diff --git a/autoplan/SKILL.md b/autoplan/SKILL.md
index 5346f1d43..826a073af 100644
--- a/autoplan/SKILL.md
+++ b/autoplan/SKILL.md
@@ -892,8 +892,14 @@ After /office-hours completes, re-run the design doc check:
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
 
diff --git a/plan-ceo-review/SKILL.md b/plan-ceo-review/SKILL.md
index 3d3208bee..586eb2d34 100644
--- a/plan-ceo-review/SKILL.md
+++ b/plan-ceo-review/SKILL.md
@@ -949,11 +949,17 @@ Then read CLAUDE.md, TODOS.md, and any existing architecture docs.
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
-If a design doc exists (from `/office-hours`), read it. Use it as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design.
+If a design doc exists, read it. Prefer repo-local `DESIGN.md` or `design-system.md` when present — that is the best signal for the current subproject in a monorepo. Otherwise, fall back to the most relevant `~/.gstack/projects/$SLUG/*-design-*.md` document from `/office-hours`. Use the selected document as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design.
 
 **Handoff note check** (reuses $SLUG and $BRANCH from the design doc check above):
 ```bash
@@ -1020,8 +1026,14 @@ After /office-hours completes, re-run the design doc check:
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
 
diff --git a/plan-ceo-review/SKILL.md.tmpl b/plan-ceo-review/SKILL.md.tmpl
index c43cfe641..374e7ca1a 100644
--- a/plan-ceo-review/SKILL.md.tmpl
+++ b/plan-ceo-review/SKILL.md.tmpl
@@ -138,11 +138,17 @@ Then read CLAUDE.md, TODOS.md, and any existing architecture docs.
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
-If a design doc exists (from `/office-hours`), read it. Use it as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design.
+If a design doc exists, read it. Prefer repo-local `DESIGN.md` or `design-system.md` when present — that is the best signal for the current subproject in a monorepo. Otherwise, fall back to the most relevant `~/.gstack/projects/$SLUG/*-design-*.md` document from `/office-hours`. Use the selected document as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design.
 
 **Handoff note check** (reuses $SLUG and $BRANCH from the design doc check above):
 ```bash
diff --git a/plan-eng-review/SKILL.md b/plan-eng-review/SKILL.md
index 5557a33fa..68b64fba2 100644
--- a/plan-eng-review/SKILL.md
+++ b/plan-eng-review/SKILL.md
@@ -913,11 +913,17 @@ sections. Read a section in full before doing its step; do not work from memory.
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
-If a design doc exists, read it. Use it as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design — check the prior version for context on what changed and why.
+If a design doc exists, read it. Prefer repo-local `DESIGN.md` or `design-system.md` when present — that is the best signal for the current subproject in a monorepo. Otherwise, fall back to the most relevant `~/.gstack/projects/$SLUG/*-design-*.md` document from `/office-hours`. Use the selected document as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design — check the prior version for context on what changed and why.
 
 ## Prerequisite Skill Offer
 
@@ -968,8 +974,14 @@ After /office-hours completes, re-run the design doc check:
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
 
diff --git a/plan-eng-review/SKILL.md.tmpl b/plan-eng-review/SKILL.md.tmpl
index 1d5be0e6f..0a2e0108b 100644
--- a/plan-eng-review/SKILL.md.tmpl
+++ b/plan-eng-review/SKILL.md.tmpl
@@ -104,11 +104,17 @@ When evaluating architecture, think "boring by default." When reviewing tests, t
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 ```
-If a design doc exists, read it. Use it as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design — check the prior version for context on what changed and why.
+If a design doc exists, read it. Prefer repo-local `DESIGN.md` or `design-system.md` when present — that is the best signal for the current subproject in a monorepo. Otherwise, fall back to the most relevant `~/.gstack/projects/$SLUG/*-design-*.md` document from `/office-hours`. Use the selected document as the source of truth for the problem statement, constraints, and chosen approach. If it has a `Supersedes:` field, note that this is a revised design — check the prior version for context on what changed and why.
 
 {{BENEFITS_FROM}}
 
diff --git a/scripts/resolvers/review.ts b/scripts/resolvers/review.ts
index 7dccd8e50..b65f61d36 100644
--- a/scripts/resolvers/review.ts
+++ b/scripts/resolvers/review.ts
@@ -309,8 +309,14 @@ After /${first} completes, re-run the design doc check:
 setopt +o nomatch 2>/dev/null || true  # zsh compat
 SLUG=$(~/.claude/skills/gstack/browse/bin/remote-slug 2>/dev/null || basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
 BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-' || echo 'no-branch')
-DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
-[ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+if [ -f DESIGN.md ]; then
+  DESIGN="$PWD/DESIGN.md"
+elif [ -f design-system.md ]; then
+  DESIGN="$PWD/design-system.md"
+else
+  DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-$BRANCH-design-*.md 2>/dev/null | head -1)
+  [ -z "$DESIGN" ] && DESIGN=$(ls -t ~/.gstack/projects/$SLUG/*-design-*.md 2>/dev/null | head -1)
+fi
 [ -n "$DESIGN" ] && echo "Design doc found: $DESIGN" || echo "No design doc found"
 \`\`\`
 
diff --git a/test/gen-skill-docs.test.ts b/test/gen-skill-docs.test.ts
index 2fb783ffd..e7a1e6327 100644
--- a/test/gen-skill-docs.test.ts
+++ b/test/gen-skill-docs.test.ts
@@ -1410,6 +1410,18 @@ describe('BENEFITS_FROM resolver', () => {
     expect(engContent).toContain('skipping these sections');
     expect(ceoContent).toContain('Follow its instructions from top to bottom');
   });
+
+  test('plan reviews prefer repo-local design docs before ~/.gstack history', () => {
+    expect(ceoContent).toContain('if [ -f DESIGN.md ]; then');
+    expect(ceoContent).toContain('DESIGN="$PWD/DESIGN.md"');
+    expect(ceoContent).toContain('design-system.md');
+    expect(ceoContent).toContain('~/.gstack/projects/$SLUG');
+
+    expect(engContent).toContain('if [ -f DESIGN.md ]; then');
+    expect(engContent).toContain('DESIGN="$PWD/DESIGN.md"');
+    expect(engContent).toContain('design-system.md');
+    expect(engContent).toContain('~/.gstack/projects/$SLUG');
+  });
 });
 
 // --- {{INVOKE_SKILL}} resolver tests ---