Bring Your Own Provider

With Bring Your Own Provider, Sendrin sends your notifications through a provider account you own. You keep your provider contract, sender numbers and pricing. Sendrin handles templates, idempotency, retries, delivery tracking and the API your application calls.

1. Providers available today

Open Providers in the Sendrin Console. Each provider is one card; connect it once, then turn on the products you need.

More providers will appear on the Providers page as they become available.

2. Connect Twilio

You need a Twilio account with an SMS-capable number, an alphanumeric sender ID or a Messaging Service. For WhatsApp through Twilio you also need a WhatsApp-enabled Twilio sender and an approved Twilio Content template for each WhatsApp message (see WhatsApp through Twilio).

1. On the Twilio card, select Connect. The connect wizard opens.
2. Products & credentials
   • Enter your Account SID (starts with AC, on the Twilio Console home page) and your Auth token.
   • Turn on each product you want. Each product becomes its own configuration.
   • For each product, give a Default sender (an E.164 number such as +14155550100, an alphanumeric sender ID, or a WhatsApp-enabled number) or a Messaging Service SID (starts with MG).
3. Scope: choose who sends through this connection.
   • This application: only the selected application uses it.
   • Whole workspace: any application without its own provider can use it. You can also make it the workspace default for the products you turned on; that replaces the current workspace default for those channels.
4. Save & test: Sendrin saves the connection, checks your Account SID and Auth Token with Twilio, and activates each product once that check passes. If it fails, the wizard shows Twilio's reason (for example, a wrong Auth Token) so you can fix the details and try again.

The check confirms your Twilio account, not each sender. A sender your account can't use (a mistyped number, or a number not enabled for WhatsApp) is only caught on the first real send, which then fails with Twilio's error in Delivery Activity. Send yourself one message on each product before going live.

WhatsApp through Twilio

Twilio sends WhatsApp messages from approved Content templates. Each WhatsApp template you send through Twilio must carry its Twilio Content SID (HX...) as content_sid in the template's content, with any variables in content_variables. A WhatsApp send without one fails with TWILIO_CONTENT_SID_MISSING and is not retried. WhatsApp one-time passwords from the OTP endpoints need a WhatsApp number connected with Meta: through Twilio they fail with TWILIO_CONTENT_SID_MISSING.

Delivery receipts are set up for you: each message Sendrin sends through Twilio asks Twilio to report its status back, so delivered and failed states appear in Delivery Activity without any setup in Twilio.

3. Connect your WhatsApp Business number (Meta)

Connect a WhatsApp Business number you own directly through Meta, without copying tokens by hand.

1. On the WhatsApp card, select Connect WhatsApp. Meta's signup window opens.
2. Sign in with your Facebook account, then choose or create your Meta business, your WhatsApp Business Account and the phone number to use. Verify the number if Meta asks.
3. When you finish, the window closes and the number appears on the WhatsApp card as a connected configuration.

Sendrin confirms with Meta that it can send from the number and subscribes it to delivery receipts. If the card later says delivery receipts aren't set up, open Manage on the WhatsApp card and select Connect WhatsApp again to finish the setup.

Meta's own rules still apply to every WhatsApp message: use templates Meta has approved and record each recipient's opt-in first. See the WhatsApp guide.

4. Manage a connected provider

Select Manage on a connected card to see its configurations. For each one you can:

• Test it again.
• Edit its name and public settings.
• Replace secret, for example after rotating your Twilio Auth Token. Secrets are write-only: Sendrin never shows a saved secret again.
• Activate or Deactivate it. Only a configuration whose last test passed can be activated.
• Make it the default for its channel: Make workspace default on a connection made in the wizard, Set default on a WhatsApp number connected with Meta.
• Remove it: Disconnect on a connection made in the wizard (removes the connection and every product on it), Archive on a WhatsApp number connected with Meta. Deactivate it first. A provider that is still a default can't be removed: make another provider the default first.

A card's status tells you its state at a glance: Healthy, Degraded (some configurations failing), Test failed, Not tested or Not connected. A card that needs your attention shows Fix setup instead of Manage.

5. Sending through your provider

Nothing changes in your API calls. Send with POST /api/v1/notifications as usual; Sendrin picks the provider configured for the application, or the workspace default for the channel. For WhatsApp through Twilio, see the Content template requirement above.

curl -X POST "https://api.sendrin.com/api/v1/notifications" \
  -H "Authorization: Bearer sendrin_a1b2c3d4e5f6.xY7z..." \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 6f1c2a9e-1b7d-4c55-9a43-0d2f7c6b1e88" \
  -d '{
    "event_key": "order_shipped",
    "channel": "sms",
    "recipient": {"phone": "+14155552671"},
    "data": {"order_id": "A-1042"}
  }'

If a send fails with a temporary error (the provider can't be reached, times out, or answers with a server error), Sendrin retries it with backoff and shows each attempt in Delivery Activity. A provider that timed out may already have accepted the message, so in rare cases a retry delivers it twice. A refusal that won't change, such as an invalid number or rejected credentials, is not retried.

6. Billing

Messages sent through your own provider are billed to you by that provider, at your rates with them. They don't use Sendrin message credits. Your application's rate limits still apply: a request over the per-minute or per-day limit gets 429 quota_exceeded.

7. Security

• Credentials are encrypted at rest and are write-only: no API response or screen ever shows a saved secret.
• A provider is only used after Sendrin has verified it.
• Only workspace members allowed to manage providers can connect, change or disconnect them.