Sendai API documentation
Send SMS to one recipient or a whole list over a plain JSON REST API — one API key, prepaid per-segment billing, and a delivery signal you can trust. These pages document the live API's exact behaviour: every response shape, charge, and error as it really is.
Guides
Task-shaped walkthroughs, from first send to production patterns.
Quickstart
From an API key to a delivered SMS in three steps.
Authentication
One API key as a bearer token — create, rotate, revoke.
Bulk SMS
One body to a list of recipients, priced as one send.
Webhooks
Signed callbacks when delivery is confirmed or fails.
AI agents (MCP)
Point Claude, Cursor, or any MCP client at your account.
API overview
Base URLs, auth, the two response conventions, and errors.
Resources
The full authored reference, one page per resource — the object first, then request, response, and errors for each operation.