diff --git a/.github/workflows/setup-repo-tests.yml b/.github/workflows/setup-repo-tests.yml
index 2222d0f..5c245e3 100644
--- a/.github/workflows/setup-repo-tests.yml
+++ b/.github/workflows/setup-repo-tests.yml
@@ -31,4 +31,5 @@ jobs:
           bash tests/setup-repo/test-python-assets.sh
           bash tests/setup-repo/test-ci-assets.sh
           bash tests/setup-repo/test-node-assets.sh
+          bash tests/setup-repo/test-precommit-assets.sh
           bash tests/setup-repo/test-scaffold.sh
diff --git a/plugins/core/.claude-plugin/plugin.json b/plugins/core/.claude-plugin/plugin.json
index 68f07ce..62fa199 100644
--- a/plugins/core/.claude-plugin/plugin.json
+++ b/plugins/core/.claude-plugin/plugin.json
@@ -1,6 +1,6 @@
 {
   "name": "core",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "Core Offworld Labs skills, commands, agents, and hooks shared across all repos.",
   "author": {
     "name": "Offworld Labs"
diff --git a/plugins/core/skills/setup-repo/SKILL.md b/plugins/core/skills/setup-repo/SKILL.md
index df217ae..506a232 100644
--- a/plugins/core/skills/setup-repo/SKILL.md
+++ b/plugins/core/skills/setup-repo/SKILL.md
@@ -36,14 +36,20 @@ interactive parts and the report.
    - **ts-frontend / ts-backend:** run `npm install` (this generates
      `package-lock.json` — remind the user to commit it, since the CI workflow uses
      `npm ci`).
+   - **pre-commit (python & ts stacks):** after the stack deps are installed,
+     register the git hook so the scaffolded `.pre-commit-config.yaml` runs on
+     every commit: `uvx pre-commit install` (or `pipx run pre-commit install`, or
+     `pip install pre-commit && pre-commit install`). Skip with a note if
+     pre-commit/uv is unavailable.
    Report the command and result; if the toolchain is unavailable, skip and note it
    rather than failing.
 
 5. **Flesh out CLAUDE.md.** The stub was just written. Ask the user for a
    one-or-two-line description of what this repo does, then fill in the
    `Project Overview`, `Build & Test Commands`, and `Local Architecture`
-   sections from their answer plus what was scaffolded (stack, `ruff check .`,
-   `ruff format --check .`, `pytest`). If they skip, leave the stub as-is. Keep
+   sections from their answer plus what was scaffolded (stack; lint/format via
+   `pre-commit run --all-files`; tests via `pytest` or `npm test`). If they skip,
+   leave the stub as-is. Keep
    CLAUDE.md under the 200-line ceiling noted in the template.
 
 6. **Report and follow-ups.** Summarise files written vs skipped, then list the
diff --git a/plugins/core/skills/setup-repo/assets/ci/ci-node.yml b/plugins/core/skills/setup-repo/assets/ci/ci-node.yml
index 67ff7ff..70cfc89 100644
--- a/plugins/core/skills/setup-repo/assets/ci/ci-node.yml
+++ b/plugins/core/skills/setup-repo/assets/ci/ci-node.yml
@@ -21,11 +21,19 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+
+      - name: Pre-commit
+        run: uvx pre-commit run --all-files --show-diff-on-failure
+
       - name: Typecheck
         run: npm run typecheck
 
-      - name: Lint
-        run: npm run lint
-
       - name: Test
         run: npm test
diff --git a/plugins/core/skills/setup-repo/assets/ci/ci-python.yml b/plugins/core/skills/setup-repo/assets/ci/ci-python.yml
index 18424b7..c2c233b 100644
--- a/plugins/core/skills/setup-repo/assets/ci/ci-python.yml
+++ b/plugins/core/skills/setup-repo/assets/ci/ci-python.yml
@@ -23,11 +23,8 @@ jobs:
       - name: Install dependencies
         run: uv pip install --system -r requirements.txt -r requirements-dev.txt
 
-      - name: Ruff lint
-        run: ruff check .
-
-      - name: Ruff format check
-        run: ruff format --check .
+      - name: Pre-commit
+        run: uvx pre-commit run --all-files --show-diff-on-failure
 
       - name: Pytest
         run: pytest
diff --git a/plugins/core/skills/setup-repo/assets/precommit/python.yaml b/plugins/core/skills/setup-repo/assets/precommit/python.yaml
new file mode 100644
index 0000000..9a6478d
--- /dev/null
+++ b/plugins/core/skills/setup-repo/assets/precommit/python.yaml
@@ -0,0 +1,16 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-json
+      - id: check-merge-conflict
+      - id: check-added-large-files
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.8.0
+    hooks:
+      - id: ruff
+        args: [--fix]
+      - id: ruff-format
diff --git a/plugins/core/skills/setup-repo/assets/precommit/ts.yaml b/plugins/core/skills/setup-repo/assets/precommit/ts.yaml
new file mode 100644
index 0000000..f257608
--- /dev/null
+++ b/plugins/core/skills/setup-repo/assets/precommit/ts.yaml
@@ -0,0 +1,18 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-json
+      - id: check-merge-conflict
+      - id: check-added-large-files
+  - repo: local
+    hooks:
+      - id: eslint
+        name: eslint
+        entry: npx eslint --fix
+        language: system
+        types_or: [ts, tsx]
+        pass_filenames: true
diff --git a/plugins/core/skills/setup-repo/scripts/scaffold-repo.sh b/plugins/core/skills/setup-repo/scripts/scaffold-repo.sh
index a96594f..669d199 100755
--- a/plugins/core/skills/setup-repo/scripts/scaffold-repo.sh
+++ b/plugins/core/skills/setup-repo/scripts/scaffold-repo.sh
@@ -50,6 +50,7 @@ case "$STACK" in
     copy "$ASSETS/stack/python/gitignore"            "$TARGET/.gitignore"
     copy "$ASSETS/stack/python/tests/.gitkeep"       "$TARGET/tests/.gitkeep"
     copy "$ASSETS/ci/ci-python.yml"                  "$TARGET/.github/workflows/ci.yml"
+    copy "$ASSETS/precommit/python.yaml"             "$TARGET/.pre-commit-config.yaml"
     ;;
   ts-frontend)
     copy "$ASSETS/stack/ts-frontend/package.json"     "$TARGET/package.json"
@@ -62,6 +63,7 @@ case "$STACK" in
     copy "$ASSETS/stack/ts-frontend/src/index.test.ts" "$TARGET/src/index.test.ts"
     copy "$ASSETS/stack/ts-frontend/src/main.tsx"      "$TARGET/src/main.tsx"
     copy "$ASSETS/ci/ci-node.yml"                     "$TARGET/.github/workflows/ci.yml"
+    copy "$ASSETS/precommit/ts.yaml"                 "$TARGET/.pre-commit-config.yaml"
     ;;
   ts-backend)
     copy "$ASSETS/stack/ts-backend/package.json"      "$TARGET/package.json"
@@ -72,6 +74,7 @@ case "$STACK" in
     copy "$ASSETS/stack/ts-backend/src/index.ts"       "$TARGET/src/index.ts"
     copy "$ASSETS/stack/ts-backend/src/index.test.ts"  "$TARGET/src/index.test.ts"
     copy "$ASSETS/ci/ci-node.yml"                     "$TARGET/.github/workflows/ci.yml"
+    copy "$ASSETS/precommit/ts.yaml"                 "$TARGET/.pre-commit-config.yaml"
     ;;
   none) ;;
 esac
diff --git a/tests/setup-repo/test-ci-assets.sh b/tests/setup-repo/test-ci-assets.sh
index 36faf01..efb2958 100755
--- a/tests/setup-repo/test-ci-assets.sh
+++ b/tests/setup-repo/test-ci-assets.sh
@@ -18,8 +18,9 @@ assert on["push"]["branches"] == ["main"], on
 assert "pull_request" in on, on
 steps = doc["jobs"]["lint-and-test"]["steps"]
 runs = "\n".join(s.get("run", "") for s in steps)
-assert "ruff check ." in runs, runs
-assert "ruff format --check ." in runs, runs
+assert "pre-commit run --all-files" in runs, runs
+assert "ruff check ." not in runs, runs      # ruff now runs via pre-commit, not a direct CI step
+assert "ruff format --check ." not in runs, runs
 assert "pytest" in runs, runs
 assert "requirements.txt" in runs and "requirements-dev.txt" in runs, runs
 # org standard: install with uv, not pip
diff --git a/tests/setup-repo/test-node-assets.sh b/tests/setup-repo/test-node-assets.sh
index e79bd41..a5ae267 100755
--- a/tests/setup-repo/test-node-assets.sh
+++ b/tests/setup-repo/test-node-assets.sh
@@ -66,10 +66,14 @@ setup_node = [s for s in steps if str(s.get("uses", "")).startswith("actions/set
 assert setup_node, uses
 assert setup_node[0]["with"]["node-version"] == "20", setup_node
 assert setup_node[0]["with"]["cache"] == "npm", setup_node
+setup_py = [s for s in steps if str(s.get("uses", "")).startswith("actions/setup-python")]
+assert setup_py and setup_py[0]["with"]["python-version"] == "3.12", setup_py
+assert any(u.startswith("astral-sh/setup-uv") for u in uses), uses
 runs = "\n".join(s.get("run", "") for s in steps)
 assert "npm ci" in runs, runs
 assert "npm run typecheck" in runs, runs
-assert "npm run lint" in runs, runs
+assert "pre-commit run --all-files" in runs, runs
+assert "npm run lint" not in runs, runs      # eslint now runs via pre-commit
 assert "npm test" in runs, runs
 print("ci-node.yml OK")
 EOF
diff --git a/tests/setup-repo/test-precommit-assets.sh b/tests/setup-repo/test-precommit-assets.sh
new file mode 100755
index 0000000..188cd73
--- /dev/null
+++ b/tests/setup-repo/test-precommit-assets.sh
@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT="$(git rev-parse --show-toplevel)"
+PC="$ROOT/plugins/core/skills/setup-repo/assets/precommit"
+
+python3 - "$PC/python.yaml" "$PC/ts.yaml" <<'EOF'
+import sys
+try:
+    import yaml
+except ModuleNotFoundError:
+    print("pyyaml missing; skipping precommit YAML parse"); sys.exit(0)
+py = yaml.safe_load(open(sys.argv[1]))
+ts = yaml.safe_load(open(sys.argv[2]))
+
+def by_repo(doc):
+    return {r.get("repo"): r for r in doc["repos"]}
+
+HYGIENE = "https://github.com/pre-commit/pre-commit-hooks"
+RUFF = "https://github.com/astral-sh/ruff-pre-commit"
+need_hygiene = {"trailing-whitespace", "end-of-file-fixer", "check-yaml",
+                "check-json", "check-merge-conflict", "check-added-large-files"}
+
+pr = by_repo(py)
+assert HYGIENE in pr, pr.keys()
+assert RUFF in pr, pr.keys()
+assert pr[HYGIENE]["rev"] == "v5.0.0", pr[HYGIENE].get("rev")
+assert pr[RUFF]["rev"] == "v0.8.0", pr[RUFF].get("rev")
+assert need_hygiene <= {h["id"] for h in pr[HYGIENE]["hooks"]}, pr[HYGIENE]
+ruff_hooks = {h["id"]: h for h in pr[RUFF]["hooks"]}
+assert {"ruff", "ruff-format"} <= ruff_hooks.keys(), ruff_hooks
+assert ruff_hooks["ruff"].get("args") == ["--fix"], ruff_hooks["ruff"]
+print("python.yaml OK")
+
+tr = by_repo(ts)
+assert HYGIENE in tr, tr.keys()
+assert tr[HYGIENE]["rev"] == "v5.0.0", tr[HYGIENE].get("rev")
+assert need_hygiene <= {h["id"] for h in tr[HYGIENE]["hooks"]}, tr[HYGIENE]
+assert "local" in tr, tr.keys()
+local_hooks = tr["local"]["hooks"]
+eslint = next((h for h in local_hooks if h.get("id") == "eslint"), None)
+assert eslint is not None, local_hooks
+assert "npx eslint --fix" in eslint.get("entry", ""), eslint
+assert eslint.get("language") == "system", eslint
+assert eslint.get("types_or") == ["ts", "tsx"], eslint
+assert eslint.get("pass_filenames") is True, eslint
+print("ts.yaml OK")
+EOF
+echo "precommit assets OK"
diff --git a/tests/setup-repo/test-scaffold.sh b/tests/setup-repo/test-scaffold.sh
index 9de14cc..1bb23bc 100755
--- a/tests/setup-repo/test-scaffold.sh
+++ b/tests/setup-repo/test-scaffold.sh
@@ -12,7 +12,7 @@ for f in .claude/settings.json CLAUDE.md .claude/rules/security.md \
          .claude/rules/code-style.md .github/workflows/claude.yml \
          .github/workflows/claude-code-review.yml .github/workflows/ci.yml \
          .editorconfig pyproject.toml requirements.txt requirements-dev.txt \
-         .gitignore tests/.gitkeep; do
+         .gitignore tests/.gitkeep .pre-commit-config.yaml; do
   test -e "$TMP/$f" || { echo "MISSING: $f" >&2; exit 1; }
 done
 
@@ -41,6 +41,7 @@ for f in pyproject.toml requirements.txt requirements-dev.txt .gitignore \
          tests/.gitkeep .github/workflows/ci.yml; do
   test -e "$TMP_NONE/$f" && { echo "UNEXPECTED (none stack): $f" >&2; exit 1; }
 done
+test -e "$TMP_NONE/.pre-commit-config.yaml" && { echo "UNEXPECTED (none stack): .pre-commit-config.yaml" >&2; exit 1; }
 
 # scaffolded python defaults are internally consistent
 mkdir -p "$TMP/src"
@@ -84,7 +85,7 @@ bash "$ENGINE" "$TMP_TSF" ts-frontend
 for f in .claude/settings.json CLAUDE.md .editorconfig \
          package.json tsconfig.json eslint.config.js vite.config.ts .gitignore \
          index.html src/index.ts src/index.test.ts src/main.tsx .github/workflows/ci.yml \
-         .github/workflows/claude.yml; do
+         .github/workflows/claude.yml .pre-commit-config.yaml; do
   test -e "$TMP_TSF/$f" || { echo "MISSING (ts-frontend): $f" >&2; exit 1; }
 done
 for f in pyproject.toml requirements.txt requirements-dev.txt; do
@@ -100,7 +101,7 @@ trap 'rm -rf "$TMP" "$TMP_NONE" "$BOGUS" "$TMP_TSF" "$TMP_TSB"' EXIT
 git -C "$TMP_TSB" init -q
 bash "$ENGINE" "$TMP_TSB" ts-backend
 for f in package.json tsconfig.json eslint.config.js vitest.config.ts .gitignore \
-         src/index.ts .github/workflows/ci.yml; do
+         src/index.ts .github/workflows/ci.yml .pre-commit-config.yaml; do
   test -e "$TMP_TSB/$f" || { echo "MISSING (ts-backend): $f" >&2; exit 1; }
 done
 grep -q '"react"' "$TMP_TSB/package.json" && { echo "ts-backend should not have react" >&2; exit 1; }