engram

claude plugin marketplace add nagisanzenin/engram
claude plugin install engram@engram

Then, inside Claude Code:

/learn kalman filters        ← or music theory, or Rust lifetimes, or anything

That's the whole onboarding. No config, no account, no cards to write. Requires python3 (stock macOS/Linux one is fine — stdlib only).

Wait — what is this?

You already ask Claude to explain things. It explains beautifully. You nod, you feel smart, and ten days later it's gone — because a chat has no memory of you, no test of whether you really got it, and no plan for the forgetting that starts the moment you close the terminal.

Engram is what's missing around the explanation: a tutor that makes you do the thinking, an examiner that checks you actually got it, and a scheduler that brings each idea back right before your brain drops it.

Concretely, installing it gives you: three slash commands (/learn, /review, /coach), a quiet session hook that tells you when reviews are due (and says nothing otherwise), and a state folder at ~/.claude/learning/ that you own and can read.

 recall
 100% ─┐ just reading                100% ─┐ with engram
       │\                                  │\      ●╌╌╌●╌╌╌╌╌●╌╌╌╌╌╌╌●╌╌
       │ \                                 │ \    ╱    ╲╱      ╲╱
       │  \__                              │  ●──╱
       │     \____                         │
       │          \_______                 │   each ● = a 2–4 minute /review,
   0% ─┴──────────────────── day 30    0% ─┴─  booked just before you'd forget

The loop

  YOU ──→  /learn transformers
            │
            ▼
  ┌────────────────────────────────────────────────────────────────┐
  │  CURRICULUM ARCHITECT                                          │
  │  breaks the topic into a first-principles concept map:         │
  │  "what must be understood before what" — never chapter order.  │
  │  flags the few THRESHOLD concepts † that unlock everything.    │
  └────────────────────────────────────────────────────────────────┘
            │
            ▼
  ┌────────────────────────────────────────────────────────────────┐
  │  THE TUTOR  (your normal Claude chat, under strict rules)      │
  │                                                                │
  │  per concept:  open a question → you PREDICT → struggle a      │
  │  little (hints, not answers) → resolve → you EXPLAIN IT BACK   │
  │                                                                │
  │  threshold concepts get a generated interactive HTML           │
  │  explorable — sliders and prediction gates, not more text.     │
  └────────────────────────────────────────────────────────────────┘
            │   your answers, verbatim (crash-safe stash on disk)
            ▼
  ┌────────────────────────────────────────────────────────────────┐
  │  THE ASSESSOR  (separate agent — grades blind)                 │
  │  sees only the rubric and your words, never the lesson.        │
  │  every grade becomes a receipt on disk. no receipts,           │
  │  no mastery claim.                                             │
  └────────────────────────────────────────────────────────────────┘
            │   receipts
            ▼
  ┌────────────────────────────────────────────────────────────────┐
  │  THE SCHEDULER  (engram.py — deterministic code, not vibes)    │
  │  FSRS-4.5 fits your personal forgetting curves and books       │
  │  each concept's next review just before you'd lose it.         │
  └────────────────────────────────────────────────────────────────┘
            │
            ▼
  next session:  [engram] 6 reviews due (transformers: 6) · ~4 min
                     │
                     ├──→  /review   2–4 minutes of free recall
                     └──→  /coach    weekly: stats · dashboard · tuning

A real session, condensed

From the first live topic taught with Engram (transformer internals). Note who does the thinking:

◆ node 6/13 · nonlinearity-necessity †

engram   Delete σ for a second. The FFN is now just W₂·(W₁·x).
         What is W₂·W₁ — and what has the two-layer FFN collapsed into?

you      i dont know really

engram   Fine — that's a commitment. Forget matrices. W₁ = "×2",
         W₂ = "×3". Run a number through both, nothing in between.
         Two steps of computation… or secretly one?

you      basically 2x3

engram   That's the whole secret, and you just said it. ×2 then ×3 = ×6:
         two linear layers fuse into ONE. Fifty of them? Still one matrix.
         Depth means nothing until a nonlinearity blocks the fuse —
         and that's why σ is not optional.

At session end, the assessor — which never saw that dialogue — graded the learner's six answers: 1 recalled · 4 partial · 1 first-retrieval, while the tutor was convinced the session went great. The schedule believed the assessor. That separation is the point: your future reviews are built on verified evidence, not on the tutor's enthusiasm (or yours).

Three commands, one habit

Everything else is ambient: the session hook nudges when reviews are due and is silent otherwise.

Why it works (the science, in one breath)

Engram implements the four most-replicated findings in learning science — and deliberately skips the popular myths (no "learning styles"; that theory failed every controlled test):

1. Structure — knowledge is a graph, so topics are decomposed by chains of necessity ("why must this be true?"), never by chapter order.
2. Generation — the mind keeps what it makes. You predict, attempt, and explain back before being told. Even failed attempts measurably improve what sticks next (the pretesting effect).
3. Retention — testing is the learning (not the measurement of it), and spacing beats bingeing. Free recall on an FSRS schedule fitted to your own review history.
4. Honest adaptation — it adapts from your measured retention, calibration, and error patterns. Confidence is only recorded when you actually state it; grades only exist as written receipts.

The load-bearing evidence: retrieval practice (Roediger & Karpicke 2006; Karpicke & Blunt 2011, Science; Dunlosky et al. 2013 "high utility"), distributed practice (Cepeda et al. 2006; Rawson & Dunlosky 2011), desirable difficulties & the fluency illusion (Bjork 1994; Koriat & Bjork 2005), pretesting (Richland, Kornell & Kao 2009), the ~85% difficulty sweet spot (Wilson et al. 2019), self-explanation & ICAP (Chi et al. 1994; Chi & Wylie 2014), multimedia principles behind the explorables (Mayer; Paivio), step-level tutoring ≈ human tutors (VanLehn 2011), FSRS scheduling (open-spaced-repetition, Anki's modern default), and the learning-styles refutation (Pashler, McDaniel, Rohrer & Bjork 2008).

Full treatment with design consequences: docs/01-foundations.md · what exists and what's missing in every other tool: docs/02-prior-art.md · system design: docs/03-architecture.md · roadmap & constitution: docs/04-roadmap.md

What it looks like

Your mastery map, any time (/learn shows it, /coach renders the full dashboard):

transformers — Transformers from first principles
██▒▒▒▒▒▒▒▒▒▒▒░░░░░░░░░░░  1 retained · 6 learning · 6 untouched

● contextual-meaning        due 2026-07-09   S=3.7d
◐ residual-stream        †  due 2026-07-06   S=1.4d
◐ nonlinearity-necessity †  due 2026-07-06   S=1.4d
· depth-necessity        †  due —            S=—

Interactive explorables for threshold concepts — self-contained HTML with prediction gates (content stays locked until you commit a guess), manipulable models, and embedded retrieval prompts. A local HTML dashboard (/coach dashboard) with per-topic maps, retention-by-strength bars vs. the 85% target band, honest calibration, and your next-7-days forecast. Both live in ~/.claude/learning/artifacts/ — no network, ever.

FAQ

How is this different from just asking Claude to explain? Asking produces understanding; understanding decays on the same curve as everything else. Engram adds the three things a chat can't: verification (did you actually get it?), memory across sessions (a