Reference¶

The import name is longeron. The most common entry points are re-exported at the top level (longeron — loads, load, validate, to_json, Interpreter, …); the pages below document each module where its objects are defined.

Core pipeline¶

Page	Modules	What lives there
Package API & errors	`longeron`, `longeron.errors`	the re-exported convenience API, exception types
Object model	`longeron.model`, `longeron.ast`	element dataclasses, expression AST
Parsing & building	`longeron.parser`, `longeron.builder`	text → parse tree → model (`loads`)
Workspaces & caching	`longeron.workspace`	`load`, multi-file merges, the model cache
Interpreter	`longeron.interpreter`	evaluation, instantiation, actions, states
Validation	`longeron.validation`	`validate()` / `longeron lint` diagnostics
Units	`longeron.units`	derived unit table, dimensional-lint substrate, `[units]` conversion facade
Model editing	`longeron.edit`	rename/value/doc/metadata mutations with round-trip guarantees, change tracking
Evidence	`longeron.evidence`	SourceEvidence citations: attach, verify, coverage
Standard library	`longeron.stdlib`	the vendored OMG model library
M0 interpretations	`longeron.m0`	populations, sequences, roll-ups, trace occurrences
Interchange	`longeron.export`, `longeron.importer`, `longeron.kerml`, `longeron.ecore`, `longeron.api`, `longeron.rdf`, `longeron.rag`	JSON/SysML/KerML exports, spec metamodel, API JSON, RDF/SPARQL, LLM retrieval substrate
API server & client	`longeron.server`, `longeron.client`	git-backed Systems Modeling API server, REST client
Command line	`longeron.cli`	the `longeron` console command

Visualization¶

Page	Modules	What lives there
Diagrams	`longeron.diagrams`, `longeron.toolbar`	interactive ELK diagrams (ipyelk) and their compact search toolbar
View persistence	`longeron.views`	saving diagrams as SysML v2 views, sidecar presentation, restore
Rendering	`longeron.render`	headless SVG/PNG export (elkjs via node)
Replay	`longeron.replay`	timeline recording for simulation/action replays (the widget lives in `longeron.widgets.replay`)

The notation gallery belongs here too: an executable notebook that shows every implemented SysML v2 glyph beside its spec figure, with self-verifying asserts. The notation coverage guide tabulates the same ground.

Analysis¶

Page	Module	What lives there
Overview	`longeron.analysis`	the solver-bridge package
MDAO	`longeron.analysis.mdao`	OpenMDAO sizing/optimization
Trade studies	`longeron.analysis.trades`	CP-SAT architecture trades
SMT	`longeron.analysis.smt`	Z3 requirement consistency
Visualization	`longeron.analysis.viz`	figures, parallel coordinates
Geometry	`longeron.analysis.geometry`	parametric to-scale meshes, CAD export
Structure views	`longeron.analysis.structure`	N2 matrix, connection networks
Dashboard	`longeron.analysis.dashboard`	linked mission-compromise dashboard
Grand tour	`longeron.analysis.grand`	the all-seams demo dashboard

Widgets¶

Page	Module	What lives there
Overview	`longeron.widgets`	THE catalog: every house widget behind one lazy import; the authors’ toolkit; the home for new widgets
Model explorer	`longeron.widgets.explorer`	the tree + diagram-pane explorer widget
Replay widget	`longeron.widgets.replay`	animated simulation/action replays
3D viewer	`longeron.widgets.viewer3d`	three.js mesh viewer
Mission viewer	`longeron.widgets.mission3d`	Cesium globe mission playback
RDF graph in 3D	`longeron.widgets.graph3d`	force-directed RDF projection explorer