GMCP --- What is GMCP? GMCP stands for Generic MUD Communication Protocol. It is an out-of-band telnet protocol used by supported clients to receive structured game data as JSON packets. In plain terms: GMCP lets your client build health bars, room panels, group windows, combat target panels, and channel windows without having to scrape normal room text. GMCP is handled automatically by clients that support it. Most players do not need to type anything to use it. --- Client setup A GMCP-capable client normally sends: Core.Hello Core.Supports.Set NukeFire answers with Core.Hello and then sends the packets your client says it supports. You can also request some packets manually from your client script, such as: Char.Vitals Char.Status Char.StatusVars Char.MaxStats Char.GPS Char.TargetAffects Room.Info Group Comm.Channel.List --- Core packets Core.Hello Sent by NukeFire when GMCP connects. Fields: name version Core.Goodbye Sent on logout. Core.Ping NukeFire answers Core.Ping with Core.Ping. --- Character vitals Char.Vitals Sent on login, combat start/end, vitals change, and periodic GMCP update ticks. Fields: hp current hit points mhp maximum hit points mana current mana mmana maximum mana move current movement mmove maximum movement devotion current Occultist devotion mdevotion maximum devotion When you have a valid combat opponent, Char.Vitals may also include: opponent name visible opponent name hp opponent current hit points mhp opponent maximum hit points mn opponent current mana mmn opponent maximum mana mv opponent current movement mmv opponent maximum movement level opponent level --- Character status Char.Status Sent on login and when level/experience status changes. Fields: name your character name title your colorized title title_plain your title without color class your class name level your level exp current experience tnl experience to next level or remort alignment alignment value gold credits/gold carried bank credits/gold in bank hitroll hitroll total damroll damroll total ac armor class position current position number wimpy wimpy threshold Char.StatusVars A field-definition packet for Char.Status. It tells clients what each Char.Status field means. --- Character maximum stats Char.MaxStats Sent on login and when maximum values change. Fields: str current strength int current intelligence wis current wisdom dex current dexterity con current constitution cha current charisma str_base base strength int_base base intelligence wis_base base wisdom dex_base base dexterity con_base base constitution cha_base base charisma maxhp maximum hit points maxmana maximum mana maxmoves maximum movement --- Target affects Char.TargetAffects This is an on-demand packet used for a specific viewed/diagnosed/stat-targeted mob or character. It is not spammed every tick. Common structure: target count effects If there is no valid target, NukeFire sends: target: null count: 0 effects: [] The exact effect entries come from NukeFire's master-modifier/affect formatter. --- Room information Room.Info Sent on login, room changes, and when requested. Fields: num current room vnum name room name with colors stripped area zone/area name with colors stripped zone internal zone index terrain room sector/terrain type exits JSON object of visible exits coords x/y/z coordinate object Exit values: If an exit is open, the value is the destination room vnum. If an exit is closed, the value is the word "closed". Coords: x y z At present, Room.Info coords are sent as 0/0/0 by this packet. --- GPS Char.GPS Sent on login, room changes, and when requested. This packet is produced by the GPS system. It is separate from Room.Info and is used by clients that support NukeFire GPS/map/path data. --- Communication packets Comm.Channel Sent when a supported channel message is emitted. Fields: chan channel name player sender name msg message text Comm.Channel.List Sent on login, after copyover resync, and when requested. Normal channel list: say tell gossip shout holler grats auction gsay SSF characters and immortals also receive: ssf Each channel entry contains: name caption command --- Group packets group NukeFire sends the group packet using lowercase "group". Top-level fields: groupname leader created status count kills exp members enemies Member info fields: hp member current hit points mhp member maximum hit points mn member current mana mmn member maximum mana mv member current movement mmv member maximum movement align member alignment tnl member experience to next level/remort qt quest timer placeholder qs quest status placeholder lvl member level here 1 if in your room, 0 otherwise Enemy info fields: hp enemy current hit points mhp enemy maximum hit points mn enemy current mana mmn enemy maximum mana mv enemy current movement mmv enemy maximum movement level enemy level here 1 if in your room, 0 otherwise If you are not grouped, NukeFire sends an empty group packet with empty member and enemy lists so clients can clear old group panels. group.remove Sent when a member is removed. Fields: name --- When GMCP updates On login: Char.Status Char.Vitals Char.MaxStats Room.Info Char.GPS Comm.Channel.List group, if grouped On logout: Core.Goodbye On room change: Room.Info Char.GPS On combat start/end: Char.Vitals On vitals change: Char.Vitals, rate-limited On level/experience status change: Char.Status, rate-limited On max stat changes: Char.MaxStats, rate-limited On group changes: group, rate-limited After copyover/full resync: Comm.Channel.List Char.Vitals Char.MaxStats Char.Status Char.GPS group, if grouped --- Rate limits To avoid flooding clients, some GMCP packets are rate-limited: Char.Vitals up to about 2 times per second Char.MaxStats about once every 1.5 seconds Char.Status about once per second group about once per second normally Large groups update more slowly: 10+ members about every 2 seconds 20+ members about every 3 seconds --- Related help prompt help screenreader help group help ssf