- Qt 6.12
- Qt GRPC
- Qt GRPC Interceptors
- Qt 6.12.0 Reference Documentation

# Qt GRPC Interceptors

For an introduction to the interception mechanism and how interceptor interfaces participate in the lifecycle of an RPC, see the Qt GRPC Interceptors Overview.

Qt GRPC provides the following interceptor interfaces as hook points in the RPC lifecycle:

Interface | Hook Point | Direction | Can Modify
--- | --- | --- | ---
QGrpcStartInterceptor | Before the RPC is initiated | Outbound | Initial message object, call options
QGrpcWriteMessageInterceptor | Before an outgoing message is written | Outbound | Message object
QGrpcWritesDoneInterceptor | When the client indicates writes are done | Outbound | —
QGrpcCancelInterceptor | When the RPC is cancelled | Outbound | —
QGrpcInitialMetadataInterceptor | When initial metadata is received | Inbound | Metadata
QGrpcMessageReceivedInterceptor | When a message payload is received | Inbound | Serialized message data
QGrpcTrailingMetadataInterceptor | When trailing metadata is received | Inbound | Metadata
QGrpcFinishedInterceptor | When the RPC completes | Inbound | Final status

The following classes and pages form the Qt GRPC interceptor mechanism:

QGrpcCancelInterceptor | Intercepts cancellation requests for an RPC
QGrpcFinishedInterceptor | Intercepts the completion status of an RPC
QGrpcInitialMetadataInterceptor | Intercepts initial metadata for an RPC
QGrpcInterceptionContext | Provides contextual information to interceptor callbacks
QGrpcInterceptorChain | Stores and manages a sequence of interceptors
QGrpcMessageReceivedInterceptor | Intercepts incoming message payloads for an RPC
QGrpcStartInterceptor | Intercepts the start of an RPC
QGrpcTrailingMetadataInterceptor | Intercepts trailing metadata for an RPC
QGrpcWriteMessageInterceptor | Intercepts outgoing messages written for an RPC
QGrpcWritesDoneInterceptor | Intercepts the completion of message writes for an RPC
Qt GRPC Interceptors Overview | Provides an overview of the Qt GRPC interceptor mechanism.
QGrpcStartInterceptor::Continuation | Controls whether an intercepted RPC should proceed
InterceptorCapability | Specifies interception hook points supported by an interceptor
InterceptorCapabilities | A QFlags type that stores a combination of InterceptorCapability values