VitaminMCP

Bots now work on 1.21 through 1.21.8, and there is one runner jar instead of one per protocol.

Added

Six protocols, one bot-runner.jar.

You no longer choose a runner. The jar carries a backend per protocol and picks one at startup by asking the server what it speaks — a server list ping, before any bot connects. Point it at 1.21.1 or at 1.21.8 and the same file does the right thing.

Two MCProtocolLib builds still cannot share a class path; every build occupies the same package names. They can share a process, which is what changed: the selected backend is loaded in a class loader of its own. The runner is still a child process, so it is still the crash boundary and still the whole cleanup.

The agent floor moved to 1.21, down from 1.21.8. It compiles against the floor now, so a call to API those older servers do not have is a compile error rather than a NoSuchMethodError on your server.

Fixed

A menu the bot closed was still reported as open. The server acts on a client-requested close without echoing it, so nothing was ever going to clear the client's own record. bot_inspect and menu() kept describing a screen the player had already left.

Bot commands were refused on a server with enforce-secure-profile on — its default. A bot has no Mojang signing key, so /say, /me and anything else carrying a signable argument came back as chat.disabled.invalid_command_signature, delivered to the player and nowhere else. Servers the orchestrator starts now set it off; if you run your own test server, do the same.

Upgrading

The runner is now bot-runner.jar, not bot-runner-772.jar.

If your session_start names runnerJar, either update the path or delete the field — omitting it makes mcp-server find the runner beside itself, which is where dist and the release both put it. Deleting it is the better fix: there is nothing left to choose.

{
  "host": "127.0.0.1",
  "port": 25565,
  "mcpPort": 25585,
  "token": "auth-token from config.yml"
}

Nothing else changed for callers. The MCP tools, their arguments and their responses are the same.

bot-runner.jar is 89 MB, because six protocol libraries live inside it. That is the cost of not having to pick one; it is downloaded once and unpacks only the backend it needs.

Verified

Every version in the table was started for real and driven through seventeen features — join, break, move, chat, commands, containers, menu contents, item model data, boss bars, the sidebar scoreboard, entity right-clicks, three bots at once — with the server's exception log checked for linkage errors afterwards. The full matrix runs all seven versions in one pass.

Setup and usage: README