Dotfiles-nix hashcards

Plain-text flashcard system using FSRS spaced repetition. Use when 'hashcards' is explicitly mentioned — for creating cards, managing decks, running reviews, or scripting card generation.

install

source · Clone the upstream repo

git clone https://github.com/not-matthias/dotfiles-nix

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/not-matthias/dotfiles-nix "$T" && mkdir -p ~/.claude/skills && cp -r "$T/modules/home/programs/cli-agents/shared/skills/hashcards" ~/.claude/skills/not-matthias-dotfiles-nix-hashcards && rm -rf "$T"

manifest: modules/home/programs/cli-agents/shared/skills/hashcards/SKILL.md

source content

Hashcards is a plain-text, Rust-based flashcard system using the FSRS algorithm. Cards are Markdown files identified by content hash — editing a card resets its review progress.

Card Syntax

Question-Answer

Q: What is the capital of France?
A: Paris

Cloze Deletion

C: The capital of France is [Paris].

Multiple deletions in one card generate multiple review items:

C: [Paris] is the capital of [France].

Escape literal brackets with backslash:

\[not a deletion\]

Separators

Use

---

between cards for visual organization (optional, ignored by parser).

Rich Content

LaTeX math: Inline
```
$E = mc^2$
```
, display
```
$$\int_0^1 x\,dx$$
```
Custom macros: Define in frontmatter or shared macro files
Images:
```
![alt](path/to/image.png)
```
(relative paths)
Audio: Standard Markdown link/embed syntax
Code blocks: Fenced with syntax highlighting
Tables: Standard Markdown tables

Deck Frontmatter (optional TOML)

+++
deck = "physics"
+++

Q: What is Newton's second law?
A: F = ma

CLI Commands

hashcards drill [DIRECTORY]   # Start review session (web UI on localhost:8000)
hashcards drill --host 0.0.0.0  # Bind to all interfaces
hashcards stats               # Collection statistics as JSON
hashcards check               # Verify collection integrity
hashcards orphans             # Manage deleted cards still in database
hashcards export              # Export collections as JSON

Drill Options

```
--host <addr>
```
— Bind address (default: 127.0.0.1)
Port selection for custom listening port
Card limit to cap review session size
Deck filtering to review specific decks only

Review Grading

Four levels: Forgot / Hard / Good / Easy (keyboard shortcuts available in web UI).

Sibling burial: when a cloze card generates multiple items, reviewing one buries the others to prevent spoilers.

Workflow Best Practices

Version control: Store card files in Git — content-addressed design works naturally with diffs and history
Scripted generation: Generate cards programmatically from CSV or structured data, writing Q:/A: or C: format to
```
.md
```
files
Deck organization: Use directories and/or TOML frontmatter
```
deck
```
field to group cards by topic
Editing awareness: Changing card text resets its FSRS progress (the hash changes). Typo fixes or rewords will lose review history
Integrity checks: Run
```
hashcards check
```
periodically to catch corrupt or malformed cards
Stats monitoring: Use
```
hashcards stats
```
to track review load and identify struggling decks