diff --git a/apps/desktop/electron-builder.config.mjs b/apps/desktop/electron-builder.config.mjs
index ddec325d76..f50786a29d 100644
--- a/apps/desktop/electron-builder.config.mjs
+++ b/apps/desktop/electron-builder.config.mjs
@@ -17,18 +17,35 @@
  * under the License.
  */
 
-import { readFileSync } from 'node:fs';
+import { mkdirSync, readFileSync, writeFileSync } from 'node:fs';
+import { join } from 'node:path';
 import {
   DESKTOP_NIGHTLY_FEED_URL,
   resolveDesktopBuildVersion,
   resolveRuntimeHostSetupPackage,
 } from '../../scripts/desktop-nightly.mjs';
+import { workspaceReleaseManifest } from '../../scripts/release-cli-file-policy.mjs';
 import { resolveProductManifestIdentity } from '../../scripts/product-release-identity.mjs';
 
 function readManifest(relativePath) {
   return JSON.parse(readFileSync(new URL(relativePath, import.meta.url), 'utf8'));
 }
 
+async function stageReleaseManifests({ packager }) {
+  const stage = await packager.info.tempDirManager.createTempDir({
+    prefix: 'maka-release-manifests',
+  });
+  for (const name of ['mcp', 'runtime', 'runtime-host']) {
+    const directory = join(stage, name);
+    mkdirSync(directory, { recursive: true });
+    writeFileSync(
+      join(directory, 'package.json'),
+      `${JSON.stringify(workspaceReleaseManifest(readManifest(`../../packages/${name}/package.json`)), null, 2)}\n`,
+    );
+  }
+  packager.config.files.push({ from: stage, to: 'node_modules/@maka' });
+}
+
 const rootManifest = readManifest('../../package.json');
 const { runtimeHostSetupPackage } = resolveProductManifestIdentity({
   rootManifest,
@@ -41,6 +58,7 @@ const baseDesktopBuilderConfig = {
   productName: 'Maka',
   artifactName: 'Maka-${version}-mac-${arch}.${ext}',
   asar: true,
+  beforePack: stageReleaseManifests,
   extraMetadata: { runtimeHostSetupPackage, makaUpdateChannel: 'release' },
   directories: {
     output: 'release',
@@ -58,6 +76,7 @@ const baseDesktopBuilderConfig = {
     'dist/**/*',
     'dist-renderer/**/*',
     'package.json',
+    '!node_modules/@maka/{mcp,runtime,runtime-host}/package.json',
     '!**/__tests__/**',
     // FakeBackend and the Desktop E2E candidate bootstrap live under
     // `test-only/`; they must not reach a packaged app.
diff --git a/scripts/package-macos-arm64-cli.mjs b/scripts/package-macos-arm64-cli.mjs
index aec5b3bd6c..dde3561b17 100644
--- a/scripts/package-macos-arm64-cli.mjs
+++ b/scripts/package-macos-arm64-cli.mjs
@@ -46,6 +46,7 @@ import {
   releaseNpmEnvironment,
   resolveReleaseWorkspacePackages,
   resolveWorkspaceReleaseFiles,
+  workspaceReleaseManifest,
 } from './release-cli-file-policy.mjs';
 
 const execFileAsync = promisify(execFile);
@@ -205,31 +206,25 @@ export async function stageWorkspacePackages(installRoot, workspacePackages) {
     ...workspacePackages.map(async ({ directory, manifest, workspacePath }) => {
       const targetDirectory = join(installRoot, workspacePath);
       await mkdir(targetDirectory, { recursive: true });
-      await copyFile(join(directory, 'package.json'), join(targetDirectory, 'package.json'));
+      await writeFile(
+        join(targetDirectory, 'package.json'),
+        `${JSON.stringify(workspaceReleaseManifest(manifest), null, 2)}\n`,
+      );
       await Promise.all(
         resolveWorkspaceReleaseFiles(directory, manifest).map(async (releaseFile) => {
           const source = join(directory, ...releaseFile.split('/'));
           const target = join(targetDirectory, ...releaseFile.split('/'));
           await mkdir(dirname(target), { recursive: true });
-          await cp(source, target, { recursive: true });
+          await cp(source, target, {
+            recursive: true,
+            filter: (path) => !isMakaDevelopmentArtifact(relative(directory, path)),
+          });
         }),
       );
-      await pruneMakaDevelopmentArtifacts(targetDirectory);
     }),
   ]);
 }
 
-async function pruneMakaDevelopmentArtifacts(directory, root = directory) {
-  for (const entry of await readdir(directory, { withFileTypes: true })) {
-    const path = join(directory, entry.name);
-    if (isMakaDevelopmentArtifact(relative(root, path))) {
-      await rm(path, { recursive: entry.isDirectory(), force: true });
-    } else if (entry.isDirectory()) {
-      await pruneMakaDevelopmentArtifacts(path, root);
-    }
-  }
-}
-
 export async function listDependencyPatchNames() {
   let entries;
   try {
diff --git a/scripts/product-release.test.mjs b/scripts/product-release.test.mjs
index 1c9262a401..334554aa76 100644
--- a/scripts/product-release.test.mjs
+++ b/scripts/product-release.test.mjs
@@ -175,6 +175,32 @@ test('Desktop packaging derives the Runtime Host setup package from product mani
   ]);
 });
 
+test('Desktop stages release manifests before electron-builder builds the archive', async (t) => {
+  const stage = await mkdtemp(join(tmpdir(), 'maka-desktop-release-manifests-'));
+  t.after(() => rm(stage, { recursive: true, force: true }));
+  const files = [{ filter: [...desktopBuilderConfig.files] }];
+
+  await desktopBuilderConfig.beforePack({
+    packager: {
+      config: { files },
+      info: { tempDirManager: { createTempDir: async () => stage } },
+    },
+  });
+
+  assert.equal(files.length, 2);
+  assert.ok(
+    files[0].filter.includes('!node_modules/@maka/{mcp,runtime,runtime-host}/package.json'),
+  );
+  assert.deepEqual(files.at(-1), { from: stage, to: 'node_modules/@maka' });
+  for (const name of ['mcp', 'runtime', 'runtime-host']) {
+    const projected = JSON.parse(await readFile(join(stage, name, 'package.json')));
+    assert.equal(
+      Object.keys(projected.exports).some((subpath) => subpath.startsWith('./test-only/')),
+      false,
+    );
+  }
+});
+
 test('Desktop packaging does not distribute the retired bundled Git runtime', () => {
   const resources = desktopBuilderConfig.extraResources.map(({ from, to }) => ({ from, to }));
   assert.equal(
@@ -554,14 +580,22 @@ test('standalone packaging applies the shared CLI file policy to dependencies',
   }
 });
 
-test('standalone workspace staging keeps runtime files and removes Maka development output', async () => {
+test('standalone workspace staging keeps manifests consistent with copied files', async () => {
   const root = await mkdtemp(join(tmpdir(), 'maka-standalone-workspace-'));
   const workspace = join(root, 'workspace');
   const install = join(root, 'install');
   try {
+    const manifest = {
+      name: '@maka/example',
+      exports: {
+        '.': './dist/index.js',
+        './test-only/fixture': './dist/__tests__/fixture.js',
+      },
+      scripts: { build: 'tsc' },
+    };
     await mkdir(join(workspace, 'dist', '__tests__'), { recursive: true });
     await mkdir(install);
-    await writeFile(join(workspace, 'package.json'), '{}\n');
+    await writeFile(join(workspace, 'package.json'), `${JSON.stringify(manifest)}\n`);
     await writeFile(join(workspace, 'dist', 'index.js'), 'runtime\n');
     await writeFile(join(workspace, 'dist', 'dev-cli.js'), 'development\n');
     await writeFile(join(workspace, 'dist', 'index.d.ts'), 'development\n');
@@ -571,11 +605,15 @@ test('standalone workspace staging keeps runtime files and removes Maka developm
     await stageWorkspacePackages(install, [
       {
         directory: workspace,
-        manifest: { name: '@maka/example' },
+        manifest,
         workspacePath: 'packages/example',
       },
     ]);
 
+    assert.deepEqual(JSON.parse(await readFile(join(install, 'packages/example/package.json'))), {
+      name: '@maka/example',
+      exports: { '.': './dist/index.js' },
+    });
     const staged = join(install, 'packages', 'example', 'dist');
     assert.equal(await readFile(join(staged, 'index.js'), 'utf8'), 'runtime\n');
     for (const path of ['dev-cli.js', 'index.d.ts', 'index.js.map', '__tests__/fixture.js']) {
diff --git a/scripts/release-cli-file-policy.mjs b/scripts/release-cli-file-policy.mjs
index 5f1d58acba..b7c9d5d300 100644
--- a/scripts/release-cli-file-policy.mjs
+++ b/scripts/release-cli-file-policy.mjs
@@ -245,6 +245,55 @@ export function isMakaDevelopmentArtifact(relativePath) {
   );
 }
 
+function releaseExportTarget(target) {
+  if (typeof target === 'string') {
+    return isMakaDevelopmentArtifact(target) ? undefined : target;
+  }
+  if (Array.isArray(target)) {
+    const projected = target.map(releaseExportTarget).filter((entry) => entry !== undefined);
+    return projected.length === 0 ? undefined : projected;
+  }
+  if (target && typeof target === 'object') {
+    const projected = Object.fromEntries(
+      Object.entries(target)
+        .map(([condition, value]) => [condition, releaseExportTarget(value)])
+        .filter(([, value]) => value !== undefined),
+    );
+    return Object.keys(projected).length === 0 ? undefined : projected;
+  }
+  return target;
+}
+
+const WORKSPACE_RELEASE_MANIFEST_FIELDS = [
+  'name',
+  'version',
+  'description',
+  'license',
+  'type',
+  'sideEffects',
+  'main',
+  'exports',
+  'bin',
+  'engines',
+  'dependencies',
+  'optionalDependencies',
+  'peerDependencies',
+  'peerDependenciesMeta',
+];
+
+export function workspaceReleaseManifest(manifest) {
+  const releaseManifest = Object.fromEntries(
+    WORKSPACE_RELEASE_MANIFEST_FIELDS.filter((field) => manifest[field] !== undefined).map(
+      (field) => [field, manifest[field]],
+    ),
+  );
+  if (releaseManifest.exports !== undefined) {
+    const projected = releaseExportTarget(releaseManifest.exports);
+    releaseManifest.exports = projected === undefined ? {} : projected;
+  }
+  return releaseManifest;
+}
+
 export function isCurrentDevelopmentJavaScript(
   workspaceRoot,
   relativePath,
diff --git a/scripts/release-cli-file-policy.test.mjs b/scripts/release-cli-file-policy.test.mjs
index 4f321c86c4..d01b3e1b1d 100644
--- a/scripts/release-cli-file-policy.test.mjs
+++ b/scripts/release-cli-file-policy.test.mjs
@@ -38,6 +38,7 @@ import {
   orderWorkspaceBuilds,
   renderNpmReadme,
   resolveWorkspaceReleaseFiles,
+  workspaceReleaseManifest,
   workspaceReleaseFiles,
 } from './release-cli-file-policy.mjs';
 
@@ -51,6 +52,62 @@ test('the npm README receives the canonical WIP disclaimer exactly once', () =>
 });
 
 describe('CLI release file policy', () => {
+  test('release manifests omit exports whose targets are excluded from Maka artifacts', () => {
+    const repoRoot = resolve(import.meta.dirname, '..');
+    for (const [directory, omitted] of Object.entries({
+      mcp: ['./test-only/stdio-server'],
+      'runtime-host': [
+        './test-only/client-capability-host',
+        './test-only/execution-candidate-e2e-main',
+      ],
+      runtime: ['./test-only/fake-backend', './test-only/observation-text-reader'],
+    })) {
+      const manifestPath = join(repoRoot, 'packages', directory, 'package.json');
+      const source = JSON.parse(readFileSync(manifestPath, 'utf8'));
+      const projected = workspaceReleaseManifest(source);
+
+      assert.deepEqual(
+        Object.keys(source.exports).filter((subpath) => !Object.hasOwn(projected.exports, subpath)),
+        omitted,
+      );
+      assert.deepEqual(JSON.parse(readFileSync(manifestPath, 'utf8')), source);
+    }
+  });
+
+  test('release manifests project conditional exports leaf by leaf', () => {
+    const source = {
+      exports: {
+        '.': {
+          types: './dist/index.d.ts',
+          default: './dist/index.js',
+        },
+        './fallback': [
+          './dist/__tests__/fixture.js',
+          { types: './dist/fallback.d.ts', default: './dist/fallback.js' },
+        ],
+      },
+    };
+    const original = structuredClone(source);
+
+    assert.deepEqual(workspaceReleaseManifest(source).exports, {
+      '.': { default: './dist/index.js' },
+      './fallback': [{ default: './dist/fallback.js' }],
+    });
+    assert.deepEqual(source, original);
+  });
+
+  test('release manifests preserve a top-level export target array', () => {
+    assert.deepEqual(
+      workspaceReleaseManifest({
+        exports: [
+          './dist/__tests__/fixture.js',
+          { types: './dist/index.d.ts', default: './dist/index.js' },
+        ],
+      }).exports,
+      [{ default: './dist/index.js' }],
+    );
+  });
+
   test('derives the runtime workspace build order from production dependencies', () => {
     const manifests = new Map([
       ['maka-agent', { name: 'maka-agent', dependencies: { '@maka/eval': '0.1.0' } }],
diff --git a/scripts/release-cli-package.mjs b/scripts/release-cli-package.mjs
index 3af096661a..3ca6e535d2 100644
--- a/scripts/release-cli-package.mjs
+++ b/scripts/release-cli-package.mjs
@@ -48,6 +48,7 @@ import {
   releaseNpmEnvironment,
   resolveReleaseWorkspacePackages,
   resolveWorkspaceReleaseFiles,
+  workspaceReleaseManifest,
 } from './release-cli-file-policy.mjs';
 
 const repoRoot = resolve(import.meta.dirname, '..');
@@ -425,27 +426,7 @@ function dependencyDestination(dependency) {
 function copyInternalPackage(source, destination) {
   mkdirSync(destination, { recursive: true, mode: 0o755 });
   const manifest = readJson(join(source, 'package.json'));
-  const allowedFields = [
-    'name',
-    'version',
-    'description',
-    'license',
-    'type',
-    'sideEffects',
-    'main',
-    'exports',
-    'bin',
-    'engines',
-    'dependencies',
-    'optionalDependencies',
-    'peerDependencies',
-    'peerDependenciesMeta',
-  ];
-  const releaseManifest = Object.fromEntries(
-    allowedFields
-      .filter((field) => manifest[field] !== undefined)
-      .map((field) => [field, manifest[field]]),
-  );
+  const releaseManifest = workspaceReleaseManifest(manifest);
   writeFileSync(join(destination, 'package.json'), `${JSON.stringify(releaseManifest, null, 2)}\n`);
   for (const releaseFile of resolveWorkspaceReleaseFiles(source, manifest)) {
     if (releaseFile === 'dist') copyRuntimeDist(source, destination, manifest.name);