ebayItem.sku);

    if (warehouseItem && warehouseItem.quantity !== ebayItem.availability.shipToLocationAvailability.quantity) {
      updates.push({
        sku: ebayItem.sku,
        shipToLocationAvailability: {
          quantity: warehouseItem.quantity
        }
      });
    }
  }

  // 4. Bulk update quantities
  if (updates.length > 0) {
    await mcp.useTool('inventory_bulkUpdatePriceQuantity', {
      requests: updates
    });

    console.log(`✅ Updated ${updates.length} inventory quantities`);
  } else {
    console.log('✅ Inventory is in sync');
  }
}

Seasonal Price Adjustments

async function seasonalPriceAdjustment(discountPercentage) {
  // Get all active offers
  const offers = await mcp.useTool('inventory_getOffers', {
    limit: 100,
    marketplace_id: 'EBAY_US'
  });

  const updates = [];

  for (const offer of offers.offers) {
    const currentPrice = parseFloat(offer.pricingSummary.price.value);
    const newPrice = (currentPrice * (1 - discountPercentage / 100)).toFixed(2);

    updates.push({
      offerId: offer.offerId,
      pricingSummary: {
        price: {
          value: newPrice,
          currency: 'USD'
        },
        // Set original price for strike-through display
        originalRetailPrice: {
          value: currentPrice.toFixed(2),
          currency: 'USD'
        }
      }
    });
  }

  // Update prices in batches
  for (const update of updates) {
    await mcp.useTool('inventory_updateOffer', update);
  }

  console.log(`✅ Applied ${discountPercentage}% discount to ${updates.length} listings`);
}

// Apply 20% off for holiday sale
await seasonalPriceAdjustment(20);

Inventory API Overview

Inventory API Overview

Core Concepts

Inventory Items

Offers

Inventory Locations

Product Compatibility

Inventory Management Workflow

Available Tools

Inventory Item Tools (30+)

Offer Tools (25+)

Location Tools (10+)

Product Compatibility Tools

Quick Start Examples

Single Item Listing

Bulk Inventory Upload

Variation Listing (Multiple SKUs)

Best Practices

Common Workflows

Daily Inventory Sync

Seasonal Price Adjustments

Next Steps

Inventory Items

Offers & Listings

Inventory Locations

First Listing Guide

Resources

Documentation Index

​Inventory API Overview

​Core Concepts

Inventory Items

Offers

Inventory Locations

Product Compatibility

​Inventory Management Workflow

​Available Tools

​Inventory Item Tools (30+)

​Offer Tools (25+)

​Location Tools (10+)

​Product Compatibility Tools

​Quick Start Examples

​Single Item Listing

​Bulk Inventory Upload

​Variation Listing (Multiple SKUs)

​Best Practices

​Common Workflows

​Daily Inventory Sync

​Seasonal Price Adjustments

​Next Steps

Inventory Items

Offers & Listings

Inventory Locations

First Listing Guide

​Resources

Inventory API Overview

Core Concepts

Inventory Management Workflow

Available Tools

Inventory Item Tools (30+)

Offer Tools (25+)

Location Tools (10+)

Product Compatibility Tools

Quick Start Examples

Single Item Listing

Bulk Inventory Upload

Variation Listing (Multiple SKUs)

Best Practices

Common Workflows

Daily Inventory Sync

Seasonal Price Adjustments

Next Steps

Resources