PROTOCOL.md

Protocol

Pokemon Showdown's protocol is relatively simple.

Pokemon Showdown is implemented in SockJS. SockJS is a compatibility layer over raw WebSocket, so you can actually connect to Pokemon Showdown directly using WebSocket:

ws://sim.smogon.com:8000/showdown/websocket
  or
wss://sim.smogon.com/showdown/websocket

Client implementations you might want to look at for reference include:

• pickdenis' chat bot (Ruby) - https://github.com/pickdenis/ps-chatbot
• Quinella and TalkTakesTime's chat bot (Node.js) - https://github.com/TalkTakesTime/Pokemon-Showdown-Bot
• the official client (HTML5 + JavaScript) - https://github.com/Zarel/Pokemon-Showdown-Client

The official client logs protocol messages in the JavaScript console, so opening that (F12 in most browsers) can help tell you what's going on.

Client-to-server messages

Messages from the user to the server are in the form:

ROOMID|TEXT

ROOMID can optionally be left blank if it's the lobby, or if the room is irrelevant (for instance, if TEXT is a command like /join lobby where it doesn't matter what room it's sent from, you can just send |/join lobby.)

TEXT can contain newlines, in which case it'll be treated the same way as if each line were sent to the room separately.

A partial list of available commands can be found with /help.

To log in, look at the documentation for the |challstr| server message.

Server-to-client messages

Messages from the server to the user are in the form:

>ROOMID
MESSAGE
MESSAGE
MESSAGE
...

>ROOMID and the newline after it can be omitted if the room is lobby or global. MESSAGE cannot start with >, so it's unambiguous whether or not >ROOMID has been omitted.

As for the payload: it's made of any number of blocks of data separated by newlines; empty lines should be ignored. In particular, it should be treated the same way whether or not it ends in a newline, and if the payload is empty, the entire message should be ignored.

If MESSAGE doesn't start with |, it should be shown directly in the room's log. Otherwise, it will be in the form:

|TYPE|DATA

For example:

|j| Some dude
|c|@Moderator|hi!
|c| Some dude|you suck and i hate you!
Some dude was banned by Moderator.
|l| Some dude
|b|battle-ou-12| Cool guy|@Moderator

This might be displayed as:

Some dude joined.
@Moderator: hi!
Some dude: you suck and i hate you!
Some dude was banned by Moderator.
Some dude left.
OU battle started between Cool guy and Moderator

For bandwidth reasons, five of the message types - chat, join, leave, name, and battle - are sometimes abbreviated to c, j, l, n, and b respectively. All other message types are written out in full so they should be easy to understand.

Four of these can be uppercase: J, L, N, and B, which are the equivalent of their lowercase versions, but are recommended not to be displayed inline because they happen too often. For instance, the main server gets around 5 joins/leaves a second, and showing that inline with chat would make it near-impossible to chat.

Some outgoing message types

USER = a user, the first character being their rank (users with no rank are represented by a space), and the rest of the string being their username.

####Room initialization

|init|ROOMTYPE

The first message received from a room when you join it. ROOMTYPE is one of: chat or battle

|users|USERLIST

USERLIST is a comma-separated list of USERs, sent from chat rooms when they're joined.

####Room messages

||MESSAGE or MESSAGE

We received a message MESSAGE, which should be displayed directly in the room's log.

|html|HTML

We received an HTML message, which should be sanitized and displayed directly in the room's log.

|join|USER or |j|USER

USER joined the room.

|leave|USER or |l|USER

USER left the room.

|name|USER|OLDID or |n|USER|OLDID

A user changed name to USER, and their previous userid was OLDID.

|chat|USER|MESSAGE or |c|USER|MESSAGE

USER said MESSAGE. Note that MESSAGE can contain | characters, so you can't just split by | and take the fourth string.

|:|TIMESTAMP

|c:|TIMESTAMP|USER|MESSAGE

c: is pretty much the same as c, but also comes with a UNIX timestamp; (the number of seconds since 1970). This is used for accurate timestamps in chat logs.

: is the current time according to the server, so that times can be adjusted and reported in the local time in the case of a discrepancy.

The exact fate of this command is uncertain - it may or may not be replaced with a more generalized way to transmit timestamps at some point.

|battle|ROOMID|USER1|USER2 or |b|ROOMID|USER1|USER2

A battle started between USER1 and USER2, and the battle room has ID ROOMID.

####Battle messages

|player|PLAYER|USERNAME|AVATAR

Appears when you join a battle room. PLAYER denotes which player it is (p1 or p2) and USERNAME is the username. AVATAR is the player's avatar identifier (usually a number, but other values can be used for custom avatars).

|gametype|GAMETYPE
|gen|GENNUM
|tier|TIERNAME
|rated
|rule|RULE: DESCRIPTION

Additional details when you join a battle room. GAMETYPE is one of singles, doubles, or triples; GENNUM denotes the generation of Pokemon being played; tier is the format; and rule appears multiple times, once for each clause in effect. rated only appears if the battle is rated.

|clearpoke
|poke|PLAYER|SPECIES
|poke|PLAYER|SPECIES
...
|teampreview

These messages appear if you're playing a format that uses team previews. PLAYER is the player ID (see |player|) and SPECIES is the species of the Pokemon. teampreview commonly appears after rule tags instead of after the Pokemon in the team preview.

|request|REQUEST

Gives a JSON object containing a request for a decision (to move or switch). To assist in your decision, REQUEST.active has information about your active Pokemon, and REQUEST.side has information about your your team as a whole.

|inactive|MESSAGE or |inactiveoff|MESSAGE

A message related to the battle timer has been sent. The official client displays these messages in red.

inactive means that the timer is on at the time the message was sent, while inactiveoff means that the timer is off.

|start

Indicates that the game has started.

|win|USER

USER has won the battle.

|tie

The battle has ended in a tie.

Major actions

In battle, most Pokemon actions come in the form |ACTION|POKEMON|DETAILS followed by a few messages detailing what happens after the action occurs.

A Pokemon is always identified in the form POSITION: NAME. POSITION is the spot that the Pokemon is in: it consists of the PLAYER of the player (see |player|), followed by a letter indicating the given Pokemon's position, counting from a.

In doubles and triples battles, a will refer to the leftmost Pokemon on one team and the rightmost Pokemon on the other (so p1a faces p2c, etc). NAME is the nickname of the Pokemon performing the action.

|move|POKEMON|MOVE|TARGET

The specified Pokemon has used move MOVE at TARGET. If a move has multiple targets or no target, TARGET should be ignored. If a move targets a side, TARGET will be a (possibly fainted) pokemon on that side.

move can be tagged with |[miss] to indicate that the move missed.

|switch|POKEMON|SPECIES|HP STATUS or |drag|POKEMON|SPECIES|HP STATUS

A Pokemon identified by POKEMON has switched in (the old Pokemon, if still there, is switched out).

The new Pokemon has species SPECIES, HP HP, and status STATUS. HP is specified as a fraction; if it is your own Pokemon then it will be CURRENT/MAX, if not, it will be /100 if HP Percentage Mod is in effect and /48 otherwise. STATUS can be left blank, or it can be slp, par, etc.

switch means it was intentional, while drag means it was unintentional (forced by Whirlwind, Roar, etc).

|detailschange|POKEMON|FORME|HP STATUS or |detailschange|POKEMON|FORME, GENDER|HP STATUS or |-formechange|POKEMON|FORME|HP STATUS

The specified Pokemon has changed formes (via Mega Evolution, ability, etc.) to FORME. If the forme change cannot be reverted (Mega Evolution or a Shaymin-Sky that is frozen), then detailschange will appear; otherwise, the client will send -formechange. GENDER can appear in detailschange if the transforming Pokemon has a gender, displayed as M or F for male and female, respectively.

|cant|POKEMON|REASON or |cant|POKEMON|REASON|MOVE

The Pokemon POKEMON could not perform a move because of the indicated REASON (such as paralysis, Disable, etc). Sometimes, the move it was trying to use is given.

|faint|POKEMON

The Pokemon POKEMON has fainted.

Minor actions

Minor actions are less important than major actions. In the official client, they're usually displayed in small font if they have a message. Pretty much anything that happens in a battle other than a switch or the fact that a move was used is a minor action. So yes, the effects of a move such as damage or stat boosts are minor actions.

Minor actions often come with tags such as |[from] EFFECT|[of] SOURCE. EFFECT will be an effect (move, ability, item, status, etc), and SOURCE will be a Pokemon. These can affect the message or animation displayed, but do not affect anything else. Other tags include |[still] (suppress animation) and |[silent] (suppress message).

|-fail|POKEMON|ACTION

The specified ACTION has failed against the POKEMON targetted. The ACTION in question can be a move that fails, or a stat drop blocked by an ability like Hyper Cutter, in which case ACTION will be unboost|STAT, where STAT indicates where the ability prevents stat drops. (For abilities that block all stat drops, like Clear Body, |STAT does not appear.)

|-damage|POKEMON|HP STATUS

The specified Pokemon POKEMON has taken damage, and is now at HP STATUS (see |switch| for details).

If HP is 0, STATUS should be ignored. The current behavior is for STATUS to be fnt, but this may change and should not be relied upon.

|-heal|POKEMON|HP STATUS

Same as -damage, but the Pokemon has healed damage instead.

|-status|POKEMON|STATUS

The Pokemon POKEMON has been inflicted with STATUS.

|-curestatus|POKEMON|STATUS

The Pokemon POKEMON has recovered from STATUS.

|-cureteam|POKEMON

The Pokemon POKEMON has used a move that cures its team of status effects, like Heal Bell.

|-boost|POKEMON|STAT|AMOUNT

The specified Pokemon POKEMON has gained AMOUNT in STAT, using the standard rules for Pokemon stat changes in-battle. STAT is a standard three-letter abbreviation fot the stat in question, so Speed will be spe, Special Defense will be spd, etc.

|-unboost|POKEMON|STAT|AMOUNT

Same as -boost, but for negative stat changes instead.

|-weather|WEATHER

Indicates the weather that is currently in effect. If |[upkeep] is present, it means that WEATHER was active previously and is still in effect that turn. Otherwise, it means that the weather has changed due to a move or ability, or has expired, in which case WEATHER will be none.

|-crit|POKEMON

A move has dealt a critical hit against the POKEMON.

|-supereffective|POKEMON

A move was super effective against the POKEMON.

|-resisted|POKEMON

A move was not very effective against the POKEMON.

|-immune|POKEMON

The POKEMON was immune to a move.

|-item|POKEMON|ITEM

The ITEM held by the POKEMON has been changed or revealed due to a move or ability. In addition, Air Balloon reveals itself when the Pokemon holding it switches in, so it will also cause this message to appear.

|-enditem|POKEMON|ITEM

The ITEM held by POKEMON has been destroyed, and it now holds no item. This can be because of an item's own effects (consumed Berries, Air Balloon), or by a move or ability, like Knock Off. If a berry is consumed, it also has an additional modifier |[eat] to indicate that it was consumed. This message does not appear if the item's ownership was changed (with a move or ability like Thief or Trick), even if the move or ability would result in a Pokemon without an item.

|-ability|POKEMON|ABILITY

The ABILITY of the POKEMON has been changed or revealed due to a move or ability. This also includes abilities that reveal themselves upon switch-in, like Mold Breaker. The only move tha does not trigger this message is Skill Swap, so that if you use Skill Swap between teammates in a doubles or triples battle, the abilities of the two Pokemon are not revealed to the opponent, similar to its behavior in game.

|-endability|POKEMON

The POKEMON has had its ability surpressed, either by a move like Gastro Acid, or by the effects of Mummy.

|-transform|POKEMON|SPECIES

The Pokemon POKEMON has transformed into SPECIES by the effect of Transform or the ability Imposter.

|-activate|EFFECT

A miscellaneous effect has activated. This is triggered whenever an effect could not be better described by one of the other minor messages: for example, healing abilities like Water Absorb simply use -heal, and items that are consumed upon use have the -enditem message instead.

|-hint|MESSAGE

Displays a message in parentheses to the client. Hint messages appear to explain and clarify why certain actions, such as Fake Out and Mat Block failing, have occurred,
when there would normally be no in-game messages.

|-message|MESSAGE

Displays a miscellaneous message to the client. These messages are primarily used for messages from game mods that aren't supported by the client, like rule clauses such as Sleep Clause, or other metagames with custom messages for specific scenarios. It is also used in triples battles for the automatic centering of Pokemon when only one remains on each side.

I'll document all the message types eventually, but for now this should be enough to get you started. You can watch the data sent and received from the server on a regular connection, or look at the client source code for a full list of message types.

####Global messages

|popup|MESSAGE

Show the user a popup containing MESSAGE. || denotes a newline in the popup.

|pm|SENDER|RECEIVER|MESSAGE

A PM was sent from SENDER to RECEIVER containing the message MESSAGE.

|usercount|USERCOUNT

USERCOUNT is the number of users on the server.

|nametaken|USERNAME|MESSAGE

You tried to change your username to USERNAME but it failed for the reason described in MESSAGE.

|challstr|KEYID|CHALLENGE

You just connected to the server, and we're giving you some information you'll need to log in.

If you're already logged in and have session cookies, you can make an HTTP GET request to http://play.pokemonshowdown.com/action.php?act=upkeep&challengekeyid=KEYID&challenge=CHALLENGE

Otherwise, you'll need to make an HTTP POST request to http://play.pokemonshowdown.com/action.php with the data act=login&name=USERNAME&pass=PASSWORD&challengekeyid=KEYID&challenge=CHALLENGE

USERNAME is your username and PASSWORD is your password, and KEYID and CHALLENGE are the values you got from |challstr|. (Also feel free to make the request to https:// if your client supports it.)

Either way, the response will start with ] and be followed by a JSON object which we'll call data.

Finish logging in (or renaming) by sending: /trn USERNAME,0,ASSERTION where USERNAME is your desired username and ASSERTION is data.assertion.

|updateuser|USERNAME|NAMED|AVATAR

Your name or avatar was successfully changed. Your username is now USERNAME. NAMED will be 0 if you are a guest or 1 otherwise. And your avatar is now AVATAR.

|formats|FORMATSLIST

This server supports the formats specified in FORMATSLIST. FORMATSLIST is a |-separated list of FORMATs. FORMAT is a format name with one or more of these suffixes: ,# if the format uses random teams, ,, if the format is only available for searching, and , if the format is only available for challenging. Sections are separated by two vertical bars with the number of the column of that section prefixed by , in it. After that follows the name of the section and another vertical bar.

|updatesearch|JSON

JSON is a JSON object representing the current state of what battles the user is currently searching for.

|updatechallenges|JSON

JSON is a JSON object representing the current state of who the user is challenging and who is challenging the user.

|queryresponse|QUERYTYPE|JSON

JSON is a JSON object representing containing the data that was requested with /query QUERYTYPE or /query QUERYTYPE DETAILS.

Possible queries include /query roomlist and /query userdetails USERNAME.