NoteSurge could already expose an MCP server for agents like Claude Desktop to consume. Now the flip side: Notey itself can connect to any external MCP server, discover what tools it offers, and call one. The stateless client handles Streamable-HTTP JSON-RPC 2.0 (bare JSON or SSE framing), validates URLs before any network hit, and surfaces server-side tool failures honestly — never collapsing errors into fake success. Both capabilities are registry-tied: mcp.tools is a read-tier discovery, mcp.call is a write-class draft gated on canWrite.
The bot webhook used a hardcoded if-chain for its single command (/selftest). Everything now goes through a slash-command registry in one file: adding a new command is a registry entry, never another conditional in the route. /help derives from the registry so it always reflects reality, and a mistyped command gets an honest "unknown command" reply instead of wasting a model turn.