Interactive demo Simulated demo

Message Flow Simulator

See how a message moves through SendiMessage — from API request to delivery, reply, and webhook.

No real message is sent from this demo.

Looking for a request builder instead? Try the API Playground, or design your integration before running it.

Message

Use case

Delivery preference

Demo recipient

+1 (555) 010-0123

Simulate iMessage unavailable

Fallback behavior depends on line configuration and destination support.

POST https://api.sendimessage.com/v1/send-message

bash

curl --request POST \
  --url "https://api.sendimessage.com/v1/send-message" \
  --max-time 15 \
  --header "Accept: application/json" \
  --header "Content-Type: application/json" \
  --header "X-API-Key: ${SENDIMESSAGE_API_KEY}" \
  --header "X-API-Secret: ${SENDIMESSAGE_API_SECRET}" \
  --data '{
  "number": "+15550100123",
  "content": "Hi Sarah — your appointment is tomorrow at 10:00 AM. Reply C to confirm.",
  "media_url": null,
  "status_callback": "https://example.com/callbacks/status",
  "line_handle": "8eb3ecaf-6487-485d-b01c-b18bdcb57180"
}'

Demo conversation preview

Waiting to send…

Architecture flow

Your app

SendiMessage API

Managed line

Customer

Lifecycle (simulation stages)

API request sent

Validated

QueuedQUEUED

Routing

Sending

SentSENT

DeliveredDELIVERED

Event timelineSimulated timeline — not a production performance metric

Run the demo to see the simulated event timeline.

Webhook Inspector

Run the demo through to a simulated customer reply to see a live webhook delivery here.