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The Hologram Cloud provides an API and an interface in your dashboard to send inbound SMS, TCP, or UDP messages to a cellular device through a SIM. By running a server on your device that listens on a given port, you can receive and process these messages. Hologram’s cloud messaging allows you to send a TCP or UDP message to a specified port on your device. This is helpful when you want to send messages to your device using only data. SMS is commonly used by IoT devices to send command, configure, and control messages. For example, setting the APN without requiring any additional device setup.
Note: Inbound SMS message are always free.

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How to send a message to a single SIM

  1. Open a SIM from the SIMs pages or using global search.
  2. Click the Manage SIM menu at the top of the page and choose Send message to SIM
  3. Select your message type (SMS, TCP, or UDP)
  4. Enter your message content, specify the port number for TCP/UDP messages, and send your message.

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How to send bulk messages

  1. Navigate to the SIMs section in your dashboard.
  2. Use filters to find and select the target SIMs.
  3. Open the Manage SIMs menu at the top of the page and choose Send message to SIMs.
  4. Select your message type (SMS, TCP, or UDP)
  5. Enter your message content, specify the port number for TCP/UDP messages, and send your message.

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Subscribing to messaging events

SIM messaging events are tracked in the Event monitoring section of your dashboard, including:
  • Outbound SMS messages sent from a SIM
  • Inbound SMS messages sent to a SIM
  • Inbound SMS messages received by a SIM
  • TCP or UDP messages sent to a SIM
  • API successful or failed responses for sending messages to a SIM
You can subscribe to these events to receive email or webhook notifications when messages are sent to or received from your SIMs using Alerts.
Beta: Alerts functionality is in beta and replaces our legacy Routes functionality. Some Routes functionality is no longer available, and you may find issues during the beta period. Please send us your feedback using the Support menu in your dashboard.

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How to send a message to SIMs using the REST API

Send cloud message to SIMs

Send a message to SIMs POST /devices/message

Send inbound SMS to SIMs

Send a SMS to SIMs POST /sms/incoming

Send outbound SMS from SIM

Send SMS from SIM to phone number POST /sms/outgoing

View SIM reporting

View outbound SMS usage details

Get outbound SMS usage

Get outbound SMS usage GET /usage/sms