
I used the rest of my Fable 5 quota to build Engram, a Claude Code plugin for learning anything (and actually keeping it)
Why I built this
Agents build faster than I can understand what they built. That's the uncomfortable part of this era for me. Claude ships a feature in twenty minutes, and I'm still the one responsible when it breaks, still the one who has to reason about it in review, still the one who's supposed to know what's going on under the hood. The bottleneck quietly moved from "how fast can we build" to "how fast can we genuinely learn." We got a 10x tool for building. I wanted one for understanding.
So I burned the rest of my Fable 5 quota building Engram. An engram is the physical trace a memory leaves in your brain, which is literally what the plugin is supposed to produce.
How it works
Three commands: /learn, /review, /coach. Under the hood it implements the boring learning science that actually replicates, and deliberately skips the fun stuff that doesn't:
- retrieval practice: it tests you constantly because testing IS the treatment, not the measurement (Roediger & Karpicke 2006)
- real spaced repetition: FSRS, the same modern scheduler Anki uses, fitted to your own review history over time
- generation first: it makes you predict or attempt before it explains. It will not just hand you the answer (unless you explicitly say "just tell me", in which case it complies and quietly schedules that concept for earlier review, because told-not-derived decays faster)
- every topic becomes a first-principles concept graph, "why must this be true given that", instead of textbook chapter order
- threshold concepts get generated interactive HTML explorables with sliders and prediction gates, because some things you need to see and poke
- explicitly no "learning styles". That theory never survived testing. It adapts from your measured retention instead.
The design decision I'm happiest with: the tutor never grades you. A separate assessor agent grades your answers blind, rubric in hand, without ever seeing the lesson, and writes a receipt to disk. In my first real session the tutor was convinced things went great and the assessor came back with 1 recalled, 4 partial, 1 lapsed. It was right. It also turned out the tutor had been logging confidence scores I never actually stated, so "never invent the learner's confidence" is now a hard rule in the code. A system that pushes back on its own optimism ended up being the whole point.
Does it work
Honest answer: the science underneath is some of the most replicated stuff in psychology, but the plugin itself currently has an n of 1, me, and my first week of retention data is still cooking. What I can report: I used it to learn transformer FFN internals yesterday and derived about half the concepts myself before being shown anything. That basically never happens when I just read about something.
Day to day it's tiny on purpose. You run /learn <anything> once (it works for non-code topics too, history or music theory or whatever). Then it pings you at session start when reviews are due, /review takes 2-4 minutes of free recall, and /coach shows retention stats and a local HTML dashboard. Everything is plain JSON in ~/.claude/learning. Nothing leaves your machine.
Install
claude plugin marketplace add nagisanzenin/engram
claude plugin install engram@engram
Needs python3, no pip installs, MIT licensed. Repo: https://github.com/nagisanzenin/engram
If you try it, tell me where it feels annoying. The failure mode of every learning tool ever made is that you stop showing up, so friction reports are worth more to me than praise.