Everything sgcHTTP does, mapped across the HTTP server, the FastCGI / SCGI gateway, the HTTP/2 client, the gRPC client and the three Google Cloud clients. Every capability works the same in Delphi and C++ Builder, and every license ships full source code. Component subpages are not published yet for this launch, each entry below is self-contained on this page.
Endpoints, static files, sessions, TLS
PHP & Python behind your server
Multiplexed streams, HPACK, ALPN
Unary & streaming RPC
Pub/Sub, Calendar & FCM
Delphi 7 to 13, C++ Builder
sgcHTTP is self-contained. It ships with the sgcWebSockets Core runtime bundled in, so it is not an add-on. The HTTP server, TsgcHTTPServer, is part of that runtime.
HTTP/2 and gRPC need sgcCustomIndy. Both classes require ALPN for TLS protocol negotiation, which the standard Indy library does not support, so they are built on sgcCustomIndy instead. It is always included in your order, and the sgcHTTP price shown already covers it. The three Google Cloud clients are plain HTTPS and do not need it. Neither does the FastCGI / SCGI gateway, which works with the standard Indy that ships with RAD Studio.
Four components on the SGC HTTP palette page and three code-only Google Cloud classes. The HTTP server is declared in the sgcHTTP_Server unit of the bundled Core runtime, the FastCGI / SCGI gateway in the sgcHTTP_Gateway unit, everything else in the sgcHTTP unit.
| Component | Class | Palette? | Description |
|---|---|---|---|
| HTTP Server | TsgcHTTPServer | Yes | HTTP server: request events, static files from a document root, compression, keep-alive, sessions, uploads, TLS and authentication. Ships with the Core runtime. |
| FastCGI / SCGI Gateway | TsgcHTTPGateway | Yes | Forwards requests received by the HTTP server to FastCGI and SCGI application servers over TCP, such as PHP-FPM or a Python SCGI server. Unit sgcHTTP_Gateway. Standard Indy, no sgcCustomIndy needed. |
| HTTP/2 Client | TsgcHTTP2Client | Yes | Native HTTP/2 client: multiplexed streams, HPACK header compression, ALPN negotiation. Needs sgcCustomIndy. |
| gRPC Client | TsgcGRPCClient | Yes | gRPC client built on the HTTP/2 client: unary, server-streaming, client-streaming and bidirectional RPC. Needs sgcCustomIndy. |
| Google Cloud Pub/Sub | TsgcHTTPGoogleCloud_PubSub_Client | No, code-only | Google Cloud Pub/Sub REST API: topics, subscriptions, snapshots, publish and pull. Plain HTTPS on Core. |
| Google Cloud Calendar | TsgcHTTPGoogleCloud_Calendar_Client | No, code-only | Google Calendar API v3: calendars and events, create, update, list, delete. Plain HTTPS on Core. |
| Google Cloud FCM | TsgcHTTPGoogleCloud_FCM_Client | No, code-only | Firebase Cloud Messaging HTTP v1 API: send a push notification payload with one call. Plain HTTPS on Core. |
TsgcHTTPServer publishes HTTP endpoints and static files from your own application. It is the same engine as the sgcWebSockets WebSocket server without the WebSocket part, and it ships with the bundled Core runtime.
| Capability | API | Notes |
|---|---|---|
| Listening | Port, Bindings, Active | Set the port, or bind to specific addresses, then activate the server. |
| Requests | OnCommandGet, OnCommandOther | Every request reaches your code with its request and response objects. OnCommandOther covers verbs such as PUT and DELETE. |
| Static files | DocumentRoot | Returns static files from the folder you point it at. |
| Compression | HTTPCompression | Response compression options. |
| Connections | KeepAlive, MaxConnections | Keep connections open between requests, and cap how many are open at once. |
| Sessions | SessionState, AutoStartSession, SessionTimeOut, OnSessionStart, OnSessionEnd | Server-side sessions with a timeout, plus start and end events. |
| Request limits | MaxRequestBodySize | Caps the size of a request body. |
| Uploads | HTTPUploadFiles | Saves uploaded files to a directory you choose. |
| TLS | SSL, SSLOptions | Serve HTTPS with your own certificate. |
| Authentication | Authentication, OnAuthentication | Validate credentials in your own code before a request is served. |
| Threads | ThreadPool, ThreadPoolOptions | Reuse worker threads from a pool instead of creating one per connection. |
| Runtime | sgcWebSockets Core | Declared in the sgcHTTP_Server unit of the bundled Core runtime, on the SGC HTTP palette page. |
TsgcHTTPGateway forwards requests received by TsgcHTTPServer or TsgcWebSocketHTTPServer to FastCGI and SCGI application servers over TCP. It does the job of Apache mod_proxy_fcgi and mod_proxy_scgi or nginx fastcgi_pass and scgi_pass, so PHP and Python applications are served from your Delphi server with no Apache or nginx in front.
| Capability | API | Notes |
|---|---|---|
| Backends | FastCGI, SCGI | PHP through PHP-FPM or php-cgi -b, and Python applications served by an SCGI or FastCGI server, for example flup. |
| Requests | Process | Call it from the server's OnCommandGet and OnCommandOther events. It returns true when a handler matched and the response is filled, and false when your own code answers the request. |
| Handlers | Handlers.Add | Handlers.Add('*.php', 'fcgi://127.0.0.1:9000') or Handlers.Add('/app/', 'scgi://127.0.0.1:4000'). A handler matches by extension (*.php), by prefix (/app/) or by exact path. |
| Handler settings | Path, URL, Protocol, Host, Port, DocumentRoot, Enabled | Point each handler at its backend with one URL, or with protocol, host and port, and set the backend's document root. |
| CGI environment | SCRIPT_NAME, PATH_INFO, SCRIPT_FILENAME, QUERY_STRING, REMOTE_ADDR, HTTPS | Built following RFC 3875, with every request header passed as an HTTP_* variable. |
| Extra variables | Environment, OnBeforeRequest | Add variables per handler through Environment, or per request in OnBeforeRequest. |
| Responses | CGI response | Parses the Status header, Location redirects, the response headers and the body. Several Set-Cookie headers are all kept. |
| Gateway errors | OnError | 502 Bad Gateway, 503 Service Unavailable when the FastCGI backend is overloaded, and 504 Gateway Timeout, each reported in OnError. |
| Backend errors | OnStdErr | Delivers the stderr output the FastCGI backend sends. |
| Connections | ConnectTimeout, ReadTimeout, KeepAlive, MaxIdleConnections | Timeouts per handler, plus an optional keep-alive connection pool for FastCGI (FCGI_KEEP_CONN), off by default. SCGI opens one connection per request. |
| FastCGI role | Responder | The FastCGI Responder role. Requests are not multiplexed on a connection. |
| Security | Built in | A Proxy request header is never passed as HTTP_PROXY (httpoxy), paths containing .. are rejected with 403, and header names with underscores are ignored. |
| Limitations | TCP, buffered | TCP backends only, Unix-domain sockets are not supported yet. The backend process must already be running, the gateway does not start it. Responses are buffered, so streaming such as server-sent events is not supported. |
| Dependency | Standard Indy | Works with the Indy library that ships with RAD Studio, no sgcCustomIndy needed. Windows and Linux. |
| Unit & demo | sgcHTTP_Gateway | On the SGC HTTP palette page. The demo is in Demos\20.HTTP_Protocol\18.FastCGI_SCGI_Gateway. |
TsgcHTTP2Client speaks HTTP/2 (RFC 9113) over a single TLS connection, negotiated with ALPN, which is why it is built on sgcCustomIndy.
| Capability | API | Notes |
|---|---|---|
| Connection | Host, Port, Active | One TLS connection carries every multiplexed request stream. |
| Connect | Connect, ConnectAsync | Opens the connection and issues an optional request in the same call. |
| Read | Get, GetAsync | Synchronous call or fire-and-forget with the response delivered by event. |
| Write | Post, PostAsync, Put, PutAsync, Patch, PatchAsync | Request bodies are streams, so uploads do not have to fit in memory. |
| Delete & Options | Delete, DeleteAsync, Options, OptionsAsync | The rest of the HTTP verb set, same synchronous/async pairing. |
| Responses | OnHTTP2Response | Delivers the request and response objects together, including Response.DataString and status. |
| Chunked bodies | OnHTTP2ResponseFragment | Fires as each fragment of a chunked response arrives, ahead of the final OnHTTP2Response. |
| Server push | OnHTTP2PushPromise | Surfaces HTTP/2 server-pushed resources as they arrive. |
| Connection lifecycle | OnHTTP2Connect, OnHTTP2Disconnect, OnHTTP2GoAway, OnHTTP2RSTStream | The connect, disconnect and stream-reset signals HTTP/2 defines. |
| Settings | HTTP2Options, Settings | The local HTTP/2 SETTINGS frame values sent to the peer. |
| Reliability | WatchDog, HeartBeat, Throttle | Auto-reconnect, keep-alive and request throttling, shared with the rest of the sgc HTTP stack. |
| Auth & TLS | Authentication, TLSOptions, OnHTTP2Authorization | Standard authentication schemes and TLS configuration, plus a hook for custom authorization headers. |
| Dependency | sgcCustomIndy | ALPN negotiates the h2 protocol during the TLS handshake; the standard Indy library cannot do this. |
TsgcGRPCClient carries Protocol Buffers payloads over the HTTP/2 client's multiplexed streams, so it covers all four gRPC call shapes.
| Capability | API | Notes |
|---|---|---|
| Transport | Client | A TsgcHTTP2Client instance; the gRPC client rides on it rather than opening its own connection. |
| Unary RPC | Call, CallAsync, CallString | One request, one response. Call blocks and returns a TsgcGRPCResponse; CallAsync delivers it through OnGRPCResponse. |
| Server streaming | ServerStreamingCall | One request, a stream of responses delivered through OnGRPCStreamMessage until OnGRPCStreamEnd. |
| Client streaming | OpenClientStream, SendStreamMessage, CloseClientStream, CloseClientStreamAsync | A stream of requests, one final response when the stream closes. |
| Bidirectional streaming | OpenBidiStream, SendBidiMessage, CloseBidiStream | Both sides stream independently over the same call. |
| Cancellation | CancelCall | Cancels a call in progress by its stream id. |
| Responses | OnGRPCResponse, OnGRPCStreamMessage, OnGRPCStreamEnd | TsgcGRPCResponse carries StatusCode, Data/DataString, Headers and Trailers. |
| Errors | OnGRPCError, OnGRPCException | gRPC status-code errors and transport-level exceptions, delivered separately. |
| Metadata | DefaultMetadata, OnGRPCBeforeRequest | Per-call and default gRPC metadata headers. |
| Resilience | RetryPolicy, Interceptors, ServiceConfig | Retry behavior, a cross-cutting interceptor chain, and service configuration, without touching individual call sites. |
| Observability | MetricsCollector | Collects call metrics for the client. |
| Dependency | sgcCustomIndy | Inherited from the HTTP/2 client it is built on; ALPN is required the same way. |
Three code-only classes, authenticated with a Google service account and reached over plain HTTPS. None of them need sgcCustomIndy.
| Capability | API | Notes |
|---|---|---|
| Authentication | GoogleCloudOptions.JWT, OnAuthToken, OnAuthTokenError | Service-account JWT: project id, client email and private key. Shared shape across all three clients. |
| Pub/Sub: publish & pull | Publish, Pull, Acknowledge, Seek | TsgcHTTPGoogleCloud_PubSub_Client. Send messages to a topic, pull and acknowledge from a subscription. |
| Pub/Sub: topics | CreateTopic, DeleteTopic, GetTopic, ListTopics | Manage topics directly from code. |
| Pub/Sub: subscriptions | CreateSubscription, DeleteSubscripton, ListSubscriptions, ModifyAckDeadlineSubscription | Full subscription lifecycle, including ack-deadline and push-config changes. |
| Pub/Sub: snapshots | CreateSnapshot, DeleteSnapshot, ListSnapshots | Snapshot a subscription's acknowledgment state for later replay. |
| Calendar: calendars | NewCalendar, UpdateCalendar, DeleteCalendar, LoadCalendars | TsgcHTTPGoogleCloud_Calendar_Client. Wraps the Google Calendar API v3 calendar list. |
| Calendar: events | NewEvent, UpdateEvent, DeleteEvent, LoadEvents | Create, change and remove events on a given calendar. |
| Calendar: sync | LoadCalendarsChanged, LoadEventsChanged, OnGetCalendar, OnGetCalendarEvent | Incremental synchronization hooks for calendars and events that changed since the last sync. |
| FCM: push | SendMessage | TsgcHTTPGoogleCloud_FCM_Client. One call sends a Firebase Cloud Messaging v1 payload to a project. |
| TLS and logging | TLSOptions, LogFile | Shared across all three Google Cloud clients. |
Public standards on the wire, and the same source across every supported compiler.
| Area | Detail |
|---|---|
| HTTP server | HTTP requests and responses, static files, sessions and HTTPS through TsgcHTTPServer. |
| FastCGI / SCGI | The FastCGI Responder role and SCGI over TCP, with the CGI environment built following RFC 3875, through TsgcHTTPGateway. |
| HTTP/2 | RFC 9113, with HPACK header compression and ALPN protocol negotiation. |
| gRPC | Protocol Buffers payloads over HTTP/2 streams, following the gRPC wire protocol. |
| Google Cloud | The Pub/Sub REST API, the Google Calendar API v3, and the Firebase Cloud Messaging HTTP v1 API, all authenticated with a Google service account. |
| Platforms | Windows Win32, Windows Win64, Linux64, macOS, iOS and Android for all five client classes. The FastCGI / SCGI gateway runs on Windows and Linux. |
| Dependency | The HTTP/2 and gRPC clients need sgcCustomIndy for ALPN. The Google Cloud clients need only the bundled Core runtime. The FastCGI / SCGI gateway works with the standard Indy that ships with RAD Studio and does not need sgcCustomIndy. |
| Compilers | Delphi and C++ Builder 7 through 13. |
| Editions | HTTP/2, gRPC and the FastCGI / SCGI gateway also ship inside sgcWebSockets from Enterprise up, and the Google Cloud clients from Standard up. The HTTP server is part of the Core runtime, so every sgcWebSockets edition includes it too. |
| Licensing | Standalone. The sgcWebSockets Core runtime is bundled in and full source code is included. |