diff --git a/package.json b/package.json
index 28e27bc9..b212f6c5 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "private": true,
   "type": "module",
   "scripts": {
+    "postinstall": "node scripts/link-plugin-dev-sdk.mjs",
     "preflight:workspace-links": "node cli/node_modules/tsx/dist/cli.mjs scripts/ensure-workspace-package-links.ts",
     "dev": "pnpm --filter @paperclipai/server exec tsx ../scripts/dev-runner.ts watch",
     "dev:watch": "pnpm --filter @paperclipai/server exec tsx ../scripts/dev-runner.ts watch",
@@ -42,7 +43,7 @@
     "smoke:openclaw-docker-ui": "./scripts/smoke/openclaw-docker-ui.sh",
     "smoke:openclaw-sse-standalone": "./scripts/smoke/openclaw-sse-standalone.sh",
     "smoke:terminal-bench-loop-skill": "node scripts/smoke/terminal-bench-loop-skill-smoke.mjs",
-    "test:release-registry": "node --test scripts/verify-release-registry-state.test.mjs scripts/release-package-map.test.mjs scripts/check-release-package-bootstrap.test.mjs scripts/check-no-git-push.test.mjs scripts/release-lib.test.mjs",
+    "test:release-registry": "node --test scripts/verify-release-registry-state.test.mjs scripts/release-package-map.test.mjs scripts/check-release-package-bootstrap.test.mjs scripts/check-no-git-push.test.mjs scripts/release-lib.test.mjs scripts/link-plugin-dev-sdk.test.js",
     "test:e2e": "npx playwright test --config tests/e2e/playwright.config.ts",
     "test:e2e:headed": "npx playwright test --config tests/e2e/playwright.config.ts --headed",
     "test:e2e:multiuser-authenticated": "npx playwright test --config tests/e2e/playwright-multiuser-authenticated.config.ts",
diff --git a/packages/plugins/plugin-workspace-diff/package.json b/packages/plugins/plugin-workspace-diff/package.json
index eec44700..e4f5c69b 100644
--- a/packages/plugins/plugin-workspace-diff/package.json
+++ b/packages/plugins/plugin-workspace-diff/package.json
@@ -42,7 +42,6 @@
     "diff"
   ],
   "scripts": {
-    "postinstall": "node ../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "tsc && node ./scripts/build-ui.mjs",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/cloudflare/package.json b/packages/plugins/sandbox-providers/cloudflare/package.json
index ecb37288..d959d6ff 100644
--- a/packages/plugins/sandbox-providers/cloudflare/package.json
+++ b/packages/plugins/sandbox-providers/cloudflare/package.json
@@ -42,7 +42,6 @@
     "cloudflare"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/daytona/package.json b/packages/plugins/sandbox-providers/daytona/package.json
index cae60c2c..bea6e657 100644
--- a/packages/plugins/sandbox-providers/daytona/package.json
+++ b/packages/plugins/sandbox-providers/daytona/package.json
@@ -41,7 +41,6 @@
     "daytona"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/e2b/package.json b/packages/plugins/sandbox-providers/e2b/package.json
index 864c0a0b..0e180ae7 100644
--- a/packages/plugins/sandbox-providers/e2b/package.json
+++ b/packages/plugins/sandbox-providers/e2b/package.json
@@ -41,7 +41,6 @@
     "e2b"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/exe-dev/package.json b/packages/plugins/sandbox-providers/exe-dev/package.json
index 94d7f5ff..c54ef859 100644
--- a/packages/plugins/sandbox-providers/exe-dev/package.json
+++ b/packages/plugins/sandbox-providers/exe-dev/package.json
@@ -41,7 +41,6 @@
     "exe.dev"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/kubernetes/package.json b/packages/plugins/sandbox-providers/kubernetes/package.json
index 4f6fdef6..74b2f1f5 100644
--- a/packages/plugins/sandbox-providers/kubernetes/package.json
+++ b/packages/plugins/sandbox-providers/kubernetes/package.json
@@ -39,7 +39,6 @@
     "kubernetes"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/modal/package.json b/packages/plugins/sandbox-providers/modal/package.json
index 86ce73ae..952900a5 100644
--- a/packages/plugins/sandbox-providers/modal/package.json
+++ b/packages/plugins/sandbox-providers/modal/package.json
@@ -41,7 +41,6 @@
     "modal"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/packages/plugins/sandbox-providers/novita/package.json b/packages/plugins/sandbox-providers/novita/package.json
index 34fa4f39..1bb6ad9d 100644
--- a/packages/plugins/sandbox-providers/novita/package.json
+++ b/packages/plugins/sandbox-providers/novita/package.json
@@ -42,7 +42,6 @@
     "novita-ai"
   ],
   "scripts": {
-    "postinstall": "node ../../../../scripts/link-plugin-dev-sdk.mjs",
     "prebuild": "pnpm -C ../../../.. --filter @paperclipai/plugin-sdk ensure-build-deps",
     "build": "rm -rf dist && tsc",
     "clean": "rm -rf dist",
diff --git a/scripts/build-standalone-public-packages.mjs b/scripts/build-standalone-public-packages.mjs
index 3a199219..7d004bb7 100644
--- a/scripts/build-standalone-public-packages.mjs
+++ b/scripts/build-standalone-public-packages.mjs
@@ -6,6 +6,8 @@ import path, { dirname } from "node:path";
 import process from "node:process";
 import { fileURLToPath } from "node:url";
 
+import { linkSdkInto } from "./link-plugin-dev-sdk.mjs";
+
 const scriptDir = dirname(fileURLToPath(import.meta.url));
 const repoRoot = path.resolve(scriptDir, "..");
 const workspacePath = path.join(repoRoot, "pnpm-workspace.yaml");
@@ -133,6 +135,11 @@ function main() {
 
     run("pnpm", installArgs, pkgDir);
 
+    // The fresh install above wipes node_modules and no longer fires a
+    // per-plugin postinstall (removed for supply-chain safety), so link the
+    // in-repo @paperclipai/plugin-sdk that the build's tsc resolves against.
+    linkSdkInto(pkgDir);
+
     if (pkgJson.scripts?.build) {
       run("pnpm", ["run", "build"], pkgDir);
     } else {
diff --git a/scripts/link-plugin-dev-sdk.mjs b/scripts/link-plugin-dev-sdk.mjs
index e4b4f425..512b67f8 100644
--- a/scripts/link-plugin-dev-sdk.mjs
+++ b/scripts/link-plugin-dev-sdk.mjs
@@ -1,41 +1,98 @@
 #!/usr/bin/env node
 
-import { existsSync, mkdirSync, lstatSync, readlinkSync, rmSync, symlinkSync } from "node:fs";
+// Dev-only: link the in-repo @paperclipai/plugin-sdk into plugin packages that
+// are excluded from the pnpm workspace (see pnpm-workspace.yaml). Workspace
+// members get their SDK link from pnpm automatically; excluded packages do not.
+//
+// Invoked from the root postinstall. Intentionally NOT referenced from any
+// plugin's own package.json so the published tarballs cannot carry a lifecycle
+// script that escapes their package directory at install time.
+
+import { existsSync, lstatSync, mkdirSync, readdirSync, readlinkSync, rmSync, symlinkSync } from "node:fs";
 import { dirname, join, relative, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const repoRoot = resolve(__dirname, "..");
-const packageDir = process.cwd();
 const sdkDir = join(repoRoot, "packages", "plugins", "sdk");
-const scopeDir = join(packageDir, "node_modules", "@paperclipai");
-const linkTarget = join(scopeDir, "plugin-sdk");
 
-if (!existsSync(join(packageDir, "package.json"))) {
-  throw new Error(`No package.json found in plugin directory: ${packageDir}`);
+// Plugin packages excluded from the workspace that still need @paperclipai/plugin-sdk
+// linked in for local dev. Keep in sync with pnpm-workspace.yaml exclusions.
+function excludedPluginDirs() {
+  return [
+    ...readPluginsUnder(join(repoRoot, "packages", "plugins", "sandbox-providers")),
+    join(repoRoot, "packages", "plugins", "examples", "plugin-orchestration-smoke-example"),
+  ];
 }
 
-mkdirSync(scopeDir, { recursive: true });
-
-try {
-  const stat = lstatSync(linkTarget);
-  if (stat.isSymbolicLink()) {
-    const existingTarget = readlinkSync(linkTarget);
-    const relativeSdkDir = relative(scopeDir, sdkDir);
-    if (existingTarget === relativeSdkDir) {
-      console.log(`  ✓ Local @paperclipai/plugin-sdk already linked for ${packageDir}`);
-      process.exit(0);
+export function linkExcludedPlugins() {
+  let linked = 0;
+  let skipped = 0;
+  for (const packageDir of excludedPluginDirs()) {
+    if (!existsSync(join(packageDir, "package.json"))) continue;
+    if (linkSdkInto(packageDir)) {
+      linked += 1;
+    } else {
+      skipped += 1;
     }
-    rmSync(linkTarget, { force: true });
-  } else {
-    console.log("  i Keeping existing installed @paperclipai/plugin-sdk directory in place");
-    process.exit(0);
   }
-} catch {
-  // target does not exist yet
+  return { linked, skipped };
 }
 
-const relativeSdkDir = relative(scopeDir, sdkDir);
-symlinkSync(relativeSdkDir, linkTarget, "dir");
+// Run as a CLI (root postinstall) when invoked directly, but stay importable so
+// repo-internal scripts (e.g. the standalone package builder) can relink a
+// single package after a fresh install.
+if (process.argv[1] && resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
+  const { linked, skipped } = linkExcludedPlugins();
+  console.log(`  ✓ Linked @paperclipai/plugin-sdk into ${linked} excluded plugin(s) (skipped ${skipped})`);
+}
 
-console.log(`  ✓ Linked local @paperclipai/plugin-sdk for ${packageDir}`);
+// Recursively collect package directories (those containing a package.json)
+// under parentDir. The matching pnpm-workspace.yaml exclusion uses a recursive
+// glob (e.g. "!packages/plugins/sandbox-providers/**"), so a provider nested
+// deeper than one level must still be discovered here.
+export function readPluginsUnder(parentDir) {
+  if (!existsSync(parentDir)) return [];
+  const found = [];
+  for (const entry of readdirSync(parentDir, { withFileTypes: true })) {
+    // Skip symlinked directories so discovery can't be steered outside the
+    // intended plugin subtree, and skip node_modules.
+    if (!entry.isDirectory() || entry.isSymbolicLink() || entry.name === "node_modules") continue;
+    const childDir = join(parentDir, entry.name);
+    if (existsSync(join(childDir, "package.json"))) {
+      found.push(childDir);
+    } else {
+      found.push(...readPluginsUnder(childDir));
+    }
+  }
+  return found;
+}
+
+export function linkSdkInto(packageDir) {
+  const scopeDir = join(packageDir, "node_modules", "@paperclipai");
+  const linkTarget = join(scopeDir, "plugin-sdk");
+  const relativeSdkDir = relative(scopeDir, sdkDir);
+
+  mkdirSync(scopeDir, { recursive: true });
+
+  try {
+    const stat = lstatSync(linkTarget);
+    if (stat.isSymbolicLink()) {
+      if (readlinkSync(linkTarget) === relativeSdkDir) {
+        // Already linked to the in-repo SDK; nothing to do.
+        return false;
+      }
+      rmSync(linkTarget, { force: true });
+    } else {
+      // A real install has already populated @paperclipai/plugin-sdk (e.g. the
+      // plugin host did `npm install` of the published tarball). Leave it.
+      return false;
+    }
+  } catch (error) {
+    // A missing target is expected (nothing linked yet); surface anything else.
+    if (error?.code !== "ENOENT") throw error;
+  }
+
+  symlinkSync(relativeSdkDir, linkTarget, "dir");
+  return true;
+}
diff --git a/scripts/link-plugin-dev-sdk.test.js b/scripts/link-plugin-dev-sdk.test.js
new file mode 100644
index 00000000..178a16ac
--- /dev/null
+++ b/scripts/link-plugin-dev-sdk.test.js
@@ -0,0 +1,89 @@
+import assert from "node:assert/strict";
+import { existsSync, lstatSync, mkdirSync, mkdtempSync, readlinkSync, rmSync, symlinkSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { after, before, test } from "node:test";
+
+import { linkSdkInto, readPluginsUnder } from "./link-plugin-dev-sdk.mjs";
+
+let workDir;
+
+before(() => {
+  workDir = mkdtempSync(join(tmpdir(), "link-plugin-dev-sdk-"));
+});
+
+after(() => {
+  rmSync(workDir, { force: true, recursive: true });
+});
+
+function makePackage(dir) {
+  mkdirSync(dir, { recursive: true });
+  writeFileSync(join(dir, "package.json"), "{}\n");
+  return dir;
+}
+
+test("readPluginsUnder returns [] for a missing directory", () => {
+  assert.deepEqual(readPluginsUnder(join(workDir, "does-not-exist")), []);
+});
+
+test("readPluginsUnder finds first-level package directories", () => {
+  const parent = join(workDir, "first-level");
+  const a = makePackage(join(parent, "a"));
+  const b = makePackage(join(parent, "b"));
+
+  assert.deepEqual(readPluginsUnder(parent).sort(), [a, b].sort());
+});
+
+test("readPluginsUnder recurses into directories that are not themselves packages", () => {
+  // Mirrors the recursive pnpm-workspace exclusion glob: a provider nested
+  // deeper than one level must still be discovered.
+  const parent = join(workDir, "nested");
+  const nested = makePackage(join(parent, "vendor", "my-plugin"));
+
+  assert.deepEqual(readPluginsUnder(parent), [nested]);
+});
+
+test("readPluginsUnder stops descending once a package.json is found and skips node_modules", () => {
+  const parent = join(workDir, "boundaries");
+  const pkg = makePackage(join(parent, "plugin"));
+  // A nested package inside an already-matched package must not be returned.
+  makePackage(join(pkg, "sub-package"));
+  // node_modules must be ignored entirely.
+  makePackage(join(parent, "node_modules", "some-dep"));
+
+  assert.deepEqual(readPluginsUnder(parent), [pkg]);
+});
+
+test("linkSdkInto creates the plugin-sdk symlink and is idempotent", () => {
+  const pkg = makePackage(join(workDir, "link-target"));
+
+  assert.equal(linkSdkInto(pkg), true);
+
+  const link = join(pkg, "node_modules", "@paperclipai", "plugin-sdk");
+  assert.ok(lstatSync(link).isSymbolicLink());
+
+  // Second call is a no-op because the link already points at the in-repo SDK.
+  assert.equal(linkSdkInto(pkg), false);
+});
+
+test("linkSdkInto leaves a real (non-symlink) install in place", () => {
+  const pkg = makePackage(join(workDir, "real-install"));
+  const scopeDir = join(pkg, "node_modules", "@paperclipai");
+  mkdirSync(scopeDir, { recursive: true });
+  // Simulate a published-tarball install: a real directory, not a symlink.
+  makePackage(join(scopeDir, "plugin-sdk"));
+
+  assert.equal(linkSdkInto(pkg), false);
+  assert.ok(!lstatSync(join(scopeDir, "plugin-sdk")).isSymbolicLink());
+});
+
+test("linkSdkInto replaces a symlink that points somewhere else", () => {
+  const pkg = makePackage(join(workDir, "stale-link"));
+  const scopeDir = join(pkg, "node_modules", "@paperclipai");
+  mkdirSync(scopeDir, { recursive: true });
+  symlinkSync("../somewhere-else", join(scopeDir, "plugin-sdk"), "dir");
+
+  assert.equal(linkSdkInto(pkg), true);
+  assert.notEqual(readlinkSync(join(scopeDir, "plugin-sdk")), "../somewhere-else");
+  assert.ok(existsSync(scopeDir));
+});