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

# Join Session

> Join a voucher session as the payer.

`POST /api/v1/vouchers/sessions/:sessionId/session-join`

After the payee opens a session, the payer joins it from their wallet. This links the payer's identity to the session so vouchers can be reserved and resolved within it.

## Parameters

### Path

| Name        | Type     | Required | Description            |
| ----------- | -------- | -------- | ---------------------- |
| `sessionId` | `string` | Yes      | The session ID to join |

### Body

No body parameters required.

## Request example

```shell theme={null}
curl --request POST 'https://payments.bleepay.com/api/v1/vouchers/sessions/ses_xyz/session-join' \
  --header 'Authorization: Bearer <payer_token>' \
  --header 'Content-Type: application/json' \
  --data '{}'
```

## Response

### Response schema

Returns the updated session object with the payer joined.

### Error responses

| Status | Code             | Description                           |
| ------ | ---------------- | ------------------------------------- |
| `400`  | `already_joined` | Payer has already joined this session |
| `400`  | `session_closed` | Cannot join a closed session          |
| `401`  | `unauthorized`   | Missing or invalid bearer token       |
| `404`  | `not_found`      | Session not found                     |