fallow: codebase intelligence for TypeScript and JavaScript

Render your codebase as an interactive map. fallow viz runs one project analysis and writes a single self-contained HTML file (no server, no external assets) styled like the rest of fallow. It is read-only and honors --production, --config, and --no-cache like the analysis commands.

fallow viz                       # writes fallow-viz.html and opens it in your browser
fallow viz --out map.html --no-open
fallow viz --viz-format dot      # emit the import graph as Graphviz DOT
fallow viz --viz-format mermaid  # emit the import graph as a Mermaid diagram

The two views

The HTML report gives you two views over the same project:

Treemap of files sized by bytes, nested by directory.
Force-directed import graph with directory and import-community clustering.

The four lenses

Both views share four lenses that recolor the same map:

Lens	What it shows
Dead code	Unused files, unused exports, and entry points
Duplication	Share of duplicated lines per file, with clone previews
Boundaries	Architecture zones from your `boundaries` config, with violating imports drawn in red
Complexity hotspots	Per-function cyclomatic and cognitive scores, including React context such as hook counts and JSX depth

Click any file to open a detail panel with the evidence behind each finding: unused export names, clone groups and their other locations, boundary crossings, cycle membership, importers and imports as click-through navigation, and a runnable fallow ... --trace command to verify the finding yourself. Search, breadcrumb drill-down, keyboard shortcuts, shareable URL deep links, and dark/light themes are built in. Findings carry a hatch texture and [E]/[W] prefixes so color is never the only signal, and all motion honors prefers-reduced-motion.

Options

Flag	Description
`--out <PATH>`	Output file path (default: `fallow-viz.html` in the project root)
`--no-open`	Do not open the output file in the browser
`--viz-format <FORMAT>`	Visualization output format: `html` (default), `dot` (Graphviz), or `mermaid`
`--root <ROOT>`	Project root directory
`--config <CONFIG>`	Path to a config file
`--production`	Production mode: exclude test/story/dev files
`--no-cache`	Disable incremental caching

Global flags such as --changed-since, --workspace, and --threads also apply; see global flags.

Text formats

--viz-format dot and --viz-format mermaid emit the import graph as text instead of the HTML map, for piping into other tools:

fallow viz --viz-format dot | dot -Tsvg -o graph.svg
fallow viz --viz-format mermaid > graph.mmd

fallow dead-code, fallow dupes, and fallow health produce the findings the lenses visualize
fallow trace verifies a single finding from the command line, matching the --trace command in each detail panel

​The two views

​The four lenses

​Options

​Text formats

​Related

The two views

The four lenses

Options

Text formats

Related