diff --git a/.github/actionlint.yml b/.github/actionlint.yml
new file mode 100644
index 0000000..2e9302b
--- /dev/null
+++ b/.github/actionlint.yml
@@ -0,0 +1,4 @@
+# See: https://github.com/rhysd/actionlint/blob/main/docs/config.md
+self-hosted-runner:
+  labels:
+    - ubuntu-latest-m
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6af4987..cf1a8fb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -42,3 +42,28 @@ jobs:
 
       - name: Run Tests
         run: ./scripts/covgate.sh
+
+  surface-lint:
+    timeout-minutes: 10
+    name: surface-lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      # yamllint disable rule:line-length
+      - name: Lint YAML
+        uses: ibiqlik/action-yamllint@2576378a8e339169678f9939646ee3ee325e845c # v3.1.1
+        with:
+          file_or_dir: .
+          config_file: .yamllint.yml
+
+      - name: Lint Shell Scripts
+        uses: ludeeus/action-shellcheck@00cae500b08a931fb5698e11e79bfbd38e612a38 # 2.0.0
+        with:
+          scandir: ./
+          ignore_paths: .agents
+
+      - name: Lint GitHub Actions Workflows
+        uses: rhysd/actionlint@914e7df21a07ef503a81201c76d2b11c789d3fca # v1.7.12
+        # yamllint enable rule:line-length
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 0515917..cc8f185 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -26,12 +26,15 @@ jobs:
           go-version-file: ./go.mod
 
       - name: Initialize CodeQL
+        # yamllint disable rule:line-length
         uses: github/codeql-action/init@38697555549f1db7851b81482ff19f1fa5c4fedc # v4
         with:
           languages: go
 
       - name: Autobuild
+        # yamllint disable rule:line-length
         uses: github/codeql-action/autobuild@38697555549f1db7851b81482ff19f1fa5c4fedc # v4
 
       - name: Perform CodeQL Analysis
+        # yamllint disable rule:line-length
         uses: github/codeql-action/analyze@38697555549f1db7851b81482ff19f1fa5c4fedc # v4
diff --git a/.yamllint.yml b/.yamllint.yml
new file mode 100644
index 0000000..02c379b
--- /dev/null
+++ b/.yamllint.yml
@@ -0,0 +1,21 @@
+# See: https://yamllint.readthedocs.io/en/stable/
+
+extends: default
+
+rules:
+  document-start:
+    present: false
+  line-length:
+    level: warning
+    allow-non-breakable-inline-mappings: true
+  # GitHub Actions uses `on:` as a workflow trigger key; YAML 1.1 treats `on`
+  # as a truthy boolean alias. Disable key checking to avoid false positives.
+  truthy:
+    check-keys: false
+  # SHA-pinned action comments use a single space before `#`. Reduce the
+  # minimum from the default 2 to 1 to match the existing convention.
+  comments:
+    min-spaces-from-content: 1
+
+ignore: |
+  .agents/
diff --git a/plans/completed/surface-linters.md b/plans/completed/surface-linters.md
new file mode 100644
index 0000000..b23a6fa
--- /dev/null
+++ b/plans/completed/surface-linters.md
@@ -0,0 +1,61 @@
+# Surface Linters for gotools
+
+## Goal
+
+Add non-Go surface linters (YAML, shell script, GitHub Actions) to the gotools repository, matching what was added to the core repository.
+
+## Background
+
+The core repository added surface linters in commits `3360e12`–`6ecf0d7`. The implementation consists of:
+- `.yamllint.yml` — yamllint configuration
+- `.github/actionlint.yml` — actionlint configuration (minimal)
+- `scripts/lint-surface.sh` — runs yamllint, shellcheck, actionlint
+- `scripts/install-lint-tools.sh` — installs the three linters
+- `surface-lint` CI job in `.github/workflows/ci.yml`
+
+## Scope
+
+Repo: `gotools` (`/home/ben/miru/workbench3/gotools`)
+
+## Steps
+
+### 1. Add `.yamllint.yml`
+
+Create `.yamllint.yml` at repo root, adapted from core:
+- Same rules (document-start, line-length, truthy, comments)
+- Ignore `.agents/` instead of `.venv/` (gotools has `.agents/` subtree, no `.venv/`)
+- No `tests/testdata/` ignore needed (gotools has no such dir)
+
+### 2. Add `.github/actionlint.yml`
+
+Create `.github/actionlint.yml` with minimal comment (no custom config needed).
+
+### 3. Add `scripts/lint-surface.sh`
+
+Copy from core verbatim — checks for yamllint, shellcheck, actionlint, then runs each.
+Make executable.
+
+### 4. Add `scripts/install-lint-tools.sh`
+
+Copy from core verbatim — installs yamllint (via pip3/.venv), shellcheck (apt/brew), actionlint (go install).
+Make executable.
+
+### 5. Update `.github/workflows/ci.yml`
+
+Add `surface-lint` job matching core:
+- Checkout
+- yamllint via `ibiqlik/action-yamllint` (SHA-pinned, same as core)
+- shellcheck via `ludeeus/action-shellcheck` (SHA-pinned, same as core)
+- actionlint via `rhysd/actionlint` (SHA-pinned, same as core)
+
+## Test Steps
+
+- `yamllint -c .yamllint.yml .` passes (run locally with yamllint installed)
+- `shellcheck scripts/*.sh` passes
+- `actionlint` passes on the workflows
+- `scripts/lint-surface.sh` runs end-to-end without error (with tools installed)
+- CI `surface-lint` job is syntactically valid (actionlint validates it)
+
+## Validation
+
+Preflight must report `clean` before a PR is opened. Run `./scripts/preflight.sh` and confirm no failures.
diff --git a/scripts/install-lint-tools.sh b/scripts/install-lint-tools.sh
new file mode 100755
index 0000000..41b81cb
--- /dev/null
+++ b/scripts/install-lint-tools.sh
@@ -0,0 +1,67 @@
+#!/bin/sh
+set -e
+
+usage() {
+	cat <<EOF
+Usage: $(basename "$0") [options]
+
+Install the surface linters required by scripts/lint-surface.sh:
+  - yamllint    (YAML linter)
+  - shellcheck  (shell script linter)
+  - actionlint  (GitHub Actions workflow linter)
+
+yamllint is installed into .venv if one exists, otherwise via system pip3.
+shellcheck is installed via apt-get or brew.
+actionlint is installed via go install.
+
+Options:
+  -h, --help   Show this help message and exit
+EOF
+}
+
+while [ $# -gt 0 ]; do
+	case "$1" in
+		-h|--help)
+			usage
+			exit 0
+			;;
+		*)
+			echo "error: unknown option: $1" >&2
+			usage >&2
+			exit 1
+			;;
+	esac
+done
+
+git_repo_root_dir=$(git rev-parse --show-toplevel)
+cd "$git_repo_root_dir"
+
+# --- yamllint ---
+echo "==> Installing yamllint..."
+if [ -d ".venv" ]; then
+	.venv/bin/pip install --quiet yamllint
+else
+	pip3 install --quiet yamllint
+fi
+echo "    done."
+
+# --- shellcheck ---
+echo "==> Installing shellcheck..."
+if command -v apt-get >/dev/null 2>&1; then
+	sudo apt-get install -y shellcheck
+elif command -v brew >/dev/null 2>&1; then
+	brew install shellcheck
+else
+	echo "error: no supported package manager found (apt-get, brew)." >&2
+	echo "Install shellcheck manually: https://github.com/koalaman/shellcheck#installing" >&2
+	exit 1
+fi
+echo "    done."
+
+# --- actionlint ---
+echo "==> Installing actionlint..."
+go install github.com/rhysd/actionlint/cmd/actionlint@latest
+echo "    done."
+
+echo ""
+echo "All surface linters installed."
diff --git a/scripts/lint-surface.sh b/scripts/lint-surface.sh
new file mode 100755
index 0000000..84490b6
--- /dev/null
+++ b/scripts/lint-surface.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+set -e
+
+command -v yamllint >/dev/null 2>&1 || { echo "error: yamllint not installed" >&2; exit 1; }
+command -v shellcheck >/dev/null 2>&1 || { echo "error: shellcheck not installed" >&2; exit 1; }
+command -v actionlint >/dev/null 2>&1 || { echo "error: actionlint not installed" >&2; exit 1; }
+
+yamllint -c .yamllint.yml .
+
+find . -name '*.sh' ! -path './.agents/*' -exec shellcheck {} +
+
+actionlint
diff --git a/scripts/preflight.sh b/scripts/preflight.sh
index 1c371b5..b488f8b 100755
--- a/scripts/preflight.sh
+++ b/scripts/preflight.sh
@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-# Local validation script that mirrors CI (lint + test + coverage).
-# Lint and covgate run in parallel to minimize wall-clock time.
+# Local validation script that mirrors CI (lint + covgate + surface lint).
+# All three run in parallel to minimize wall-clock time.
 
 git_repo_root_dir=$(git rev-parse --show-toplevel)
 cd "$git_repo_root_dir"
@@ -19,12 +19,17 @@ lint_pid=$!
 ./scripts/covgate.sh &
 covgate_pid=$!
 
-# Wait for both processes regardless of individual exit codes.
-# set -e must not short-circuit here — both must run to completion.
+./scripts/lint-surface.sh &
+surface_pid=$!
+
+# Wait for all processes regardless of individual exit codes.
+# set -e must not short-circuit here — all must run to completion.
 lint_rc=0
 covgate_rc=0
+surface_rc=0
 wait "$lint_pid"    || lint_rc=$?
 wait "$covgate_pid" || covgate_rc=$?
+wait "$surface_pid" || surface_rc=$?
 
 echo ""
 
@@ -34,8 +39,11 @@ fi
 if [[ $covgate_rc -ne 0 ]]; then
 	echo "=== Covgate FAILED ==="
 fi
-if [[ $lint_rc -eq 0 && $covgate_rc -eq 0 ]]; then
+if [[ $surface_rc -ne 0 ]]; then
+	echo "=== Surface lint FAILED ==="
+fi
+if [[ $lint_rc -eq 0 && $covgate_rc -eq 0 && $surface_rc -eq 0 ]]; then
 	echo "=== All checks passed ==="
 fi
 
-exit $(( lint_rc | covgate_rc ))
+exit $(( lint_rc | covgate_rc | surface_rc ))