# Certificates

> Manage the mTLS and public domain certificates the deployment depends on.

Source: https://joinnasnet.com/en/guides/nasnet-linux/certificates/
Last updated: 2026-08-14

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## Overview

**Certificates** is the inventory of every certificate the panel knows about,
split into internal mTLS certificates and public domain certificates. It exists
so certificate expiry never surprises you: you can see what is issued, what is
about to lapse, and renew or revoke without leaving the panel. The panel also
publishes seconds-until-expiry per domain as a Prometheus metric, so you can
alert on it externally.

## Before you start

- Public certificates issued through ACME renew automatically when
  `ACME_AUTO_RENEW` is on; you should rarely need to renew one by hand here.
- Revoking is not the same as deleting. Revoke invalidates the certificate;
  delete only removes the record.

## Steps

1. Open **Certificates** from the sidebar.
2. Switch between the **Internal** and **Public** tabs depending on which set
   you are working on.
3. Search by name, or scan the stats row at the top for the shape of the
   inventory.
4. Switch between **List View** and **Timeline View**, where the timeline lays
   certificates out by expiry, which is the faster way to spot what lapses next.
5. Click a certificate to open its details.
6. Use **Select Multiple** to act on several certificates at once.
7. Issue a new certificate, or renew, revoke or delete an existing one. Each of
   these asks for confirmation.

## Reference

| Tab | What it holds |
| --- | ------------- |
| Internal | mTLS certificates used inside the deployment. |
| Public | Certificates for your public domains. |

| Action | Effect |
| ------ | ------ |
| Issue | Requests a new certificate. |
| Renew | Re-issues an existing certificate before it expires. |
| Revoke | Invalidates the certificate. |
| Delete | Removes the certificate record. |

A banner at the top of the page reports the certificate authority's status when
there is something to say about it.

## Related

- [Domains](/en/guides/nasnet-linux/certificates/domains/)
- [TLS and domains](/en/guides/nasnet-linux/tls-and-domains/)
- [Metrics and monitoring](/en/guides/nasnet-linux/monitoring/)