01Case study
Missed Lead Responder
A missed call becomes an instant SMS reply, an owner alert and a logged lead.
Offered asMissed-call responderEnquiry tracker
01The problem
A missed call is a lost customer.
For most local and service businesses, an unanswered phone is one of the most expensive gaps in the whole operation. A caller who doesn't leave a voicemail has usually just tried the next business on the list.
By the time anyone notices the missed call sitting in the log, the window to win that customer back has usually closed. The fix isn't answering every call. It's making sure nobody who calls is left without a reply.
02Replay
One missed call, start to finish
Simulated data, real system flow. Switch between the customer's phone and the owner's side: both run on the same clock.
Caller's phone
- Incoming call · 10:42••• 0182Unanswered
Hi, it's Northgate Plumbing. Sorry we missed your call! What can we help with? Reply here and we'll get straight back to you.
Hi, the kitchen sink is leaking under the cabinet. Can someone come today?
Thanks, that's logged. So we can send someone today, reply with your address and a time that suits you.
22 Elm Row, flat 3. Any time after 2pm.
Got it, thank you. Your request is logged, and Northgate Plumbing will call to confirm the visit.
Owner · Northgate Plumbing
- Lead Deskbot
Missed call from ••• 0182. Auto-reply sent. No response yet.
Call backMark handled - Leads
Time Caller Need Visit Status 10:42 ••• 0182 Leaking kitchen sink 22 Elm Row, after 2pm Ready to book - Owner pinged again with the reply
- Owner pinged: address and visit time are in
- Reminder set if the lead stays unhandled
03How it works
Missed call in. Structured lead out.
- 01
The call goes unanswered
The business line runs through Twilio. The moment a call ends without being picked up, a webhook fires to the FastAPI service.
- 02
The caller gets a reply within seconds
An SMS goes back automatically: it acknowledges the call, answers the obvious first question, and invites a reply.
- 03
The owner is alerted on Telegram
A bot message arrives with the caller's number and two buttons, Call back and Mark handled, so it can be dealt with from anywhere.
- 04
A lead row lands in Google Sheets
Number, time and status are written to the business's own sheet, so there's always a live list of who called and where each one stands.
- 05
Replies update the row
When the caller texts back, the row changes to Replied with their reason, and the owner is pinged again.
- 06
Unhandled leads come back round
If a lead is still open, a reminder fires, so nothing drifts between "the phone rang" and "someone followed up."
04Stack
What it runs on
- Twilio
- The phone line: missed-call webhooks, outbound and inbound SMS
- FastAPI
- The service that receives every event and decides what happens next
- MongoDB
- Lead state: who called, what's been sent, what's still open
- Telegram Bot API
- Owner alerts with inline Call back and Mark handled actions
- Google Sheets
- The lead list the business actually looks at
What it doesn't do
It doesn't answer the call or hold a live conversation. It gets the first reply out fast and makes sure a person follows up.
Try the phone side
+1 470 470 6323 Call to try our IVR and missed-call responder. Calling from India needs international calling enabled on your SIM.A self-initiated project, built to prove the pattern before bringing it to a client. The system is complete and tested end to end; connecting it to a specific business's number and accounts is a standard onboarding step.
05Walkthrough
The real thing, recorded.
The replay above uses simulated data. This is the system itself, walked through end to end on video.
06Source
Read the code
The repository is public: the webhooks, the data model, the deploy setup. The Notion write-up covers the design decisions.
Want this running for your business?
Connecting it to your own number and accounts is a standard onboarding step. Tell us how your business works and we'll tell you what it needs.