Shop API — free mock REST API for testing

A small e-commerce flow: browse products, build a cart, apply coupons and check out. Out-of-stock items return 409, invalid coupons 422, expired coupons 410, and checkout honors Idempotency-Key so retries never double-charge.

The Shop API is a checkout: products with real stock counts, carts, and coupons that expire. Stock is decremented on checkout, so the interesting failures happen between adding an item and paying for it — which is precisely the window most e-commerce test suites skip.

Base URL: https://funapi.dev/api/shop/v1 · 9 endpoints · OpenAPI 3.1 spec and Postman collection available. New here? Read the getting started guide.

What you can practise here

• Add the last unit to a cart, check out twice, and read the conflict on the second attempt.
• Apply an expired coupon and see the 410 rather than a validation error.
• Check out with an empty cart and read the 422.
• Add a quantity larger than the stock on hand and confirm the error names the constraint.

products

things you do not need

• GET /shop/v1/products — List products, filter by category
• GET /shop/v1/products/{id} — Get one product

carts

add, remove, regret

• POST /shop/v1/carts — Create an empty cart
• GET /shop/v1/carts/{id} — Get a cart with its running total
• POST /shop/v1/carts/{id}/items — Add a product (409 when out of stock)
• DELETE /shop/v1/carts/{id}/items/{productId} — Remove a product from the cart

checkout

where the money pretends to move

• GET /shop/v1/coupons/{code} — Validate a coupon (410 when expired)
• POST /shop/v1/carts/{id}/checkout — Check out (idempotent, coupon-aware)
• GET /shop/v1/orders/{id} — Get an order

Related APIs

• Pizza Orders API — Place & track orders. Includes a guaranteed 500.
• Coffee Shop API — Drinks & orders. Home of the legendary 418.
• Football API — Teams, squads, standings & simulated matches.
• Bank API — Accounts, transfers & cursor pagination. Home of the 402.

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