Resolves #238

Why is this feature needed?

The lack of clear documentation for the authentication API has led to confusion when integrating or maintaining the authentication flow. By reverse-engineering the API specification from app/api/auth/[...nextauth]/route.ts, we now have a comprehensive Markdown document that clarifies the behavior of the GET and POST endpoints, details the authentication flow, and outlines the necessary configuration parameters. This documentation will help developers better understand how the authentication process is implemented using NextAuth and JWT.

What and how are we changing? Why this approach?

We are adding a new file, API_Spec_Auth.md, that serves as the API specification for the authentication logic. The document includes:

• An overview of the API and supported HTTP methods (GET and POST).
• A detailed description of the authentication flow, including provider configuration (GitHub), JWT generation, session callback, and JWT callback implementations.
• An explanation of endpoint details for both GET and POST requests.
• A list of configuration parameters required for the API to function correctly.

We chose this approach to ensure that the documentation accurately reflects the code in app/api/auth/[...nextauth]/route.ts, making it easier to maintain and reducing onboarding time for new developers.

What actions are required from users?

No direct actions are required from users. However, developers should review this documentation for a better understanding of how the authentication API is structured and to ensure that any future changes to the authentication logic are reflected in this document. Additionally, if any configuration parameters (such as GITHUB_CLIENT_ID, GITHUB_CLIENT_SECRET, JWT_SECRET, or NEXTAUTH_SECRET) are updated, the documentation should be revisited to maintain its accuracy.

How does it work? (Technical details)

• The GET method retrieves the current session details, including user information and the JWT token, effectively validating the session.
• The POST method initiates the authentication process using NextAuth.
• The API uses a GitHub provider for authentication. When a user logs in, a JWT token is generated using the HS256 algorithm and is set to expire in 100 days.
• The session callback augments the session object with a userId and the generated jwtToken.
• The JWT callback captures the user's account information and transfers the providerAccountId into the token.

The documentation was reverse-engineered based on the implementation details found in app/api/auth/[...nextauth]/route.ts and is intended to provide clarity on how the authentication process has been architected.

Is it backwards compatible?

Yes, this documentation update is fully backwards compatible. It does not impact the API’s functionality, only provides additional clarity for developers.

Any other considerations?

• The new API specification will serve as a reference point for any future modifications to the authentication logic.
• Teams should consider updating the documentation alongside significant changes to the authentication code to keep everything in sync.
• This reverse-engineered approach ensures that the API documentation reflects the current implementation accurately, and can be used as a baseline for further enhancements or integrations.

git fetch origin
git checkout gitauto-wes/issue-238-20250303-142725
git pull origin gitauto-wes/issue-238-20250303-142725