diff --git a/hosts/codex.ts b/hosts/codex.ts
index e447b8153..0f2594626 100644
--- a/hosts/codex.ts
+++ b/hosts/codex.ts
@@ -20,8 +20,9 @@ const codex = defineHost({
 
   // generateMetadata emits agents/openai.yaml (the format is hardcoded in
   // gen-skill-docs.ts). Codex also gets a repo-local sidecar at
-  // .agents/skills/gstack (symlinked runtime assets: bin, browse, review, qa,
-  // ETHOS.md) — that behavior lives in setup's create_agents_sidecar, not here.
+  // .agents/skills/gstack (symlinked runtime assets: bin, lib, browse, review,
+  // qa, design/dist, make-pdf/dist, ETHOS.md) — that behavior lives in setup's
+  // create_agents_sidecar, not here.
   generation: {
     generateMetadata: true,
     skipSkills: ['codex'],
@@ -38,6 +39,15 @@ const codex = defineHost({
     { from: 'CLAUDE.md', to: 'AGENTS.md' },
   ],
 
+  // Mirrors create_codex_runtime_root in setup. design/dist and make-pdf/dist
+  // back $GSTACK_DESIGN and $GSTACK_MAKE_PDF (#2891).
+  runtimeRoot: {
+    globalSymlinks: ['bin', 'lib', 'browse/dist', 'browse/bin', 'design/dist', 'make-pdf/dist', 'gstack-upgrade', 'ETHOS.md'],
+    globalFiles: {
+      'review': ['checklist.md', 'design-checklist.md', 'greptile-triage.md', 'TODOS-format.md'],
+    },
+  },
+
   // Outside-review resolvers route to Claude Code; Review Army has its own restriction.
   suppressedResolvers: ['REVIEW_ARMY', ...GBRAIN_RESOLVERS],
 
diff --git a/hosts/define-host.ts b/hosts/define-host.ts
index d2b9927e1..a90010e37 100644
--- a/hosts/define-host.ts
+++ b/hosts/define-host.ts
@@ -126,7 +126,7 @@ export function defineHost<const N extends string>(overrides: HostOverrides<N>):
     toolRewrites,
     suppressedResolvers = [...GBRAIN_RESOLVERS],
     runtimeRoot = {
-      globalSymlinks: ['bin', 'browse/dist', 'browse/bin', 'gstack-upgrade', 'ETHOS.md'],
+      globalSymlinks: ['bin', 'lib', 'browse/dist', 'browse/bin', 'design/dist', 'make-pdf/dist', 'gstack-upgrade', 'ETHOS.md'],
       globalFiles: {
         'review': ['checklist.md', 'TODOS-format.md'],
       },
diff --git a/hosts/opencode.ts b/hosts/opencode.ts
index 30da3f7ea..038267a0f 100644
--- a/hosts/opencode.ts
+++ b/hosts/opencode.ts
@@ -14,7 +14,7 @@ const opencode = defineHost({
   // OpenCode links a wider runtime asset set than the shared default
   // (design binary, review specialists, qa templates/references, DX hall of fame).
   runtimeRoot: {
-    globalSymlinks: ['bin', 'browse/dist', 'browse/bin', 'design/dist', 'gstack-upgrade', 'ETHOS.md', 'review/specialists', 'qa/templates', 'qa/references', 'plan-devex-review/dx-hall-of-fame.md'],
+    globalSymlinks: ['bin', 'lib', 'browse/dist', 'browse/bin', 'design/dist', 'make-pdf/dist', 'gstack-upgrade', 'ETHOS.md', 'review/specialists', 'qa/templates', 'qa/references', 'plan-devex-review/dx-hall-of-fame.md'],
     globalFiles: {
       'review': ['checklist.md', 'design-checklist.md', 'greptile-triage.md', 'TODOS-format.md'],
     },
diff --git a/setup b/setup
index cbb1ed14c..87c9573e9 100755
--- a/setup
+++ b/setup
@@ -496,6 +496,21 @@ _link_or_copy() {
   fi
 }
 
+# _link_runtime_dists SOURCE ROOT — the compiled design and make-pdf binaries
+# behind $GSTACK_DESIGN and $GSTACK_MAKE_PDF on every env-var host (#2891).
+# dist/ only, never the whole directory: make-pdf/ ships a Claude SKILL.md a
+# host scanning its skills root would discover as a duplicate skill.
+_link_runtime_dists() {
+  local d
+  for d in design/dist make-pdf/dist; do
+    [ -d "$1/$d" ] || continue
+    if [ "$IS_WINDOWS" -eq 1 ] || [ -L "$2/$d" ] || [ ! -e "$2/$d" ]; then
+      mkdir -p "$2/${d%/dist}"
+      _link_or_copy "$1/$d" "$2/$d"
+    fi
+  done
+}
+
 # ─── Ownership gate for skill entries (#2119) ─────────────────────────────────
 # setup and gstack-relink must never delete or link over a skill they do not
 # own. This is the single rule both use (relink carries the same logic — keep
@@ -2322,6 +2337,8 @@ create_agents_sidecar() {
     fi
   done
 
+  _link_runtime_dists "$SOURCE_GSTACK_DIR" "$agents_gstack"
+
   # supabase/config.sh — required by gstack-telemetry-sync to resolve GSTACK_SUPABASE_URL
   # (file-level on purpose: migrations/ and functions/ are dev-only)
   if [ -f "$SOURCE_GSTACK_DIR/supabase/config.sh" ]; then
@@ -2398,6 +2415,7 @@ create_codex_runtime_root() {
   if [ -d "$gstack_dir/browse/bin" ]; then
     _link_or_copy "$gstack_dir/browse/bin" "$codex_gstack/browse/bin"
   fi
+  _link_runtime_dists "$gstack_dir" "$codex_gstack"
   if [ -f "$agents_dir/gstack-upgrade/SKILL.md" ]; then
     _link_or_copy "$agents_dir/gstack-upgrade/SKILL.md" "$codex_gstack/gstack-upgrade/SKILL.md"
   fi
@@ -2453,6 +2471,7 @@ create_factory_runtime_root() {
   if [ -d "$gstack_dir/browse/bin" ]; then
     _link_or_copy "$gstack_dir/browse/bin" "$factory_gstack/browse/bin"
   fi
+  _link_runtime_dists "$gstack_dir" "$factory_gstack"
   if [ -f "$factory_dir/gstack-upgrade/SKILL.md" ]; then
     _link_or_copy "$factory_dir/gstack-upgrade/SKILL.md" "$factory_gstack/gstack-upgrade/SKILL.md"
   fi
@@ -2489,7 +2508,7 @@ create_opencode_runtime_root() {
     rm -rf "$opencode_gstack"
   fi
 
-  mkdir -p "$opencode_gstack" "$opencode_gstack/browse" "$opencode_gstack/design" "$opencode_gstack/gstack-upgrade" "$opencode_gstack/review" "$opencode_gstack/qa" "$opencode_gstack/plan-devex-review"
+  mkdir -p "$opencode_gstack" "$opencode_gstack/browse" "$opencode_gstack/gstack-upgrade" "$opencode_gstack/review" "$opencode_gstack/qa" "$opencode_gstack/plan-devex-review"
 
   if [ -f "$opencode_dir/gstack/SKILL.md" ]; then
     _link_or_copy "$opencode_dir/gstack/SKILL.md" "$opencode_gstack/SKILL.md"
@@ -2506,9 +2525,7 @@ create_opencode_runtime_root() {
   if [ -d "$gstack_dir/browse/bin" ]; then
     _link_or_copy "$gstack_dir/browse/bin" "$opencode_gstack/browse/bin"
   fi
-  if [ -d "$gstack_dir/design/dist" ]; then
-    _link_or_copy "$gstack_dir/design/dist" "$opencode_gstack/design/dist"
-  fi
+  _link_runtime_dists "$gstack_dir" "$opencode_gstack"
   if [ -f "$opencode_dir/gstack-upgrade/SKILL.md" ]; then
     _link_or_copy "$opencode_dir/gstack-upgrade/SKILL.md" "$opencode_gstack/gstack-upgrade/SKILL.md"
   fi
@@ -2671,6 +2688,7 @@ create_cursor_runtime_root() {
   if [ -d "$gstack_dir/browse/bin" ]; then
     _link_or_copy "$gstack_dir/browse/bin" "$cursor_gstack/browse/bin"
   fi
+  _link_runtime_dists "$gstack_dir" "$cursor_gstack"
   if [ -f "$cursor_dir/gstack-upgrade/SKILL.md" ]; then
     _link_or_copy "$cursor_dir/gstack-upgrade/SKILL.md" "$cursor_gstack/gstack-upgrade/SKILL.md"
   fi
@@ -2728,6 +2746,7 @@ create_cursor_sidecar() {
       _link_or_copy "$repo_root/browse/bin" "$cursor_gstack/browse/bin"
     fi
   fi
+  _link_runtime_dists "$repo_root" "$cursor_gstack"
   if [ -f "$cursor_dir/gstack-upgrade/SKILL.md" ]; then
     if [ "$IS_WINDOWS" -eq 1 ] || [ -L "$cursor_gstack/gstack-upgrade/SKILL.md" ] || [ ! -e "$cursor_gstack/gstack-upgrade/SKILL.md" ]; then
       _link_or_copy "$cursor_dir/gstack-upgrade/SKILL.md" "$cursor_gstack/gstack-upgrade/SKILL.md"
@@ -2838,6 +2857,7 @@ create_copilot_runtime_root() {
       _link_or_copy "$gstack_dir/$asset" "$copilot_gstack/$asset"
     fi
   done
+  _link_runtime_dists "$gstack_dir" "$copilot_gstack"
   if [ -f "$copilot_dir/gstack-upgrade/SKILL.md" ]; then
     _link_or_copy "$copilot_dir/gstack-upgrade/SKILL.md" "$copilot_gstack/gstack-upgrade/SKILL.md"
   fi
@@ -3122,6 +3142,7 @@ if [ "$INSTALL_KIRO" -eq 1 ]; then
     _link_or_copy "$SOURCE_GSTACK_DIR/lib" "$KIRO_GSTACK/lib"
     _link_or_copy "$SOURCE_GSTACK_DIR/browse/dist" "$KIRO_GSTACK/browse/dist"
     _link_or_copy "$SOURCE_GSTACK_DIR/browse/bin" "$KIRO_GSTACK/browse/bin"
+    _link_runtime_dists "$SOURCE_GSTACK_DIR" "$KIRO_GSTACK"
     if [ -f "$SOURCE_GSTACK_DIR/ETHOS.md" ]; then
       _link_or_copy "$SOURCE_GSTACK_DIR/ETHOS.md" "$KIRO_GSTACK/ETHOS.md"
     fi
diff --git a/test/setup-codex-design-pdf-runtime.test.ts b/test/setup-codex-design-pdf-runtime.test.ts
new file mode 100644
index 000000000..86a1a4416
--- /dev/null
+++ b/test/setup-codex-design-pdf-runtime.test.ts
@@ -0,0 +1,158 @@
+import { describe, test, expect } from 'bun:test';
+import { spawnSync } from 'child_process';
+import * as path from 'path';
+import * as fs from 'fs';
+import * as os from 'os';
+import { HOST_PATHS, type TemplateContext } from '../scripts/resolvers/types';
+import { generateDesignSetup } from '../scripts/resolvers/design';
+import { generateMakePdfSetup } from '../scripts/resolvers/make-pdf';
+
+// #2891 (C2): Codex design and make-pdf skills resolve their binaries from the
+// repo-local .agents sidecar first, then from $GSTACK_DESIGN / $GSTACK_MAKE_PDF
+// under the global ~/.codex/skills/gstack root. setup never linked either
+// dist/ into those roots, so both preflights printed *_NOT_AVAILABLE on a
+// fresh install even though the binaries were built.
+//
+// Each root is built with the real setup shell functions, then the bash block
+// the generator emits for Codex runs in a fresh process (the way Codex runs
+// every shell call).
+
+const ROOT = path.resolve(import.meta.dir, '..');
+const SETUP_SRC = fs.readFileSync(path.join(ROOT, 'setup'), 'utf-8');
+
+function extractFunction(name: string): string {
+  const start = SETUP_SRC.indexOf(`\n${name}() {`);
+  const end = SETUP_SRC.indexOf('\n}\n', start);
+  if (start < 0 || end < 0) throw new Error(`Could not locate ${name}() in setup`);
+  return SETUP_SRC.slice(start + 1, end + 2);
+}
+
+function codexCtx(skillName: string): TemplateContext {
+  return { skillName, tmplPath: `${skillName}/SKILL.md.tmpl`, host: 'codex', paths: HOST_PATHS.codex };
+}
+
+function firstBashBlock(rendered: string): string {
+  const m = rendered.match(/```bash\n([\s\S]*?)```/);
+  if (!m) throw new Error('no bash block in rendered section');
+  return m[1];
+}
+
+const DESIGN_PREFLIGHT = firstBashBlock(generateDesignSetup(codexCtx('design-shotgun')));
+const MAKE_PDF_PREFLIGHT = firstBashBlock(generateMakePdfSetup(codexCtx('make-pdf')));
+
+// A minimal gstack source tree: both built binaries, plus make-pdf's own
+// SKILL.md and design sources, which must NOT leak into a Codex-scanned root.
+function makeSource(sandbox: string): string {
+  const src = path.join(sandbox, 'gstack');
+  for (const [rel, body] of [
+    ['design/dist/design', '#!/bin/sh\necho design\n'],
+    ['make-pdf/dist/pdf', '#!/bin/sh\necho pdf\n'],
+  ] as const) {
+    fs.mkdirSync(path.dirname(path.join(src, rel)), { recursive: true });
+    fs.writeFileSync(path.join(src, rel), body, { mode: 0o755 });
+  }
+  fs.mkdirSync(path.join(src, 'design', 'src'), { recursive: true });
+  fs.writeFileSync(path.join(src, 'make-pdf', 'SKILL.md'), '---\nname: make-pdf\n---\n');
+  return src;
+}
+
+function run(cmd: string, opts: { cwd: string; env?: Record<string, string> }) {
+  const env: Record<string, string> = { PATH: process.env.PATH ?? '/usr/bin:/bin', ...opts.env };
+  return spawnSync('bash', ['-c', cmd], { cwd: opts.cwd, encoding: 'utf-8', timeout: 30000, env });
+}
+
+interface Built { script: string; rootDir: string; preflight: { cwd: string; env: Record<string, string> } }
+
+const BUILDERS: Record<string, (sandbox: string, src: string) => Built> = {
+  'codex global root': (sandbox, src) => {
+    const rootDir = path.join(sandbox, 'home', '.codex', 'skills', 'gstack');
+    const outside = path.join(sandbox, 'not-a-repo');
+    fs.mkdirSync(outside, { recursive: true });
+    return {
+      script: `create_codex_runtime_root "${src}" "${rootDir}"`,
+      rootDir,
+      preflight: {
+        cwd: outside,
+        env: {
+          HOME: path.join(sandbox, 'home'),
+          GSTACK_DESIGN: path.join(rootDir, 'design', 'dist'),
+          GSTACK_MAKE_PDF: path.join(rootDir, 'make-pdf', 'dist'),
+        },
+      },
+    };
+  },
+  'agents sidecar': (sandbox, src) => {
+    const repo = path.join(sandbox, 'repo');
+    fs.mkdirSync(repo, { recursive: true });
+    spawnSync('git', ['init', '-q'], { cwd: repo, timeout: 30000 });
+    return {
+      script: `SOURCE_GSTACK_DIR="${src}"\ncreate_agents_sidecar "${repo}"`,
+      rootDir: path.join(repo, '.agents', 'skills', 'gstack'),
+      preflight: {
+        cwd: repo,
+        env: {
+          HOME: path.join(sandbox, 'home'),
+          GSTACK_DESIGN: path.join(sandbox, 'missing'),
+          GSTACK_MAKE_PDF: path.join(sandbox, 'missing'),
+        },
+      },
+    };
+  },
+};
+
+const FUNCTIONS = ['_link_or_copy', '_link_runtime_dists', '_sidecar_root_user_owned', '_gstack_generated_header', 'create_agents_sidecar', 'create_codex_runtime_root']
+  .filter(name => SETUP_SRC.includes(`\n${name}() {`))
+  .map(extractFunction)
+  .join('\n');
+
+describe.skipIf(process.platform === 'win32')('setup: Codex roots expose design and make-pdf binaries (#2891)', () => {
+  for (const [name, build] of Object.entries(BUILDERS)) {
+    for (const isWindows of ['0', '1'] as const) {
+      const mode = isWindows === '1' ? 'Windows copy install' : 'symlink install';
+      test(`${name} (${mode}): design and make-pdf preflights report READY`, () => {
+        const sandbox = fs.mkdtempSync(path.join(os.tmpdir(), 'gstack-codex-dist-'));
+        try {
+          const src = makeSource(sandbox);
+          const built = build(sandbox, src);
+          const b = run(`IS_WINDOWS=${isWindows}\n${FUNCTIONS}\n${built.script}`, { cwd: sandbox });
+          expect(b.stderr).toBe('');
+          expect(b.status).toBe(0);
+
+          expect(fs.lstatSync(path.join(built.rootDir, 'design', 'dist')).isSymbolicLink()).toBe(isWindows === '0');
+          expect(fs.existsSync(path.join(built.rootDir, 'make-pdf', 'SKILL.md'))).toBe(false);
+          expect(fs.existsSync(path.join(built.rootDir, 'design', 'src'))).toBe(false);
+
+          const d = run(DESIGN_PREFLIGHT, built.preflight);
+          expect(d.stdout).toContain('DESIGN_READY:');
+          expect(d.stdout).not.toContain('DESIGN_NOT_AVAILABLE');
+          const p = run(MAKE_PDF_PREFLIGHT, built.preflight);
+          expect(p.stdout).toContain('MAKE_PDF_READY:');
+          expect(p.stdout).not.toContain('MAKE_PDF_NOT_AVAILABLE');
+        } finally {
+          fs.rmSync(sandbox, { recursive: true, force: true });
+        }
+      });
+    }
+  }
+
+  // Negative control: a root without design/dist and make-pdf/dist fails both
+  // preflights, so the READY cells are not vacuous.
+  test('a Codex root without design/dist and make-pdf/dist reports NOT_AVAILABLE', () => {
+    const sandbox = fs.mkdtempSync(path.join(os.tmpdir(), 'gstack-codex-dist-'));
+    try {
+      const rootDir = path.join(sandbox, 'home', '.codex', 'skills', 'gstack');
+      fs.mkdirSync(path.join(rootDir, 'browse'), { recursive: true });
+      const outside = path.join(sandbox, 'not-a-repo');
+      fs.mkdirSync(outside, { recursive: true });
+      const env = {
+        HOME: path.join(sandbox, 'home'),
+        GSTACK_DESIGN: path.join(rootDir, 'design', 'dist'),
+        GSTACK_MAKE_PDF: path.join(rootDir, 'make-pdf', 'dist'),
+      };
+      expect(run(DESIGN_PREFLIGHT, { cwd: outside, env }).stdout).toContain('DESIGN_NOT_AVAILABLE');
+      expect(run(MAKE_PDF_PREFLIGHT, { cwd: outside, env }).stdout).toContain('MAKE_PDF_NOT_AVAILABLE');
+    } finally {
+      fs.rmSync(sandbox, { recursive: true, force: true });
+    }
+  });
+});
diff --git a/test/setup-kiro-native.test.ts b/test/setup-kiro-native.test.ts
index aac6d8e8a..229a37529 100644
--- a/test/setup-kiro-native.test.ts
+++ b/test/setup-kiro-native.test.ts
@@ -17,7 +17,7 @@ const fn = (name: string) => {
 const blockStart = setup.indexOf('# 6. Install for Kiro CLI');
 const block = setup.slice(blockStart, setup.indexOf('# 6b.', blockStart));
 const helpers = [
-  '_link_or_copy', '_sidecar_root_user_owned', '_claude_entry_is_ours',
+  '_link_or_copy', '_link_runtime_dists', '_sidecar_root_user_owned', '_claude_entry_is_ours',
   '_claude_entry_owned_strongly', '_gstack_link_target_abs', '_gstack_target_is_ours',
   '_gstack_generated_header', '_backup_skill_md', '_prune_stale_generated',
   '_skill_source_exists', '_owned_for_windows_refresh', '_cleanup_weak_dir',
diff --git a/test/setup-windows-rerun-refresh.test.ts b/test/setup-windows-rerun-refresh.test.ts
index b68ad23a1..f9e18401d 100644
--- a/test/setup-windows-rerun-refresh.test.ts
+++ b/test/setup-windows-rerun-refresh.test.ts
@@ -159,6 +159,7 @@ function runInstaller(
     `IS_WINDOWS=${isWindows}`,
     extraVars,
     extractFn('_link_or_copy'),
+    extractFn('_link_runtime_dists'),
     // Ownership gates (#2142) — dependencies of every installer under test.
     extractFn('_owned_for_windows_refresh'),
     extractFn('_sidecar_root_user_owned'),