The .well-known directory is a standardized location in Web Hosting environments where web servers can place files that are discoverable by clients or user agents, such as web browsers or other applications. The specific use of .well-known/.well-known is a bit more niche:
- Purpose: The primary purpose of the .well-known/.well-known path is to provide a consistent place for hosting specific well-known URIs. This double-directory setup is intended for use cases where a service or protocol requires a file or directory to be located at a well-known location, but the content of that directory might itself be another well-known URI. This can be useful for complex protocols or services that involve multiple layers of well-known information.
- Historical Context: The concept of the .well-known directory was formalized in RFC 5785 in 2010, which defines a mechanism for defining well-known URIs in the root of a domain name. While RFC 5785 does not specifically address .well-known/.well-known, the idea of nesting well-known directories has evolved from the need to manage more complex service discovery or configuration scenarios.
- Usage:
- Security Protocols: Some security protocols might use .well-known/.well-known to store keys or certificates for domain validation or to facilitate secure communications.
- Configuration Files: Configuration files for web services or applications might be placed here to ensure they can be easily discovered by clients or services.
- Interoperability: This setup allows for interoperability between different systems or services that need to locate certain resources within the same domain but in a structured manner.
- Example: An example of how this might be used includes:
- A web service might look for an authentication key at
/well-known/.well-known/auth-key to validate the domain's identity or for some other form of domain-wide configuration.
For more detailed information and updates on standards related to .well-known/.well-known, refer to: