Your AI Second Brain
Save what matters from any analysis, and Cruxly connects it to everything else you've saved: by meaning, not by folder.
An analysis gives you the summary of one video or one PDF. Second Brain is where the specific pieces that actually matter to you live on after that: a highlight from a lecture breakdown, a number from a report, a clause from a contract, or any other passage worth keeping. Save one and Cruxly looks for what it connects to among everything else you've saved, groups related thoughts by theme, and brings older ones back into view once they've had time to fade a little. There's a dedicated chat too, grounded only in your own saved thoughts, so you can ask what you've learned about a topic across every analysis instead of digging through each one separately. It's part of every registered Cruxly account: register a free Study plan and it's included from the first thought you save.
How This Actually Works
How connections, themes, resurfacing, and the graph actually work under the hood is covered in the complete guide.
Read the complete guide to Cruxly's AI second brainHow Second Brain Works
- 1Register a free Study account, or use an existing Study or Pro account
- 2Analyze a video, PDF, or contract the way you normally would
- 3Highlight any passage in the result (one of the summary's own key points or anything else) and save it as a thought
- 4Open Thoughts anytime to browse connections, group by theme, view the graph, or ask the chat a question grounded in what you've saved
What People Save
- A key insight pulled from a video or PDF breakdown
- A specific piece of practical advice worth acting on
- An action item with a deadline attached
- The main topic of a long document, kept for later
- Any other passage you highlight yourself, beyond what the summary already categorized
Example Use Cases
Student
Saves key definitions and arguments from lecture breakdowns, and finds them again automatically when a related topic comes up in a different course.
Consultant
Saves the specific numbers and recommendations that matter from a client report, then asks the Second Brain chat before a follow-up meeting instead of rereading the whole thing.
Researcher
Saves an argument from one paper, and Cruxly links it to a related point saved from a different paper weeks earlier.
Content Creator
Saves ideas and quotes worth reusing from videos it analyzes, grouped by theme instead of scattered across separate notes.
Freelancer
Saves action items from contract and project-brief analyses in one place instead of digging back through old summaries to find them.
Lifelong Learner
Saves a thought from a podcast breakdown one month and a related one from a book PDF the next, and Second Brain connects the two automatically.
Frequently Asked Questions
Start Your Second Brain
Register a free Study account, then save your first thought from any analysis.