Sidelong

Sidelong is an advanced writing and knowledge management platform designed to power content creation through artificial intelligence. Unlike conventional editors, this tool functions as an ecosystem where users centralize their information sources to transform them into high-quality text. Its primary focus is the concept of human writing with superpowers, allowing authors to maintain creative control while technology handles organization, filtering, and data retrieval to improve the retention and utility of everything learned.

The application operates by building an active personalized library. Using a browser extension or direct imports, users can save articles, YouTube videos, podcasts, social media threads, and books—including Kindle highlights. Sidelong's AI automatically processes these materials, generating summaries, extracting key insights, and enabling semantic search across all stored content. This ensures information isn't just buried in a folder but remains a dynamic resource ready for the creative process.

At the core of the tool is its smart editor, which integrates library content in real-time. As you write, the platform detects the context and automatically surfaces relevant snippets, quotes, or sources that match your current draft. This streamlines source attribution and ensures informational rigor without breaking your flow. Additionally, it features writing assistance to enhance grammar, style, and flow, ensuring a professional final product.

Key technical and functional capabilities include:

Ask Sidelong: A conversational assistant that lets you interact with your personal knowledge base to brainstorm ideas, find evidence for an argument, or get feedback on drafts based exclusively on your saved data.

Deep Research: The ability to generate comprehensive research reports on specific topics, delivered fully cited, organized, and ready for use as a reference.

Project Management: Dedicated workspaces to organize newsletters, blogs, or books, facilitating easy tracking from the initial concept to publication.

Multi-platform Publishing: Tools to export content to Substack, Beehiiv, or Ghost, and to publish or schedule threads on social networks like LinkedIn and X directly from the interface.

This tool is particularly valuable for writers, researchers, and content creators who manage large volumes of information and need a system that bridges the gap between research and final production. Sidelong optimizes the workflow by eliminating friction between data retrieval and writing, allowing users to focus on the quality of their ideas while the AI manages their knowledge base.