diff --git a/.gitignore b/.gitignore
index a588dbd..3f5f01c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ __pycache__/
 target/
 dist/
 build/
+uml-viewer-log.txt
diff --git a/examples/crapper.edn b/examples/crapper.edn
new file mode 100644
index 0000000..9c44219
--- /dev/null
+++ b/examples/crapper.edn
@@ -0,0 +1,314 @@
+;; Generated by clj -M:ir from the policy file. Do not edit.
+{:hierarchical true,
+ :title "Crapper",
+ :prefix "crapper",
+ :edge-kinds {},
+ :omit-edges [],
+ :levels
+ [[:model :discover :crapper]
+  [:crap :coverage :metrics :report :languages]
+  [:analyze :runners]
+  [:cli]
+  [:__main__]],
+ :policy-file "examples/crapper.policy.edn",
+ :order
+ [:model
+  :discover
+  :crapper
+  :crap
+  :coverage
+  :metrics
+  :report
+  :languages
+  :analyze
+  :runners
+  :cli
+  :__main__],
+ :omit [],
+ :edges
+ [{:from :__main__, :to :cli, :kind :dependency}
+  {:from :languages.python, :to :languages.treesitter, :kind :dependency}
+  {:from :languages, :to :languages.typescript, :kind :dependency}
+  {:from :languages.rust, :to :languages.treesitter, :kind :dependency}
+  {:from :languages.java, :to :languages.treesitter, :kind :dependency}
+  {:from :crap, :to :model, :kind :implements}
+  {:from :languages.rust, :to :pathlib, :kind :dependency}
+  {:from :analyze, :to :pathlib, :kind :dependency}
+  {:from :languages.java, :to :re, :kind :dependency}
+  {:from :runners, :to :shlex, :kind :dependency}
+  {:from :coverage, :to :model, :kind :dependency}
+  {:from :languages.typescript, :to :languages.treesitter, :kind :dependency}
+  {:from :runners, :to :json, :kind :dependency}
+  {:from :languages.golang, :to :languages.language, :kind :inheritance}
+  {:from :cli, :to :subprocess, :kind :dependency}
+  {:from :languages.treesitter, :to :tree_sitter_language_pack, :kind :dependency}
+  {:from :languages.typescript, :to :model, :kind :dependency}
+  {:from :languages.golang, :to :pathlib, :kind :dependency}
+  {:from :coverage, :to :urllib, :kind :dependency}
+  {:from :analyze, :to :languages, :kind :dependency}
+  {:from :languages, :to :languages.clojure, :kind :dependency}
+  {:from :languages.python, :to :languages.language, :kind :inheritance}
+  {:from :report, :to :model, :kind :dependency}
+  {:from :languages.golang, :to :languages.treesitter, :kind :dependency}
+  {:from :languages, :to :languages.java, :kind :dependency}
+  {:from :coverage, :to :xml, :kind :dependency}
+  {:from :languages, :to :languages.python, :kind :dependency}
+  {:from :cli, :to :sys, :kind :dependency}
+  {:from :cli, :to :pathlib, :kind :dependency}
+  {:from :analyze, :to :model, :kind :dependency}
+  {:from :languages.clojure, :to :re, :kind :dependency}
+  {:from :languages.treesitter, :to :functools, :kind :dependency}
+  {:from :discover, :to :os, :kind :dependency}
+  {:from :analyze, :to :discover, :kind :dependency}
+  {:from :coverage, :to :pathlib, :kind :dependency}
+  {:from :languages.language, :to :model, :kind :dependency}
+  {:from :languages, :to :model, :kind :dependency}
+  {:from :analyze, :to :crap, :kind :dependency}
+  {:from :runners, :to :subprocess, :kind :dependency}
+  {:from :cli, :to :coverage, :kind :dependency}
+  {:from :languages, :to :languages.rust, :kind :dependency}
+  {:from :languages.typescript, :to :languages.language, :kind :inheritance}
+  {:from :cli, :to :report, :kind :dependency}
+  {:from :metrics, :to :pathlib, :kind :dependency}
+  {:from :runners, :to :shutil, :kind :dependency}
+  {:from :model, :to :dataclasses, :kind :dependency}
+  {:from :languages.rust, :to :languages.language, :kind :inheritance}
+  {:from :languages.java, :to :model, :kind :dependency}
+  {:from :languages.rust, :to :re, :kind :dependency}
+  {:from :cli, :to :dataclasses, :kind :dependency}
+  {:from :discover, :to :pathlib, :kind :dependency}
+  {:from :coverage, :to :dataclasses, :kind :dependency}
+  {:from :languages, :to :languages.language, :kind :dependency}
+  {:from :cli, :to :runners, :kind :dependency}
+  {:from :languages.clojure, :to :languages.language, :kind :inheritance}
+  {:from :languages.rust, :to :model, :kind :dependency}
+  {:from :runners, :to :sys, :kind :dependency}
+  {:from :languages.clojure, :to :model, :kind :dependency}
+  {:from :languages.golang, :to :model, :kind :dependency}
+  {:from :languages.java, :to :languages.language, :kind :inheritance}
+  {:from :languages.python, :to :model, :kind :dependency}
+  {:from :analyze, :to :coverage, :kind :dependency}
+  {:from :cli, :to :metrics, :kind :dependency}
+  {:from :runners, :to :discover, :kind :dependency}
+  {:from :languages, :to :languages.golang, :kind :dependency}
+  {:from :cli, :to :analyze, :kind :dependency}
+  {:from :coverage, :to :re, :kind :dependency}
+  {:from :metrics, :to :model, :kind :dependency}
+  {:from :cli, :to :discover, :kind :dependency}
+  {:from :runners, :to :pathlib, :kind :dependency}],
+ :classes
+ [{:ns "crapper",
+   :name "Crapper",
+   :file "src/crapper/__init__.py",
+   :level 0,
+   :lang :python,
+   :id :crapper}
+  {:ns "crapper.__main__",
+   :name "__main__",
+   :file "src/crapper/__main__.py",
+   :level 4,
+   :lang :python,
+   :id :__main__}
+  {:ns "crapper.analyze",
+   :name "Analyze",
+   :file "src/crapper/analyze.py",
+   :ops [{:name "analyze_files", :text "analyze_files"}],
+   :level 2,
+   :lang :python,
+   :id :analyze}
+  {:ns "crapper.cli",
+   :name "Cli",
+   :file "src/crapper/cli.py",
+   :ops
+   [{:name "Options", :text "Options"}
+    {:name "parse_args", :text "parse_args"}
+    {:name "select_files", :text "select_files"}
+    {:name "run", :text "run"}
+    {:name "main", :text "main"}],
+   :level 3,
+   :lang :python,
+   :id :cli}
+  {:ns "crapper.coverage",
+   :name "Coverage",
+   :file "src/crapper/coverage.py",
+   :ops
+   [{:name "normalize_path", :text "normalize_path"}
+    {:name "suffix_match", :text "suffix_match"}
+    {:name "coverage_percent", :text "coverage_percent"}
+    {:name "percent_for_range", :text "percent_for_range"}
+    {:name "parse_form_coverage", :text "parse_form_coverage"}
+    {:name "parse_lcov", :text "parse_lcov"}
+    {:name "parse_go_profile", :text "parse_go_profile"}
+    {:name "go_percent", :text "go_percent"}
+    {:name "JacocoMethod", :text "JacocoMethod"}
+    {:name "parse_jacoco_index", :text "parse_jacoco_index"}
+    {:name "CoverageBundle", :text "CoverageBundle"}
+    {:name "load_bundle", :text "load_bundle"}],
+   :level 1,
+   :lang :python,
+   :id :coverage}
+  {:ns "crapper.crap",
+   :name "Crap",
+   :file "src/crapper/crap.py",
+   :ops
+   [{:name "crap_score", :text "crap_score"}
+    {:name "round_metric", :text "round_metric"}
+    {:name "make_entry", :text "make_entry"}
+    {:name "sort_entries", :text "sort_entries"}],
+   :level 1,
+   :lang :python,
+   :id :crap}
+  {:ns "crapper.discover",
+   :name "Discover",
+   :file "src/crapper/discover.py",
+   :ops
+   [{:name "language_of", :text "language_of"}
+    {:name "is_test_file", :text "is_test_file"}
+    {:name "iter_source_files", :text "iter_source_files"}],
+   :level 0,
+   :lang :python,
+   :id :discover}
+  {:ns "crapper.languages",
+   :name "Languages",
+   :file "src/crapper/languages/__init__.py",
+   :ops [{:name "functions_in_file", :text "functions_in_file"}],
+   :level 1,
+   :lang :python,
+   :id :languages}
+  {:ns "crapper.languages.clojure",
+   :name "Clojure",
+   :file "src/crapper/languages/clojure.py",
+   :ops
+   [{:name "without_strings_and_comments", :text "without_strings_and_comments"}
+    {:name "cyclomatic_complexity", :text "cyclomatic_complexity"}
+    {:name "extract_functions", :text "extract_functions"}
+    {:name "declared_namespace", :text "declared_namespace"}
+    {:name "namespace_from_path", :text "namespace_from_path"}
+    {:name "functions_in_source", :text "functions_in_source"}
+    {:name "Clojure", :text "Clojure"}],
+   :level 1,
+   :lang :python,
+   :id :languages.clojure}
+  {:ns "crapper.languages.golang",
+   :name "Golang",
+   :file "src/crapper/languages/golang.py",
+   :ops
+   [{:name "package_namespace", :text "package_namespace"}
+    {:name "functions_in_source", :text "functions_in_source"}
+    {:name "Go", :text "Go"}],
+   :level 1,
+   :lang :python,
+   :id :languages.golang}
+  {:ns "crapper.languages.java",
+   :name "Java",
+   :file "src/crapper/languages/java.py",
+   :ops
+   [{:name "functions_in_source", :text "functions_in_source"}
+    {:name "Java", :text "Java"}],
+   :level 1,
+   :lang :python,
+   :id :languages.java}
+  {:ns "crapper.languages.language",
+   :name "Language",
+   :file "src/crapper/languages/language.py",
+   :ops [{:name "Language", :text "Language"} {:name "Unknown", :text "Unknown"}],
+   :level 1,
+   :lang :python,
+   :id :languages.language}
+  {:ns "crapper.languages.python",
+   :name "Python",
+   :file "src/crapper/languages/python.py",
+   :ops
+   [{:name "functions_in_source", :text "functions_in_source"}
+    {:name "Python", :text "Python"}],
+   :level 1,
+   :lang :python,
+   :id :languages.python}
+  {:ns "crapper.languages.rust",
+   :name "Rust",
+   :file "src/crapper/languages/rust.py",
+   :ops
+   [{:name "functions_in_source", :text "functions_in_source"}
+    {:name "Rust", :text "Rust"}],
+   :level 1,
+   :lang :python,
+   :id :languages.rust}
+  {:ns "crapper.languages.treesitter",
+   :name "Treesitter",
+   :file "src/crapper/languages/treesitter.py",
+   :ops
+   [{:name "parser_for", :text "parser_for"}
+    {:name "parse", :text "parse"}
+    {:name "node_text", :text "node_text"}
+    {:name "start_line", :text "start_line"}
+    {:name "end_line", :text "end_line"}
+    {:name "child_of_type", :text "child_of_type"}
+    {:name "descendants", :text "descendants"}
+    {:name "complexity", :text "complexity"}
+    {:name "binary_logic", :text "binary_logic"}],
+   :level 1,
+   :lang :python,
+   :id :languages.treesitter}
+  {:ns "crapper.languages.typescript",
+   :name "Typescript",
+   :file "src/crapper/languages/typescript.py",
+   :ops
+   [{:name "functions_in_source", :text "functions_in_source"}
+    {:name "TypeScript", :text "TypeScript"}],
+   :level 1,
+   :lang :python,
+   :id :languages.typescript}
+  {:ns "crapper.metrics",
+   :name "Metrics",
+   :file "src/crapper/metrics.py",
+   :ops
+   [{:name "metrics_path", :text "metrics_path"}
+    {:name "render_edn", :text "render_edn"}
+    {:name "write_metrics", :text "write_metrics"}],
+   :level 1,
+   :lang :python,
+   :id :metrics}
+  {:ns "crapper.model",
+   :name "Model",
+   :file "src/crapper/model.py",
+   :ops [{:name "Function", :text "Function"} {:name "Entry", :text "Entry"}],
+   :level 0,
+   :lang :python,
+   :id :model}
+  {:ns "crapper.report",
+   :name "Report",
+   :file "src/crapper/report.py",
+   :ops [{:name "format_report", :text "format_report"}],
+   :level 1,
+   :lang :python,
+   :id :report}
+  {:ns "crapper.runners",
+   :name "Runners",
+   :file "src/crapper/runners.py",
+   :ops
+   [{:name "run_shell", :text "run_shell"}
+    {:name "typescript_packages", :text "typescript_packages"}
+    {:name "typescript_command", :text "typescript_command"}
+    {:name "rust_modules", :text "rust_modules"}
+    {:name "python_roots", :text "python_roots"}
+    {:name "uses_pytest", :text "uses_pytest"}
+    {:name "python_sources", :text "python_sources"}
+    {:name "python_coverage_commands", :text "python_coverage_commands"}
+    {:name "rust_coverage_command", :text "rust_coverage_command"}
+    {:name "run_coverage", :text "run_coverage"}],
+   :level 2,
+   :lang :python,
+   :id :runners}
+  {:id :dataclasses, :name "dataclasses", :foreign true}
+  {:id :functools, :name "functools", :foreign true}
+  {:id :json, :name "json", :foreign true}
+  {:id :os, :name "os", :foreign true}
+  {:id :pathlib, :name "pathlib", :foreign true}
+  {:id :re, :name "re", :foreign true}
+  {:id :shlex, :name "shlex", :foreign true}
+  {:id :shutil, :name "shutil", :foreign true}
+  {:id :subprocess, :name "subprocess", :foreign true}
+  {:id :sys, :name "sys", :foreign true}
+  {:id :tree_sitter_language_pack, :name "tree_sitter_language_pack", :foreign true}
+  {:id :urllib, :name "urllib", :foreign true}
+  {:id :xml, :name "xml", :foreign true}]}
diff --git a/examples/crapper.policy.edn b/examples/crapper.policy.edn
new file mode 100644
index 0000000..20c6ed6
--- /dev/null
+++ b/examples/crapper.policy.edn
@@ -0,0 +1,18 @@
+{:title "Crapper"
+ :prefix "crapper"
+ :lang :python
+ :src "src"
+ :out "examples/crapper.edn"
+ :hierarchical true
+ :foreign [dataclasses functools json os pathlib re shlex shutil subprocess sys
+           tree_sitter_language_pack urllib xml]
+ :order [model discover crapper
+         crap coverage metrics report languages
+         analyze runners
+         cli
+         __main__]
+ :levels [[model discover crapper]
+          [crap coverage metrics report languages]
+          [analyze runners]
+          [cli]
+          [__main__]]}
diff --git a/uml b/uml
new file mode 100755
index 0000000..391e8d9
--- /dev/null
+++ b/uml
@@ -0,0 +1,61 @@
+#!/bin/zsh
+# Loader for this project. Points at the local uml-viewer checkout so the
+# Python scanner is on the classpath.
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")" && pwd)"
+cd "$ROOT"
+
+DEPS='{:deps {uml-viewer/uml-viewer {:local/root "/Users/unclebob/projects/uml-viewer"} quil/quil {:mvn/version "4.3.1563"}}}'
+
+edn_path() {
+  local name base f
+  name="$(basename "$ROOT")"
+  if [[ -f "examples/${name}.edn" ]]; then
+    echo "examples/${name}.edn"
+    return
+  fi
+  if [[ -d examples ]]; then
+    for f in examples/*.edn(N); do
+      [[ -f "$f" ]] || continue
+      base="${f:t}"
+      [[ "$base" == *.policy.edn ]] && continue
+      echo "$f"
+      return
+    done
+  fi
+}
+
+LOG="uml-viewer-log.txt"
+
+launch_viewer() {
+  {
+    printf '----- %s starting uml-viewer' "$(date '+%Y-%m-%d %H:%M:%S')"
+    [[ $# -gt 0 ]] && printf ' %s' "$@"
+    printf '\n'
+  } >> "$LOG"
+  # `clj` is rlwrap on Homebrew; a background rlwrap stops (SIGTTOU) and
+  # never starts the JVM. `clojure` is the same CLI without the tty wrapper.
+  nohup clojure -Sdeps "$DEPS" -M -m uml-viewer.main.uml-viewer "$@" >> "$LOG" 2>&1 </dev/null &
+  disown
+  echo "UML viewer started (pid $!). Log: $LOG"
+}
+
+if [[ "${1:-}" == "-h" || "${1:-}" == "--help" ]]; then
+  echo "usage: ./uml [--restart]" >&2
+  echo "  (no args)   fresh window; companion writes the diagram" >&2
+  echo "  --restart   new JVM, same companion; restores last view" >&2
+  echo "  The viewer detaches; exceptions go to $LOG." >&2
+  exit 0
+fi
+
+if [[ "${1:-}" == "--restart" ]]; then
+  edn="$(edn_path)"
+  if [[ -n "$edn" ]]; then
+    launch_viewer --restart "$edn"
+  else
+    launch_viewer --restart
+  fi
+  exit 0
+fi
+
+launch_viewer "$@"