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Send your first SMS with the Hypersender SMS API in Postman. The interactive demo below walks through configuring the request; the written steps mirror it so you can build the same call in your own code. Messages are sent by the Android phone linked to your instance, so the recipient sees your own SIM card number.

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What you need

  • A Hypersender account with an active instance.
  • Your API token and instance UUID from the dashboard.
  • The Hypersender Android app installed, linked, and online — see the SMS quick start.
  • Postman installed, or the SMS Postman collection imported.
  • The recipient phone number in international format, for example +1119122018.

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Request

POST https://app.hypersender.com/api/sms/v1/{instance}/send-message
request_id is your own idempotency key, so retrying the same request never sends the message twice. You can also pass schedule_send_at to queue the message for a later time, max_send_attempts, and message_expiration_seconds.

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What the phone does

  1. The API hands the message to the linked Android phone.
  2. The phone sends it through your SIM card and reports back the status.
  3. Delivery updates arrive on your configured webhook — see SMS webhooks.
The message arrives from your phone number, not a custom sender name. Custom sender names require carrier and regulatory approval that Hypersender does not currently offer.

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Troubleshooting

The Authorization header is missing or the token was rotated. Generate a new token in the dashboard and update the header.
The API confirms the request before the phone sends it. Check the heartbeat status of your device — if there has been no heartbeat for more than two hours, Hypersender marks it offline.
Verify the number is in international format and that the SIM card has credit for the destination country. International messages are billed by your carrier.

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Next steps

Send Message reference

Every parameter for the SMS send endpoint.

Heartbeats

Monitor whether your phone is online and ready to send.

Create your Hypersender account

Get your API token, link the Android app, and send your first SMS.
Last modified on October 16, 2026