cadmium-docs-legacy/protocol-spec/account-login-by-username.md

# Account login by username
## Introduction
This extension is intended for logging into user account on a server by username

## Message type identifiers
- `profile:login`  

## Error codes
- 0: limit exceed
- 1: user ID/password isn't valid

## Use cases
*Request*:
```json
{
    "id": "abcd",
    "type": "profile:login",
    "to": "cadmium.org",
    "payload": {
        "username": "juliet",
        "password": "romeo1"
    }
}
```

*Response*:
```json
{
    "id": "abcd",
    "type": "profile:login",
    "from": "cadmium.org",
    "ok": true,
    "payload": {
        "authToken": "3b5135a5-aff5-4396-a629-a254f383e82f",
        "deviceID": "ABCDEFG"
    }
}
```

*<b>Error</b> response*:
```json
{
    "id": "abcd",
    "type": "profile:login",
    "from": "cadmium.org",
    "ok": false,
    "payload": {
        "errCode": 1,
        "errText": "Username/password isn't valid"
    }
}
```

## Business Rules
None.

## JSON Schema
**Payload**

- Request:
```typescript
interface LoginRequestPayload {
    /**
     * The username of account which user wants to login
     */
    username: string,
    
    /**
     * Password of new account
     */
    password: string
}
```
- Response:
```typescript
interface LoginResponsePayload {
    /**
     * Authentication token which required for various user actions (UUID)
     */
    authToken: string,
    
    /**
     * Identifier of new user device (created by this login action)
     */
    deviceID: string
}
```