Model

SOFE Architecture Graph — a directed in-memory graph with typed relations. No database — pure in-memory, built for fast analysis (blast radius, impact, cost) in agents, CLI and CI.

Node

A deployable unit / resource / service / document.

Field	Type	Description
id	string	Unique identifier
label	string?	Display label
type	string?	e.g. aws.lambda, python-library, cf-worker
attrs	Record<string, any>	Free attrs: owner, monthly_cost, region, repo…

Analysis functions consume attrs.monthly_cost (cost) and attrs.owner (team).

Edge

A directed, typed relation between two nodes.

Field	Type	Description
from	string	Source node
to	string	Target node
relType	string	e.g. routes_to, reads_writes, triggers, depends, calls, bundles
label	string?	Edge label / action

Adding an edge auto-creates missing nodes.

relType

Open convention: routes_to, reads, writes, reads_writes, triggers, calls, depends, bundles, proxies, uses, monitors.

Filtering by relType is key: traverse only the edges that matter (e.g. only reads_writes for data impact).

Traversal

• BFS (traverseBFS): level-by-level (queue)
• DFS (traverseDFS): depth-first (stack, pre-order)

Options: relTypes?, maxDepth?, direction?: 'outgoing' | 'incoming' | 'both'. Returns reachable ids excluding start.

Blast Radius

What breaks if this service fails.

All nodes reachable downstream (BFS outgoing) from a start node.

blastRadius(g, 'api'); // everything that depends on api

Cost Chain

How much (USD/mo) if this goes down.

Sum of attrs.monthly_cost for: the start node + all of its blast radius.

costChain(g, 'api'); // start + downstream monthly cost

Team Cost

Sum of attrs.monthly_cost for all nodes where attrs.owner === X.

Fan-in / SPOF

• Fan-in: how many incoming edges a node has (how many depend on it)
• SPOF: nodes with fan-in >= threshold — critical if they fail

singlePointsOfFailure(g, 3); // nodes with fan-in >= 3

Direction

Direction	Semantics
outgoing	this node → others
incoming	others → this node
both	both

Sources

nan-graph extracts analysis from: SOFE engine/architecture.py (blast_radius, cost_chain, fan_in, single_points_of_failure), cc-mng graph/data.ts (GraphNode/GraphEdge), and dependency-graph.yaml input format. Fusion of Ñan × BYaML v2.