WhatsApp Business API for post-purchase review request
The scenario sends the client a personalized WhatsApp template after a purchase when a review is due, asking them to rate the product and share feedback.
Use case overview
The scenario sends the client a personalized WhatsApp template after a purchase when a review is due, asking them to rate the product and share feedback. The message includes the client name, order number, and product name. A static URL button opens the review form or product page.
Template example
Hello, {{1}}! Your order #{{2}} for "{{3}}" is complete. Please share your review — it takes about a minute.
- {{1}}customer name
- {{2}}order number
- {{3}}product name
- “Leave review”button — fixed in the Meta template

When to use it
Use this scenario when an order reaches a post-purchase window and the team needs a structured product review request on WhatsApp rather than a manual agent message or email-only follow-up. It fits e-commerce and D2C brands collecting star ratings after delivery, marketplaces tying review asks to order number and product name, and agencies connecting review triggers from Shopify, WooCommerce, or custom OMS workflows.
Workflow
- Build & send
The e-commerce platform fires a post-purchase review trigger when the order is eligible.
POST/sendTemplate - Capture event
The system resolves the recipient phone number and order fields.
phone:"+…" - A personalized template message
A personalized template message is built with three body variables and a static URL button.
POST/sendTemplate - Delivered
The client receives the WhatsApp review request with order and product context.
delivered - Status tracked
Delivery result is logged; review submission is tracked outside WhatsApp.
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_PRODUCTNAME="___" # {{3}} product name
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_PRODUCTNAME=$TEST_PRODUCTNAME"; do
val="${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}} product name → ${TEST_PRODUCTNAME}
read -r -d '' PAYLOAD <<JSON || true
{
"phone": "${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_PRODUCTNAME}" }
]
}
]
}
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,
"id": "wamid.HBgLMzgwNjM5...",
"message": "Message accepted for delivery"
}sentAccepted for sending — not yet on the customer's phone
idStore it; delivery callbacks and
hookInfoare keyed on this
Delivery itself arrives later, as a separate callback. Register a webhook (POST …/webhook) and 1MSG POSTs status updates to your HTTPS endpoint in a top-level hooks[] payload.
{
"hooks": [
{
"id": "gBGGeSaGViBfAgnlzOSHEwK9O6F",
"type": "message",
"status": "sent",
"timestamp": "1654864094",
"recipient_id": "556123122026"
}
]
}statussent,delivered,read— or a failure status when applicableidCorrelates the callback with the
idreturned by the send calltimestampUnix seconds, as a string
If you would rather not receive callbacks, poll GET {base}/{channel}/hookInfo?messageId=<id> instead. In practice delivery often completes within seconds — but the API contract does not guarantee it, so never block a flow waiting on it.
Common errors
| Status | Response | Cause |
|---|---|---|
| 200 | Message was not sent: template is not defined | namespace, template or language missing from the request body. |
| 200 | template name (…) does not exist in <language> | The template is approved in a different language than the one requested. |
| 200 | Message was not sent: provide chatId, phone, bsuid, or username | No recipient the channel could resolve. |
| 403 | access denied | The token is wrong, or belongs to a different channel than the URL. |
| 429 | too many requests. please try later | The channel is over its send rate. |

