Cardseekers API

Read-only JSON access to the Cardmarket catalogue behind Cardseekers: every Pokémon single and sealed product with Cardmarket's price guide, the lowest price and the 5 cheapest offers from Dutch sellers of English cards, price history, sets, and the watchlist the monitor tracks.

Base URL https://cardmarket.davey-dd3.workers.dev/api/v1

Quick start

Get a key. Keys are personal and handed out by the Cardseekers team; ask Davey or Hugo. A key looks like cm_live_ followed by 32 letters and digits. Treat it like a password.
Send it with every request as Authorization: Bearer <key> (or X-API-Key: <key>).

Try a search:

curl -H "Authorization: Bearer $CARDSEEKERS_KEY" \
  "https://cardmarket.davey-dd3.workers.dev/api/v1/cards?q=umbreon&limit=5"

or use Try it below, right in this page.

What the prices mean

filtered_price: Cardmarket's card page checked with ?sellerCountry=23&language=1: sellers in the Netherlands, English cards, any condition. lowest is the cheapest such offer, offers how many there were, and cheapest_offers the 5 cheapest (price in EUR, condition, quantity, seller), cheapest first. Next to each other they show the real spread: one cheap outlier next to four higher offers is a lucky find, not the price. Every card is re-checked daily; checked_at says when.
price_guide: Cardmarket's own EU-wide daily price guide: all sellers, languages and conditions (low, avg, trend, 1/7/30-day averages, and the same for holo/reverse).
listing: From the expansion's list page on Cardmarket: offers available and the "from" price, all sellers.
cardmarket_url: Always carries the ?sellerCountry=23&language=1 filter, so it opens on the same offers.

These are asking prices. Cardmarket doesn't publish what cards actually sold for.

Keys, limits and expiry

Each key can make 120 requests per minute unless it was given another limit. Every response says where you are: X-RateLimit-Limit, X-RateLimit-Remaining and X-RateLimit-Reset (Unix time the window resets).
Over the limit you get 429 rate_limited with Retry-After (seconds). Wait that long, then retry.
Keys can have an expiry date and can be revoked; GET /me shows yours.
Everything is GET. Responses are JSON in UTF-8; prices are euros as numbers (3200 = €3,200.00).
Browsers may call the API directly (CORS is open), but never put a key in a public web page: anyone can read it there.

Errors

Errors always have the same shape, with a machine-readable code:

{"error": {"code": "invalid_parameter", "message": "'limit' must be between 1 and 100."}}

Status	code	When
400	`invalid_parameter`	A parameter is out of range or not allowed.
401	`unauthorized`	No key was sent.
401	`invalid_api_key`	The key is wrong or malformed.
401	`expired_api_key`	The key's expiry date has passed.
401	`revoked_api_key`	The key was switched off.
403	`insufficient_scope`	The key may not read this.
404	`not_found`	No such card, set or watchlist product.
405	`method_not_allowed`	Anything other than GET.
409	`ambiguous_slug`	A watchlist slug matches more than one product.
429	`rate_limited`	Too many requests; see `Retry-After`.
500	`internal_error`	Something broke on our side; try again later.

Pagination

Lists take limit and offset and return data plus:

"pagination": {"limit": 50, "offset": 0, "returned": 50, "has_more": true, "next_offset": 50}

Keep asking with offset=next_offset until has_more is false.

Endpoints

Loading the endpoint list…

Try it

Send a real request from this page. Your key stays in this browser tab only (session storage) and goes nowhere but this API.

OpenAPI

The full machine-readable description (OpenAPI 3.1) is public at /api/v1/openapi.json. Import it into Postman, Insomnia or a code generator to get a typed client.