diff --git a/.changeset/fix-genui-api-extractor-dist-race.md b/.changeset/fix-genui-api-extractor-dist-race.md
new file mode 100644
index 0000000000..92a5362ede
--- /dev/null
+++ b/.changeset/fix-genui-api-extractor-dist-race.md
@@ -0,0 +1,5 @@
+---
+
+---
+
+Fix a flaky CI failure in genui API extraction where `@lynx-js/genui-cli`'s `tsc` (and `@lynx-js/genui#api-extractor`) could fail with `TS2307` / `TS7016` ("Cannot find module `@lynx-js/genui-a2ui-prompt`"). `run-api-extractor.mjs` rebuilt each package in-script (`pnpm run build`), rewriting its `dist/` while turbo-scheduled consumer builds read the same `dist/`, so `tsc` could observe `index.js` without its freshly-cleaned `index.d.ts`. The script no longer builds — turbo's task graph builds each package, and the api-extractor task now depends on the package build for the rust-free genui packages — and the file lock that only existed to serialize those in-script builds is removed.
diff --git a/packages/genui/a2ui-catalog-extractor/turbo.json b/packages/genui/a2ui-catalog-extractor/turbo.json
index 294effadb6..0e27bb3695 100644
--- a/packages/genui/a2ui-catalog-extractor/turbo.json
+++ b/packages/genui/a2ui-catalog-extractor/turbo.json
@@ -33,6 +33,13 @@
       "outputs": [
         "dist/**"
       ]
+    },
+    "api-extractor": {
+      "dependsOn": [
+        "//#build",
+        "build"
+      ],
+      "cache": false
     }
   }
 }
diff --git a/packages/genui/a2ui-prompt/package.json b/packages/genui/a2ui-prompt/package.json
index c98ad3045d..3b9b1c7690 100644
--- a/packages/genui/a2ui-prompt/package.json
+++ b/packages/genui/a2ui-prompt/package.json
@@ -23,8 +23,7 @@
   ],
   "scripts": {
     "api-extractor": "node ../scripts/run-api-extractor.mjs",
-    "build": "rslib build",
-    "build:api": "rslib build"
+    "build": "rslib build"
   },
   "devDependencies": {
     "@microsoft/api-extractor": "catalog:",
diff --git a/packages/genui/a2ui-prompt/turbo.json b/packages/genui/a2ui-prompt/turbo.json
index c56f63f014..6adbe71600 100644
--- a/packages/genui/a2ui-prompt/turbo.json
+++ b/packages/genui/a2ui-prompt/turbo.json
@@ -23,24 +23,12 @@
         "dist/**"
       ]
     },
-    "build:api": {
+    "api-extractor": {
       "dependsOn": [
+        "//#build",
         "build"
       ],
-      "inputs": [
-        "src/**",
-        "../server/agent/a2ui-catalog.ts",
-        "../server/agent/a2ui-examples.ts",
-        "../server/agent/a2ui-prompt.ts",
-        "../server/agent/catalog/**/*.json",
-        "package.json",
-        "rslib.config.ts",
-        "tsconfig.build.json",
-        "tsconfig.json"
-      ],
-      "outputs": [
-        "dist/**"
-      ]
+      "cache": false
     }
   }
 }
diff --git a/packages/genui/scripts/run-api-extractor.mjs b/packages/genui/scripts/run-api-extractor.mjs
index 0c9649e786..65c2a29455 100644
--- a/packages/genui/scripts/run-api-extractor.mjs
+++ b/packages/genui/scripts/run-api-extractor.mjs
@@ -3,63 +3,14 @@
 // LICENSE file in the root directory of this source tree.
 import { spawnSync } from 'node:child_process';
 import { existsSync } from 'node:fs';
-import { open, readFile, rm } from 'node:fs/promises';
-import { dirname, join } from 'node:path';
-import { fileURLToPath } from 'node:url';
+import { readFile } from 'node:fs/promises';
+import { join } from 'node:path';
 
-const genuiRoot = dirname(dirname(fileURLToPath(import.meta.url)));
-const lockPath = join(genuiRoot, '.api-extractor.lock');
-const lockTimeoutMs = 10 * 60 * 1000;
 const entryPointTimeoutMs = 5 * 1000;
 const retryDelayMs = 500;
 
 const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
 
-const isProcessAlive = (pid) => {
-  try {
-    process.kill(pid, 0);
-    return true;
-  } catch {
-    return false;
-  }
-};
-
-const acquireLock = async () => {
-  const start = Date.now();
-
-  while (Date.now() - start < lockTimeoutMs) {
-    try {
-      const file = await open(lockPath, 'wx');
-      await file.writeFile(JSON.stringify({
-        cwd: process.cwd(),
-        pid: process.pid,
-        startedAt: new Date().toISOString(),
-      }));
-      await file.close();
-      return;
-    } catch (error) {
-      if (error?.code !== 'EEXIST') {
-        throw error;
-      }
-
-      try {
-        const current = JSON.parse(await readFile(lockPath, 'utf8'));
-        if (typeof current.pid === 'number' && !isProcessAlive(current.pid)) {
-          await rm(lockPath, { force: true });
-          continue;
-        }
-      } catch {
-        await rm(lockPath, { force: true });
-        continue;
-      }
-
-      await sleep(retryDelayMs);
-    }
-  }
-
-  throw new Error(`Timed out waiting for ${lockPath}`);
-};
-
 const run = (command, args) => {
   const result = spawnSync(command, args, {
     shell: process.platform === 'win32',
@@ -127,14 +78,14 @@ const ensureMainEntryPoint = async () => {
   );
 };
 
-await acquireLock();
-
-try {
-  run('pnpm', ['run', 'build']);
-  await ensureMainEntryPoint();
-  run('api-extractor', ['run', '--verbose']);
-} finally {
-  if (existsSync(lockPath)) {
-    await rm(lockPath, { force: true });
-  }
-}
+// No lock is needed: turbo's task graph builds each package before its
+// `api-extractor` task (which depends on `build`) and before every consumer
+// build, so api-extractor only ever reads a finished `dist/`. Do NOT build
+// here — a rebuild would re-clean and rewrite `dist/` while turbo-scheduled
+// consumer builds (e.g. `genui-cli#build`) read the same `dist/`, transiently
+// removing the `.d.ts` and breaking their `tsc` (TS2307/TS7016).
+// `ensureMainEntryPoint` stays only as a last-resort build if the entry point
+// is somehow missing. Concurrent api-extractor runs across packages touch only
+// their own per-package outputs, so they need no mutual exclusion.
+await ensureMainEntryPoint();
+run('api-extractor', ['run', '--verbose']);
diff --git a/packages/genui/turbo.json b/packages/genui/turbo.json
index f25fb8c151..5d6532af58 100644
--- a/packages/genui/turbo.json
+++ b/packages/genui/turbo.json
@@ -41,7 +41,7 @@
         "//#build",
         "@lynx-js/genui-a2ui#build:api",
         "@lynx-js/genui-a2ui-catalog-extractor#build:api",
-        "@lynx-js/genui-a2ui-prompt#build:api",
+        "@lynx-js/genui-a2ui-prompt#build",
         "@lynx-js/genui-openui#build:api"
       ],
       "cache": false