KYC data clarification request via WhatsApp API
The scenario sends the client a personalized WhatsApp template when identity or KYC verification cannot be completed until specific data is clarified.
Use case overview
The scenario sends the client a personalized WhatsApp template when identity or KYC verification cannot be completed until specific data is clarified. The message includes the client name, the verification process, and what needs to be updated or confirmed. A static URL button opens the verification portal or data-update form.
Template example
Hello, {{1}}! To complete your {{2}}, we need to clarify some details: {{3}} Please update the information using the button below. If you have questions — we are here to help.
- {{1}}customer name
- {{2}}verification process (e.g. identity verification, KYC check, document review)
- {{3}}clarification request detail (e.g. confirm your registered address and date of birth)
- “Clarify details”button — fixed in the Meta template

When to use it
Reach for this scenario when a client is mid identity or KYC verification and the review team cannot finish the check until specific data is clarified or corrected — and they have no open WhatsApp chat, so only an approved template can reach them. It fits fintech teams unblocking KYC queues, marketplaces resolving ambiguous seller identity data, and agencies wiring eKYC or compliance review events from CRM into WhatsApp outbound.
Workflow
- Customer acts
Verification review flags that specific client data must be clarified to complete the check.
user action - Capture event
The system resolves the recipient phone number and clarification fields.
phone:"+…" - Build & send
A personalized template message is built with three body variables and a static URL button.
POST/sendTemplate - Delivered
The client receives the WhatsApp clarification request with verification context and required detail.
delivered - Status tracked
Delivery result is logged; the client may update data via portal and continue in session after reply.
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_PROCESS="___" # {{2}} process name
TEST_REQUESTDETAIL="___" # {{3}} request detail
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=$TEST_CUSTOMERNAME" \
"TEST_PROCESS=$TEST_PROCESS" \
"TEST_REQUESTDETAIL=$TEST_REQUESTDETAIL"; do
val="${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}} process name → ${TEST_PROCESS}
# {{3}} request detail → ${TEST_REQUESTDETAIL}
read -r -d '' PAYLOAD <<JSON || true
{
"phone": "${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": "${TEST_PROCESS}" },
{ "type": "text", "text": "${TEST_REQUESTDETAIL}" }
]
}
]
}
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. |
