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

# Hangup Reasons

> Understanding call termination reasons in CallKaro AI

## What are Hangup Reasons?

Hangup reasons are status codes that indicate why a call ended or failed to connect. Every call in CallKaro AI is assigned a hangup reason that helps you understand the outcome of the call attempt.

The `hangup_reason` field is included in the webhook payload sent to your server after each call ends, allowing you to process and respond to different call outcomes programmatically.

## Hangup Reason Values

Below is a comprehensive table of all possible hangup reasons:

| Value                    | Description                                                      |
| ------------------------ | ---------------------------------------------------------------- |
| `CLIENT_INITIATED`       | Call was picked and hungup by the client                         |
| `PARTICIPANT_REMOVED`    | Call was picked and hungup by the AI Agent                       |
| `SESSION_TIMEOUT`        | Call was picked and reached maximum duration, set for that agent |
| `VOICEMAIL_DETECTED`     | Call was picked and reached voicemail                            |
| `USER_REJECTED`          | Call was rejected by the client                                  |
| `USER_UNAVAILABLE`       | Call rang but client didn't answer                               |
| `USER_UNRESPONSIVE`      | Call not rang                                                    |
| `INVALID_PHONE_NUMBER`   | Call triggered on invalid phone number                           |
| `UNKNOWN`                | Unknown hangup reason                                            |
| `OUTSIDE_TRIGGER_WINDOW` | Call attempted outside of the allowed window                     |
| `DELETED_SCH_CALL_ALL`   | All scheduled call instances were deleted                        |
| `DELETED_SCH_CALL_ONE`   | A single scheduled call instance was deleted                     |
| `PRE_CALL_FN_FAILED`     | Pre-call function execution failed                               |

## Categorizing Hangup Reasons

### Successful Call Completion

These reasons indicate the call was successfully connected:

* `CLIENT_INITIATED` - Normal call completion where the client ended the call
* `PARTICIPANT_REMOVED` - AI agent intentionally ended the call (e.g., conversation completed)
* `SESSION_TIMEOUT` - Call reached the configured maximum duration limit

### Voicemail

* `VOICEMAIL_DETECTED` - Call was answered but went to voicemail

### No Answer / Unreachable

These reasons indicate the client didn't answer or couldn't be reached:

* `USER_REJECTED` - Client actively declined the call
* `USER_UNAVAILABLE` - Phone rang but wasn't answered
* `USER_UNRESPONSIVE` - Call didn't ring (network/carrier issues)

### Configuration / System Issues

These reasons indicate problems with call setup or configuration:

* `INVALID_PHONE_NUMBER` - Phone number format is invalid or non-existent
* `OUTSIDE_TRIGGER_WINDOW` - Call attempted outside configured time window
* `PRE_CALL_FN_FAILED` - Pre-call function failed to execute properly

### Cancelled Calls

* `DELETED_SCH_CALL_ALL` - User cancelled all scheduled calls
* `DELETED_SCH_CALL_ONE` - User cancelled a specific scheduled call instance

### Other

* `UNKNOWN` - Rare cases where the reason couldn't be determined