CodeRecall

Anki + LeetCode inside Obsidian — spaced repetition for code, with automatic grading.

Русская версия → README.ru.md

---

What it is

CodeRecall turns code blocks in your Obsidian notes into spaced-repetition cards. You hide part of the code, and during review you retype it from memory. Instead of "reveal → grade yourself", the plugin runs your code against test cases and grades you automatically — a card counts as recalled only if your code actually works.

Cards without tests (or without a language) are checked by comparing your text to the hidden answer, so it works for plain snippets and prose too.

A card

{{c1::…}} is a cloze deletion — the fragment that gets hidden during review.

```coderecall
lang: python
name: Two Sum
code: |
  def two_sum(nums, target):
      seen = {}
      {{c1::for i, n in enumerate(nums):
          if target - n in seen:
              return [seen[target - n], i]
          seen[n] = i}}
tests:
  - in: "[[2, 7, 11, 15], 9]"
    out: "[0, 1]"
  - in: "[[3, 2, 4], 6]"
    out: "[1, 2]"
```

During review the hidden part becomes an input box. You type your answer, hit Run & check, and the plugin runs the tests in a sandbox and shows pass/fail.

Card format

A card is one fenced block with the coderecall info string; the body is YAML:

Field	Required	Meaning
code	yes	Your code, with one or more {{cN::…}} cloze deletions.
lang	no	Language id (python, javascript, c++, java). Omit it for a plain text/prose card that's graded by comparison, not execution.
tests	no	List of { in, out } pairs. No tests → the card is graded by comparing your answer to the hidden text.
name	no	A label shown in the review view.
entry	no	Entry function to call in tests (inferred if absent).
mode	no	call (invoke the entry function, compare its return) or stdio (pipe in to stdin, compare stdout). Defaults: call for JS/Python, stdio for C++/Java.
id	no	Stable id override (defaults to a content hash).

Instead of an inline code: | block, you can separate header / code / tests with --- lines — then the code is taken verbatim, indentation and tabs and all:

```coderecall
name: Capital of France
---
The capital of France is {{c1::Paris}}.
```

That card has no lang and no tests, so it's graded by text: your answer is compared to the hidden content, ignoring whitespace (print(x + y) and print(x+y) both match a hidden print(x + y)).

Cloze syntax: {{cN::hidden}} hides hidden as group N; the first unescaped }} closes it. To use a literal {{ or }} inside hidden content, escape it as \{{ / \}} — every other backslash (\n, \\) is left as-is.

Languages

Language	Runner	Notes
JavaScript	Web Worker	offline, call mode
Python	Pyodide (WASM)	downloads once on first run, call mode
C++	local g++/clang++	full STL, stdio mode; JSCPP fallback (no STL) if no compiler
Java	local JDK 11+	stdio mode, single-file launcher

C++/Java run real programs on your machine via local toolchains, so the plugin is desktop-only — toggle Native execution in settings and only review notes you trust. Syntax highlighting works for these plus any language Obsidian knows (TypeScript, Go, Rust, …), even if it can't be executed.

Review and grading

Run Review current note (ribbon brain icon or command). For each card:

• Run & check / Check — grades your answer (runs the tests, or compares text for tests-less cards) and shows the result. This doesn't change the schedule.
• Reveal answer — shows the reference solution and switches to manual grading.
• After a run you get an auto-verdict — Continue (all passed / partial / failed) applies quality 5 / 3 / 1, with Override buttons to overrule it. When you reveal or self-grade, pick Again / Hard / Good / Easy.

Each grade drives the SM-2 schedule stored in data.json:

Button	Quality	Effect
Again	1	Lapse: streak resets, due again in 1 day
Hard	3	Pass, ease −0.14 (intervals grow slower)
Good	4	Pass, ease unchanged
Easy	5	Pass, ease +0.10 (intervals grow faster)

A passing streak schedules the next review at 1 day → 6 days → previous × ease (ease starts at 2.5, floored at 1.3).

Language / localization

CodeRecall's interface is available in English and Russian. It follows Obsidian's UI language automatically; you can force a language under Settings → CodeRecall → Language (Auto / English / Русский).

Install

Not in Community Plugins yet. To run it manually, build (below) and copy manifest.json, main.js and styles.css into <vault>/.obsidian/plugins/coderecall/, then enable the plugin. A ready-made deck to try lives in examples/sample-deck.md.

Development

npm install
npm run dev     # build in watch mode
npm test        # unit tests (vitest)
npm run build   # type-check + production bundle

License

MIT — see LICENSE.

Credits

• obsidian-spaced-repetition
• obsidian-execute-code
• The SM-2 algorithm (SuperMemo)