Bring MerchLine's fan-made merch marketplace into your own app with a spec-first REST API and a TypeScript SDK.
Browse listings, categories, events, and vendor menus with cursor pagination.
Server-priced carts and an idempotent, async-shaped checkout that survives the move to real payments.
Order history plus signed order.created / order.status_changed webhooks instead of polling.
mlk_test_ keys run the full flow against live catalog data without touching real inventory, coupons, or seller dashboards.
The full contract is the OpenAPI 3.1 document at /api/v1/openapi, and the @merchline/sdk TypeScript SDK (React Native compatible) wraps every endpoint with retries, token rotation, and webhook signature verification.
A quick liveness check against production:
curl https://merchline.onlot.net/api/v1/health
API keys are provisioned per partner while the program is in early access. Contact us to request access and we will set you up with sandbox credentials.