Example deployment: CRM customer follow-up

The business problem

Follow-up speed decides conversion, but reps forget, emails go unopened, and the CRM timeline doesn't show what the customer actually received.

Recommended architecture

System trigger

Any CRM automation that can fire a webhook or HTTP request: Salesforce Flow, HubSpot Workflows, Zoho Deluge, Pipedrive webhooks, or Dynamics Power Automate. This example uses a generic middleware pattern that works with all of them.

SendiMessage API request

curl -sS https://api.sendimessage.com/v1/send-message \
  -H "X-API-Key: $SENDIMESSAGE_KEY" \
  -H "X-API-Secret: $SENDIMESSAGE_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "number": "+15555550123",
    "content": "Hi {{contact.first_name}}, thanks for reaching out — when works for a quick call this week?",
    "status_callback": "https://your-endpoint.example.com/status?crm=your_crm&contact_id={{contact.id}}&owner_id={{owner.id}}&workflow=lead_follow_up"
  }'
# → {
#   "status": "QUEUED",
#   "message_handle": "4e828182-a640-483f-bfe9-17ffcaa51d48",
#   "to": "+14155550123",
#   "service": null,
#   "is_outbound": true,
#   "error_message": null,
#   "date_sent": null
# }

Channel behavior and SMS fallback

Sales follow-up benefits from iMessage's conversational feel where supported; SMS fallback keeps coverage complete. iMessage delivery is available on supported messaging lines and destinations. Recipients without iMessage receive SMS when fallback is configured — never assume universal iMessage availability.

Incoming replies

Replies route deterministically: the metadata you attached comes back on receive, so middleware knows the record and the owning rep. Automatic CRM synchronization is not claimed — your middleware performs the write-back via the CRM's API.

// "outbound" event → your your_crm endpoint
// Verify the SendiMessage-Signature header (t={timestamp},v1=HMAC-SHA256 of
// "{timestamp}.{raw body}", keyed with your webhook secret), then use
// GET /v2/messages/{message_handle} for authoritative state and match it to
// your contact_id in your_crm.

Messaging-line setup

Typically one line per sales team or brand. Keep outreach and support on separate lines for clean reply routing.

Security checklist

• API key in server environment variables or a secrets manager — never in client code.
• Webhook signatures verified before any record is updated.
• Only the fields a message needs (phone, first name, reference id) leave your system.
• Consent state checked in middleware before every send — STOP replies update the CRM immediately.

Run the full implementation readiness checklist →

Pricing and managed onboarding

Per active line plus usage. Follow-up volume is usually modest — a single line covers most teams at the start. Every line goes through managed onboarding: use-case review, test line, credentials delivered securely, and guided production activation.