@pubnub/mcp

# Publish/Subscribe API – Ruby SDK (Condensed) Below is an abridged version of the PubNub Publish/Subscribe documentation. All code blocks, method signatures, parameters, and server-response examples are preserved verbatim. --- ## Publish Essential facts * `publish_key` required at initialization; subscription to the same channel not required. * One channel per call; max payload 32 KiB (optimum < 1800 bytes). * Supports SSL/TLS (`ssl: true`) and optional message encryption. * Message is any JSON-serializable object. **Do NOT pre-serialize `message` or `meta`.** * Soft in-memory queue limit: 100 messages per subscriber. * Optional `custom_message_type` (3–50 characters; no `pn_` / `pn-` prefix). ### Method ``` `publish( channel: String, message: Object, store: Boolean, compressed: Boolean, publish_key: String, http_sync: Boolean, custom_message_type: String, meta: Object, callback: Lambda ) ` ``` ### Sample code ``` `require 'pubnub' def publish_message(pubnub) pubnub.publish( channel: 'my_channel', message: { text: 'Hi!' }, custom_message_type: 'text-message' ) do |envelope| puts "Publish status: #{envelope.status[:code]}" end end def main # Configuration for PubNub instance pubnub = PubNub.new( ` ``` (show all 28 lines) #### REST response ``` `[1, "Sent", "13769558699541401"] ` ``` ### Other publish examples ``` `pubnub.publish( message: { key: { inner_key: :value } }, custom_message_type: 'text-message', channel: :whatever, meta: { sender_uuid: 'user123-uuid', priority: 'high', location: 'office' } ) ` ``` ``` `pubnub.publish(message: 'Not gonna store that', store: false) ` ``` --- ## Fire Sends data only to Functions Event Handlers/Illuminate. No replication, storage, or delivery to channel subscribers. ### Method ``` `fire( channel: channel, message: message, compressed: compressed, publish_key: publish_key, http_sync: http_sync, callback: callback ) ` ``` ### Example ``` `pubnub.fire( channel: 'my_channel', message: { text: 'Hi!' } ) do |envelope| puts envelope.status end ` ``` --- ## Signal Lightweight (< 64 bytes payload) real-time signalling to current subscribers. ### Method ``` `pubnub.signal( message: Object, channel: String, compressed: Boolean, custom_message_type: String ) ` ``` ### Example ``` `pubnub.signal( channel: 'foo', message: { msg: 'Hello Signals' }, custom_message_type: 'text-message' ); ` ``` #### REST response ``` `[1, "Sent", "13769558699541401"] ` ``` --- ## Subscribe Creates a socket to receive messages, signals, and presence events. Key points * Requires `subscribe_key`. * `restore: true` will attempt reconnection and catch-up. * Wildcard channels and Channel Groups require Stream Controller add-on. * Presence events require Presence add-on. * Use `envelope.status` to confirm connectivity before publishing. ### Method ``` `subscribe( channels: channels, channel_groups: group, presence: presence, presence_callback: presence_callback, with_presence: with_presence, http_sync: http_sync, callback: callback ) ` ``` ### Basic example ``` `# Subscribe to channel 'my_channel'. pubnub.subscribe( channels: :my_channel ) ` ``` #### REST response ``` `[[], "Time Token"] ` ``` ### Multiplex / Presence / Wildcard examples ``` `# Subscribe to channels (with presence) and groups pubnub.subscribe( channels: ['debug', 'info', 'warn'], channel_groups: ['ruby_group', 'jruby_group', 'rbx_group'], presence: ['debug', 'info', 'warn'] ) # You will be subscribed to channels: debug, info, warn, debug-pnpres, info-pnpres and warn-pnpres # and to groups: ruby_group, jruby_group, rbx_group. ` ``` ``` `# Subscribes to room0, room0-pnpres, room1, room1-pnpres, room2, room2-pnpres pubnub.subscribe( channels: ['room0', 'room1', 'room2'], with_presence: true ) ` ``` ##### Presence event samples ``` `{ "action": "join", "timestamp": 1345546797, "uuid": "175c2c67-b2a9-470d-8f4b-1db94f90e39e", "occupancy": 2 } ` ``` ``` `{ "action" : "leave", "timestamp" : 1345549797, "uuid" : "175c2c67-b2a9-470d-8f4b-1db94f90e39e", "occupancy" : 1 } ` ``` ``` `{ "action": "timeout", "timestamp": 1345549797, "uuid": "76c2c571-9a2b-d074-b4f8-e93e09f49bd", "occupancy": 0 } ` ``` ``` `{ "action": "state-change", "uuid": "76c2c571-9a2b-d074-b4f8-e93e09f49bd", "timestamp": 1345549797, "data": { "isTyping": true } } ` ``` ``` `{ "action":"interval", "timestamp":1474396578, "occupancy":2 } ` ``` ``` `{ "action" : "interval", "occupancy" : , "timestamp" : , "joined" : ["uuid2", "uuid3"], "timedout" : ["uuid1"] } ` ``` ``` `{ "action" : "interval", "occupancy" : , "timestamp" : , "here_now_refresh" : true } ` ``` ##### Wildcard subscribe ``` `# Subscribe to wildcard channel 'ruby.*' (make sure you have wildcard subscribe enabled in your pubnub admin console!) # specify two different callbacks for messages from channels and presence events in channels. pubnub.subscribe( channels: 'ruby.*' ) ` ``` ##### Subscribe with state (Presence required) ``` `require 'pubnub' PUBKEY = 'demo' SUBKEY = 'demo' pubnub = Pubnub.new( subscribe_key: SUBKEY, publish_key: PUBKEY, ssl: true ) callback = Pubnub::SubscribeCallback.new( message: ->(envelope) { puts "MESSAGE: #{envelope.result[:data]}" }, ` ``` (show all 32 lines) ##### Channel group subscribe ``` `# Subscribe to group pubnub.subscribe( channel_groups: 'ruby_group' ) ` ``` ##### Presence on a channel group ``` `pubnub = Pubnub.new( subscribe_key: :demo, publish_key: :demo ) callback = Pubnub::SubscribeCallback.new( message: ->(_envelope) { }, presence: ->(envelope) { puts "PRESENCE: #{envelope.result[:data]}" }, status: ->(_envelope) { } ) ` ``` (show all 18 lines) ##### Subscribe sync loop ``` `require 'pubnub' pubnub = Pubnub.new( subscribe_key: :demo, publish_key: :demo ) pubnub.subscribe(channels: :whatever) while pubnub.subscribed_channels.size > 0 do sleep 1 end ` ``` --- ## Unsubscribe Removes specified channels/groups; closes socket when none remain. Unsubscribing from *all* channels resets last `timetoken` (possible message gaps). ### Method ``` `unsubscribe( channels: channels, channel_groups: group, http_sync: http_sync, callback: callback ) ` ``` ### Example ``` `pubnub.unsubscribe( channel: 'my_channel' ) do |envelope| puts envelope.status end ` ``` #### Response ``` `# @status = { :code => 200, :operation => :leave, :category => :ack, :error => false, # [...] }, # [...] > ` ``` ### Multiple channel/group examples ``` `pubnub.unsubscribe( channel: ['chan1','chan2','chan3'] ) do |envelope| puts envelope.status end ` ``` ``` `pubnub.unsubscribe( channel: ['chan1','chan2','chan3'] ) do |envelope| puts envelope.result[:data][:messages] end ` ``` ``` `{ "action" : "leave" } ` ``` ``` `pubnub.leave(channel_group: "cg1") do |envelope| puts envelope.status end ` ``` ``` `pubnub.leave(group: ["cg1", "cg2"]) do |envelope|** puts envelope end ` ``` _Last updated: Jul 15 2025_