Micro DB Authentication: Local Data Security (2026)

Authentication overview

Micro DB, often referred to as lowdb, is a lightweight JSON-based database designed for local data storage within Node.js applications and web browsers. Unlike server-side databases or cloud services, Micro DB does not implement or require traditional authentication mechanisms such as API keys, OAuth tokens, or username/password combinations. Its operational model involves direct file access, meaning that authentication and authorization are managed by the host operating system's file permissions and the security context of the application running Micro DB.

The core principle is that if an application has permission to read and write to the JSON file that constitutes the Micro DB database, it has full access to the data. This makes securing Micro DB fundamentally different from securing a networked database. Instead of authenticating API requests, the focus shifts to securing the environment where the application and its database file reside. This approach simplifies development for local projects and mock APIs but necessitates careful consideration of the host system's security posture, as outlined in the official Micro DB documentation on GitHub.

Developers should prioritize securing the file system that hosts the Micro DB data file and ensuring the application itself adheres to secure coding practices to prevent unauthorized access or data manipulation. For applications requiring external access or robust authentication, Micro DB is typically used as an embedded component rather than exposing its data directly.

Supported authentication methods

As Micro DB does not inherently provide authentication methods, the concept of "supported methods" refers to the security measures external to the database itself that protect access to its data file. The primary mechanism is operating system-level file permissions. There are no direct API authentication methods like API keys, OAuth, or JWT because Micro DB operates as a local file rather than a networked service.

The table below summarizes the relevant security considerations:

For scenarios where Micro DB applications are deployed in environments like Google Cloud, Microsoft Azure, or AWS, securing the virtual machine or container running the application becomes the indirect method of "authenticating" access to the Micro DB instance. This involves configuring IAM policies, network security groups, and disk encryption as described in cloud provider documentation like the Google Cloud data protection overview or AWS EC2 security documentation.

Getting your credentials

Micro DB does not require or issue specific credentials like API keys, client IDs, or secret keys for its operation. The "credentials" in this context are synonymous with the permissions granted to the application process that runs Micro DB. To "get your credentials" for Micro DB, you need to ensure the following:

1. File System Permissions: The user account or service account running your application must have appropriate read and write permissions for the directory containing your Micro DB .json file. For example, on a Linux system, you might use chmod and chown commands to set permissions. On Windows, you would configure NTFS permissions via the file properties.
2. Application Security Context: The application itself should be run with the minimum necessary privileges. Granting excessive permissions to the application process can create security vulnerabilities.
3. Environment Variables (Optional for sensitive data): If your application needs to connect to other services (e.g., retrieving data to populate Micro DB), those services might require credentials. These should be managed securely, often through environment variables or secret management services, not stored directly within the Micro DB file.

Refer to the Micro DB official documentation for examples of how to initialize and use the database, which inherently demonstrates the direct file access model.

Authenticated request example

Since Micro DB operates through direct file access and not network requests, there isn't a traditional "authenticated request example" in the sense of an HTTP request with an Authorization header. Instead, interaction with Micro DB occurs through its JavaScript API, and the "authentication" is implicit in the application's ability to execute code and access files on the host system.

Here's a conceptual example demonstrating how an application interacts with Micro DB, illustrating that no explicit authentication token is passed:

import { Low, JSONFile } from 'lowdb';

// 1. Define the path to the database file
const file = 'db.json';

// 2. Configure the database adapter (reads/writes directly to the file)
const adapter = new JSONFile(file);
const db = new Low(adapter);

async function runDbOperations() {
  // 3. Read data from db.json (no authentication token needed)
  await db.read();

  // Initialize database if it's empty
  db.data = db.data || { posts: [], users: [] };

  // 4. Access data (requires file access permissions for the running process)
  console.log('Current posts:', db.data.posts);

  // 5. Write data (requires file write permissions)
  db.data.posts.push({ id: 1, title: 'Micro DB is simple' });
  await db.write();

  console.log('Posts after adding:', db.data.posts);
}

runDbOperations().catch(console.error);

In this example, the db.read() and db.write() operations succeed because the Node.js process executing this code has the necessary file system permissions to interact with db.json. If the operating system denied access to db.json for the running user, these operations would fail with a file permission error, not an authentication error from Micro DB itself.

Security best practices

While Micro DB simplifies data storage, its file-based nature requires specific security considerations, particularly when used in any environment beyond purely isolated local development. Adhering to these best practices helps mitigate common risks:

• Restrict File Permissions: Apply the principle of least privilege to your database file. Ensure that only the application process that needs to access the Micro DB .json file has read and write permissions. Other users or processes on the system should not have access. For example, on Unix-like systems, set permissions to 600 (read/write for owner only) or 640 (read/write for owner, read for group, no access for others) if group access is necessary.

• Secure the Host Environment: The security of your Micro DB data is directly tied to the security of the operating system or container hosting your application. Implement strong security practices for the host, including:

  • Regular patching and updates.
  • Firewall rules to restrict network access.
  • Strong user account policies and password management.
  • Using containerization (e.g., Docker) with hardened images to isolate the application and its data.

• Avoid Storing Sensitive Data: Due to its local, file-based nature, Micro DB is generally not recommended for storing highly sensitive data like personally identifiable information (PII), financial records, or credentials without additional encryption at the application or disk level. If sensitive data must be stored, ensure it is encrypted before being written to the database file and decrypted upon retrieval. The W3C's security FAQs emphasize the importance of data protection strategies beyond basic access control.

• Input Validation and Sanitization: Any data written to Micro DB should be properly validated and sanitized to prevent injection attacks or data corruption. While Micro DB itself is not a SQL database, malicious input could still lead to application logic errors or unintended data structures.

• Protect Configuration Files: If your Micro DB application uses configuration files that point to the database file or contain other sensitive settings, ensure these are also secured with appropriate file permissions.

• Backups: Regularly back up the Micro DB .json file, especially in production or critical development environments, to prevent data loss due to system failure or accidental deletion. Ensure backups are stored securely.

• Application-Level Access Control (If Applicable): If your application serves multiple users, implement your own authentication and authorization logic at the application layer. This would determine which users can read or modify specific data within the Micro DB, as the database itself offers no such features.

• Encrypt Data at Rest (Full Disk Encryption): For maximum protection against physical theft or unauthorized access to the host machine, consider implementing full disk encryption (FDE) for the entire drive where the Micro DB file resides. This ensures that even if the raw disk is accessed, the data remains unreadable without the encryption key.