Complete the invitation by registering the user and returning authentication tokens.

This is an atomic operation that validates the invitation, creates/updates the user account, activates organization membership, and returns JWT tokens for immediate login.

#### Request Body

**`email_key`** string required

Invitation key from the URL (`invkey_` prefixed).

**`full_name`** string required

User's full name (1-255 characters).

**`password`** string required

User's password (minimum 8 characters).

## Returns

Returns authentication tokens for immediate login.

## Notes

- Public endpoint used during registration flow
- Atomic operation: validates invitation, creates user, and returns tokens
- User is immediately logged in after successful completion
- Invitation is marked as used and cannot be reused


## Authorization

None (Public endpoint)


```bash
curl -X POST https://api.aitronos.com/v1/invitations/complete \
  -H "Content-Type: application/json" \
  -d '{
    "email_key": "invkey_f87d706d08504aacb5fec46316ce5f23",
    "full_name": "John Doe",
    "password": "SecurePass123!"
  }'
```


```python
import requests

response = requests.post(
    "https://api.aitronos.com/v1/invitations/complete",
    headers={"Content-Type": "application/json"},
    json={
        "email_key": "invkey_f87d706d08504aacb5fec46316ce5f23",
        "full_name": "John Doe",
        "password": "SecurePass123!"
    }
)

auth_data = response.json()
```


```javascript
const response = await fetch('https://api.aitronos.com/v1/invitations/complete', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    email_key: 'invkey_f87d706d08504aacb5fec46316ce5f23',
    full_name: 'John Doe',
    password: 'SecurePass123!'
  })
});

const authData = await response.json();
```

**Response:**

200 OK

```json
{
  "success": true,
  "user_id": "usr_abc123",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "refresh_token": {
    "token": "refresh_token_xyz789...",
    "expires_at": "2026-02-06T10:30:00Z"
  },
  "device_id": null
}
```

400 Bad Request

```json
{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request data",
    "status": 400
  }
}
```

404 Not Found

```json
{
  "success": false,
  "error": {
    "code": "INVITATION_NOT_FOUND",
    "message": "Invitation not found",
    "status": 404,
    "details": {
      "email_key": "invkey_f87d706d08504aacb5fec46316ce5f23"
    }
  }
}
```

422 Validation Error - Already Used

```json
{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invitation has already been used",
    "status": 422,
    "details": {
      "email_key": "invkey_f87d706d08504aacb5fec46316ce5f23",
      "used_at": "2026-01-05T20:30:00Z"
    }
  }
}
```

422 Validation Error - Invalid Password

```json
{
  "success": false,
  "error": {
    "code": "INVALID_PASSWORD_FORMAT",
    "message": "Password must be at least 8 characters long",
    "status": 422
  }
}
```