> For the complete documentation index, see [llms.txt](https://docs.buzzy.buzz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.buzzy.buzz/troubleshooting/mcp-issues.md).

# MCP Issues

Buzzy has two different MCP surfaces:

* **Buzzy Builder MCP** helps agents create or edit Buzzy app definitions.
* **Buzzy Custom MCP** exposes enabled app-specific tools so MCP clients can work with a particular app's data.

## Builder MCP Symptoms

* agent cannot connect to Builder MCP
* app generation or artifact update fails
* generated app has missing screens, broken bindings, or wrong data model relationships
* Builder MCP edits do not appear in the Workspace
* tests or security review reveal issues after an MCP change

Start with [Buzzy Builder MCP](/the-building-blocks/mcp/buzzy-builder-mcp.md). If the issue is visible in a screen, inspect it with [In-App Debugging](/troubleshooting/in-app-debugging.md).

## Custom MCP Symptoms

* MCP client cannot see expected tools
* tool is exposed but cannot access the expected rows
* Create, read, update, or delete behavior is wrong
* permission model allows too much or too little access
* app-specific data tools do not match the current datamodel

Start with [Buzzy Custom MCP](/the-building-blocks/mcp/buzzy-custom-mcp.md). Check that the app has the intended datatables, fields, row permissions, field permissions, People/Teams settings, and exposed tool configuration.

## First Checks

1. Confirm whether the issue is Builder MCP or Custom MCP.
2. Check the app ID and environment the client is connected to.
3. Check the user's app permissions.
4. Confirm the datamodel has not changed since the MCP tool or agent prompt was configured.
5. Use [Tests](/the-building-blocks/release-tests.md) and [Security Review](/the-building-blocks/security-review.md) after MCP-driven app changes.