REST Overview
Overview
The Marketplace Data REST API provides access to item listings, buy orders, price history, and sales data from third-party Steam marketplaces. It is a separate service from the main Steam API and lives on its own host.
Base URL
All REST endpoints are served from a single host.
https://marketplaceapi.steamapis.com/v2/
Authentication
Include your API key as the X-API-Key request header. HTTP headers are case-insensitive, so x-api-key works too.
X-API-Key: YourSecretAPIKey
Alternatively, pass the key as an apiKey query parameter. The header is preferred.
https://marketplaceapi.steamapis.com/v2/marketplaces?apiKey=YourSecretAPIKey
Response format
{ "success": true, "response": {...} } envelope. Parse the response body directly.A successful response is either a single object or an array of objects, depending on the endpoint. For example, GET /v2/marketplaces returns an array directly at the top level of the body.
Errors
Errors are returned with a non-2xx HTTP status and a JSON body containing an error message and a machine-readable code.
{
"error": "Marketplace not found",
"code": "NOT_FOUND"
}
Caching and rate limits
Responses are cached server-side for 10 seconds. There are no client-side rate limits — the cache absorbs repeat traffic.
Available endpoints
- GET /v2/marketplaces — list supported marketplaces
- GET /v2/items — fetch a single item with offers and buy orders
- GET /v2/items/search — search items by name
- GET /v2/items/compare — compare an item across marketplaces
- GET /v2/buy-orders — list buy orders
- GET /v2/price-history — price history time series
- GET /v2/sales — recent sales