Platform
The plumbing messaging needs, already built
SMS21 handles providers, compliance, money and delivery tracking, so your application only makes one API call and reads one status.
How a message flows
From your request to a delivery report
Every message follows the same five steps, whatever the channel.
- 1
Accepted
Your key, scope, IP and rate limit are checked; the request is validated and made idempotent.
- 2
Checked
DLT template and header, opt-outs, blocked destinations and your daily limit.
- 3
Funded
The price in force is held from the wallet in the same transaction as the message.
- 4
Routed
The best provider for the country and channel is chosen; failures fall over to the next.
- 5
Delivered
Provider reports become one status; your webhook is signed, sent and retried.
Capabilities
Everything around the send call
Routing and failover
Providers ranked per country, channel and message type. A circuit breaker takes a failing provider out and the next one carries the traffic — no code change.
DLT compliance built in
Principal entities, headers and templates live in SMS21. Every live Indian SMS is matched to an approved template before a provider sees it.
Prepaid wallet and ledger
Holds, captures and refunds are immutable ledger entries. Top up by UPI or card and download GST invoices.
Signed webhooks
Delivery, failure and reply events, HMAC-signed, retried with back-off and replayable from the dashboard.
Projects, roles and keys
Separate projects per application, role-based permissions per member, and scoped API keys restricted to your servers’ IPs.
Reports and API logs
Messages, delivery, inbound, failures, usage and every API request — filterable in the dashboard and available over the API.
Idempotent by design
Send an Idempotency-Key and a retry returns the original message instead of sending twice — on every sending endpoint.
Limits you control
Per-key and per-project rate limits, daily live-message caps, and an emergency stop per channel.
Plugins
Switch on WhatsApp Official or WhatsApp Connect for your company, per message or with a subscription plan.
Reseller accounts
Resellers create sub-accounts, set their prices within their own rates, and fund their wallets.
Two API styles
The full JSON API with templates and variables, or the simple v2 API — number, message, header and DLT ID from any tool.
A real sandbox
Test keys hit the same API and statuses, deliver nothing, charge nothing, and follow magic numbers for failures.
For developers
Integrate in an afternoon
Consistent JSON, stable error codes, cursor pagination and one authentication scheme across every endpoint.
Node.js SDK
Typed, with retries and idempotency built in.
OpenAPI 3.1
Import into Postman or generate a client.
Examples
cURL, PHP, Laravel, NestJS and Next.js.
Start today
Build against the sandbox, go live when you are ready
Create an account and a test key in minutes. Nothing is delivered and nothing is charged until you switch to a live key.