Developers
Sandbox in 5 minutes.
Clean REST. Bearer + timestamp signing. Idempotent writes. Webhooks with replay. SDKs incoming.
Quick start
1. Request sandbox keys
Drop us a line — sandbox keys land in your inbox within one business day.
2. Open a card
POST /v1/cards with the cardholder reference. Single API call.
3. Subscribe webhooks
We sign callbacks with HMAC-SHA256. Verify and replay safely.
Full reference
docs.coshine.com (in preparation). For early access to the docs and Postman collection, contact sales — we'll set you up.