Player-session MUD protocol

MXP

MUD eXtension Protocol

In use today Documented current use Legacy

Adds links, menus, formatting, entities, gauges, frames, images, and other interactive presentation features to text output.

Protocol overview

First seen
1998; v1.0 in 2003
Present-day status
In use today
In use today?
Yes, with documented current use.
Legacy?
Yes. It may still matter for compatibility or historical systems.
Layer
Player-session MUD protocol
Transport
Telnet option 91 plus streaming markup
Telnet option
91
Research validated

Current use and fit

Clickable SEND links remain useful and supported, while full implementations vary substantially between clients.

Implementation essentials

  • Negotiate option 91 and probe supported elements.
  • Start with an allowlisted SEND/link subset and provide plain-text or OSC 8 fallback.
  • Keep secure server markup separate from open player-generated text.

Compatibility and safety notes

  • Never pass untrusted player text into secure MXP.
  • Do not assume negotiation means every MXP tag is supported.
  • The full historical feature surface is complex and inconsistently implemented.

Original specifications and sources

Where an original site has disappeared, a preservation archive is linked and identified as such. MUDVerse does not claim authorship of the original protocol.