> ## Documentation Index
> Fetch the complete documentation index at: https://docs.turncall.io/llms.txt
> Use this file to discover all available pages before exploring further.

# A/B Testing

> Weighted traffic routing on phone numbers

Split traffic between agent versions to test performance. Routing is deterministic by caller number (SHA256 hash) — the same caller always gets the same variant.

## Set Weights

Weights must sum to 100:

```bash theme={null}
curl -X PUT http://localhost:8090/v1/phone-numbers/PHONE_ID/routing \
  -H "Authorization: Bearer tc_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "weights": [
      {"agent_id": "agent-v1-uuid", "weight": 80},
      {"agent_id": "agent-v2-uuid", "weight": 20}
    ]
  }'
```

## Check Routing

```bash theme={null}
curl http://localhost:8090/v1/phone-numbers/PHONE_ID/routing \
  -H "Authorization: Bearer tc_xxx"
```

Response:

```json theme={null}
{"mode": "weighted", "weights": [...]}
```

## Clear Test

Revert to single-agent routing:

```bash theme={null}
curl -X DELETE http://localhost:8090/v1/phone-numbers/PHONE_ID/routing \
  -H "Authorization: Bearer tc_xxx"
```

## How It Works

1. Inbound call arrives on a phone number with weighted routing
2. TurnCall hashes the caller's phone number (SHA256)
3. The hash determines which agent variant handles the call
4. Same caller always gets the same variant (deterministic)