Inactive user reminder: WhatsApp template via API

The scenario sends the client a personalised WhatsApp template when they have been inactive or stalled mid-process for a configured period.

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Use case overview

The scenario sends the client a personalised WhatsApp template when they have been inactive or stalled mid-process for a configured period. The message includes the client name and what they have not yet completed. A static URL button opens the portal or continue page.

Template example

Hello, {{1}}! We noticed you have not yet completed {{2}}. If you would like to continue — we are ready to help and answer your questions at any time.

Continue

{{1}}
customer name
{{2}}
incomplete action or process (e.g. account setup, order checkout, document upload)
“Continue”
button — fixed in the Meta template

WhatsApp Business API for client inactivity notification

When to use it

Reach for this scenario when a client registered, started onboarding, or stalled mid-purchase and has gone quiet past your inactivity threshold — and you need to nudge them back before they churn without an open WhatsApp chat. It fits SaaS teams finishing setup flows, e-commerce stores chasing cart or checkout abandonment, and agencies wiring CRM inactivity rules or product analytics into WhatsApp outbound.

Fewer silent churns

Two body variables carry the client's name and the process they have not finished, so the reminder names what stalled instead of sending a generic blast.

Re-engagement without email or calls

An approved WhatsApp template can reach the client when there is no open session, so the nudge lands in a channel they already use instead of a mailbox they ignore or a support call.

One tap back to the stalled step

The Continue URL button is fixed in the Meta template and opens the portal or continue page, so the client returns to the flow from the chat without hunting for a link.

No manual chase lists

CRM, analytics, or a workflow fires the send when inactivity crosses the threshold and resolves phone plus stalled-action context, so no rep rebuilds segments or retypes reminders.

Delivery logged for follow-up

The delivery result is logged after send for CRM or analytics follow-up, and errors are handled according to platform rules.

Workflow

Trigger
CRM, analytics, or workflow detects inactivity beyond the threshold.
event · triggered
Capture event
The system resolves the recipient phone number and stalled action context.
phone: "+…"
Build & send
A personalised template message is built with two body variables and a static URL button.
POST /sendTemplate
Delivered
The client receives the WhatsApp inactivity reminder.
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_INCOMPLETEACTION="___"         # {{2}} incomplete action

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=$TEST_CUSTOMERNAME" \
            "TEST_INCOMPLETEACTION=$TEST_INCOMPLETEACTION"; 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}} incomplete action → ${TEST_INCOMPLETEACTION}
read -r -d '' PAYLOAD <<JSON || true
{
  "phone": "${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_INCOMPLETEACTION}" }
      ]
    }

  ]
}
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.

200 OKResponse

{
  "sent": true,
  "message": "Sent to [email protected]",
  "description": "Message has been sent to the provider",
  "id": "wamid.HBgLMzgwNjM5..."
}

sent
Accepted for sending — not yet on the customer's phone
id
Store it; delivery callbacks and hookInfo are keyed on this

Delivery statuses and webhooks →

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.