# Component Visibility (/docs/configuration/components)

Use the optional `components` field in `xmcp.config.ts` to control which tools,
prompts, static resources, and resource templates your server registers. Update
both `xmcp` and `@xmcp-dev/compiler` to use this option.

```typescript title="xmcp.config.ts"
import type { XmcpConfig } from "xmcp";

export default {
  http: true,
  components: {
    exclude: {
      names: ["delete-account"],
      tags: ["internal", "experimental"],
    },
  },
} satisfies XmcpConfig;
```

A component matches a selector when its name appears in `names` **or** any of
its `metadata.tags` appear in `tags`. Names and tags are exact, case-sensitive
strings. Names come from `metadata.name`, falling back to the file name without
its extension. Use resource names in the `names` list.
The rules apply to all component types, so a name shared by a tool and a prompt
matches both.

For example, this tool and its generated MCP Apps UI resource are excluded by
the configuration above:

```typescript title="src/tools/internal-dashboard.ts"
import type { ToolMetadata } from "xmcp";

export const metadata: ToolMetadata = {
  name: "internal-dashboard",
  description: "An internal dashboard",
  tags: ["internal"],
  _meta: { ui: {} },
};

export default function internalDashboard() {
  return "<main><h1>Internal dashboard</h1></main>";
}
```

## Include a subset

Add `include` to limit registration to matching names or tags:

```typescript title="xmcp.config.ts"
import type { XmcpConfig } from "xmcp";

export default {
  http: true,
  components: {
    include: {
      names: ["greet", "review-code"],
      tags: ["configuration"],
    },
    exclude: { tags: ["internal"] },
  },
} satisfies XmcpConfig;
```

| Configuration                             | Behavior                                            |
| ----------------------------------------- | --------------------------------------------------- |
| `components` or `include` omitted         | All enabled components are eligible                 |
| `include` provided                        | Only components matching a name or tag are eligible |
| Both `include` and `exclude` match        | Exclusion wins                                      |
| `include: {}` or only empty include lists | No components are included                          |
| `exclude: {}` or only empty exclude lists | Nothing is excluded                                 |
| `metadata.enabled: false`                 | The component stays disabled, even when included    |

Selectors accept optional `names: string[]` and `tags: string[]`. Entries must
be nonempty strings. No wildcard expansion is performed.

## Registration and UI resources

Excluded components are absent from MCP listings. Direct tool calls, prompt
fetches, resource reads, and completion requests for excluded components return
not-found errors. When an entire component category is unavailable, the SDK may
report that its method is not found.

Generated UI resources follow their owning tool: including the tool makes its
generated UI resource available, and excluding it removes both. The generated
resource does not need its own matching tags. Manually authored resources use
their own metadata.

Rules are applied during server setup and are the same for every client.
Component modules are still imported and compiled. Rebuild and restart the
server after changing the configuration in production.

The [HTTP transport example](https://github.com/basementstudio/xmcp/tree/main/examples/http-transport)
includes the excluded `internal-dashboard` tool and requests that demonstrate
its tool and UI resource returning not-found errors.