Ecwid by Lightspeed vs Swell

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.

Swell

Live /:models schema with field types and descriptions for every store. One full-access secret key per environment, with no scoped or read-only key.

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

Swell

1. Call GET /:models once and cache it. It's the ground truth for custom fields
2. Check result.errors after every write. A failed validation still returns 200
3. Use $set to replace an array. A plain PUT merges arrays by element id and never shrinks them
4. Use an sk_test_ key while testing. A bare sk_ prefix is live
5. Keep expand and include small. Each level past the first three points adds rate-limit weight