sgcQUIC — QUIC & HTTP/3 for Delphi, C++ Builder & .NET

sgcQUIC — QUIC & HTTP/3 for Delphi, C++ Builder & .NET

A complete QUIC and HTTP/3 stack for Delphi, C++ Builder and .NET. sgcQUIC gives you four palette components — a raw QUIC transport client and server (RFC 9000) plus an HTTP/3 client and server (RFC 9114) — built on the native QUIC engine in OpenSSL 3.5. QPACK header compression, Alt-Svc discovery, 0-RTT, connection migration and WebTransport ship in the box, and the same API runs in Object Pascal and C#.

QUIC transport (RFC 9000)
HTTP/3 (RFC 9114) + QPACK
OpenSSL 3.5 native QUIC
Delphi / C++ Builder / .NET
WebTransport (RFC 9220)
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HOW IT WORKS

The Same HTTP Semantics, a New Transport

HTTP/3 keeps the methods, status codes and headers you already know and replaces TCP with QUIC, a UDP-based transport with TLS 1.3 built in. sgcQUIC drives it through the native QUIC support in OpenSSL 3.5, so you get modern transport from Delphi, C++ Builder or .NET without a separate library.

One handshake, no head-of-line blocking

QUIC (RFC 9000) combines the transport and TLS 1.3 handshakes into a single flight and removes transport-level head-of-line blocking — a lost packet only stalls the streams whose data it carried, not the whole connection.

Built on OpenSSL 3.5 native QUIC

The engine is detected automatically when OpenSSL loads. With the shipped OpenSSL 3.5 binaries you get the qmBuiltin engine, which supports multiple streams per connection and is the engine the components are built around.

QPACK header compression

HTTP/3 compresses headers with QPACK (RFC 9204), the HTTP/3 replacement for HPACK, designed for QUIC's out-of-order delivery with dynamic-table updates carried on dedicated encoder and decoder streams.

Connection migration

QUIC connections are identified by a connection ID rather than the address four-tuple, so a session survives the client changing network — a connection can follow a device from Wi-Fi to mobile data without a new handshake.

0-RTT and multiple streams

A fresh connection completes in a single round trip and a resumed session can carry 0-RTT data in the first flight. On the builtin engine, EnableMultiStream and OpenStream put several independent QUIC streams on one connection.

WebTransport sessions

WebTransport (RFC 9220) is negotiated over Extended CONNECT and hands the application QUIC streams directly, built for low-latency bidirectional traffic on top of the builtin engine.

COMPONENTS

Four Components, Two Layers

A raw QUIC transport pair for streams and datagrams, and an HTTP/3 pair that speaks request/response over the same engine. Each links to its own page with Delphi, C++ Builder and .NET examples.

TsgcQUICClient

Raw QUIC transport client. Opens a QUIC connection, sends and receives bytes over one or many streams (RFC 9000), with 0-RTT and connection migration — QUIC without HTTP semantics.

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TsgcQUICServer

Raw QUIC transport server. Binds a UDP port, terminates TLS 1.3 and raises an event for every QUIC connection and stream, so you build your own protocol on top of QUIC.

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TsgcHTTP3Client

HTTP/3 client (RFC 9114). All the verbs as blocking or asynchronous calls, QPACK compression, Alt-Svc discovery, server push, Extended CONNECT tunnels and WebTransport sessions.

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TsgcHTTP3Server

HTTP/3 server. Serves requests over QUIC, descends from TsgcQUICServer, raises an event per request and can push responses, open WebTransport sessions and send datagrams.

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See the full feature matrix →

QUICK START

A GET Request Over HTTP/3

Connect to a host and port, then issue requests. The default port is 443. The same API in Delphi, C++ Builder and .NET.

uses
  sgcHTTP3_Client;

var
  oClient: TsgcHTTP3Client;
  vBody: string;
begin
  oClient := TsgcHTTP3Client.Create(nil);
  oClient.OnResponse := OnResponseHandler;
  oClient.OnAltSvc   := OnAltSvcHandler;

  oClient.Connect('www.example.com', 443);
  vBody := oClient.Get('https://www.example.com/');   // request over QUIC
  oClient.Disconnect;
end;
// includes: sgcHTTP3_Client.hpp

TsgcHTTP3Client *oClient = new TsgcHTTP3Client(NULL);
oClient->OnResponse = OnResponseHandler;
oClient->OnAltSvc   = OnAltSvcHandler;

oClient->Connect("www.example.com", 443);
String vBody = oClient->Get("https://www.example.com/");   // request over QUIC
oClient->Disconnect();
using esegece.sgcWebSockets;

var oClient = new TsgcHTTP3Client();
oClient.OnResponse += OnResponseHandler;
oClient.OnAltSvc   += OnAltSvcHandler;

oClient.Connect("www.example.com", 443);
var vBody = oClient.Get("https://www.example.com/");   // request over QUIC
oClient.Disconnect();
STANDARDS

The RFCs sgcQUIC Implements

A standards-based stack, not a proprietary transport.

RFC 9000 — QUIC

The QUIC transport: a single combined transport + TLS 1.3 handshake, independent streams, connection IDs and migration. Exposed directly through TsgcQUICClient and TsgcQUICServer.

RFC 9114 — HTTP/3

HTTP semantics over QUIC: the methods, status codes and headers you know, mapped onto QUIC streams. Implemented by TsgcHTTP3Client and TsgcHTTP3Server.

RFC 9204 — QPACK

Header compression for HTTP/3, designed for QUIC's out-of-order delivery, with a dynamic table synchronised over dedicated encoder and decoder streams.

RFC 9220 — WebTransport

Bootstrapping WebTransport over HTTP/3 with Extended CONNECT, handing the application QUIC streams for low-latency bidirectional traffic.

PRICING

An Add-On to sgcWebSockets

sgcQUIC is licensed as an add-on. All licenses include full source code, 1 year of updates and a 70% renewal discount.

sgcQUIC

€149

Single, Team and Site licenses available. Full source code included.

  • TsgcQUICClient & TsgcQUICServer
  • TsgcHTTP3Client & TsgcHTTP3Server
  • Delphi, C++ Builder & .NET
  • Full Source Code
  • 1 Year Updates

★ Requires sgcWebSockets

sgcQUIC requires sgcWebSockets Enterprise.

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3,000+Developers
20+Years
761+Components
30+API Integrations
5Platforms
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Ship QUIC and HTTP/3 Without Leaving Your IDE

Add the transport the modern web is moving to — to your Delphi, C++ Builder or .NET application, with the language you already use.

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