Everything sgcMQ does, mapped across the seven client components and the specifications they implement. Every capability works the same in Delphi and C++ Builder, and every license ships full source code. Click a component for its own page with usage and examples.
3.1.1 and 5.0
0.9.1 and 1.0
Native wire protocol
1.0 / 1.1 / 1.2
Plain TCP and TLS
Delphi 7 to 13, C++ Builder
sgcMQ is self-contained. It ships with the sgcWebSockets Core runtime bundled in, so it is not an add-on and there is no base license to buy.
Transport: plain TCP and TLS. sgcMQ connects over plain TCP and TLS. If you need to run the protocol over WebSocket, for example MQTT over WebSocket or AMQP over WebSocket, that requires a sgcWebSockets package, which provides the WebSocket client.
Every capability in the tables below is reached over the raw TCP carrier TsgcTCPClient, which sgcMQ ships in the box.
Four protocol families, registered on the SGC MQ palette page.
| Component | Class | Family | Description |
|---|---|---|---|
| MQTT Client | TsgcWSPClient_MQTT | MQTT | MQTT 3.1.1 and 5.0 publish/subscribe: QoS 0/1/2, retained messages, Last Will and Testament, sessions and MQTT 5 properties. |
| AMQP 0.9.1 Client | TsgcWSPClient_AMQP | AMQP | Channels, exchanges, queues and bindings, consumers, acknowledgements, prefetch QoS and transactions. |
| AMQP 1.0 Client | TsgcWSPClient_AMQP1 | AMQP | Sessions, sender and receiver links, credit-based flow control, SASL authentication and Azure CBS token helpers. |
| Kafka Client | TsgcWSPClient_Kafka | Kafka | Producer with acks and gzip, consumer groups with rebalance and offset commits, topic administration. |
| STOMP Client | TsgcWSPClient_STOMP | STOMP | STOMP 1.0/1.1/1.2 frames: SEND, SUBSCRIBE, ACK, NACK, receipts, heart-beating and transactions. |
| STOMP RabbitMQ Client | TsgcWSPClient_STOMP_RabbitMQ | STOMP | STOMP tuned for RabbitMQ: queue, topic, exchange, external-queue and temporary-queue helpers, over TCP or TLS. |
| STOMP ActiveMQ Client | TsgcWSPClient_STOMP_ActiveMQ | STOMP | STOMP tuned for Apache ActiveMQ, with queue and topic helpers plus an ActiveMQ_Options property. |
The publish/subscribe protocol of IoT, with the full quality-of-service machinery exposed rather than hidden.
| Capability | 3.1.1 | 5.0 | Notes |
|---|---|---|---|
| Protocol version select | ✓ | ✓ | MQTTVersion takes mqtt311 or mqtt5. |
| QoS 0, 1 and 2 | ✓ | ✓ | The QoS 2 exchange is surfaced as OnMQTTPubRec, OnMQTTPubRel and OnMQTTPubComp, not swallowed. |
| Retained messages | ✓ | ✓ | The retain flag is the fourth argument of Publish. |
| Last Will and Testament | ✓ | ✓ | LastWillTestament carries topic, message, QoS and retain. |
| Wildcard subscriptions | ✓ | ✓ | + for one level, # for the rest of the tree. |
| Sessions | ✓ | ✓ | The Session argument of OnMQTTConnect reports whether the broker resumed one. |
| Publish and wait | ✓ | ✓ | PublishAndWait blocks until the broker acknowledges the packet. |
| Publish a stream | ✓ | ✓ | Publish has a TStream overload for binary payloads. |
| Reason codes and names | — | ✓ | MQTT 5 returns a numeric reason code and its name on CONNACK and DISCONNECT. |
| CONNECT properties | — | ✓ | ConnectProperties sets session expiry, receive maximum, maximum packet size and topic alias maximum. |
| Topic aliases | — | ✓ | A short integer replaces a long topic name on the wire, resolved automatically on inbound packets. |
| User properties | — | ✓ | Arbitrary key/value pairs travel with CONNECT, PUBLISH, SUBSCRIBE and DISCONNECT. |
| Shared subscriptions | — | ✓ | Subscribe to $share/<group>/<topic> to spread deliveries across a group of clients. |
| Enhanced authentication | — | ✓ | The AUTH packet round trip through Auth and OnMQTTAuth, for challenge/response schemes. |
| Keep-alive | ✓ | ✓ | HeartBeat drives PINGREQ, with OnMQTTPing raised on the response. |
Two protocols that share a name and nothing else, so sgcMQ ships a separate component for each rather than pretending one API fits both.
| Capability | AMQP 0.9.1 | AMQP 1.0 | Notes |
|---|---|---|---|
| Component | TsgcWSPClient_AMQP | TsgcWSPClient_AMQP1 | Different wire format, different object model, different component. |
| Unit of multiplexing | Channel | Session | OpenChannel against CreateSession. |
| Topology declaration | DeclareExchange, DeclareQueue, BindQueue | — | AMQP 1.0 addresses nodes on the broker instead of declaring them. |
| Sending | PublishMessage(channel, exchange, routingKey, body) | SendMessage(session, link, text) | Routing key on 0.9.1, target address on 1.0. |
| Receiving | Consume then OnAMQPBasicDeliver | CreateReceiverLink then OnAMQPMessage | Both are push-based once established. |
| Acknowledgement | AckMessage / RejectMessage | OnAMQPMessageSentAck | 0.9.1 acks a delivery tag, 1.0 settles a delivery. |
| Flow control | SetQoS prefetch, EnableChannel / DisableChannel | Credit based (CreditSize, WindowSize) | Both stop a fast producer overwhelming a slow consumer. |
| Transactions | SelectTransaction, CommitTransaction, RollbackTransaction | — | The 0.9.1 tx class, exposed per channel. |
| Queue maintenance | PurgeQueue, DeleteQueue, DeleteExchange, UnBindQueue | CloseLink, CloseSession | Each with a blocking ...Ex variant that waits for the broker reply. |
| Redelivery | Recover / RecoverAsync | — | Ask the broker to redeliver unacknowledged messages. |
| Authentication | OnAMQPAuthentication, OnAMQPChallenge | Authentication.AuthType, OnAMQPSASLAuthentication | 1.0 offers SASL ANONYMOUS, PLAIN and EXTERNAL. |
| Cloud helpers | — | CreateCBSLink, PutCBSToken, CreateAzureCbsSasToken, CreateAzureCbsJWT | Claims-Based Security for Azure Service Bus and Event Hubs. |
| Liveness | HeartBeat | Ping, AMQPOptions.IdleTimeout | Negotiated with the broker on connect. |
| Connection tuning | AMQPOptions.VirtualHost, MaxChannels, MaxFrameSize, Locale | AMQPOptions.ContainerId, ChannelMax, MaxFrameSize, MaxLinksPerSession | Sent in the opening handshake and negotiated with the broker. |
| Prefetch | SetQoS(channel, prefetchSize, prefetchCount, global) | AMQPOptions.CreditSize | How many unacknowledged messages the broker may have in flight. |
| Frame inspection | — | OnAMQPBeforeReadFrame, OnAMQPBeforeWriteFrame | See or rewrite raw frames before they are processed or sent. |
The binary Kafka protocol implemented in Object Pascal, with no REST proxy in front and no librdkafka underneath.
| Capability | API | Notes |
|---|---|---|
| Produce a record | Produce(topic, value, key, partition) | Key and partition are optional. ProduceBytes takes TBytes for both. |
| Produce a batch | ProduceMessages(topic, partition, messages) | Returns the broker's produce response for the whole batch. |
| Delivery guarantee | KafkaOptions.Producer.Acks | kafkaAcksNone, kafkaAcksLeader or kafkaAcksAll. |
| Compression | KafkaOptions.Producer.Compression | kafkaCompressionNone or kafkaCompressionGzip. |
| Consume | Subscribe([topics]) then Poll(timeoutMs) | Poll returns a TsgcKafkaMessages list and also raises OnKafkaMessage per record. |
| Consumer groups | KafkaOptions.Consumer.GroupId | Coordinator discovery, join, sync and heartbeat are handled for you. OnKafkaRebalance reports assignment changes. |
| Offset policy | KafkaOptions.Consumer.OffsetReset | kafkaOffsetEarliest or kafkaOffsetLatest when there is no committed offset. |
| Commit offsets | CommitSync, CommitOffset(topic, partition, offset) | Or set Consumer.AutoCommit with AutoCommitIntervalMs. |
| Read a partition directly | FetchMessages(topic, partition, offset, maxBytes) | Bypasses the consumer group entirely. |
| Offset lookup | GetEarliestOffset, GetLatestOffset, GetCommittedOffset | Per topic and partition. |
| Fetch tuning | Consumer.MinBytes, MaxBytes, MaxPartitionBytes, MaxWaitMs | Trade latency against batch size. |
| Topic administration | CreateTopic, DeleteTopic, GetMetadata | Partition count and replication factor on create. |
| Group administration | ListGroups, DescribeGroups | Inspect consumer groups from your own tooling. |
| Broker capability probe | GetApiVersions | Ask the broker which protocol API versions it supports. |
| SASL | kafkaSaslNone, kafkaSaslPlain | SASL/PLAIN username and password authentication. |
One generic client plus two broker-specific descendants that turn RabbitMQ and ActiveMQ destination conventions into named methods.
| Capability | STOMP | RabbitMQ | ActiveMQ | Notes |
|---|---|---|---|---|
| Send a frame | Send | PublishEx | PublishEx | Destination, body, content type and optional transaction. |
| Subscribe | Subscribe(id, destination) | SubscribeEx | SubscribeEx | The descendants add durable, exclusive and ack-mode arguments. |
| Queue helpers | — | SubscribeQueue, PublishQueue, UnSubscribeQueue | SubscribeQueue, PublishQueue, UnSubscribeQueue | The /queue/ destination prefix, wrapped. |
| Topic helpers | — | SubscribeTopic, PublishTopic, UnSubscribeTopic | SubscribeTopic, PublishTopic, UnSubscribeTopic | The /topic/ destination prefix, wrapped. |
| Exchange helpers | — | SubscribeExchange, PublishExchange | — | RabbitMQ's /exchange/ destination with a routing pattern. |
| External queues | — | SubscribeQueueOutside, PublishQueueOutside | — | RabbitMQ's /amq/queue/, for queues declared elsewhere. |
| Temporary reply queues | — | SubscribeTemporaryQueue, PublishTemporaryQueue | — | RabbitMQ's /temp-queue/ request/reply pattern. |
| Acknowledge | ACK / NACK | ✓ | ✓ | Ack mode selected per subscription (ackAuto and friends). |
| Transactions | BeginTransaction, CommitTransaction, AbortTransaction | ✓ | ✓ | Group several SEND and ACK frames into one atomic unit. |
| Receipts | OnSTOMPReceipt | OnRabbitMQReceipt | OnActiveMQReceipt | The broker confirms a frame it processed. |
| Message event | OnSTOMPMessage | OnRabbitMQMessage | OnActiveMQMessage | Delivers the destination, body and frame headers. |
| Heart-beating | HeartBeat, Ping | ✓ | ✓ | Negotiated in the CONNECT frame, both directions. |
| Version negotiation | Versions.V1_0, V1_1, V1_2 | ✓ | ✓ | Advertise the versions you accept, the broker picks one. |
| Virtual host | Options.VirtualHost | ✓ | ✓ | Sent as the host header on CONNECT. |
| Broker extensions | — | — | ActiveMQ_Options | ActiveMQ-specific headers, exposed as a published property. |
Every protocol component attaches to a TsgcTCPClient through its Client property. That one carrier gives you plain TCP and TLS without changing protocol code.
| Area | Detail |
|---|---|
| Plain TCP | Assign a TsgcTCPClient to Client and the protocol runs straight over the socket, on the broker's native port. |
| WebSocket | Not in sgcMQ. A WebSocket carrier, for example MQTT over WebSocket or Web-STOMP, needs the WebSocket client that ships with sgcWebSockets. |
| TLS | TLSOptions on the carrier, with TLSOptions.IOHandler choosing OpenSSL for cross-platform builds or SChannel on Windows. |
| Client certificates | Mutual TLS through the same TLSOptions, from a PEM file, a PKCS#12 bundle or the Windows certificate store. |
| Proxies | HTTP CONNECT proxy support on the carrier, so a broker behind a corporate proxy is reachable. |
| Reconnect | WatchDog on the carrier reconnects after a dropped link, with a configurable interval and attempt count. |
| IPv6 | Supported by the carrier, so an IPv6 broker address needs no extra configuration. |
| Threading | Reading runs on its own thread. Set the carrier's notify settings to marshal events onto the main thread for VCL and FMX code. |
Published protocols, and the same source across every supported compiler.
| Area | Detail |
|---|---|
| MQTT | OASIS MQTT 3.1.1 and MQTT 5.0. |
| AMQP 0.9.1 | The AMQP 0-9-1 specification: channels, exchanges, queues, bindings and the basic class. |
| AMQP 1.0 | OASIS AMQP 1.0, also published as ISO/IEC 19464. |
| Kafka | The Apache Kafka wire protocol over TCP, including the v2 record batch format. |
| STOMP | STOMP 1.0, 1.1 and 1.2. |
| WebSocket | Not included. A WebSocket carrier requires sgcWebSockets, which provides the WebSocket client. |
| TLS | TLS 1.2 and TLS 1.3 through OpenSSL, or Windows SChannel. |
| Compilers | Delphi and C++ Builder 7 through 13. |
| Platforms | Win32, Win64, Linux64, macOS, iOS and Android. |
| Licensing | Standalone. The sgcWebSockets Core runtime is bundled in and full source code is included. |