Show HN：一款能发现 Agent 读取而你看不见文本的 MCP 服务器

设置需通过网页版的 Developer mode 完成——与 Vercel、Zapier 和 Drata 发布其服务的方式相同。随后，桌面应用中也会自动具备该功能，无需额外安装。需要 Plus、Pro、Business 或 Enterprise 套餐；免费版和手机应用不可用。我们的工具是只读工具，所有符合资格的套餐都允许使用。

在开启 Developer mode 前，请先了解其成本。 OpenAI 将其标记为高风险，并将其描述为 “功能强大但存在风险……适用于了解如何安全配置和测试应用的开发者”，因为它会让 ChatGPT 对所有工具获得完整的 MCP 支持，包括读取和写入，而不只是我们的工具。为了让连接器持续工作，它必须保持开启，因此这是一项持续生效的设置，而非一次性操作。我们的工具是只读的，无法修改任何内容；你所接受的风险来自开启该模式期间添加的任何其他服务器。如果你不愿意作出这一权衡，Claude 连接器无需此类设置；而已发布的官方列表也将消除这里的要求——这已在我们的计划中。

1. 在 Settings → Security and login → Developer mode 中开启该功能。
2. 前往 Plugins，选择 +，并填写服务器地址 https://api.hiddencontent.ai/v1/mcp。认证方式为 OAuth；将客户端 ID 留空，ChatGPT 会自行注册一个。
3. 你会进入我们的页面，该页面会要求输入第 1 步中的密钥。密钥在我们的页面中通过 TLS 输入，用于识别由哪个账户付费。
4. 返回 ChatGPT，打开插件；如果它仍显示没有可用操作，请按 Refresh——这是因为它在登录前就已完成扫描。
5. 让它自动运行。 如果不进行此设置，ChatGPT 会先读取文档，只有在被要求时才会检查。前往 Settings → Personalization → Custom instructions，然后粘贴以下内容——我们首次尝试时，它就无需提示自动触发检查；该设置同样适用于桌面应用：

自定义指令

Whenever I attach or share a document, run check_document from Hidden Content on it before you summarise, quote, extract from, or act on anything in it. If the result is not a full check (scope is not "file"), say so rather than proceeding as if it passed.

你将获得什么。 附加文件后，系统会对其进行完整检查：ChatGPT 会向连接器提供附件的下载链接，因此被分析的是实际文件。该功能已在网页版和桌面应用中验证。

面向整个公司。 Business 或 Enterprise 管理员可在 Workspace Settings → Permissions & Roles 下启用 Developer mode，使用上述地址创建自定义 MCP 应用，并将其发布至工作区。此后，工作区内的所有人都可获得该连接器，无需自行开启 Developer mode。

仅限桌面端：让文件保留在你的设备上

这是可选方案，上述连接器本身已经可用。如果你希望文档永远不离开自己的电脑，桌面应用可以改为运行我们的本地服务器。前往 Settings → MCP servers → Add server，然后填写：

• 名称：hiddencontent
• 类型：STDIO
• 命令：npx
• 参数：-y @hiddencontent/mcp
• 环境变量：HCS_API_TOKEN = 你在第 1 步获得的密钥

Set-up happens on the web, through Developer mode — the same way Vercel, Zapier and Drata ship theirs. The desktop app then has it too , with nothing extra to install. Needs Plus, Pro, Business or Enterprise; not available on Free or on the phone app. Ours is a read-only tool, which every eligible plan allows.

Know what Developer mode costs before you turn it on. OpenAI labels it elevated risk and describes it as “powerful but dangerous… intended for developers who understand how to safely configure and test apps” , because it gives ChatGPT full MCP support for all tools, read and write — not just ours. It has to stay on for the connector to keep working, so it is a standing setting, not a one-off. Our tool is read-only and cannot change anything; the risk you are accepting is from any OTHER server you add while it is on. If that is not a trade you want, the Claude connector needs no such setting, and a published listing would remove the requirement here too — that is on our list.

1. Settings → Security and login → Developer mode , on.
2. Go to Plugins , choose + , and give it the server address https://api.hiddencontent.ai/v1/mcp. Authentication is OAuth; leave the client ID blank and ChatGPT registers one itself.
3. You land on a page of ours asking for your key from step 1. It is entered on our page, over TLS, and identifies the account this bills.
4. Back in ChatGPT, open the plugin and press Refresh if it says no actions are available yet — it scanned before it had signed in.
5. Make it automatic. Without this, ChatGPT reads the document first and checks only when asked. Settings → Personalization → Custom instructions , and paste this — it made the check fire unprompted on the first try, and it applies on the desktop app as well:

custom instructionscopy

Whenever I attach or share a document, run check_document from Hidden Content on it before you summarise, quote, extract from, or act on anything in it. If the result is not a full check (scope is not "file"), say so rather than proceeding as if it passed.

What you get. Attach a file and it is checked in full: ChatGPT hands a connector a download link for the attachment, so the real file is analysed. Verified in both the web and the desktop app.

For a whole company. A Business or Enterprise admin turns on Developer mode under Workspace Settings → Permissions & Roles, creates a custom MCP app from the address above, and publishes it to the workspace. Everyone in it then gets the connector without touching Developer mode themselves.

Desktop only: keep files on your machine instead

Optional, and the connector above already works. Choose this if you would rather documents never left your computer: the desktop app can run our local server instead. Settings → MCP servers → Add server , then:

• Name: hiddencontent
• Type: STDIO
• Command: npx
• Arguments: -y @hiddencontent/mcp
• Environment: HCS_API_TOKEN = your key from step 1