Decision Tree CLI

An interactive terminal tool for building, editing, and visualizing decision trees. Renders to Graphviz DOT, Mermaid diagrams, and ASCII previews. Pure Go standard library, no external dependencies.

Installation

# Install as `dt` on your PATH
make install

# Or build locally without installing
make build

Quick Start

dt

Initialize from a template

Decision Tree CLI (type 'help' for commands)
> init
Available templates:
  1. auth-flow — Authentication flow
  2. approval — Approval workflow
  3. troubleshooting — Troubleshooting guide
Usage: init <template-name>
> init auth-flow
Initialized tree from template "auth-flow" (5 nodes)
> preview
([Start])
└── <Authenticated?>
    ├── [yes] [Grant access]
    │   └── ([End])
    └── [no] [Show login form]

Build a tree manually

> add startend "Start"
Added node n1
> add decision "Authenticated?"
Added node n2
> add action "Grant access"
Added node n3
> add io "Show login form"
Added node n4
> connect n1 n2
Connected n1 -> n2
> connect n2 n3 yes
Connected n2 -> n3
> connect n2 n4 no
Connected n2 -> n4
> set-root n1
Root set to n1
> preview
([Start])
├── <Authenticated?>
│   ├── [yes] [Grant access]
│   └── [no] //Show login form//
> render dot
digraph untitled {
  rankdir=TB;
  ...
}
> save auth-flow.json
Saved to auth-flow.json
> quit
Goodbye!

Command Reference

Command	Description
init [name]	Initialize tree from a template (list templates with no args)
add <type> <label>	Add a node. Types: decision, action, startend, io
connect <from> <to> [label]	Connect two nodes with an optional edge label
disconnect <from> <to>	Remove edge between two nodes
remove <node-id>	Remove a node and its connected edges
edit <id> label <text>	Change a node's label
edit <id> type <type>	Change a node's type
set-root <node-id>	Set the root node for preview/rendering
list	List all nodes with their types
preview	ASCII tree preview with box-drawing characters
render dot [file]	Output Graphviz DOT diagram (optionally to file)
render mermaid [file]	Output Mermaid flowchart (optionally to file)
copy <node-id>	Copy a subtree to clipboard
paste	Paste clipboard contents (IDs are remapped)
save <filename>	Save tree to JSON file
load <filename>	Load tree from JSON file
undo	Undo last action
redo	Redo last undone action
browse	Open interactive full-screen tree browser
help	Show command help
quit / exit	Exit the program

Interactive Browser

Launch a full-screen tree browser with browse:

> browse

Key bindings:

Key	Action
j / k	Move cursor down / up
a	Add child node (or root if tree is empty)
d	Delete selected node
e	Edit selected node
c	Connect mode (select source, move to target, confirm)
i	Init from template (empty tree only)
u / r	Undo / Redo
q	Quit browser

Templates

Available templates for init:

Name	Description
auth-flow	Authentication flow: Start → Authenticated? → Grant access / Show login form
approval	Approval workflow: Start → Submit → Approved? → Process / Revise (loop)
troubleshooting	Troubleshooting guide: Start → Plugged in? → Plug it in / Check settings → Resolved?
bug-triage	Bug triage and incident response with severity routing, investigation, fix/test/deploy cycle
hiring	Hiring pipeline from application screening through interviews, offer negotiation, and onboarding
medical-triage	Emergency room triage: consciousness check, vitals, pain assessment, trauma routing, imaging
loan-application	Loan approval: credit check, debt-to-income, employment, collateral appraisal, underwriting

Use from the REPL with init <name> or from the browser with i on an empty tree.

Node Types and Shapes

Type	DOT Shape	Mermaid Syntax	ASCII Preview
decision	diamond	{label}	<label>
action	box	[label]	[label]
startend	ellipse	([label])	([label])
io	parallelogram	[/label/]	//label//

JSON File Format

Trees are saved as JSON with the following structure:

{
  "name": "auth-flow",
  "root_id": "n1",
  "nodes": {
    "n1": { "id": "n1", "type": 0, "label": "Authenticated?" }
  },
  "edges": [
    { "from": "n1", "to": "n2", "label": "yes" }
  ],
  "counter": 2
}

Node type values: 0 = decision, 1 = action, 2 = startend, 3 = io.

Project Structure

cmd/decision-tree-cli/   Main entrypoint
internal/
  model/                 Node, Edge, Tree data structures
  tree/                  Operations, clipboard, undo/redo history
  render/                DOT and Mermaid renderers
  preview/               ASCII tree preview
  storage/               JSON save/load
  cli/                   Parser, commands, REPL loop, templates, browser
  terminal/              Raw-mode terminal I/O and line reader
testdata/                Sample fixtures and golden files
docs/                    Architecture and examples
.github/workflows/       CI: build, test, security scanning

Development

make install  # Install as `dt` to GOPATH/bin
make build    # Build binary to bin/
make test     # Run all tests
make vet      # Static analysis
make run      # Build and run
make clean    # Remove build artifacts

CI

A GitHub Actions workflow runs on push and PR to main:

• Build & Vet — go build, go vet, go test
• govulncheck — Scans dependencies for known vulnerabilities
• gosec — Security-focused static analysis
• staticcheck — Advanced Go linter
• Dependency Review — Reviews new dependencies on PRs
• Module Integrity — Verifies checksums and tidy modules