Pre-visit documents checklist via WhatsApp API
The scenario sends the client a personalised WhatsApp template with a documents checklist before a visit.
Use case overview
The scenario sends the client a personalised WhatsApp template with a documents checklist before a visit. The message includes the client name, service, visit date, and checklist in the fourth variable. A static URL button opens booking details.
Template example
Hello, {{1}}! For your {{2}} on {{3}}, please bring: {{4}}
- {{1}}customer name
- {{2}}service or appointment type
- {{3}}visit date
- {{4}}documents checklist
- “View booking”button — fixed in the Meta template

When to use it
Reach for this scenario when an upcoming visit requires specific documents and the checklist cannot wait for the client to open email, SMS, or a portal — especially where there is no open WhatsApp conversation, so only an approved template can go out first. It fits healthcare and compliance visits, visa and legal appointments where missing papers delay the meeting, and integrators wiring CRM document rules into WhatsApp reminders.
Workflow
- Trigger
The scheduling system fires a pre-visit documents reminder event.
event·triggered - Capture event
The system resolves the client phone number and booking fields.
phone:"+…" - Build & send
A personalised template message is built with four body variables and a static URL button.
POST/sendTemplate - Delivered
The client receives the WhatsApp checklist notification.
delivered - Status tracked
Delivery result is logged for scheduling or CRM follow-up.
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_SERVICE="___" # {{2}} service name
TEST_BOOKINGDATE="___" # {{3}} booking date
TEST_ADDITIONALINFO="___" # {{4}} additional info
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=$TEST_CUSTOMERNAME" \
"TEST_SERVICE=$TEST_SERVICE" \
"TEST_BOOKINGDATE=$TEST_BOOKINGDATE" \
"TEST_ADDITIONALINFO=$TEST_ADDITIONALINFO"; 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}} service name → ${TEST_SERVICE}
# {{3}} booking date → ${TEST_BOOKINGDATE}
# {{4}} additional info → ${TEST_ADDITIONALINFO}
read -r -d '' PAYLOAD <<JSON || true
{
"phone": "${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": "${TEST_SERVICE}" },
{ "type": "text", "text": "${TEST_BOOKINGDATE}" },
{ "type": "text", "text": "${TEST_ADDITIONALINFO}" }
]
}
]
}
JSON
RESPONSE="$(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. |
