> For the complete documentation index, see [llms.txt](https://docs.toolkit.equs.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.toolkit.equs.ai/standards/api/authentication.md).

# Authentication

Get an access token with your Client ID and Secret, and use it to call the EQUS APIs securely from your server.

Three steps to your first API call 🔑 Get a token, use it, renew it.

Your back end calls the platform APIs as your **Tenant**. It proves who it is with the **Client ID** and **Client Secret** you received when you set up your account (see [Registration](/standards/onboarding/registration.md)), using the standard OAuth 2.0 **Client Credentials** flow: exchange the credentials for a short-lived access token, then send that token with every API call.

### 1. Get an access token 🎟️

Send your client credentials to the token endpoint as a form-encoded `POST`:

```bash
curl -X POST 'https://auth.us.equs.ai/realms/agents/protocol/openid-connect/token' \
  -d 'grant_type=client_credentials' \
  -d 'client_id=<CLIENT_ID>' \
  -d 'client_secret=<CLIENT_SECRET>'
```

The response is a standard OAuth 2.0 token response. The fields you need:

| Field          | Meaning                                |
| -------------- | -------------------------------------- |
| `access_token` | The token to send with your API calls  |
| `expires_in`   | How many seconds the token stays valid |
| `token_type`   | Always `Bearer`                        |

### 2. Call the APIs 📡

Send the token in the `Authorization` header of every request to the [Control API](/api/control-api.md) and the [Integration API](/api/integration-api.md):

```bash
curl 'https://control-api.us.equs.ai/api/v1/issuers' \
  -H 'Authorization: Bearer <ACCESS_TOKEN>'
```

The token identifies your Tenant, so every call is scoped to your own Issuers, Verifiers, schemas and credentials. You don't need to send the optional `x-tenant-id` header shown in the API reference.

### 3. Renew the token 🔄

Tokens are short-lived, and this flow has no refresh token. When a token is about to expire, request a new one with the same call. Cache the token and reuse it until then, rather than requesting a new one for every API call.

A call made with an expired or invalid token is rejected with `401 Unauthorized`.

### Keep the secret on your back end 🤫

* Call the token endpoint and the protected APIs only from your back end. Never put the Client Secret or an access token in a browser, a mobile app or a public repository.
* Embedded UI never holds your credentials: the calls that need them go through your back end.
* Keep the secret in a secrets manager, not in code or in configuration files under source control.

### If the secret is lost or exposed 🚨

Generate a new one in the [Operator Portal](https://portal.us.equs.ai/) under **Instructions → APIs**, then update your back end with it. Your Client ID stays the same.

{% hint style="info" %}
If your Tenant's access has an end date, your client credentials stop working when it passes. The Operator Portal shows the time remaining.
{% endhint %}

### Next steps 🚀

<table data-view="cards"><thead><tr><th></th><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><h3><i class="fa-plug" style="color:$primary;">:plug:</i></h3></td><td><strong>Integration API</strong></td><td>Start and manage Issuance and Presentation flows from your back end.</td><td><a href="/api/integration-api.md">Integration API</a></td></tr><tr><td><h3><i class="fa-sliders" style="color:$primary;">:sliders:</i></h3></td><td><strong>Control API</strong></td><td>Set up Issuers, Verifiers and schemas, and revoke credentials.</td><td><a href="/api/control-api.md">Control API</a></td></tr><tr><td><h3><i class="fa-gauge" style="color:$primary;">:gauge:</i></h3></td><td><strong>Rate Limits</strong></td><td>Know the limits your API calls run under.</td><td><a href="/standards/api/rate-limits.md">Rate Limits</a></td></tr></tbody></table>


---

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