Onboarding completion reminder via WhatsApp API
The scenario sends the user a personalised WhatsApp template when account onboarding is started but not finished.
Use case overview
The scenario sends the user a personalised WhatsApp template when account onboarding is started but not finished. The message includes the customer name, the pending onboarding stage, and the next step to complete. A static URL button opens the onboarding wizard where they left off.
Template example
Hello, {{1}}! Your account onboarding is not complete yet — the {{2}} step is still pending. {{3}} Tap the button below to finish setup. If you need help, reply to this message.
- {{1}}customer name
- {{2}}pending onboarding stage (e.g. business profile verification, document upload)
- {{3}}next step instruction (e.g. upload company documents and confirm details in the portal)
- “Finish onboarding”button — fixed in the Meta template

When to use it
Reach for this scenario when a user registers and starts account onboarding — profile setup, document upload, or verification — but stops before all required steps are done. It fits SaaS and fintech teams recovering stalled KYC flows, marketplaces nudging sellers to finish verification, and agencies wiring onboarding progress events from a client's app to WhatsApp reminders.
Workflow
- Customer acts
The user starts onboarding but leaves before all required steps are complete.
user action - Capture event
The system detects the incomplete onboarding state and resolves the recipient phone number.
phone:"+…" - Build & send
A personalised template message is built with three body variables and a static URL button.
POST/sendTemplate - Delivered
The user receives the WhatsApp reminder with the pending stage and next step to finish setup.
delivered - Status tracked
Delivery result is logged; errors are handled according to platform rules.
status:"read"

Technical implementation
Prerequisites
- 1MSG API Key · How to get API Key
- WhatsApp Business account · How to Connect WABA
- WhatsApp Template · How to Approve WABA Template
- Customer opt-in · How to Manage Customers Consent
Code examples
#!/usr/bin/env bash
set -euo pipefail
# === Configuration (replace "___" placeholders) ===
API_BASE_URL="https://api.1msg.io" # production 1MSG API base URL
CHANNEL_ID="___" # channel ID from 1MSG dashboard
API_TOKEN="___" # channel JWT token (Bearer)
TEMPLATE_NAME="___" # approved template name
TEMPLATE_NAMESPACE="___" # template namespace (required — send fails without it)
TEMPLATE_LANGUAGE="___" # template language code, e.g. "en"
# === Test data ===
TEST_PHONE="___" # client phone in international format
TEST_CUSTOMERNAME="___" # {{1}} customer name
TEST_STAGE="___" # {{2}} stage name
TEST_NEXTSTEP="___" # {{3}} next step
PHONE_NORM="$(printf '%s' "$TEST_PHONE" | tr -cd '0-9')"
for pair in "CHANNEL_ID=$CHANNEL_ID" "API_TOKEN=$API_TOKEN" \
"TEMPLATE_NAME=$TEMPLATE_NAME" "TEMPLATE_NAMESPACE=$TEMPLATE_NAMESPACE" \
"TEMPLATE_LANGUAGE=$TEMPLATE_LANGUAGE" "TEST_PHONE=$TEST_PHONE" \
"TEST_CUSTOMERNAME=$TEST_CUSTOMERNAME" \
"TEST_STAGE=$TEST_STAGE" \
"TEST_NEXTSTEP=$TEST_NEXTSTEP"; do
val="${pair#*=}"
if [ -z "$val" ] || [ "$val" = "___" ]; then
echo "Missing configuration value: ${pair%%=*}" >&2
exit 1
fi
done
if [ -z "$PHONE_NORM" ]; then
echo "Error: phone number has no digits after normalization" >&2
exit 1
fi
URL="${API_BASE_URL%/}/${CHANNEL_ID}/sendTemplate"
# params carries body ONLY. Button text is fixed in the Meta template — no button param.
# {{1}} customer name → ${TEST_CUSTOMERNAME}
# {{2}} stage name → ${TEST_STAGE}
# {{3}} next step → ${TEST_NEXTSTEP}
read -r -d '' PAYLOAD <<JSON || true
{
"phone": "${PHONE_NORM}",
"template": "${TEMPLATE_NAME}",
"namespace": "${TEMPLATE_NAMESPACE}",
"language": { "policy": "deterministic", "code": "${TEMPLATE_LANGUAGE}" },
"params": [
{
"type": "body",
"parameters": [
{ "type": "text", "text": "${TEST_CUSTOMERNAME}" },
{ "type": "text", "text": "${TEST_STAGE}" },
{ "type": "text", "text": "${TEST_NEXTSTEP}" }
]
}
]
}
JSON
RESPONSE="$(curl -s -w '\n%{http_code}' -X POST "$URL" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer ${API_TOKEN}" \
-d "$PAYLOAD")"
HTTP_CODE="$(printf '%s' "$RESPONSE" | tail -n1)"
BODY="$(printf '%s' "$RESPONSE" | sed '$d')"
case "$BODY" in
*'"sent":true'*) ok=1 ;;
*) ok=0 ;;
esac
if [ "$HTTP_CODE" -ge 200 ] && [ "$HTTP_CODE" -lt 300 ] && [ "$ok" -eq 1 ]; then
echo "Message sent to client."
echo "API response: $BODY"
else
echo "Send failed. HTTP status: $HTTP_CODE" >&2
echo "$BODY" >&2
exit 1
fi
Response and delivery status
HTTP 2xx and JSON "sent": true mean 1MSG accepted the message for sending — not that it already reached the customer's phone. Save the id field (looks like wamid.…) to correlate delivery callbacks.
{
"sent": true,
"message": "Sent to [email protected]",
"description": "Message has been sent to the provider",
"id": "wamid.HBgLMzgwNjM5..."
}sentAccepted for sending — not yet on the customer's phone
idStore it; delivery callbacks and
hookInfoare keyed on this
Common errors
| Status | API response | Cause | Fix |
|---|---|---|---|
| 200 | Message was not sent: template is not defined | namespace, template or language is missing from the request body. | Send all three. Take namespace and the exact template name from GET /templates; language is an object: {"policy": "deterministic", "code": "en"}. |
| 200 | template name (…) does not exist in <language> | The template is approved in a different language than the one requested. | Use the exact language code the template was approved in (for example es_MX is not the same as es). Check it in GET /templates. |
| 200 | Message was not sent: provide chatId, phone, bsuid, or username | No recipient the channel could resolve. | Pass exactly one recipient: phone (country code plus number, digits only), chatId (for example [email protected]) or bsuid. |
