diff --git a/.gitignore b/.gitignore
index a45eacc..42c29f2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -262,3 +262,7 @@ skills-external/.higgsfield-stage.*/
 # ── gitflow standard socle (added by gitflow_init; additive, safe to edit) ──
 *.log
 !.claude/deploy/
+
+# mods/: the engine lays tsconfig.json beside a loaded mod; its
+# .claude-plugin/types/ ignores itself
+mods/*/tsconfig.json
diff --git a/CLAUDE.md b/CLAUDE.md
index 5e0bfcf..c58878d 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -59,6 +59,28 @@ Gotcha, learned the hard way: `git rm --cached` keeps the working file,
 but if the branch you merge into still tracks it, the merge deletes it
 from disk. Untrack and merge, then restore with the command above.
 
+## mods/ — function-hooks plugins (Claude Code mods)
+
+A mod lives in `mods/<name>/` (`.claude-plugin/plugin.json` + hooks). It
+loads through the tracked relative symlink `skills/<name>` -> `../mods/<name>`
+(`~/.claude/skills` links to `skills/`) as `<name>@skills-dir`, in place,
+live at the next session or `/reload-plugins`. New mod: `ln -s ../mods/<name>
+skills/<name>` from the repo root (guard with `[ -L ]`, a re-run nests a link).
+Not `CLAUDE_CODE_PLUGIN_DIRS` (absolute path, settings `env` has no `$HOME`
+expansion, settings.json is tracked), nor a local marketplace (`add` writes
+an absolute path into settings.json).
+- The engine lays `mods/<name>/tsconfig.json` and `.claude-plugin/types/`;
+  both are gitignored.
+- Optional user config: `~/.claude/<name>.json`. Its `"enabled": false` is the
+  per-machine off switch (untracked). `"<name>@skills-dir": false` in
+  `enabledPlugins` also works but lands in the TRACKED settings.json and
+  dirties every machine's tree.
+- A dev copy of the same name (`--plugin-dir`, hot-reload link in
+  `~/.claude/dev-mods/<session>/`) shadows the skills-dir copy for that
+  session: remove it before reading `/reload-plugins` as a test of the link.
+- Tests: `make test suite=lib/tests/mods.test.sh` (manifest, link,
+  `claude plugin validate`, `claude plugin test`). `doctor.sh` has a Mods section.
+
 ## Transient planning artifacts
 
 `docs/superpowers/specs/**` and `docs/superpowers/plans/**` are run-time
diff --git a/doctor.sh b/doctor.sh
index 63f281b..8bfe308 100644
--- a/doctor.sh
+++ b/doctor.sh
@@ -155,6 +155,64 @@ unset _dv_active_profile _dv_profile_file
 
 echo ""
 
+# ────────────────────────────────────────────────────────────
+# 2c. Mods (mods/<name>/ plugins, loaded through the tracked
+# skills/<name> symlink as <name>@skills-dir). Fail-soft: a missing link
+# is info (the user may have removed it on purpose), never an error.
+# ────────────────────────────────────────────────────────────
+echo "── Mods ──"
+
+# Prints enabled|disabled|absent|unknown for $1 read from the JSON on stdin;
+# always exits 0 so a bad payload cannot abort doctor under set -e.
+mod_state() {
+  python3 -c '
+import json, sys
+try:
+    rows = json.load(sys.stdin)
+    row = [r for r in rows if r.get("id") == sys.argv[1] + "@skills-dir"]
+    print("absent" if not row else
+          "enabled" if row[0].get("enabled") is True else "disabled")
+except Exception:
+    print("unknown")
+' "$1" 2>/dev/null || true
+}
+
+_mods_list=""
+if command -v claude &>/dev/null; then
+  if ! _mods_list=$(claude plugin list --json 2>/dev/null); then
+    warn "mods: claude plugin list failed — load state not checked"
+    _mods_list=""
+  fi
+fi
+
+_mods_seen=0
+for _mod_manifest in "$REPO"/mods/*/.claude-plugin/plugin.json; do
+  [ -f "$_mod_manifest" ] || continue
+  _mods_seen=$((_mods_seen + 1))
+  _mod=$(basename "$(dirname "$(dirname "$_mod_manifest")")")
+  _mod_link="$HOME/.claude/skills/$_mod"
+  if ! { [ -L "$_mod_link" ] || [ -e "$_mod_link" ]; }; then
+    info "mod $_mod: not linked (skills/$_mod absent) — git checkout skills/$_mod if wanted"
+    continue
+  fi
+  if [ "$_mod_link" -ef "$REPO/mods/$_mod" ]; then
+    pass "mod $_mod: loading link ~/.claude/skills/$_mod"
+  else
+    warn "mod $_mod: ~/.claude/skills/$_mod does not resolve to $REPO/mods/$_mod"
+  fi
+  [ -n "$_mods_list" ] || continue
+  case "$(printf '%s' "$_mods_list" | mod_state "$_mod")" in
+    enabled) pass "mod $_mod: enabled as $_mod@skills-dir" ;;
+    disabled) warn "mod $_mod: disabled (\"$_mod@skills-dir\": false in enabledPlugins)" ;;
+    absent) warn "mod $_mod: not listed as @skills-dir — run: claude plugin validate mods/$_mod (policy, manifest or name conflict)" ;;
+    *) warn "mod $_mod: claude plugin list output not understood" ;;
+  esac
+done
+[ "$_mods_seen" -gt 0 ] || info "no mods"
+unset _mods_list _mods_seen _mod_manifest _mod _mod_link
+
+echo ""
+
 # ── Playwright browsers (read-only report; NOT nested under gstack — 2 of
 # the 3 registered installs are gsd-pi, not gstack) ──
 echo "── Playwright browsers ──"
diff --git a/lib/tests/mods.test.sh b/lib/tests/mods.test.sh
new file mode 100644
index 0000000..dcc7f9c
--- /dev/null
+++ b/lib/tests/mods.test.sh
@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+# lib/tests/mods.test.sh — every mods/<name>/ plugin: the manifest name
+# equals the folder, skills/<name> is the relative loading symlink
+# ../mods/<name>, and (when the CLI offers `claude plugin test`) the mod
+# passes `claude plugin validate` without warning and `claude plugin test`.
+# MODS_ROOT overrides the repo root (fixture controls). Fails when no mod
+# is found, so it can never pass vacuously.
+set -u
+ROOT="${MODS_ROOT:-$(cd "$(dirname "$0")/../.." && pwd)}"
+CLI_TIMEOUT=120
+pass=0; fail=0
+ok() { pass=$((pass+1)); echo "PASS $1"; }
+ko() { fail=$((fail+1)); echo "FAIL $1"; }
+check() { if [ "$2" = "$3" ]; then ok "$1"; else ko "$1: got[$2] want[$3]"; fi; }
+
+# bounded CMD...: stdout+stderr on stdout, rc 124 on timeout.
+bounded() {
+  local t
+  t=$(command -v timeout || command -v gtimeout || true)
+  if [ -n "$t" ]; then "$t" "$CLI_TIMEOUT" "$@" 2>&1; return; fi
+  local out rc=0 pid i=0
+  out=$(mktemp) || return 1
+  "$@" >"$out" 2>&1 & pid=$!
+  while kill -0 "$pid" 2>/dev/null && [ "$i" -lt "$CLI_TIMEOUT" ]; do
+    sleep 1; i=$((i+1))
+  done
+  if kill -0 "$pid" 2>/dev/null; then kill "$pid" 2>/dev/null; rc=124
+  else wait "$pid" || rc=$?; fi
+  cat "$out"; rm -f "$out"; return "$rc"
+}
+
+manifest_name() {
+  python3 -c 'import json,sys; print(json.load(open(sys.argv[1])).get("name",""))' \
+    "$1" 2>/dev/null
+}
+
+# cli_unavailable: prints the reason and returns 0 when the capability is missing.
+cli_unavailable() {
+  command -v claude >/dev/null 2>&1 || { echo "claude not found"; return 0; }
+  local rc=0
+  bounded claude plugin test --help >/dev/null || rc=$?
+  [ "$rc" -eq 124 ] && { echo "probe timed out after ${CLI_TIMEOUT}s"; return 0; }
+  [ "$rc" -ne 0 ] && { echo "no 'claude plugin test' command"; return 0; }
+  return 1
+}
+
+check_cli() {
+  local name="$1" dir="$2" out rc=0
+  out=$(bounded claude plugin validate "$dir") || rc=$?
+  if [ "$rc" -eq 124 ]; then ko "$name: validate timed out after ${CLI_TIMEOUT}s"
+  elif ! printf '%s' "$out" | grep -q 'Validation passed'; then
+    ko "$name: validate did not pass: $(printf '%s' "$out" | head -3 | tr '\n' ' ')"
+  elif printf '%s' "$out" | grep -qi 'warning'; then
+    ko "$name: validate printed a warning"
+  else ok "$name: validate passed, no warning"; fi
+  rc=0
+  out=$(bounded claude plugin test "$dir") || rc=$?
+  if [ "$rc" -eq 124 ]; then ko "$name: plugin test timed out after ${CLI_TIMEOUT}s"
+  elif [ "$rc" -ne 0 ]; then
+    ko "$name: plugin test rc=$rc: $(printf '%s' "$out" | tail -3 | tr '\n' ' ')"
+  else ok "$name: plugin test passed"; fi
+}
+
+manifests=()
+for m in "$ROOT"/mods/*/.claude-plugin/plugin.json; do
+  [ -f "$m" ] && manifests+=("$m")
+done
+if [ "${#manifests[@]}" -eq 0 ]; then ko "no mod found under $ROOT/mods"; fi
+
+use_cli=1
+if reason=$(cli_unavailable); then
+  use_cli=0
+  echo "SKIP: claude plugin test unavailable ($reason) — validate/test not run"
+fi
+
+for m in ${manifests[@]+"${manifests[@]}"}; do
+  dir="$(dirname "$(dirname "$m")")"; name="$(basename "$dir")"
+  check "$name: manifest name matches folder" "$(manifest_name "$m")" "$name"
+  link="$ROOT/skills/$name"
+  if [ -L "$link" ]; then
+    check "$name: loading link target" "$(readlink "$link")" "../mods/$name"
+  else ko "$name: skills/$name is not a symlink"; fi
+  [ "$use_cli" -eq 1 ] && check_cli "$name" "$dir"
+done
+
+echo "mods: $pass pass, $fail fail"
+[ "$fail" -eq 0 ]
diff --git a/skills/model-router b/skills/model-router
new file mode 120000
index 0000000..e051553
--- /dev/null
+++ b/skills/model-router
@@ -0,0 +1 @@
+../mods/model-router
\ No newline at end of file