Send a contact card via WhatsApp API (sendContact)

This scenario sends a WhatsApp contact card with sendContact during the 24-hour customer service window.

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.

WhatsApp Business API for specialist handoff — share contact card

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.

Fewer wrong-number calls

sendContact delivers the specialist display name and E.164 phone as a vCard in the active session, so the client taps to call instead of retyping digits from a plain-text message.

Contact saved in one tap

The card opens WhatsApp's native save flow, so the specialist name and number land in the client's phone book without manual entry.

Handoff stays in the same thread

The message goes out inside the open session after an agent marks the ticket ready for escalation, so the client never leaves the support chat to hunt for a number elsewhere.

No manual number sharing by agents

Your backend loads the specialist name and phone from the integration contract when escalation is approved, so front-line agents do not copy-paste or dictate digits.

Workflow

Trigger
An agent marks the ticket ready for specialist escalation.
event · triggered
Capture event
Your backend loads the specialist display name and phone number.
phone: "+…"
Build & send
sendContact delivers the contact card in the active session.
POST /send_contact
Delivered
The client saves or calls the specialist from WhatsApp.
delivered

Technical implementation

Prerequisites

1MSG API Key · How to get API Key
WhatsApp Business account · How to Connect WABA
Open 24-hour session window · How the 24-hour window works
Customer opt-in · How to Manage Customers Consent
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.

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: 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.
401	token is required	The request has no token.	Add your channel token as the token query parameter: https://api.1msg.io/{channelId}/{method}?token=…
429	too many requests. please try later	The channel is over its send rate.	Queue messages on your side and retry with exponential backoff.