💡 [FEATURE REQUEST] Add to MCP configuration to pull in READ-ONLY toolsets

[Sayvai]

Describe your feature request

I would like to be able to pull in read-only toolsets that are available from the Render MCP server.

This would allow the local LLM models to 👉 safely 👈 call tools which do not make any mutations / changes to Render platform / databases, and rather performs retrieval /queries of structured data from the Render platform, thus enabling fine-grained access-controls, avoiding potential unsafe LLM-driven accidental data writes to the Render platform.

A similar configuration can be considered like we see with the GitHub MCP server configuration 👇

{
  "servers": {
    "github": {
      "type": "http",
      "url": "https://api.githubcopilot.com/mcp/",
      "headers": {
        "X-MCP-Readonly": "true" // 👈  to pull down and access limited read-only toolsets
      }
    }
  }
}

Render MCP Config - Similar Suggestion?

{
  "mcpServers": {
    "render": {
      "url": "https://mcp.render.com/mcp",
      "headers": {
        "Authorization": "Bearer <YOUR_API_KEY>"
        "X-MCP-Readonly": "true" // 👈  to pull down and access limited read-only toolsets
      }
    }
  }
}

[aaijazi]

Thanks for the feature request! This seems pretty reasonable. We initially avoided doing dynamic toolsets because it wasn't well supported by the MCP spec, but:

1. That has changed, and it appears to be well supported during the MCP lifecycle now: https://modelcontextprotocol.io/specification/2025-06-18/server/tools#list-changed-notification
2. Readonly seems like a subset that is unlikely to change during a session lifecycle.

I think we can implement this with a simple "if the request to tools/list has this header set, only return ready only tools" and we will assume it doesn't change. I'll aim to add this in the next few weeks, when I next pick up work for the MCP server.

[Sayvai]

Thanks @aaijazi .

For a separate (unrelated) project, I opened a PR to add in a --read-only flag as a CLI argument (since that MCP project runs locally), and which also adds in listChanged configuration to the McpServer() constructor which you highlighted from your previous comment!

You can see how I applied the --read-only flag implementation, below 👇

• feat: add read-only mode support for tools husamabusafa/hasura_mcp#7