WhatsApp Business API for specialist handoff — share contact card

Use case overview

This scenario sends a WhatsApp contact card with sendContact during the 24-hour customer service window. The client receives the specialist name and phone without copying digits manually.

Template example

Please reach our specialist using the contact card below.

When to use it

Reach for this scenario when first-line support has approved escalation to a named specialist and the 24-hour customer service window is still open. It fits helpdesk workflows where a human expert must take over without losing chat context — especially when sharing a phone number as plain text would risk a wrong dial.

Workflow

1. Trigger

   An agent marks the ticket ready for specialist escalation.

   event · triggered

2. Capture event

   Your backend loads the specialist display name and phone number.

   phone: "+…"

3. Build & send

   sendContact delivers the contact card in the active session.

   POST /send_contact

4. Delivered

   The client saves or calls the specialist from WhatsApp.

   delivered

Technical implementation

Prerequisites

1. 1MSG API Key · How to get API Key
2. WhatsApp Business account · How to Connect WABA
3. Open 24-hour session window · How the 24-hour window works
4. Customer opt-in · How to Manage Customers Consent
5. Webhook endpoint · How to Set Up Webhooks

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)



# === Test data ===
TEST_PHONE="___"                 # client phone in international format

PHONE_NORM="$(printf '%s' "$TEST_PHONE" | tr -cd '0-9')"
URL="${API_BASE_URL%/}/${CHANNEL_ID}/sendContact"

# specialist display name (code_contract)
# specialist phone in E.164 format
read -r -d '' PAYLOAD <<JSON || true
{
  "phone": "${PHONE_NORM}",
  "contacts": [
    {
      "name": { "formatted_name": "Jane Specialist", "first_name": "Jane Specialist" },
      "phones": [{ "phone": "+12025550199", "type": "CELL" }]
    }
  ]
}
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 ] && [ "$ok" -eq 1 ]; then
  echo "Message sent to client."
else
  echo "$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"
}

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"
    }
  ]
}

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

FAQ