GitHub - mat-mgm/kb-prolog: A hyper-relational knowledge base with content-addressable storage, built on Prolog, SQLite, and C.
A local-first, hyper-relational knowledge base with content-addressable storage (CAS). Built as a Master's thesis prototype.
What it is
[](https://github.com/mat-mgm/kb-prolog#what-it-is)
- **Hyper-relational graph**: Knowledge is stored as `statement(Subject, Predicate, Object, Properties)`. Subjects and objects can themselves be statements (reification), enabling claims about claims.
- **Content-addressable storage**: Files are staged, SHA-256 hashed, and committed atomically alongside their graph metadata. Deduplication is automatic.
- **Time-travel**: Updates create new statement versions linked via `replaces_id`. `pl history` walks the version chain.
- **Prolog-first**: Trealla Prolog is the main runtime. SQLite and Raylib are accessed via C shared libraries loaded through FFI.
- **Interactive GUI**: A Raylib-based graph viewer with image previews, a query bar, and node search.
Build
[](https://github.com/mat-mgm/kb-prolog#build) **Dependencies**: Clang, X11 (Linux) or Xcode CLT (macOS). Trealla Prolog, Raylib, raygui, and SQLite are included as submodules.
git clone --recurse-submodules <repo-url> cd kb make
This builds `libcas.so`, `libgui.so`, and `libsqlite3.so` in the project root. Raylib is compiled from source during `make`.
To build Trealla from source:
cd vendor/trealla && make
Then ensure `tpl` is on your `$PATH`.
Usage
[](https://github.com/mat-mgm/kb-prolog#usage)
Load a context into memory and open a REPL
tpl -l main.pl -- pl load concept(mathematics)
Assert a new statement
tpl -l main.pl -- pl assert \ "statement(concept(mathematics), foundation_of, concept(logic), [])"
Full-text search
tpl -l main.pl -- pl search mathematics
View version history of a term
tpl -l main.pl -- pl history concept(mathematics)
Ingest a file into CAS
tpl -l main.pl -- cas add document.pdf
List CAS objects
tpl -l main.pl -- cas list
Launch the GUI
tpl -l main.pl -- gui
Check database consistency
tpl -l main.pl -- pl verify
Run garbage collection
tpl -l main.pl -- pl gc
Architecture
[](https://github.com/mat-mgm/kb-prolog#architecture)
``` main.pl CLI router and REPL prolog/ sync.pl 2-phase commit: marshal Prolog terms ↔ SQLite cas.pl FFI bindings to libcas.so db.pl SQLite queries gui.pl Raylib frontend (yield-loop pattern) ontology.pl In-memory knowledge graph src/ cas.c / cas.h CAS: stage, SHA-256 hash, commit atomically, verify gui.c / gui.h Raylib renderer and input handler graph.c / graph.h Graph layout util.c / util.h SHA-256, MD5 sql/ schema.sql SQLite schema (WAL mode, FTS5, reification) vendor/ Trealla, Raylib, raygui, SQLite (submodules) ```
Data model
[](https://github.com/mat-mgm/kb-prolog#data-model) Every piece of knowledge is a `statement/4` term:
statement(Subject, Predicate, Object, Properties)
Subject and Object are Prolog terms or integer IDs pointing to other rows in the `statement` table, enabling arbitrary nesting. The SQLite schema mirrors this with `ANY`-typed columns and a `replaces_id` foreign key for versioning.
Example:
% Alice claims (with certainty 0.9) that Bob likes pizza statement( person(alice), claims, statement(person(bob), likes, food(pizza), []), [certainty(0.9)] )
Context loading uses bidirectional recursive CTEs to pull only the subgraph reachable from a seed term into Prolog's in-memory working set.
Nix
[](https://github.com/mat-mgm/kb-prolog#nix) A `kb.nix` shell is provided for reproducible builds:
nix-shell kb.nix
License
[](https://github.com/mat-mgm/kb-prolog#license) GPL-3.0 — see LICENSE.md.