CardTrader API Integration

Comprehensive guide for working with CardTrader's REST API to manage trading card marketplace operations.

When to Use This Skill

Use this skill when working with:

• Trading card marketplace operations - buying, selling, searching for cards
• Inventory management systems - syncing stock with CardTrader, bulk updates
• E-commerce integrations - building apps or services that connect to CardTrader
• Order fulfillment automation - processing purchases, shipping orders
• Price comparison tools - searching marketplace for best prices
• Collection management - wishlists, tracking cards

Do not use for general e-commerce APIs, non-CardTrader marketplaces, or other trading card platforms (TCGplayer, Card Market, etc.).

Base Configuration

Base URL: https://api.cardtrader.com/api/v2

Authentication: All requests require Bearer token authentication

Authorization: Bearer [YOUR_AUTH_TOKEN]

Rate Limits:

• General: 200 requests per 10 seconds
• Marketplace products: 10 requests per second
• Jobs: 1 request per second

Core Concepts

• Game: Trading card game (e.g., Magic: The Gathering, Pokemon)
• Category: Item grouping within a game (Single Cards, Booster Box, etc.)
• Expansion: Specific game expansion/set (e.g., "Core Set 2020")
• Blueprint: Sellable item template with properties (language, condition, etc.)
• Product: Physical item for sale with quantity and price (you own this)
• Order: Purchase transaction (you sold or purchased products)

Quick Start

Test Authentication

curl https://api.cardtrader.com/api/v2/info \
-H "Authorization: Bearer [YOUR_AUTH_TOKEN]"

Common Workflow: Sell a Card

1. Get games: GET /games
2. Get expansions: GET /expansions
3. Find blueprint: GET /blueprints/export?expansion_id={id}
4. Create product: POST /products with blueprint_id, price, quantity

Marketplace Operations

Search Products

# By expansion
GET /marketplace/products?expansion_id={id}

# By blueprint (specific card)
GET /marketplace/products?blueprint_id={id}

# Filter by foil/language
GET /marketplace/products?blueprint_id={id}&foil=true&language=en

Response includes 25 cheapest products per blueprint with seller info, price, quantity.

Response structure: Keys are blueprint IDs, values are arrays of up to 25 products sorted by price.

Example: See examples/marketplace-products.json

Cart & Purchase Flow

1. Add to cart: POST /cart/add

   {
     "product_id": 105234025,
     "quantity": 1,
     "via_cardtrader_zero": true,
     "billing_address": {...},
     "shipping_address": {...}
   }
   

2. Check cart: GET /cart

3. Remove from cart (optional): POST /cart/remove

4. Purchase: POST /cart/purchase

Wishlists

• List: GET /wishlists?game_id={id}
• Show: GET /wishlists/{id} - See examples/wishlist.json for response
• Create: POST /wishlists
• Delete: DELETE /wishlists/{id}

Inventory Management

List Your Products

# All products (may take 120-180s for large collections)
GET /products/export

# Filter by blueprint
GET /products/export?blueprint_id={id}

# Filter by expansion
GET /products/export?expansion_id={id}

Single Product Operations

Create:

POST /products
{
  "blueprint_id": 16,
  "price": 62.58,
  "quantity": 1,
  "error_mode": "strict",  # optional: fail on invalid properties
  "user_data_field": "warehouse B, shelf 10C",  # optional
  "properties": {
    "condition": "Near Mint",
    "mtg_language": "en",
    "mtg_foil": false
  }
}

Update: PUT /products/{id} (same body as create)

Delete: DELETE /products/{id}

Increment/Decrement:

POST /products/{id}/increment
{"delta_quantity": 4}

Images:

• Add: POST /products/{id}/upload_image (multipart form-data)
• Remove: DELETE /products/{id}/upload_image

Batch Operations (Recommended for Multiple Products)

All batch operations are asynchronous and return a job UUID for status checking.

Create: POST /products/bulk_create

{
  "products": [
    {
      "blueprint_id": 13,
      "price": 3.5,
      "quantity": 4
    },
    {...}
  ]
}

Update: POST /products/bulk_update

{
  "products": [
    { "id": 3936985, "quantity": 4 },
    { "id": 3936986, "price": 2.5 }
  ]
}

Delete: POST /products/bulk_destroy

{
  "products": [{ "id": 3936985 }, { "id": 3936986 }]
}

Check job status: GET /jobs/{uuid}

Job states: pending → running → completed (or unprocessable on error)

CSV Import/Export

Upload CSV:

POST /product_imports
-F csv=@path_to_csv.csv
-F game_id=1
-F replace_stock_or_add_to_stock=replace_stock  # or add_to_stock
-F column_names=expansion_code|_|name|quantity|language|condition|_|price_cents

Required column combinations (at least one):

• name + expansion_code/expansion_name/expansion_id
• collector_number + expansion_code/expansion_name/expansion_id
• mkm_id, tcgplayer_id, scryfall_id, or blueprint_id

Check import status: GET /product_imports/{id}

Get skipped items: GET /product_imports/{id}/skipped

Order Management

List Orders

GET /orders?page=1&limit=20&from=2019-01-01&to=2019-03-01&state=paid&order_as=seller

Parameters:

• page, limit: Pagination (default: page=1, limit=20)
• from, to: Date range (YYYY-MM-DD)
• from_id, to_id: ID range filtering
• state: Filter by order state
• order_as: Your role (seller or buyer)
• sort: id.asc, id.desc, date.asc, date.desc

Order States & Lifecycle

Standard Orders: paid → sent → arrived → done

CardTrader Zero Orders: hub_pending → paid → sent → arrived → done

Special States: request_for_cancel, canceled, lost

Order Operations

Get order details: GET /orders/{id}

Set tracking code:

PUT /orders/{id}/tracking_code
{"tracking_code": "ABC123"}

(Required BEFORE shipping CardTrader Zero orders)

Mark as shipped: PUT /orders/{id}/ship

Request cancellation:

PUT /orders/{id}/request-cancellation
{"cancel_explanation": "Reason (min 50 chars)", "relist_if_cancelled": true}

Confirm cancellation: PUT /orders/{id}/confirm-cancellation

CardTrader Zero Inventory Decrementing

When to decrement stock for CardTrader Zero orders:

*For pre-sale enabled accounts, also check: order id == order_item hub_pending_order_id

CT0 Box Items

• List your CT0 Box: GET /ct0_box_items
• Get item details: GET /ct0_box_items/{id}

Reference Data

Games

GET /games
# Returns: [{"id": 1, "name": "Magic", "display_name": "Magic: the Gathering"}]

Categories

GET /categories?game_id={id}
# Returns categories with their properties

Expansions

GET /expansions

Example: See examples/expansions.json

Your expansions only:

GET /expansions/export

Blueprints

GET /blueprints/export?expansion_id={id}

Example: See examples/blueprints.json

Key fields:

• editable_properties: Available properties for creating products (with type, default values, and possible values)
• scryfall_id, card_market_ids, tcg_player_id: External IDs

Properties

Properties define item characteristics (condition, language, foil, etc.). Each property has:

• name: Identifier (e.g., "condition", "mtg_foil")
• type: "string" or "boolean"
• possible_values: Array of allowed values

Common Magic properties:

• condition: Mint, Near Mint, Slightly Played, Moderately Played, Played, Heavily Played, Poor
• mtg_language: en, it, fr, jp, etc.
• mtg_foil: true/false
• signed, altered: true/false

Shipping Methods

GET /shipping_methods?username={seller_username}

Returns available shipping methods from a seller to you.

Webhooks

CardTrader can POST to your endpoint when orders are created, updated, or deleted.

Webhook payload:

{
  "id": "uuid",
  "time": 1632240962,
  "cause": "order.update",  // or order.create, order.destroy
  "object_class": "Order",
  "object_id": 733733,
  "mode": "live",  // or test
  "data": {...}  // Order object (empty for destroy)
}

Verify authenticity: Check Signature header = base64(HMAC-SHA256(body, shared_secret))

Error Handling

401 Unauthorized: Invalid/missing Bearer token

{ "error_code": "unauthorized", "errors": [], "extra": { "message": "..." } }

404 Not Found: Resource doesn't exist

{ "error_code": "not_found", "errors": [], "extra": { "message": "..." } }

422 Unprocessable Entity: Missing/invalid parameters

{
  "error_code": "missing_parameter",
  "errors": [],
  "extra": { "message": "..." }
}

429 Rate Limit:

{ "error": "Too many requests: max 200 requests per 10 seconds" }

Best Practices

1. Use batch operations for multiple products (more efficient than single operations)
2. Set large timeouts for /products/export (120-180s for large inventories)
3. Use error_mode: "strict" during development to catch property errors
4. Check job status after batch operations before assuming success
5. Handle rate limits with exponential backoff
6. Use user_data_field to store your internal IDs/references
7. For CardTrader Zero, set tracking code BEFORE shipping
8. Cache reference data (games, expansions, categories) - they change infrequently

Common Patterns

Sync External Inventory to CardTrader

1. Export your inventory: GET /products/export
2. Compare with your system
3. Use POST /products/bulk_create for new items
4. Use POST /products/bulk_update for changed items
5. Use POST /products/bulk_destroy for removed items
6. Check job status: GET /jobs/{uuid}

Process New Orders

1. Poll for new orders: GET /orders?state=paid&order_as=seller
2. For each order:
   • Decrement local inventory
   • Prepare shipment
   • Set tracking: PUT /orders/{id}/tracking_code
   • Mark shipped: PUT /orders/{id}/ship

Search Best Price for Card

1. Get blueprint_id (from expansion or by name)
2. GET /marketplace/products?blueprint_id={id}
3. Filter by condition/language in response
4. Take first item (sorted by price ascending)

Additional Resources

• Postman Collection: Available at CardTrader API docs with pre-configured auth
• API Token: Obtain from CardTrader profile settings page: https://www.cardtrader.com/en/docs/api/full/reference