Roadmap

Effort estimates are for one engineer working full time and are rough (±50%).

Milestone	Scope	Exit criteria	Effort
M0	Benchmark harness, corpora, baseline scores for mermaid (ELK and dagre), beautiful-mermaid, mmdr, MSAGL.js	Baseline report published; ADR-0004 confirmed or revised by MSAGL’s scores; the p99 of every limit in architecture.md over docs recorded, and each default at least 10× that p99; W010 StyleRejected count over docs recorded	1–2 weeks
M1	Flowchart: parser with repairs, Inter metric tables, layered layout (dominator layering, three-pass crossing minimisation, Brandes–Köpf, container fit, orthogonal routing, clusters), SVG contract, outline, CLI	0 runtime dependencies in CI; compat pass rate for flowcharts ≥ 90%; layout quality at least equal to mermaid-ELK on crossings and stress; native and WASM output byte-identical on compat; every fuzz target in security.md in CI	8–12 weeks
M2	Stable layout (ADR-0006); @fractalbox/merlion-wasm; @fractalbox/merlion-rehype; @fractalbox/merlion-astro	Mean displacement across edits below mermaid-ELK’s; WASM size recorded; fuel default calibrated (ADR-0008)	3–4 weeks
M3	<merlion-view>, semantic zoom; types with fixed geometry: gantt, timeline, pie, XY, packet, kanban	Viewer ≤ 6 KB gzip; compat ≥ 90% for each new type	4–6 weeks
M3b	Hover interaction (ADR-0010): node and edge ids and the CSS layer in the core, @fractalbox/merlion-view/interact (interaction.md)	Every compat flowchart passes the hover, keyboard and popover acceptance tests; interact ≤ 3 KB gzip and the base viewer still ≤ 6 KB; no new axe violations; the render fuzz target checks the #{id}:has( rules	2–3 weeks
M4	Sequence, state, class, ER	compat ≥ 90% for each	4–6 weeks
M5	Sleeve routing (edge_style: spline); first reader panel (ADR-0007)	Panel results published	4–6 weeks
M5b	merlion lsp; merlion-vscode (VS Code Marketplace and Open VSX, serving Cursor); Zed extension for the language server	Extension renders every compat flowchart in the preview; theme follows the editor	3–4 weeks
M6	1.0: stable public API, token names, hint format v1, WASM ABI	Reproducible release verified by a second build on a different runner image; SECURITY.md published	2 weeks

Mindmap, gitGraph, C4, architecture, block, sankey, quadrant, requirement, journey, radar and treemap are outside 1.0. TODO(owner): rank them after M4 by frequency in the docs corpus.