diff --git a/tools/test_heal_loop.sh b/tools/test_heal_loop.sh
new file mode 100755
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+++ b/tools/test_heal_loop.sh
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+#!/bin/bash
+# test_heal_loop.sh — self-healing test loop for CODEC.
+#
+# The until-pattern: keep invoking headless Claude until the suite is green.
+# Each iteration makes ONE focused fix, then the suite re-runs. Ctrl-C to stop.
+#
+#   ./tools/test_heal_loop.sh              # full suite
+#   ./tools/test_heal_loop.sh tests/test_overlays.py   # scope to a file
+#
+# Notes:
+#  - Tests are the spec: Claude is told to fix CODE, never tests.
+#  - If a built-in skill file is edited, the PR-1A manifest must be regenerated
+#    or the skill silently fails to load — the prompt covers it, and the tool is
+#    allowlisted.
+#  - MAX_ITERS guards against an infinite burn if something is truly wedged.
+
+set -u
+cd "$(dirname "$0")/.."
+
+SCOPE="${1:-}"
+MAX_ITERS="${MAX_ITERS:-8}"
+PYTEST_CMD="python3 -m pytest -q -x ${SCOPE}"
+
+i=0
+until $PYTEST_CMD; do
+  i=$((i + 1))
+  if [ "$i" -gt "$MAX_ITERS" ]; then
+    echo "[heal-loop] still red after ${MAX_ITERS} iterations — stopping for a human."
+    exit 1
+  fi
+  echo ""
+  echo "[heal-loop] suite RED — iteration ${i}/${MAX_ITERS}: asking Claude for one focused fix..."
+  claude -p "The CODEC test suite is failing. Run '${PYTEST_CMD}', find the root cause, and fix the CODE — do not edit the tests. Make ONE focused change. CODEC rule: if you edit any file under skills/, you MUST run 'python3 tools/generate_skill_manifest.py --write' afterward or the skill will be refused at load time." \
+    --allowedTools "Bash(python3 -m pytest*),Bash(python3 tools/generate_skill_manifest.py*),Edit,Read,Grep,Glob" \
+    --max-turns 30
+done
+
+echo ""
+echo "[heal-loop] ✅ suite GREEN after ${i} fix iteration(s)."