Costco Same-Day API & Scraper
This API reads sameday.costco.com, Costco Same-Day's online shop, live and returns it as JSON.
🤖 Using an AI assistant? Copy this link into ChatGPT / Claude / Cursor — it reads every endpoint and parameter instantly and tells you if this API fits your use case.
Prices are set per store, so every call is answered for one Costco store: give a ZIP code or a store_id from `stores` (without either, a fixed default store, Issaquah near 98027, is used and the response says store_defaulted: true). `search` returns the site's own ranked results (cheese: 139 products at the default store), `category` lists a collection such as Milk, `offers` returns Weekly Savings, `product/detail` adds ingredients, warnings and images, `categories` lists the category tree and `stores` lists Costco stores around a ZIP code with distance and services. The price matched the price printed on the sameday.costco.com product page for 8 of 8 products we checked.
What a Costco Same-Day field actually contains
Fields that read differently from how they look, measured on live responses on 2026-10-18.
| Field | What it holds |
|---|---|
| price, price_display | The price at the chosen store as the sameday.costco.com product page prints it (matched on 8/8 products, e.g. Kirkland Signature Eggs, Large, 24-cou $3.96). |
| original_price, discount_percent | The struck-through regular price on sale items and the discount computed from the two prices; null when the item is not on sale. |
| promotions, buy_one_get_one | Deals shown on the item: BOGO, multi-buy ('Buy 2 for $9.16'), member offers. They are never folded into price. |
| loyalty_price | A separate card or member price when the site shows one next to the regular price; null otherwise. |
| store, store_defaulted | The Costco store that priced the response (id, name, street, city). store_defaulted is true when you gave neither postal_code nor store_id. |
| unit_price_text | The unit price as the site prints it ("$0.03/fl oz"). For items sold by weight, price is the estimated package price and price_is_estimate is true. |
| stock_level, likely_out_of_stock | many_in_stock, in_stock, likely_out_of_stock or out_of_stock for that store. |
| matches_query | Whether the row shares a word with your search. The site fills a search that matches nothing with unrelated products; such pages are dropped and counted in unmatched_dropped. |
Prices differ between stores: the same 14 products cost differently on 7 of them at a store near 90210 on the same day.
Real request and response JSON
Captured from the indexed primary action, search, on .
{
"method": "POST",
"url": "https://api.reefapi.com/costco-sameday/v1/search",
"headers": {
"x-api-key": "$REEF_KEY",
"content-type": "application/json"
},
"body": {
"query": "milk",
"postal_code": "98027"
}
}{
"ok": true,
"meta": {
"api": "costco-sameday",
"endpoint": "search",
"mode": "live",
"latency_ms": 1814.2,
"record_count": 20,
"bytes": 155813,
"cache_hit": false,
"warnings": [
"ignored unknown parameter(s): include_pii"
],
"pagination": {
"page": 1,
"has_more": true,
"total": 41
},
"upstream_requests": 3,
"charged_credits": 3,
"version": "1.0.0",
"request_id": "49f9c1261aca4754",
"fetched_at": "2026-10-18T17:44:58.139Z"
},
"data": {
"products": [
{
"product_id": "19208138",
"item_id": "items_407-19208138",
"name": "Kirkland Signature Whole Milk, 1 Gallon, 2-count",
"brand": "kirkland signature",
"size": "each",
"url": "https://sameday.costco.com/store/costco/products/19208138-kirkland-signature-homogenized-milk-2-gal-2-gal",
"image": "https://d2lnr5mha7bycj.cloudfront.net/product-image/file/large_e343bcea-c952-4476-8edb-57573eee5b8d.jpg",
"available": true,
"stock_level": "many_in_stock",
"stock_label": null,
"likely_out_of_stock": false,
"sold_by": "each",
"weight_option": false,
"par_weight": null,
"max_order_quantity": 9999,
"on_sale": false,
"buy_one_get_one": false,
"coupon_available": false,
"store_brand": true,
"dietary": [],
"nutrition_highlights": null,
"variant_values": [],
"retailer_reference_code": "2",
"retailer_lookup_code": null,
"currency": "USD",
"price": 8.5,
"price_display": "$8.50",
"original_price": null,
"discount_percent": null,
"savings": null,
"loyalty_price": null,
"loyalty_label": null,
"loyalty_card_offer": false,
"unit_price_text": "$2.12 each",
"size_text": "2 ct",
"price_is_estimate": false,
"estimated_weight_text": null,
"promotions": [],
"deal_terms": null,
"great_price": false,
"badge": null,
"retailer": {
"retailer_id": "5",
"slug": "costco",
"name": "Costco",
"shop_id": "3048",
"service_type": "delivery",
"retailer_location_id": "407"
},
"service_type": "delivery",
"matches_query": true
},
{
"product_id": "25691969",
"item_id": "items_407-25691969",
"name": "Kirkland Signature Organic 2% Milk, 1/2 gal, 4-count",
"brand": "kirkland signature",
"size": "each",
"url": "https://sameday.costco.com/store/costco/products/25691969-kirkland-signature-2-milkfat-organic-reduced-fat-milk-2-gal",
"image": "https://d2lnr5mha7bycj.cloudfront.net/product-image/file/large_2c78d313-e7cf-4ece-bb36-169ff05337df.jpg",
"available": true,
"stock_level": "many_in_stock",
"stock_label": null,
"likely_out_of_stock": false,
"sold_by": "each",
"weight_option": false,
"par_weight": null,
"max_order_quantity": 9999,
"on_sale": false,
"buy_one_get_one": false,
"coupon_available": false,
"store_brand": true,
"dietary": [],
"nutrition_highlights": null,
"variant_values": [],
"retailer_reference_code": "1550393",
"retailer_lookup_code": null,
"currency": "USD",
"price": 17.58,
"price_display": "$17.58",
"original_price": null,
"discount_percent": null,
"savings": null,
"loyalty_price": null,
"loyalty_label": null,
"loyalty_card_offer": false,
"unit_price_text": null,
"size_text": null,
"price_is_estimate": false,
"estimated_weight_text": null,
"promotions": [],
"deal_terms": null,
"great_price": false,
"badge": null,
"retailer": {
"retailer_id": "5",
"slug": "costco",
"name": "Costco",
"shop_id": "3048",
"service_type": "delivery",
"retailer_location_id": "407"
},
"service_type": "delivery",
"matches_query": true
},
{
"product_id": "133044124",
"item_id": "items_407-133044124",
"name": "Kirkland Signature Organic Whole Milk, Half Gallon, 4-count",
"brand": "kirkland signature",
"size": "4 ct",
"url": "https://sameday.costco.com/store/costco/products/133044124-kirkland-signature-organic-whole-milk-1-89-l",
"image": "https://d2lnr5mha7bycj.cloudfront.net/product-image/file/large_f69c4129-c3a7-4760-8cd8-316dd5dd8655.jpg",
"available": true,
"stock_level": "many_in_stock",
"stock_label": null,
"likely_out_of_stock": false,
"sold_by": "each",
"weight_option": false,
"par_weight": null,
"max_order_quantity": 9999,
"on_sale": false,
"buy_one_get_one": false,
"coupon_available": false,
"store_brand": true,
"dietary": [
"Organic"
],
"nutrition_highlights": null,
"variant_values": [],
"retailer_reference_code": "2070113",
"retailer_lookup_code": null,
"currency": "USD",
"price": 19.28,
"price_display": "$19.28",
"original_price": null,
"discount_percent": null,
"savings": null,
"loyalty_price": null,
"loyalty_label": null,
"loyalty_card_offer": false,
"unit_price_text": "$4.82 each",
"size_text": "4 ct",
"price_is_estimate": false,
"estimated_weight_text": null,
"promotions": [],
"deal_terms": null,
"great_price": false,
"badge": null,
"retailer": {
"retailer_id": "5",
"slug": "costco",
"name": "Costco",
"shop_id": "3048",
"service_type": "delivery",
"retailer_location_id": "407"
},
"service_type": "delivery",
"matches_query": true
}
],
"count": 20,
"total": 41,
"page": 1,
"per_page": 20,
"last_page": 3,
"has_more": true,
"unmatched_dropped": 0,
"next_cursor": "ACF7ImsiOiJhMzdkMTg4M2M5M2IiLCJwIjoyLCJvIjoyMH0BJRfKAYgHQQfuF5wBCDZlBqfByQGwamIABGMRAwT7NAcGD3gBQViRAdEBhAD_0tcAAxt1Bi-JrgEXfm8H7hWiAAJN2wEzRC0HRHQbA5mgMA",
"query": "milk",
"store": {
"store_id": "407",
"name": "Issaquah",
"street": "1801 10th Ave NW",
"city_state_zip": "Issaquah, WA 98027",
"latitude": 47.551444,
"longitude": -122.053224
},
"service_type": "delivery",
"postal_code": "98027",
"store_defaulted": false,
"currency": "USD"
}
}What the Costco Same-Day API does
| Action | Description | Concrete use case | Key params |
|---|---|---|---|
| search | Search sameday.costco.com at one Costco store: regular price (price list), was-price, member/card price and promotions apart, unit price, stock level, brand and size, in the site's own result order. | Pricing teams call search to search sameday.costco.com at one Costco store. | query, page, per_page, include_unmatched, cursor, ... |
| category | Every product of a sameday.costco.com collection (a category, a brand or a diet collection from `categories`) priced at one store. | Marketplace operators call category to get every product of a sameday.costco.com collection (a category, a brand or a diet collection fr…. | slug, page, per_page, cursor, postal_code, ... |
| product/detail | One Costco product: name, brand, size, category, ingredients, directions, warnings, images, rating — and its price, unit price, promotions and stock at one store. | Catalog enrichment teams call product/detail to get one Costco product. | product_id, postal_code, store_id |
| categories | The sameday.costco.com category tree (departments and their collections) or one collection's sub-collections; slugs feed `category`. | Retail analysts call categories to get the sameday.costco.com category tree (departments and their collections) or one collection's…. | slug, postal_code, store_id |
| stores | Costco stores around a US ZIP code, nearest first, with address, coordinates, distance and which services sameday.costco.com offers there. | Pricing teams call stores to get costco stores around a US ZIP code, nearest first, with address, coordinates, distance and wh…. | postal_code, page, limit |
| offers | Costco's current deal lists at one store: Weekly Savings. | Marketplace operators call offers to get costco's current deal lists at one store. | type, page, per_page, cursor, postal_code, ... |
| promotions | Which Costco deal lists are live now at one store, each with its name and product count. | Catalog enrichment teams call promotions to get which Costco deal lists are live now at one store, each with its name and product count.. | postal_code, store_id |
Call search from your stack
curl -X POST https://api.reefapi.com/costco-sameday/v1/search \
-H "x-api-key: $REEF_KEY" \
-H "content-type: application/json" \
-d '{"query":"milk","postal_code":"98027"}'import requests
r = requests.post(
"https://api.reefapi.com/costco-sameday/v1/search",
headers={"x-api-key": REEF_KEY},
json={
"query": "milk",
"postal_code": "98027"
},
)
print(r.json()["data"])const res = await fetch("https://api.reefapi.com/costco-sameday/v1/search", {
method: "POST",
headers: {
"x-api-key": process.env.REEF_KEY,
"content-type": "application/json",
},
body: JSON.stringify({
"query": "milk",
"postal_code": "98027"
}),
});
const { ok, data, meta, error } = await res.json();Ask your MCP-connected assistant: call reefapi.costco-sameday.search with {"query":"milk","postal_code":"98027"}.Who uses this API and why
- Track Costco Same-Day prices per warehouse and ZIP code.
- Compare Kirkland Signature prices between Costco warehouses.
- Publish Costco Weekly Savings in a deals feed.
- Build a Costco warehouse finder for same-day delivery coverage.
- Monitor Costco Same-Day price changes on bulk groceries.
Questions developers ask before integrating
Does Costco Same-Day have a public API?
No public product API. This API reads what sameday.costco.com shows a logged-out visitor and returns it as JSON. No account is needed.
Why do I need a ZIP code?
Costco prices are set per store. Pass postal_code or store_id; without them a fixed default store is used and store_defaulted is true.
Which price is returned?
The Costco Same-Day delivery price of the chosen warehouse, as sameday.costco.com prints it on its product page (8 of 8 products matched). In-warehouse shelf prices are not shown on the site and are not returned.
Can I get Costco's weekly savings?
Yes. offers with type weekly_savings returns the Weekly Savings list priced at one warehouse; promotions lists it with its product count.
Are these Costco warehouse prices?
These are the Costco Same-Day prices sameday.costco.com shows for a warehouse; they matched the price printed on the site's own product page for 8 of 8 products. No member-only price is shown to a visitor without a Costco login, so none is returned.
How do I find Costco stores near a ZIP code?
Call stores with postal_code. Around 98027 it returned 14 stores, nearest first, with address, coordinates, distance in miles and the services each offers. Use a store_id in any other call to price at that store.
Does search return everything the site finds?
Yes, in the site's own order, 20 per page by default (up to 40). cheese returned 139 products. The site can re-rank its list between two calls, so reading by page number can repeat or skip a product; follow next_cursor from each answer for a complete scan: it never returns a product twice and fills the page from the rest of the list.
How fresh is the data?
Every call reads sameday.costco.com live; nothing is cached on our side.
What is the Costco Same-Day API?
Costco Same-Day API is a ReefAPI endpoint group for sameday.costco.com prices as json per store: search, categories, weekly savings, product details and the store locator. It returns live JSON through POST requests under /costco-sameday/v1.
Is the Costco Same-Day API free to try?
Yes. ReefAPI starts with 1,000 free credits, no card required. Costco Same-Day calls use the same shared credit balance as every other ReefAPI engine.
Do I need a Costco Same-Day login or account?
No login to Costco Same-Day is needed for the API response. You call ReefAPI with your x-api-key header, and the playground can run live examples before you create a production key.
How fresh is the Costco Same-Day data?
The page example is captured from a live search call, and production requests fetch live data through ReefAPI rather than a static sample.
How many credits does the Costco Same-Day API use?
Costco Same-Day actions currently cost 1-3 credits per successful call. Failed or blocked calls are free. All APIs draw from one credit pool.
Can I call Costco Same-Day from an AI assistant or MCP client?
Yes. Connect ReefAPI once through MCP and your assistant can call costco-sameday actions with the same key, credit pool and JSON envelope used by normal REST requests.