Receive SMS in n8n and Auto-Reply From Your Own Number

Description and use

Automated SMS reply via n8n and SimGate using the same SIM number.

Problem

Need a two‑way SMS workflow that replies from the same SIM number using an Android phone and n8n.

Outcome

A functional two‑way SMS auto‑reply that uses the same SIM number for responses, enabling support requests or notifications.

Workflow

• Install SimGate nodes in n8n
• Create SimGate API credential with API key and base URL
• Import the HELP auto‑reply workflow JSON
• Configure Receive SMS node with credential and SMS Received event
• Replace REPLACE_WITH_YOUR_TEST_NUMBER in Prepare HELP reply node
• Replace REPLACE_WITH_DEVICE_ID with gateway phone’s device ID
• Activate workflow (webhook registers)
• Send "HELP" from test phone to trigger reply

Evidence

Someone texts HELP to your SIM number → Android phone receives the SMS → SimGate forwards the event to n8n → Code node checks the sender, device, and keyword → SimGate sends an acknowledgement to the sender

Source

The starter only replies to one test sender through one configured device. It ignores other messages.

Source

For self-hosted n8n, your webhook URL must be publicly reachable over HTTPS. The hosted SimGate service cannot deliver an event to localhost.

Source