NotebookLM Citation Mapper Smart Citation Management for Research Workflows
Chrome Extension
Starting Point & Challenge
Google NotebookLM has established itself as an innovative AI tool for research and knowledge management. It allows users to upload documents and ask intelligent questions via chat – perfect for academic work, literature research, and complex analyses.
However, one problem remained: citation management. NotebookLM assigns citation numbers like [1], [2], [3] in answers, but the mapping to actual source files was not automated. With projects containing 10, 20, or more documents, it quickly became confusing.
For students, researchers, and knowledge workers, this meant: manual lookup, copying without source references, and increased risk of mix-ups. The idea: A Chrome extension that closes this gap and automates the workflow.
Approach & Implementation
The solution is a Chrome extension that integrates directly into Google NotebookLM and works in the background. The core principle: intelligent detection and mapping of citation numbers to source files.
The extension uses the following technologies:
- MutationObserver: Monitors dynamic DOM changes in real-time to detect new chat messages and citations
- Chrome Extension API (Manifest V3): Modern extension architecture with content scripts for secure page manipulation
- Smart Fallback Mechanism: Multiple detection strategies for robust functionality even with layout changes
Development was collaborative on GitHub: The original concept came from @nicremo, while @DerSchiman contributed significant improvements such as automatic scanning and export functions. Open source allows the community to further develop the tool and adapt it to individual needs.
Main features of the extension:
- Automatic Citation Mapping: Citation numbers are automatically detected and linked with file names
- Copy with Citations: Chat text can be copied while preserving source references
- Export Function: Complete mapping can be exported for external use
- Manual Rescan: Mapping can be manually rescanned when needed
Result & Impact
The NotebookLM Citation Mapper extension is fully functional and available on GitHub as an open-source project. It solves a real problem for Google NotebookLM users and measurably improves the research workflow.
Status: The extension has been submitted to the Chrome Web Store and is currently in the review process. I'm excited about the upcoming release and look forward to more users benefiting from this tool.
Benefits for users:
- Time Savings: No more manual citation mapping needed
- Precision: Automatic detection reduces sources of error
- Workflow Integration: Seamless integration into existing NotebookLM usage
- Transparency: Sources are always traceable and exportable
The project demonstrates how small, focused tools can have major impacts on productivity. It also shows the strength of open-source collaboration: Two developers with different perspectives together created a solution that is more robust and feature-rich than originally planned.
Technology & Outlook
The extension's technology stack is deliberately kept lean: JavaScript as the main language (85.3%), HTML (14.7%) for UI elements, and native Chrome Extension APIs. Avoiding large frameworks ensures fast performance and easy maintainability.
The MutationObserver API enables real-time detection of DOM changes – essential for dynamic web applications like NotebookLM that load content asynchronously. The smart fallback mechanism ensures the extension remains functional even with changes to the NotebookLM layout.
Possible future enhancements:
- Support for various citation styles (APA, MLA, Harvard)
- Integration with reference management software (Zotero, Mendeley)
- Extended export options (BibTeX, EndNote)
- Visual highlighting of citations in chat
- Cross-browser support (Firefox, Edge)
The project exemplifies how modern web technologies can be used to make AI tools even more useful. It's an example of pragmatic problem-solving: A small tool with big impact for a specific target audience.