The Last Step Won’t Work! · Brendan's AI Community

Ryan Smith

16d • General discussion 💬

The Last Step Won’t Work!

**NEED HELP: Complex Call Routing System - Transfers Not Reaching Intended Phone Numbers**

**THE SYSTEM I’VE BUILT:**

I’m working on an emergency call routing system for a disaster restoration company. Here’s how it’s supposed to work:

**Tech Stack:**

- **Retell AI** - AI phone agent (“Julia”) that answers calls

- **Relay.app** - Handles the routing logic via webhooks

- **Google Sheets** - Stores zip codes, schedules, and contact info

**How It Should Work:**

1. Customer calls the emergency line

1. Julia (AI agent) answers, collects zip code and emergency info

1. Julia triggers a Custom Function that calls my Relay webhook

1. Relay looks up the zip code → determines EAST or WEST region

1. Relay checks the current time/day to determine routing:

- **Weeknights** (Mon-Thu 4:30 PM - 7:30 AM) → Project Coordinator

- **Weekends** (Fri 4:30 PM - Mon 7:30 AM) → Project Manager from weekly rotation

1. Relay returns the correct phone number to Retell

1. Julia does a warm transfer to that number

**THE PROBLEM I’M EXPERIENCING:**

The system logic works - Relay correctly identifies the region, time, and which person should get the call. BUT when Julia tries to transfer, one of these happens:

1. **Call goes straight to voicemail** (phone never rings)

1. **Long silence, then disconnects**

1. **Operator message “call cannot be connected”**

1. **System pulls from FALLBACK data** instead of the correct coordinator

**WHAT I’VE ALREADY TRIED:**

✅ Phone numbers formatted correctly in E.164 format (+12085551234)

✅ Outbound calling ENABLED in Retell phone number settings

✅ Webhook URL is correct and Relay receives the calls

✅ Custom Function in Retell is configured with proper JSON schema

✅ Testing with my own phone numbers (so I know they work)

✅ Verified the Google Sheets lookup is finding the right person/number

**ADDITIONAL COMPLEXITY:**

I also battled a **timestamp/timezone bug** where Retell was sending incorrect UTC timestamps to my webhook, causing Sunday night calls to be tagged as Monday morning (business hours). I worked around this by having my Relay workflow generate the current Mountain Time instead of trusting Retell’s timestamp.

**TECHNICAL DETAILS:**

The Relay webhook receives:

```json

{

"call_datetime": "2025-11-20T04:12:00Z",

"zip_code": "83401",

"caller_phone": "+12085551234"

}

```

And returns:

```json

{