Add Product Add-Ons to a cart with the Store API

Add a product with a configured Product Add-Ons field to a WooCommerce cart using the Store API.

For endpoint and field definitions, see the Product Add-Ons REST API reference.

Before you start

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Use a test store with WooCommerce and Product Add-Ons active. Create a purchasable test product with a short text add-on, and obtain the product ID and add-on ID. This example uses a fresh cart and sends the text Hello. Store API cart writes need a valid Nonce or Cart-Token for that cart session.

Start a cart session

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Request the cart and keep the cookies. Copy the Nonce response header for the next request; use the same cookie file. Treat the nonce and cookies as private session data.

curl -i -c cookies.txt https://example.com/wp-json/wc/store/v1/cart

Add the configured product

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Replace PRODUCT_ID, ADDON_ID, and YOUR_NONCE with values from the test store and response. The add-on ID is the key inside addons_configuration.

curl -X POST 'https://example.com/wp-json/wc/store/v1/cart/add-item' \
  -b cookies.txt \
  -H 'Nonce: YOUR_NONCE' \
  -H 'Content-Type: application/json' \
  -d '{
    "id": PRODUCT_ID,
    "quantity": 1,
    "addons_configuration": {
      "ADDON_ID": "Hello"
    }
  }'

Verify and troubleshoot

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Check the returned cart for the product and the short text add-on value. If the server reports invalid JSON, confirm the numeric product ID is unquoted and remove comments from the JSON. For a missing or invalid nonce, request a fresh cart nonce and reuse the matching session cookies. Confirm the product is purchasable and the add-on ID belongs to it.

Other add-on types accept different values. Use the field type and valid options for your product; this example does not cover file uploads.