Auth support

[NHagar]

This pull request introduces support for accessing paywalled Substack content using user-provided authentication via session cookies. It includes updates to the library's core functionality, documentation, and examples to reflect this new feature.

Core Functionality Enhancements

• Added the SubstackAuth class to handle authentication using session cookies, enabling access to paywalled content. (docs/api-reference/auth.md, docs/authentication.md, README.md, [1] [2]
• Updated the Newsletter and Post classes to accept an optional auth parameter for authenticated access to paywalled content. (docs/api-reference/newsletter.md, docs/api-reference/post.md, [1] [2]

Documentation Updates

• Added a comprehensive guide on setting up and using authentication, including cookie export instructions and security considerations. (docs/authentication.md, docs/authentication.mdR1-R172)
• Updated API reference and user guides to include examples and explanations for accessing paywalled content. (docs/api-reference/auth.md, docs/user-guide.md, README.md, [1] [2]

Example Code and Usage

• Provided example code for authenticated workflows with Newsletter and Post, demonstrating how to access paywalled content programmatically. (README.md, docs/index.md, docs/user-guide.md, [1] [2]

Security and Compliance

• Highlighted the importance of using personal session cookies, keeping them secure, and complying with Substack's terms of service. (docs/authentication.md, README.md, [1] [2]

Miscellaneous

• Updated quick start and feature lists to reflect the addition of authentication support. (docs/index.md, README.md, [1] [2]

[Copilot]

Pull Request Overview

This pull request adds support for authentication using session cookies to access paywalled Substack content. Key changes include:

• Introducing the new SubstackAuth class and integrating authentication into Post and Newsletter classes.
• Updating tests, documentation, and example usage to demonstrate authenticated workflows.
• Adjusting package metadata and navigation to reflect the new authentication feature.

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/test_auth.py	New tests added for authentication-related functionality.
substack_api/post.py	Updated Post to accept an auth parameter and use authenticated requests.
substack_api/newsletter.py	Updated Newsletter to accept an auth parameter and pass it to Post objects.
substack_api/auth.py	New authentication class for managing session cookies.
substack_api/init.py	Exposed the SubstackAuth class in the package API.
pyproject.toml	Minor dependency and metadata updates.
mkdocs.yml	Updated docs navigation to include authentication.
examples/usage_walkthrough.ipynb	Added usage examples demonstrating authentication workflows.
docs/user-guide.md	Updated guide with authentication setup and usage instructions.
docs/index.md	Updated quick start with authentication details.
docs/authentication.md	New authentication guide with comprehensive setup instructions.
docs/api-reference/post.md	Updated API reference for Post to include authentication parameter.
docs/api-reference/newsletter.md	Updated API reference for Newsletter to include authentication parameter.
docs/api-reference/auth.md	New API reference documentation for the SubstackAuth class.
README.md	Enhanced documentation and examples to reflect authentication support.

Comments suppressed due to low confidence (1)

substack_api/post.py:108

• Consider replacing print statements with a logging mechanism to provide configurable and consistent error reporting.

print("Warning: This post is paywalled. Provide authentication to access full content.")