# Ticket Validation - REST Protocol

Source: https://apereo.github.io/cas/development/protocol/REST-Protocol-ServiceTicket-Validation.html

Service ticket validation is handled through the [CAS Protocol](https://apereo.github.io/cas/development/protocol/CAS-Protocol.html) via any of the validation endpoints such as `/p3/serviceValidate`.

```bash
GET /cas/p3/serviceValidate?service={service url}&ticket={service ticket}
```

## Unsuccessful Response

CAS will send a 400 Bad Request. If an incorrect media type is sent, it will send the 415 Unsupported Media Type.