@pubnub/mcp

# Publish/Subscribe – C# SDK (Condensed) ## Request Execution Use try/catch to handle parameter errors (exception) and transport/API errors (`PNStatus`). ```csharp try { PNResult<PNPublishResult> publishResponse = await pubnub.Publish() .Message("Why do Java developers wear glasses? Because they can't C#.") .Channel("my_channel") .ExecuteAsync(); Console.WriteLine($"Server status : {publishResponse.Status.StatusCode}"); } catch (Exception ex) { Console.WriteLine($"Request can't be executed: {ex.Message}"); } ``` --- ## Publish • Requires `publishKey`. • One channel per call. • Max payload ≈ 32 KiB (optimum < 1.8 KB). • Throughput limited by subscriber capacity (in-memory queue = 100). • Optional SSL/TLS and message encryption. • Do **not** pre-serialize `message` / `meta`. ### Method ```csharp pubnub.Publish() .Message(object) // required .Channel(string) // required .ShouldStore(bool) // override history setting .Meta(Dictionary<string,object>) // for filter expressions .UsePOST(bool) // default: GET .Ttl(int) // per-message TTL .QueryParam(Dictionary<string,object>) .CustomMessageType(string) // 3-50 chars: text, action, … ``` ### Return `Task<PNResult<PNPublishResult>>` → • `PNPublishResult.Timetoken : long` • `PNStatus` (HTTP code, error info) ### Code Samples ``` ` ` ``` --- ## Fire Sends payload only to Functions/Illuminate Event Handlers (no replication, history, or delivery to subscribers). ### Method ```csharp pubnub.Fire() .Message(object) // required .Channel(string) // required .Meta(Dictionary<string,object>) .UsePOST(bool) .QueryParam(Dictionary<string,object>) ``` ### Code Sample ``` ` ` ``` --- ## Signal Lightweight (≤ 64 B payload) broadcast to channel subscribers. ### Method ```csharp pubnub.Signal() .Message(object) // required .Channel(string) // required .CustomMessageType(string) ``` ### Response `Timetoken : long` ### Code Sample ``` ` ` ``` --- ## Subscribe Requires `subscribeKey`. Opens streaming TCP socket for messages/events. ### Create Subscription (single entity) ```csharp // entity-scoped Channel firstChannel = pubnub.Channel("first"); Subscription sub = firstChannel.Subscription(SubscriptionOptions options); ``` ### Create Subscription Set (multi-entity) ```csharp // client-scoped SubscriptionSet set = pubnub.SubscriptionSet( channels: string[], channelGroups: string[], options: SubscriptionOptions ); ``` Keep strong references to `Subscription` / `SubscriptionSet`. #### SubscriptionOptions `ReceivePresenceEvents` – deliver presence updates. ### Subscribe Method ```csharp subscription.Subscribe<object>(SubscriptionCursor cursor) ``` `cursor` = `{ Timetoken?: long; Region?: int }` (best-effort replay). ### Code Samples ``` ` ` ``` ``` ` ` ``` No return value. --- ## Entities Create local representations to build subscriptions. ```csharp pubnub.Channel(string) pubnub.ChannelGroup(string) pubnub.ChannelMetadata(string) pubnub.UserMetadata(string) ``` Samples ``` ` ` ``` ``` ` ` ``` ``` ` ` ``` ``` ` ` ``` --- ## Event Listeners Attach to `Subscription`, `SubscriptionSet`, or client. ``` ` ` ``` Add connection status listener: ```csharp pubnub.AddListener(listener) ``` Sample ``` ` ` ``` --- ## Unsubscribe ```csharp subscription.Unsubscribe<object>() subscriptionSet.Unsubscribe<object>() ``` Sample ``` ` ` ``` --- ## Unsubscribe All (client-wide) ```csharp pubnub.UnsubscribeAll<object>() ``` Sample ``` ` ` ``` --- (All original code blocks retained verbatim.)