quic_lib library

A comprehensive, pure-Dart implementation of the QUIC protocol stack.

quic_lib provides a fully Dart-native networking stack covering four major subsystems built on top of each other:

QUIC transport — RFC 9000/9001/9002 compliant wire format, packet protection, handshake, stream multiplexing, flow control, congestion control, and connection migration.
HTTP/3 — RFC 9114 mapping of HTTP semantics onto QUIC streams with QPACK header compression.
WebTransport — RFC 9220 datagram and stream sessions over HTTP/3.
libp2p QUIC — Transport, multiaddr parsing, and PeerId handling for libp2p networks.

Quick start

Import the full public API in one line:

import 'package:quic_lib/quic_lib.dart';

Create an endpoint, connect to a peer, and open a bidirectional stream:

import 'dart:io';
import 'dart:typed_data';
import 'package:quic_lib/quic_lib.dart';

Future<void> main() async {
  final endpoint = await QuicEndpoint.bind(InternetAddress.anyIPv4, 0);
  final connection = await endpoint.connect(
    InternetAddress.loopbackIPv4,
    4433,
  );

  final streamId = connection.openBidirectionalStream();
  final frame = StreamFrame(
    streamId: streamId,
    data: Uint8List.fromList([1, 2, 3]),
    fin: true,
  );
  // Packetize and send via PacketSender...

  connection.close();
  endpoint.close();
}

Subsystem barrel files

If you only need a subset of the API, import one of the focused barrel files instead:

Barrel file	Exports
`quic_lib.dart`	Everything — wire format, crypto, connection, streams, recovery, HTTP/3, WebTransport, libp2p
`quic.dart`	QUIC transport core only — endpoint, connection, stream scheduler, isolates
`http3.dart`	HTTP/3 layer — connection, request, response, frames, QPACK
`webtransport.dart`	WebTransport sessions, capsules, and stream types
`libp2p.dart`	libp2p transport — multiaddr, peer IDs, QUIC dial/listen

Classes

AckEcnFrame: An ACK frame with ECN (Explicit Congestion Notification) counts (RFC 9000 Section 19.3.2).
AckFrame: An ACK frame (RFC 9000 Section 19.3).
AckFrequencyFrame: An ACK_FREQUENCY frame allows a receiver to request the sender to change its acknowledgement frequency.
AckFrequencyPolicy: Policy state derived from ACK_FREQUENCY frames (RFC 9298).
AckGenerator: Generates ACK frames based on received packets.
AckRange: A single range of contiguous packet numbers acknowledged in an ACK frame.
AeadAlgorithm: AEAD algorithm descriptor.
AeadResult: Result of an AEAD encryption operation.
Aes128Gcm: AES-128-GCM AEAD algorithm constants.
Aes256Gcm: AES-256-GCM AEAD algorithm constants.
ApplicationCloseFrame: A CONNECTION_CLOSE frame for application errors (RFC 9000 Section 19.19).
BbrCongestionController: BBR (Bottleneck Bandwidth and Round-trip propagation time) congestion controller per RFC 8382.
CertificateEntry: TLS 1.3 CertificateEntry structure per RFC 8446 Section 4.4.2.
CertificateMessage: TLS 1.3 Certificate structure per RFC 8446 Section 4.4.2.
CertificateVerify: TLS 1.3 CertificateVerify structure per RFC 8446 Section 4.4.3.
ChaCha20Poly1305: ChaCha20-Poly1305 AEAD algorithm constants.
CipherSuite: TLS cipher suite identifier (2 bytes).
ClientHello: TLS 1.3 ClientHello structure per RFC 8446 Section 4.1.2.
CoalescedPacket: Splits UDP datagrams that may contain multiple QUIC coalesced packets.
CongestionController: NewReno congestion controller per RFC 9002 Section 7.
ConnectionCloseFrame: A CONNECTION_CLOSE frame for transport errors (RFC 9000 Section 19.19).
ConnectionIdManager: Manages the lifecycle of Connection IDs for a single QUIC connection.
ConnectionIsolate: Manages a single QUIC connection inside its own isolate.
ConnectionRegistry: A registry that maps destination connection IDs to connection objects.
ConnectionStateMachine: Manages the QUIC connection lifecycle state machine.
CryptoBackend: Crypto primitive backend abstraction.
CryptoFrame: A CRYPTO frame (RFC 9000 Section 19.6).
CubicCongestionController: RFC 8312 / RFC 9002 CUBIC congestion controller.
DataBlockedFrame: A DATA_BLOCKED frame (RFC 9000 Section 19.12).
DatagramFrame: A DATAGRAM frame (RFC 9221 Section 4).
DCUtRStateMachine: Finite state machine that tracks DCUtR handshake progress.
DefaultCryptoBackend: Default implementation of CryptoBackend using package:cryptography and package:pointycastle.
EncryptedExtensions: TLS 1.3 EncryptedExtensions structure per RFC 8446 Section 4.3.1.
FinishedMessage: TLS 1.3 Finished message per RFC 8446 Section 4.4.4.
FlowController: QUIC flow controller for connection-level and stream-level flow control.
Frame: Base class for all QUIC frames.
FrameCodec: Codec for serializing and parsing QUIC frames (RFC 9000 Section 12 and 19).
HandshakeDoneFrame: A HANDSHAKE_DONE frame (RFC 9000 Section 19.20).
HandshakeStateMachine: Manages the TLS 1.3 handshake lifecycle for a single QUIC connection (RFC 8446).
HashAlgorithm: Hash algorithm descriptor.
HeaderProtection: QUIC header protection per RFC 9001 Section 5.4.
Http3CancelPushFrame: HTTP/3 CANCEL_PUSH frame payload.
Http3Frame: An HTTP/3 frame consisting of a type, length, and payload.
Http3GoawayFrame: HTTP/3 GOAWAY frame payload.
Http3HeadersFrame: HTTP/3 HEADERS frame payload.
Http3PushPromiseFrame: HTTP/3 PUSH_PROMISE frame payload.
Http3SettingsFrame: HTTP/3 SETTINGS frame payload.
Http3StreamHandler: Handles classification of an HTTP/3 stream based on its QUIC stream ID.
Hystart: Hystart++ / basic Hystart helper for early slow-start exit.
InitialSecrets: QUIC Initial Secret derivation per RFC 9001 Section 5.2.
IsolateSupervisor: Tracks active connection isolates by connection ID.
KeyDerivation: QUIC key derivation from a traffic secret per RFC 9001 Section 5.1.
KeyManager: Derives and manages packet protection keys for all QUIC packet number spaces.
KeyPair: Opaque handle to a key pair.
KeyUpdate: QUIC Key Update derivation per RFC 9001 Section 6.
Libp2pCertificateGenerator: Generates an ephemeral self-signed X.509 certificate with the libp2p TLS extension for use in libp2p QUIC handshakes.
Libp2pExtension: The libp2p TLS X.509 certificate extension.
Libp2pQuicConnection: A libp2p-friendly wrapper around a QUIC connection.
Libp2pQuicTransport: A libp2p transport backed by QUIC.
LongHeader: QUIC long header used during handshake (Initial, 0-RTT, Handshake, Retry).
LossDetector: QUIC loss detector per RFC 9002 Section 6.
MaxDataFrame: A MAX_DATA frame (RFC 9000 Section 19.9).
MaxStreamDataFrame: A MAX_STREAM_DATA frame (RFC 9000 Section 19.10).
MaxStreamsFrame: A MAX_STREAMS frame (RFC 9000 Section 19.11).
MigrationHelper: Helper for QUIC connection path validation via PATH_CHALLENGE / PATH_RESPONSE.
Multiaddr: A self-describing network address following the libp2p multiaddr format.
MultiaddrComponent: A single protocol/value pair within a Multiaddr.
MultistreamSelect: libp2p multistream-select / protocol negotiation.
NewConnectionIdFrame: A NEW_CONNECTION_ID frame (RFC 9000 Section 19.15).
NewSessionTicket: RFC 8446 NewSessionTicket handshake message.
NewTokenFrame: A NEW_TOKEN frame (RFC 9000 Section 19.7).
NonceGenerator: QUIC packet nonce construction per RFC 9001 Section 5.3.
PacingCalculator: QUIC packet pacing calculator.
PacketBuilder: Builds complete QUIC packets from headers and frames.
PacketHeader: Base class for all QUIC packet headers.
PacketHeaderParser: Parses QUIC packet headers from raw bytes.
PacketNumber: QUIC packet number encoding and reconstruction per RFC 9000 Section 17.1.
PacketNumberSpaceManager: Manages packet number allocation, tracking of largest acknowledged, and largest received packet numbers across all three QUIC packet number spaces.
PacketProtector: QUIC Packet Protection (AEAD encrypt/decrypt).
PacketReceiver: Processes incoming QUIC packets from raw UDP datagrams.
PacketSender: Builds and tracks outgoing QUIC packets.
PaddingFrame: A PADDING frame (RFC 9000 Section 19.1).
PathChallengeFrame: A PATH_CHALLENGE frame (RFC 9000 Section 19.17).
PathResponseFrame: A PATH_RESPONSE frame (RFC 9000 Section 19.18).
PeerId: A libp2p PeerId represented as the raw multihash bytes of a public key.
PingFrame: A PING frame (RFC 9000 Section 19.2).
PtoScheduler: QUIC Probe Timeout (PTO) scheduler per RFC 9002 Section 6.2.
PublicKey: Opaque handle to a public key.
QpackDecoder: QPACK field line decoder per RFC 9204 Section 4.3.
QpackEncoder: QPACK field line encoder per RFC 9204 Section 4.3. Supports both static and dynamic table lookups.
QpackFieldLine: A decoded QPACK field line.
QpackInteger: QPACK integer encoder/decoder per RFC 9204 Section 4.1.
QpackStaticTable: QPACK static table per RFC 9204 Appendix A.
QpackStaticTableEntry: A single entry in the QPACK static table.
QpackString: QPACK string literal encoder/decoder per RFC 9204 Section 4.2 (same as RFC 7541 §6.2).
QuicBitGreaser: Implements RFC 9287 greasing of the QUIC bit.
QuicConnection: Orchestrates all subsystems of a single QUIC connection.
QuicEndpoint: A QUIC endpoint that listens for and initiates connections over UDP.
QuicReceiveStream: QUIC receive-side stream.
QuicSendStream: QUIC send-side stream.
QuicStream: Base interface for a QUIC stream.
QuicVersions: QUIC version constants and helpers per RFC 9000 and RFC 9369.
ReassemblyBuffer: Reassembles out-of-order STREAM frame data into contiguous byte sequences.
ReceiveStateMachine: State machine for the receive side of a QUIC stream.
ResetStreamFrame: A RESET_STREAM frame (RFC 9000 Section 19.4).
RetireConnectionIdFrame: A RETIRE_CONNECTION_ID frame (RFC 9000 Section 19.16).
RetryIntegrityTag: QUIC Retry Integrity Tag computation and verification per RFC 9001 §5.8.
RetryPacketBuilder: Builds QUIC Retry packets per RFC 9000 Section 17.2.5.
RoundRobinScheduler: A round-robin implementation of StreamScheduler.
RttEstimator: QUIC RTT Estimator per RFC 9002 Section 5.
SecretKey: Opaque handle to a secret key.
SendStateMachine: Manages the lifecycle of the sending half of a QUIC stream (RFC 9000 Section 3.1).
SentPacketInfo: Metadata for a sent packet used by SentPacketTracker.
SentPacketTracker: Tracks sent packets per packet number space.
ServerHello: TLS 1.3 ServerHello structure per RFC 8446 Section 4.1.3.
Sha256: SHA-256 hash algorithm constants.
Sha384: SHA-384 hash algorithm constants.
ShortHeader: QUIC short header used for 1-RTT application data.
SignedKey: A protobuf-encoded signed key used in the libp2p TLS extension.
StatelessResetGenerator: Generates and validates QUIC stateless reset packets per RFC 9000 Section 10.3.
StopSendingFrame: A STOP_SENDING frame (RFC 9000 Section 19.5).
StreamDataBlockedFrame: A STREAM_DATA_BLOCKED frame (RFC 9000 Section 19.13).
StreamFrame: A STREAM frame (RFC 9000 Section 19.8).
StreamId: QUIC Stream ID encoding and allocation.
StreamIdAllocator: Allocates stream IDs for each of the four QUIC stream categories.
StreamsBlockedFrame: A STREAMS_BLOCKED frame (RFC 9000 Section 19.14).
StreamScheduler: Abstract interface for selecting the next QUIC stream to process.
TlsConstants: Protocol-wide constants for TLS 1.3 (RFC 8446).
TlsExtension: TLS extension as a generic type + opaque data block.
UdpSocket
V2LongHeader: QUIC v2 long header per RFC 9369.
VarInt: QUIC variable-length integer encoding per RFC 9000 Section 16.
VersionInformation: RFC 9368 version_information transport parameter.
VersionNegotiationPacket: Version negotiation packet sent when a peer doesn't support the requested version.
WebTransportSession: Manages the state of a single WebTransport session over HTTP/3.
WebTransportSessionManager: Manages multiple WebTransport sessions over a single QUIC connection.
WebTransportStreamId: Discriminator and encoder/decoder for WebTransport stream IDs.
ZeroRttHelper: 0-RTT helper for QUIC.

Enums

BbrState
CapsuleType: Capsule types for WebTransport over HTTP/3 (RFC 9220).
ConnectionState: The states of a QUIC connection lifecycle.
HandshakeRole: Role of the endpoint in the TLS handshake.
HandshakeState: Discrete states of the TLS 1.3 handshake state machine (RFC 8446).
Http3FrameType: HTTP/3 frame types per RFC 9114 Section 7.2.
Http3SettingsId: HTTP/3 SETTINGS identifiers per RFC 9114 Section 7.2.4.
Http3StreamType: HTTP/3 stream types per RFC 9114 Section 4.1.
PacketNumberSpace: QUIC packet number spaces per RFC 9000.
QuicTransportErrorCode: QUIC transport error codes per RFC 9000 Section 20.1.
QuicTransportParameterId: QUIC transport parameter identifiers (RFC 9000 and extensions).
ReceiveStreamState: QUIC receive-side stream states per RFC 9000 Section 3.2.
SendStreamState: Lifecycle states for the sending half of a QUIC stream (RFC 9000 Section 3.1).
TlsContentType: TLS record-layer content types (RFC 8446 Section 5.1).
TlsExtensionType: TLS extension type identifiers (RFC 8446 Section 4.2).
TlsHandshakeType: Identifiers for TLS 1.3 handshake message types (RFC 8446 Section 4).
WebTransportStreamType: WebTransport stream type discriminator.

Typedefs

Capsule = WebTransportCapsule: Deprecated alias for WebTransportCapsule.
ConnectionIdRecord = ({List<int> connectionId, int sequenceNumber, List<int> statelessResetToken}): Record representing an active Connection ID.

quic_lib library

Quick start

Subsystem barrel files

Classes

Enums

Typedefs

quic_lib package

quic_lib library