# Inicio de sesión

El proceso de autenticación para el Social Service implica interactuar con el [Matrix server](https://matrix.org/), usado internamente para el subsistema de chat privado. Los usuarios deben iniciar sesión en Matrix usando su address, firmando una operación fetch para obtener un token de autenticación. Este token se utiliza luego para autorizar las interacciones con el Social Service.

### HTTP Request

Para adquirir el token de autenticación, como [la documentación de Matrix indica](https://spec.matrix.org/v1.3/client-server-api/#login), se debe realizar una solicitud POST a la siguiente URL: `https://social.decentraland.org/_matrix/client/r0/login` como en el ejemplo siguiente.

Para iniciar sesión en Matrix, necesitas crear y firmar un mensaje con AuthChain.

#### Request Body

```json
{
  "auth_chain": authChain,
  "identifier": {
    "type": "m.id.user",
    "user": address
  },
  "timestamp": timestamp.toString(),
  "type": "m.login.decentraland"
}
```

#### Response Body

```json
{
  "user_id": "@0x123abC:decentraland.org",
  "social_user_id": "0x123abC",
  "access_token": "syt_SomETokEN",
  "device_id": "FRFREGRG",
  "home_server": "decentraland.org",
  "well_known": {
      "m.homeserver": {
          "base_url": "https://synapse.decentraland.org/"
      }
  }
}
```

El token de autenticación, presente en el `access_token` campo, es necesario para interacciones posteriores con el Social Service.

### JS Code Example

```javascript
import fetch from 'cross-fetch'
import { AuthIdentity, Authenticator } from '@dcl/crypto'

export async function getMatrixToken(matrixUrl: string, address: string, identity: AuthIdentity): Promise<string> {
  const timestamp = Date.now()
  const authChain = Authenticator.signPayload(identity, timestamp.toString())

  try {
    const response = await fetch(`${matrixUrl}/_matrix/client/r0/login`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        auth_chain: authChain,
        identifier: {
          type: 'm.id.user',
          user: address
        },
        timestamp: timestamp.toString(),
        type: 'm.login.decentraland'
      })
    })

    if (response.ok) {
      const responseBody = await response.json()
      return responseBody.access_token
    } else {
      throw new Error(`Matrix server responded with a ${response.status} status code`)
    }
  } catch (error) {
    throw new MatrixLoginError(isErrorWithMessage(error) ? error.message : 'Unknown error')
  }
}
```

Code from [social-rpc-client-js](https://github.com/decentraland/social-rpc-client-js/blob/main/src/client.ts#L14)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.decentraland.org/contributor/contributor-es/servicio-social/login.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.