---
title: Timestamp Server
description: Configure timestamp servers and signature appearance for document signing.
---

import { Callout } from 'fumadocs-ui/components/callout';

Timestamp servers add a trusted timestamp to signatures, proving when the document was signed. This enables Long-Term Validation (LTV) and archival timestamps.

## Environment Variable

| Variable                                   | Description                                      |
| ------------------------------------------ | ------------------------------------------------ |
| `NEXT_PRIVATE_SIGNING_TIMESTAMP_AUTHORITY` | Comma-separated list of timestamp authority URLs |

## Configuration

```bash
NEXT_PRIVATE_SIGNING_TIMESTAMP_AUTHORITY=http://timestamp.digicert.com,http://timestamp.globalsign.com/tsa/r6advanced1
```

## Free Timestamp Servers

| Provider   | URL                                               |
| ---------- | ------------------------------------------------- |
| DigiCert   | `http://timestamp.digicert.com`                   |
| GlobalSign | `http://timestamp.globalsign.com/tsa/r6advanced1` |
| FreeTSA    | `https://freetsa.org/tsr`                         |
| Sectigo    | `http://timestamp.sectigo.com`                    |

<Callout type="info">
  Timestamp servers add latency to the signing process. Each server in the list is tried in order
  until one succeeds.
</Callout>

## Benefits of Timestamping

- Proves when the document was signed
- Signature remains valid after certificate expiration
- Required for some compliance standards
- Enables long-term archival

## Signature Appearance

### Contact Information

Set contact information embedded in PDF signatures:

```bash
NEXT_PUBLIC_SIGNING_CONTACT_INFO=support@example.com
```

If not set, defaults to your `NEXT_PUBLIC_WEBAPP_URL`.

### Legacy Signature Format

For compatibility with older PDF readers, use the legacy signature subfilter:

```bash
NEXT_PRIVATE_USE_LEGACY_SIGNING_SUBFILTER=true
```

| Subfilter             | Description                   | Default |
| --------------------- | ----------------------------- | ------- |
| `ETSI.CAdES.detached` | Modern CAdES-based signatures | Yes     |
| `adbe.pkcs7.detached` | Legacy PKCS#7 signatures      | No      |

Use the legacy format only if recipients report compatibility issues with older software.
