---
name: edge-merge-shift-coverage
title: "Edge Merge Shift Coverage"
description: "Manager texts need a closer tonight."
language: python
framework: flask
telnyx_products: [Edge Compute, Voice, Messaging]
integrations: [Merge HRIS]
channel: [voice, sms]
---

# Edge Merge Shift Coverage

> Also known as: shift coverage, schedule filling, employee availability, shift management.

Manager texts need a closer tonight. Edge worker checks HRIS schedule via Merge, calls available employees in priority order, negotiates, confirms via SMS to both parties.

## Why Telnyx

This example runs SMS, outbound voice calls, and AI inference over Telnyx's **AI Communications Infrastructure** -- a single private global network where messaging, programmable voice, and AI live together instead of being stitched across separate vendors. The inbound manager text, the priority-ordered employee calls with TTS negotiation, and the confirmation SMS to both parties all flow through one Telnyx account and one set of credentials, so a shift-coverage workflow stays low-latency and easy to operate end to end.

## Telnyx API Endpoints Used

- **Call Control: Gather Using Speak**: `POST /v2/calls/{id}/actions/gather_using_speak` -- [API reference](https://developers.telnyx.com/api/call-control/gather-using-speak)
- **Call Control: Speak (TTS)**: `POST /v2/calls/{id}/actions/speak` -- [API reference](https://developers.telnyx.com/api/call-control/speak)
- **Call Control: Hangup**: `POST /v2/calls/{id}/actions/hangup` -- [API reference](https://developers.telnyx.com/api/call-control/hangup)
- **AI Inference**: `POST /v2/ai/chat/completions` -- [API reference](https://developers.telnyx.com/api/inference/chat-completions)
- **Send Message (SMS)**: `POST /v2/messages` -- [API reference](https://developers.telnyx.com/api/messaging/send-message)
- **Create Outbound Call**: `POST /v2/calls` -- [API reference](https://developers.telnyx.com/api/call-control/create-call)

## Telnyx Webhook Events

This app handles these webhook events ([Call Control docs](https://developers.telnyx.com/docs/api/v2/call-control)):

- `call.answered` -- Call connected, app begins interaction with greeting
- `call.gather.ended` -- Caller input received (speech or DTMF), app processes response
- `call.speak.ended` -- TTS playback finished, transitions to next action
- `call.hangup` -- Call ended, cleans up session state and logs outcome

## Environment Variables

Copy `.env.example` to `.env` and fill in:

| Variable | Type | Example | Required | Description | Where to get it |
|----------|------|---------|----------|-------------|-----------------|
| `TELNYX_API_KEY` | `string` | `KEY0123456789` | **yes** | Telnyx API v2 key | [Portal](https://portal.telnyx.com/api-keys) |
| `TELNYX_PHONE_NUMBER` | `string` | `+18005551234` | **yes** | Telnyx phone number | [Portal](https://portal.telnyx.com/numbers/my-numbers) |
| `TELNYX_CONNECTION_ID` | `string` | `149440475714` | **yes** | Call Control app ID | [Portal](https://portal.telnyx.com/call-control/applications) |
| `MERGE_API_KEY` | `string` | `your-key` | **yes** | Merge.dev API key | [Merge](https://app.merge.dev/keys) |
| `MERGE_ACCOUNT_TOKEN` | `string` | `your-token` | **yes** | Merge linked account token | [Merge](https://app.merge.dev) |
| `AI_MODEL` | `string` | `moonshotai/Kimi-K2.6` | no | AI model | [Models](https://developers.telnyx.com/docs/inference/models) |
| `PORT` | `integer` | `5000` | no | Server port | -- |

## Setup

```bash
git clone https://github.com/team-telnyx/telnyx-code-examples.git
cd telnyx-code-examples/edge-merge-shift-coverage-python
cp .env.example .env
pip install -r requirements.txt
python app.py
```

### Webhook Configuration

1. Expose your local server: `ngrok http 5000`
2. Configure in [Telnyx Portal](https://portal.telnyx.com/call-control/applications):
   - Call Control Application -> Webhook URL -> `https://<id>.ngrok.io/webhooks/voice`

## API Reference

### `GET /shifts`

Shifts.

```bash
curl http://localhost:5000/shifts
```

**Response:**

```json
{"status": "ok", "service": "edge-merge-shift-coverage"}
```

### `GET /health`

Health.

```bash
curl http://localhost:5000/health
```

**Response:**

```json
{"status": "ok", "service": "edge-merge-shift-coverage"}
```


## Webhook Endpoints

### `POST /webhooks/voice`

Telnyx sends call events here. Your app processes them and responds with the next action.

**Events handled:**

- `call.answered` -- Call connected, app begins interaction with greeting
- `call.gather.ended` -- Caller input received (speech or DTMF), app processes response
- `call.speak.ended` -- TTS playback finished, transitions to next action
- `call.hangup` -- Call ended, cleans up session state and logs outcome

**Example payload:**

```json
{
  "data": {
    "event_type": "call.initiated",
    "id": "evt_123",
    "payload": {
      "call_control_id": "v3:abc123",
      "direction": "incoming",
      "from": "+12125551234",
      "to": "+18005559876"
    }
  }
}
```

## All Endpoints

| Method | Path | Purpose |
|--------|------|---------|
| `POST` | `/webhooks/sms` | Sms |
| `POST` | `/webhooks/voice` | Voice |
| `GET` | `/shifts` | Shifts |
| `GET` | `/health` | Health |

## Troubleshooting

| Issue | Likely cause | Fix |
|-------|--------------|-----|
| `401 invalid signature` on `/webhooks/sms` or `/webhooks/voice` | `TELNYX_PUBLIC_KEY` is missing, wrong, or the request was tampered with | Set `TELNYX_PUBLIC_KEY` to the Ed25519 public key from [Portal -> Keys & Credentials](https://portal.telnyx.com); it must be the base64 value, not the API key. |
| Webhooks never arrive / call never starts | The webhook URL is not reachable from Telnyx, or `ngrok` is down | Re-run `ngrok http 5000`, then point the Call Control Application webhook URL at `https://<id>.ngrok.io/webhooks/voice`. The manager-text SMS profile must point at `/webhooks/sms`. |
| App exits or calls fail with auth errors | A required env var is unset (`TELNYX_API_KEY`, `TELNYX_PHONE_NUMBER`, `TELNYX_CONNECTION_ID`) | Confirm `.env` is filled in from `.env.example`; `TELNYX_CONNECTION_ID` must be the Call Control Application ID used to place outbound calls. |
| `"Calling 0 available employees now."` | Merge returned no employees with phone numbers | Verify `MERGE_API_KEY` and `MERGE_ACCOUNT_TOKEN`, that the linked HRIS account has `ACTIVE` employees, and that those records include phone numbers. |

## Related Examples

- [shift-fill-engine-python](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/shift-fill-engine-python/README.md) -- standalone shift-fill workflow without the Edge/Merge layer
- [edge-merge-ai-receptionist-python](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/edge-merge-ai-receptionist-python/README.md) -- sibling Edge + Merge HRIS example using voice and AI
- [route-phone-calls-to-ai-agent-python](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/route-phone-calls-to-ai-agent-python/README.md) -- Call Control routing and AI-driven voice interaction
- [merge-employee-hotline-python](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/merge-employee-hotline-python/README.md) -- employee-facing voice line backed by Merge HRIS data

## Resources

- [Telnyx Developer Docs](https://developers.telnyx.com)
- [Call Control quickstart](https://developers.telnyx.com/docs/voice/call-control)
- [AI Inference docs](https://developers.telnyx.com/docs/inference)
- [Merge.dev API docs](https://docs.merge.dev)
- [Telnyx Portal](https://portal.telnyx.com)