---
title: Modules
---

ZITADEL provides the following modules.

## HTTP

This module provides functionality to call REST APIs.

### Import

```js
    let http = require('zitadel/http')
```

### `fetch()` function

This function allows to call HTTP servers. The function does NOT fulfil the [Fetch API specification](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API).

#### Parameters

- `url` *string*
- `options`
  **Optional**, containing custom settings that you want to apply to the request.
  - `headers`
    Overwrites the default headers. One of the following types
    - *map[string] string*
      The value is split into separate values after each comma `,`.
    - *map[string] Array of string*
      The value is a string array
    - default:
      - `Content-Type`: `application/json`
      - `Accept`: `application/json`
  - `method`
    The request method. Allowed values are `GET`, `POST`, `PUT`, `DELETE`
  - `body` *Object*
    JSON representation

#### Response

If the request was invalid, an error will be thrown, otherwise a Response object will be returned.

The object has the following fields and methods:

- `status` *number*
  Status code of response
- `body` *string*
  Return value
- `json()` *Object*
  Returns the body as JSON object, or throws an error if the body is not a json object.
- `text()` *string*
  Returns the body

### Example

```js reference
https://github.com/zitadel/actions/blob/main/examples/make_api_call.js#L10-L20
```

## Log

The log module provides you with the functionality to log to stdout.

### Import

```js
   let logger = require("zitadel/log")
```

### `log()`, `warn()`, `error()` function

The logger offers three distinct log levels (info, warn, and error) to effectively communicate messages based on their severity, enhancing debugging and troubleshooting efficiency.
Use the function that reflects your log level.

- log()
- warn()
- error()

### Example

```js
logger.log("This is an info log.")

logger.warn("This is a warn log.")

logger.error("This is an error log.")
```

#### Parameters

- `msg` *string*
  The message you want to print out.

## UUID

This module provides functionality to generate a UUID

### Import

```js
    let uuid = require("zitadel/uuid")
```

### `uuid.vX()` function

This function generates a UUID using [google/uuid](https://github.com/google/uuid). `vX` allows to define the UUID version:

- `uuid.v1()` *string*
  Generates a UUID version 1, based on date-time and MAC address
- `uuid.v3(namespace, data)` *string*
  Generates a UUID version 3, based on the provided namespace using MD5
- `uuid.v4()` *string*
  Generates a UUID version 4, which is randomly generated
- `uuid.v5(namespace, data)` *string*
  Generates a UUID version 5, based on the provided namespace using SHA1

#### Parameters

- `namespace` *UUID*/*string*
  Namespace to be used in the hashing function. Either provide one of defined [namespaces](#namespaces) or a string representing a UUID.
- `data` *[]byte*/*string*
  data to be used in the hashing function. Possible types are []byte or string.

### Namespaces

The following predefined namespaces can be used for `uuid.v3` and `uuid.v5`:

- `uuid.namespaceDNS` *UUID*
  6ba7b810-9dad-11d1-80b4-00c04fd430c8
- `uuid.namespaceURL` *UUID*
  6ba7b811-9dad-11d1-80b4-00c04fd430c8
- `uuid.namespaceOID` *UUID*
  6ba7b812-9dad-11d1-80b4-00c04fd430c8
- `uuid.namespaceX500` *UUID*
  6ba7b814-9dad-11d1-80b4-00c04fd430c8

### Example
```js
let uuid = require("zitadel/uuid")
function setUUID(ctx, api) {
  if (api.metadata === undefined) {
    return;
  }

  api.v1.user.appendMetadata('custom-id', uuid.v4());
}
```