diff --git a/.changeset/temporary-marketplace-isolation.md b/.changeset/temporary-marketplace-isolation.md
new file mode 100644
index 000000000..6478b29e7
--- /dev/null
+++ b/.changeset/temporary-marketplace-isolation.md
@@ -0,0 +1,5 @@
+---
+"agent-bundle": patch
+---
+
+Preserve `output.repositoryMarketplace` files during temporary MCP, hook, and `serve-app` builds, including failed operations (#828).
diff --git a/packages/agent-bundle/src/api.ts b/packages/agent-bundle/src/api.ts
index 2c51df559..1268c2069 100644
--- a/packages/agent-bundle/src/api.ts
+++ b/packages/agent-bundle/src/api.ts
@@ -791,6 +791,7 @@ const temporaryArtifact = async <Result>(
         logger: options.logger,
         mode: options.mode,
         output: artifact,
+        repositoryMarketplaces: false,
         registry: options.registry,
         root: options.root,
         targets: options.targets,
@@ -1620,6 +1621,7 @@ const scopedThrowawayArtifact = (
   logger: options.logger,
   mode: options.mode,
   output: artifact,
+  repositoryMarketplaces: false,
   registry: options.registry,
   root: options.root,
   targets: options.targets,
diff --git a/packages/agent-bundle/tests/api.test.ts b/packages/agent-bundle/tests/api.test.ts
index ef75c592c..2042405fe 100644
--- a/packages/agent-bundle/tests/api.test.ts
+++ b/packages/agent-bundle/tests/api.test.ts
@@ -5,7 +5,7 @@ import { join } from 'node:path';
 
 import { expect, it } from '@rstest/core';
 
-import { TargetRegistry, build, createDefaultRegistry, inspect, invokeMcp, listHooks, listMcp, simulateHook, validate } from '../src/api.ts';
+import { TargetRegistry, build, createDefaultRegistry, inspect, invokeMcp, listHooks, listMcp, serveApp, simulateHook, validate } from '../src/api.ts';
 import { unavailableCapability } from '../src/adapters/capability-state.ts';
 import {
   nativeHookWrapperSource,
@@ -386,6 +386,18 @@ it('emits repository marketplaces from the selected host plans without making ou
     const first = await build({ root });
     const second = await build({ root });
     expect(second.projectContext.sourceInputs).toEqual(first.projectContext.sourceInputs);
+    const marketplaceBeforeOperations = await readFile(join(root, '.cursor-plugin/marketplace.json'), 'utf8');
+    await listHooks({ root, target: 'cursor' });
+    expect(await readFile(join(root, '.cursor-plugin/marketplace.json'), 'utf8')).toBe(marketplaceBeforeOperations);
+    const serveEvents: string[] = [];
+    await expect(serveApp({
+      app: 'missing/missing',
+      logger: { log: (event) => { serveEvents.push(event); } },
+      root,
+      target: 'cursor',
+    })).rejects.toThrow();
+    expect(serveEvents).toContain('artifact.build');
+    expect(await readFile(join(root, '.cursor-plugin/marketplace.json'), 'utf8')).toBe(marketplaceBeforeOperations);
     for (const path of ['.claude-plugin/marketplace.json', '.cursor-plugin/marketplace.json', '.agents/plugins/marketplace.json']) {
       const repository = JSON.parse(await readFile(join(root, path), 'utf8'));
       const artifact = JSON.parse(await readFile(join(root, 'artifact', path), 'utf8'));
diff --git a/website/docs/en/reference/configuration.mdx b/website/docs/en/reference/configuration.mdx
index 510c353fb..ff61fd02e 100644
--- a/website/docs/en/reference/configuration.mdx
+++ b/website/docs/en/reference/configuration.mdx
@@ -162,6 +162,8 @@ the selected marketplace files; do not hand-edit them. It refuses symlinked dest
 paths that overlap the artifact, custom adapters, and authored marketplace source or
 `metadata.pluginRoot` overrides. These generated files are excluded from source snapshots.
 Development and evaluation staging do not publish repository marketplaces.
+Temporary builds used by MCP commands, hook inspection/simulation, and `serve-app` also
+leave these files unchanged, including when the operation fails.
 
 `output.distPath` is the artifact output directory relative to the project root — the composite
 plugin root every selected host reads, with no per-host subdirectory beneath it. The CLI
diff --git a/website/docs/zh/reference/configuration.mdx b/website/docs/zh/reference/configuration.mdx
index f17998f7d..f709e76b8 100644
--- a/website/docs/zh/reference/configuration.mdx
+++ b/website/docs/zh/reference/configuration.mdx
@@ -141,6 +141,7 @@ Claude Code 的 `.claude-plugin/plugin.json` 不携带描述字段——其固
 一起提交后，即可从 GitHub 直接安装。编译器会替换所选市场清单，请勿手工编辑。它会拒绝符号链接、
 与产物目录重叠的路径、自定义适配器，以及手写的市场来源或 `metadata.pluginRoot` 覆盖。
 这些生成文件不计入源码快照。开发与评估的暂存构建不会发布项目根目录市场清单。
+MCP 命令、钩子查看或模拟以及 `serve-app` 使用的临时构建也不会修改这些文件，即使操作失败。
 
 `output.distPath` 是相对项目根目录的产物输出目录——每个所选宿主都读取的组合插件根目录，其下没有逐宿主
 子目录。命令行（`build`、`prepack`、`dev`）把它默认为 `artifact`，