Introduction
What Leyline is, and the one decision everything else follows from.
Leyline is a distributed graph database. It keeps the graph as immutable compressed-sparse-row segments in S3 and runs traversal on stateless compute, so a query reads the neighbourhoods it walks and nothing else.
That single decision is where the rest of the design comes from.
Storage
Every vertex's neighbours sit contiguously in one array. offsets[v] and
offsets[v+1] bracket the slice, so expanding a vertex is one read at a known
length rather than a walk through the structure to find the structure.
Segments are sealed when they are written. Nothing mutates them afterwards, which means any reader can cache one forever, no reader takes a lock, and no reader ever sees a torn view.
Query
A subset of Cypher: MATCH, variable-length paths, WHERE, aggregation, and
shortestPath. The planner's unit of work is a segment fetch rather than a
table scan, and it names the segments it intends to touch before it touches
them.
Cost
Graph databases usually price the graph — resident memory for all of it, whether or not you query it. Leyline prices the traversal. A graph you do not walk this month costs object storage and nothing else.
Scaffolding
These pages are a placeholder proving the docs pipeline builds and deploys. Real reference documentation is still to be written.