Ecwid by Lightspeed vs Snipcart API + MCP

Ecwid by Lightspeed

The REST API has 40 access scopes, a published limit of 600 requests a minute per token with Retry-After on a 429, field selection through responseFields, and Markdown docs with an llms.txt index. Tokens never expire, there is no test mode or idempotency key, API access needs a paid plan, and carts are built only in the browser.

Snipcart API + MCP

Hosted MCP server with 38 documented tools and a self-hostable Bun build. No server-side cart or checkout. Orders only come from the browser widget.

Ecwid by Lightspeed

1. Send the token as Authorization: Bearer to https://app.ecwid.com/api/v3/{storeId}. Tokens in the query string stopped working in March 2025
2. Use the secret token server-side only. The public token reads enabled products and places orders that are not marked paid
3. Add responseFields, for example total,items(id,name,price), to keep responses small, and page with offset and limit (maximum 100)
4. Stay under 600 requests a minute per token and wait the Retry-After seconds on a 429. Repeated calls with a bad token get the token and IP blocked for longer
5. Work in a separate test store. There is no test mode, and POST /orders writes a real order with no idempotency key
6. After changing an app's scopes, uninstall and reinstall it, then replace the stored tokens. The old ones stop working

Snipcart API + MCP

1. Use the agent for back-office jobs (orders, refunds, discounts, stock, abandoned carts), not for placing orders
2. Start with a test-mode key (ST_ prefix) before switching to live (SL_)
3. Send the key in X-Snipcart-Api-Key. OAuth-only clients can't connect
4. Stay under 100 MCP requests a minute and 10 in flight per key
5. Ignore unknown response fields. Snipcart adds fields without a new version