> For the complete documentation index, see [llms.txt](https://docs.wallid.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.wallid.io/architecture/databases.md).

# Databases

Databases are a crucial component of WalliD CertiShop, serving as the **source of truth** for all certificate data and ensuring robust verification capabilities. Whenever someone verifies a certificate—whether through a QR code, the embedded PDF, or a link—the system checks the original data stored in the database. This enables retrieval of the **certificate's current state** (e.g., valid, revoked, or expired) or verification of the cryptographic proof through the chosen protocol.

#### Key Features of the Database:

1. **Certificate Data Storage**
   * All certificate data is securely stored in the database.
   * Provides easy access for verification queries.
2. **Verification Backbone**
   * Real-time verification connects to the database to ensure accuracy.
   * Cross-checks the current state of the certificate (valid, revoked, or expired).

### Database options

{% hint style="info" %}
**Check how you can use your own databases** [**here!**](/certishop-on-prem/intro.md)
{% endhint %}

WalliD CertiShop provides flexible storage options for certificate data with a cloud based solution managed by WalliD and an On Prem solution for issuers with high levels of privacy needs.

### **1. Cloud-Based Storage**

Managed by WalliD, ensuring high availability and security. Used by default.

### **2. On-Premises Storage**

Clients can host and manage their own databases for greater control.

<figure><img src="/files/iKBwvHfOfRRQ8OpizcUZ" alt=""><figcaption></figcaption></figure>

The On Prem architecture consists of the following components:

1. **CertiShop SDK:** Integrated into the client's website, it interacts with the Gateway or Webhooks.
2. **CertiShop API:** Centralized service that manages authentication and monitors all operations.
3. **Client-Gateway:** A pre-built service deployed in the client’s infrastructure to handle credential operations.
4. **Client's Data Layer:** The client's custom implementation for storing and managing credential data.

#### Communication Flow

1. CertiShop makes an initial call to the API to retrieve the On Prem configuration.
2. Based on the configuration:
   * The SDK calls the **webhooks** provided by the client.
   * OR interacts with the **Client-Gateway**, which handles operations locally.
3. Once an operation is complete, the Gateway or Webhooks notify the API for logging purposes.

#### Diagrams

* **Solution Overview:** Show SDK → API → Gateway → Client DB.
* **Communication Sequence:** Include an interaction diagram for both Webhook and Gateway flows.