Speki

Speki is an ontological flashcard app.

It models knowledge explicitly, not as loose cards in decks, but as a structured system with well-defined dependencies. This leads to fundamentally different behavior from traditional flashcard apps.

Core ideas

Ontological cards

Cards are typed. They represent things like concepts, instances, attributes, and relations. Not just text prompts. Knowledge has structure.

Knowledge as a directed acyclic graph

All cards live in a single DAG. Each card declares its dependencies. A card is only valid once its prerequisites are learned.

What this enables

• Prerequisite-safe reviews
  Speki will never ask a question if you have not learned all its transitive dependencies.
  Example. You will not be asked for the gender of perro before learning what perro means.

• No duplicate decks
  Traditional apps duplicate the same knowledge across countless decks.
  Speki has one global knowledge graph. Each fact exists once.

• Truly atomic cards
  Cards can be minimal and precise.
  No need to repeat context. Dependencies guarantee the required background.

• No hidden knowledge gaps
  Creating cards forces you to explicitly model prerequisites.
  Missing foundations surface immediately instead of later during review.