The knowledge graph

Everything Spine answers is grounded in a Provenance Knowledge Graph (PKG) — a deterministic fact model extracted from your code and your documentation.

Why a graph, not a chat log

Spine’s architecture forbids force-directed layouts: a picture that redraws differently for an identical commit can’t be diffed. Positions are computed once with a seeded layout, so the same commit renders the identical graph every time. Determinism is the feature, not a limitation.

7 node kinds

Node	What it is
`Module`	a file or package
`Type`	class, struct, interface
`Function`	a callable unit
`Field`	attribute or constant
`Endpoint`	HTTP route / handler
`Entity`	data-layer table
`Doc`	ingested documentation

9 edge kinds

IMPORTS · CONTAINS · CALLS · IMPLEMENTS · READS · WRITES · EXPOSES · REFERENCES · MENTIONS

Every edge carries a location. For example:

auth.validate   — CALLS →      models.get_user
models.get_user — READS →      password_hash
docs/auth.md    — MENTIONS →   auth.validate

Documentation is a first-class citizen

Spine ingests 9 document formats — .md .markdown .rst .txt .html .htm .pdf .docx .xlsx — and turns each into a Doc node linked to the symbols it MENTIONS. That’s what powers doc drift: detecting when a document claims a symbol that no longer exists, or says code is tested when it isn’t.