diff --git a/tools/wave_judge.py b/tools/wave_judge.py
index 3f1dcac052..dec6c5095d 100644
--- a/tools/wave_judge.py
+++ b/tools/wave_judge.py
@@ -1,14 +1,15 @@
 #!/usr/bin/env python3
-"""T4 judge — per-arm whole-binary gate (G3/P9, exit codes checked per R53), tree reset between arms,
+"""Wave judge (tools/wave_judge.py; born as the T4 judge) — per-arm whole-binary gate (G3/P9, exit codes checked per R53), tree reset between arms,
 then the union (best arm per fn) gated once and left in the tree for the commit. Reads targets from
 .run/t4/targets.json and drafts from .run/t4/<arm>/<fn>.c. Writes .run/t4/judge.json.
 Usage: judge.py [arms...]   (default haiku sonnet opus ds)"""
 import sys, os, json, glob, subprocess, shutil, time
 REPO = '/home/musashi/bfm-decomp'; os.chdir(REPO)
+WAVEDIR = os.environ.get('WAVE', '.run/t4')   # the wave's dir: <WAVEDIR>/targets.json, <WAVEDIR>/<arm>/<fn>.c
 sys.path.insert(0, 'tools'); import corpus
 UNION = '--union' in sys.argv
 ARMS = [a for a in sys.argv[1:] if not a.startswith('--')] or ['haiku', 'sonnet', 'opus', 'ds']
-targets = json.load(open('.run/t4/targets.json'))
+targets = json.load(open(WAVEDIR + '/targets.json'))
 T = {t['name']: t for t in targets}
 def sh(cmd, timeout=3600):
     return subprocess.run(cmd, capture_output=True, text=True, timeout=timeout)
@@ -22,10 +23,10 @@ def reset_tree():
     r = sh(['git', 'status', '--porcelain', '--', 'src/', 'config/'])
     assert not r.stdout.strip(), 'tree not clean after reset:\n' + r.stdout
 def stage(arm, fns):
-    d = '.run/t4/stage_%s' % arm; shutil.rmtree(d, ignore_errors=True)
+    d = WAVEDIR + '/stage_%s' % arm; shutil.rmtree(d, ignore_errors=True)
     n = 0
     for fn in fns:
-        src = '.run/t4/%s/%s.c' % (arm, fn)
+        src = WAVEDIR + '/%s/%s.c' % (arm, fn)
         if not os.path.exists(src) or os.path.getsize(src) == 0: continue
         b = T[fn]['binary']; os.makedirs('%s/%s' % (d, b), exist_ok=True)
         shutil.copy(src, '%s/%s/%s.c' % (d, b, fn)); n += 1
@@ -34,10 +35,10 @@ def gate(arm, fns):
     before = open_fns()
     d, n = stage(arm, fns)
     if n == 0: return {}, 'no drafts'
-    bins = ','.join(sorted({T[f]['binary'] for f in fns if os.path.exists('.run/t4/%s/%s.c' % (arm, f))}))
+    bins = ','.join(sorted({T[f]['binary'] for f in fns if os.path.exists(WAVEDIR + '/%s/%s.c' % (arm, f))}))
     t0 = time.time()
     r = sh(['flock', '.run/auto/draw.lock', '.venv/bin/python', 'tools/sweep_parallel.py', '--drafts', d, '--only', bins, '-j', '4'], 7200)
-    open('.run/t4/gate_%s.log' % arm, 'w').write(r.stdout + r.stderr)
+    open(WAVEDIR + '/gate_%s.log' % arm, 'w').write(r.stdout + r.stderr)
     # banked = INCLUDE_ASM lines the gate removed (git diff; immune to corpus's per-process cache)
     d = sh(['git', 'diff', '-U0', '--', 'src/']).stdout
     import re as _re
@@ -47,14 +48,14 @@ def gate(arm, fns):
 def main():
     reset_tree()
     res = {'arms': {}, 'fns': {}}
-    if os.path.exists('.run/t4/judge.json'):
-        old = json.load(open('.run/t4/judge.json')); res['arms'] = old.get('arms', {})
+    if os.path.exists(WAVEDIR + '/judge.json'):
+        old = json.load(open(WAVEDIR + '/judge.json')); res['arms'] = old.get('arms', {})
         for a, v in res['arms'].items():
             for f in v.get('banked', []): res['fns'].setdefault(f, []).append(a)
     for arm in ARMS:
         fns = [t['name'] for t in targets]
         banked, note = gate(arm, fns)
-        res['arms'][arm] = {'banked': sorted(banked), 'n_banked': len(banked), 'drafts': sum(1 for f in fns if os.path.exists('.run/t4/%s/%s.c' % (arm, f))), 'note': note}
+        res['arms'][arm] = {'banked': sorted(banked), 'n_banked': len(banked), 'drafts': sum(1 for f in fns if os.path.exists(WAVEDIR + '/%s/%s.c' % (arm, f))), 'note': note}
         print('%-7s banked %2d / %2d drafts  (%s)' % (arm, len(banked), res['arms'][arm]['drafts'], note), flush=True)
         for f in banked: res['fns'].setdefault(f, []).append(arm)
         reset_tree()
@@ -63,20 +64,20 @@ def main():
     pick = {}
     for f, arms in res['fns'].items():
         pick[f] = sorted(arms, key=lambda a: order.index(a) if a in order else 99)[0]
-    ud = '.run/t4/stage_union'; shutil.rmtree(ud, ignore_errors=True)
+    ud = WAVEDIR + '/stage_union'; shutil.rmtree(ud, ignore_errors=True)
     for f, a in pick.items():
         b = T[f]['binary']; os.makedirs('%s/%s' % (ud, b), exist_ok=True)
-        shutil.copy('.run/t4/%s/%s.c' % (a, f), '%s/%s/%s.c' % (ud, b, f))
+        shutil.copy(WAVEDIR + '/%s/%s.c' % (a, f), '%s/%s/%s.c' % (ud, b, f))
     if pick and UNION:
         bins = ','.join(sorted({T[f]['binary'] for f in pick}))
         r = sh(['flock', '.run/auto/draw.lock', '.venv/bin/python', 'tools/sweep_parallel.py', '--drafts', ud, '--only', bins, '-j', '4'], 7200)
-        open('.run/t4/gate_union.log', 'w').write(r.stdout + r.stderr)
+        open(WAVEDIR + '/gate_union.log', 'w').write(r.stdout + r.stderr)
         d = sh(['git', 'diff', '-U0', '--', 'src/']).stdout
         import re as _re
         removed = set(_re.findall(r'^-INCLUDE_ASM\("[^"]+",\s*(func_\w+)\);', d, _re.M))
         res['union'] = {'picked': pick, 'banked': sorted(f for f in pick if f in removed), 'rc': r.returncode}
         print('union: %d picked, %d banked (rc=%d) — LEFT IN TREE for the commit' % (len(pick), len(res['union']['banked']), r.returncode))
-    json.dump(res, open('.run/t4/judge.json', 'w'), indent=1)
+    json.dump(res, open(WAVEDIR + '/judge.json', 'w'), indent=1)
     # per-band table (R41: denominators)
     band = lambda n: '<=50' if n <= 50 else ('51-120' if n <= 120 else '>120')
     for arm in res['arms']: