Notes

Written from running it

The catalog is the registry. These notes are R21 writing about a tool after using it — not a secondhand roundup, and not live until someone at R21 marks the file published.

• 2026-09-21

  Keep Secrets Out of the Prompt with MCP Connectors

  A practical look at how MCP servers front real systems so your assistant calls tools without ever seeing a password or API key.