Write actions blocked on custom MCP server – Business plan workspace, Developer Mode unavailable at workspace level

ChatGPT Apps SDK
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1

We’ve built a remote MCP server (Streamable HTTP) with both read and write tools and are trying to integrate it into a ChatGPT Business workspace. The server is fully functional — it works correctly as an MCP client in Claude, Copilot, and passes all tool calls when tested via MCP Inspector and direct API calls.

We followed the documented setup flow:

- Created and published the custom app from Workspace Settings → Apps → Drafts (Owner role)

- The app is available to all workspace members

- Connection is established successfully

- Read tools are discovered and called without issues

The problem is with writing tools, and we’ve narrowed it down to two separate but related issues.

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ISSUE 1: Write tool calls are blocked before reaching our server

When ChatGPT attempts to invoke any write tool, it never reaches our MCP server. No request hits our logs or API. ChatGPT returns these exact messages:

“This tool call was blocked by OpenAI’s safety checks. Please double check what you are sending.”

“No response returned from the write tool.”

We confirmed this is not specific to our custom server — the same behavior occurs with native apps like Google Drive (write actions blocked at the workspace level).

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ISSUE 2: Developer Mode is locked at workspace level (shows as Enterprise-only)

According to the documentation, write actions require Developer Mode enabled. We enabled it at the user level (Settings → Apps → Advanced Settings → Developer Mode) — that toggle works fine.

However, in Workspace Settings → Permissions & roles → Connected data, the section shows an “Enterprise” badge and the “Developer mode / Create custom MCP connectors” option has no toggle, it cannot be enabled at the workspace level for Business plans.

This directly contradicts the official Apps capabilities table, which lists both Write actions and Custom (MCP) as available for Business plans.

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Environment:

- Plan: ChatGPT Business

- Workspace role: Owner

- MCP transport: Streamable HTTP

- Developer Mode: enabled at user level only

- App published to workspace: yes

- Read tools: working

- Write tools: blocked, no server logs

- Same issue on native apps (e.g. Google Drive write actions)

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Questions:

1. Is workspace-level write action support for custom MCP apps intentionally restricted to Enterprise in the current beta, despite the documentation stating otherwise for Business?

2. Is there a workaround to enable write tools on a Business workspace without Enterprise-level Developer Mode?

3. Are the safety checks that block write tool calls configurable at the workspace level (e.g. via Action Control in Workspace Settings → Apps)?

4. Is there any MCP server-side configuration (beyond readOnlyHint annotations) required for write tools to be approved by ChatGPT’s safety checks on a Business workspace?

References:

-https://help.openai.com/en/articles/12584461-developer-mode-and-mcp-apps-in-chatgpt

-https://help.openai.com/en/articles/11487775-apps-in-chatgpt

-https://help.openai.com/en/articles/11509118-admin-controls-security-and-compliance-in-apps-enterprise-edu-and-business

2

Welcome to the dev Community, @Tade95!

Thanks for sharing the detailed breakdown.

Based on what you described, the connection and read tool discovery appear to be working, but the write tool calls are being blocked before they reach your MCP server.

According to the Help Center, full MCP support, including write/modify actions, is currently rolling out in beta for ChatGPT Business, Enterprise, and Edu.

For write/modify actions, ChatGPT may ask for confirmation depending on the app permissions, the action context, and the potential impact of the action. In some cases, especially risky actions may be blocked instead of being presented for approval, which could explain why the request is not reaching your server.

One clarification: OpenAI-built apps are currently search-only and do not support write actions, so behavior with apps like Google Drive may not be directly comparable to a custom MCP app.

If you’ve already opened a Support ticket, could you please share the ticket number here? That will help us investigate this further with the relevant context. If not, please open one and include the workspace ID, app name, exact error text, timestamps, affected write tool details, and any relevant MCP server/tool metadata.

Thanks again for flagging this.

~ Smith

3

No, write actions are available to everyone.

Developer mode is not an enterprise level feature, disabling it is. Could you show me what you’re trying to do in a screenshot?

I’m less certain about this, so I won’t say for certain what’s available at what tier here, but the workspace level thing you’re describing can mostly just be done per-app at this point.

No, if you publish an MCP to your workspace and you configure to allow writes, you should (probably) be good.