zitadel/apps/docs/content/guides/integrate/zitadel-apis/access-zitadel-system-api.mdx

---
title: Access ZITADEL System API
sidebar_label: System API
---

<Callout>
This guide focuses on the ZITADEL System API. To access the other APIs (Admin, Auth, Management), please checkout [this guide](./access-zitadel-apis).
The ZITADEL System API is currently only available for ZITADEL Self-Hosted deployments.
</Callout>

## System API User

The System API works superordinate over all instances. Therefore, you need to define a separate users to get access to this API.
You can do so by customizing the [runtime configuration](/self-hosting/manage/configure/configure#runtime-configuration-file).

To authenticate the user a self-signed JWT will be created and utilized.

You can define any id for your user. This guide will assume it's `system-user-1`.

**NOTE:** system user id cannot contain capital letters

## Generate an RSA keypair

Generate an RSA private key with 2048 bit modulus:

```bash
openssl genrsa -traditional -out system-user-1.pem 2048
```

and export a public key from the newly created private key:

```bash
openssl rsa -in system-user-1.pem -outform PEM -pubout -out system-user-1.pub
```

## Runtime Configuration

Provide the **public** key to the ZITADEL runtime configuration.

Either with the path to the key:

```yaml
SystemAPIUsers:
  - system-user-1:
      Path: /system-user-1.pub
```

or with a base64 encoded value of the key:

```yaml
SystemAPIUsers:
  - system-user-1:
      KeyData: <base64 encoded value of system-user-1.pub>
```

You can define memberships for the user as well:

```yaml
SystemAPIUsers:
 - system-user-1:
     Path: /system-user-1.pub
     Memberships:
       # MemberType System allows the user to access all APIs for all instances or organizations
       - MemberType: System
         Roles:
           - "SYSTEM_OWNER"
           - "IAM_OWNER"
           - "ORG_OWNER"
       # MemberType IAM and Organization let you restrict access to a specific instance or organization by specifying the AggregateID
       - MemberType: IAM
         Roles: "IAM_OWNER"
         AggregateID: "123456789012345678"
       - MemberType: Organization
         Roles: "ORG_OWNER"
         AggregateID: "123456789012345678"
 - superuser2:
     # If no memberships are specified, the user has a membership of type System with the role "SYSTEM_OWNER"
     KeyData: <base64 encoded key>     # or you can directly embed it as base64 encoded value
```

If you don't specify any memberships, you are allowed to access the whole [ZITADEL System API](/reference/api/system).

## Generate JWT

Similar to the OAuth 2.0 JWT Profile, we will create and sign a JWT. For this API, the JWT will not be used to authenticate against ZITADEL Authorization Server, but rather directly to the API itself.

The JWT payload will need to contain the following claims:

```json
{
  "iss": "<userid>",
  "sub": "<userid>",
  "aud": "<https://${CUSTOM_DOMAIN}>",
  "exp": <now+1h>,
  "iat": <now>
}
```

So for your instance running on `custom-domain.com` the claims could look like this:

```json
{
  "iss": "system-user-1",
  "sub": "system-user-1",
  "aud": "https://custom-domain.com",
  "iat": 1659957184,
  "exp": 1659960784
}
```

<Callout>
If your system is exposed without TLS or on a dedicated port, be sure to provide this in your audience, e.g. http://localhost:8080
</Callout>

### ZITADEL Tools

If you want to manually create a JWT for a test, you can also use our [ZITADEL Tools](https://github.com/zitadel/zitadel-tools). Download the latest release and run:

```bash
zitadel-tools key2jwt --audience=https://custom-domain.com --key=system-user-1.pem --issuer=system-user-1
```

## Call the System API

Now that you configured ZITADEL and created a JWT, you can call the System API and authenticate using the token:

```bash
curl --request POST \
  --url ${CUSTOM_DOMAIN}/system/v1/instances/_search \
  --header 'Authorization: Bearer {token}' \
  --header 'Content-Type: application/json'
```

You should get a successful response with a `totalResult` number of 1 and the details of your instance:

```json
{
	"details": {
		"totalResult": "1"
	},
	"result": [
		{
			"id": "172698969497928101",
			"details": {
				"sequence": "102",
				"creationDate": "2022-08-02T09:30:10.781068Z",
				"changeDate": "2022-08-02T09:30:10.781068Z",
				"resourceOwner": "172698969497928101"
			},
			"state": "STATE_RUNNING",
			"name": "ZITADEL",
			"domains": [
				{
					"details": {
						"sequence": "108",
						"creationDate": "2022-08-02T09:30:10.781068Z",
						"changeDate": "2022-08-02T09:30:10.781068Z",
						"resourceOwner": "172698969497928101"
					},
					"domain": "custom-domain.com",
					"primary": true
				},
				{
					"details": {
						"sequence": "108",
						"creationDate": "2022-08-02T09:30:10.781068Z",
						"changeDate": "2022-08-02T09:30:10.781068Z",
						"resourceOwner": "172698969497928101"
					},
					"domain": "zitadel-gnft7o.custom-domain.com",
					"generated": true
				}
			]
		}
	]
}
```

## Summary

* Create an RSA keypair
* Provide the public key with a userID to ZITADEL using the runtime configuration
* Authorize the request with a JWT signed with your private key

Where to go from here:

* [ZITADEL API Documentation](/apis/introduction)