🥮 mooncakes.io
    Sign in

    rtc

    Experimental Sans-I/O WebRTC stack for MoonBit

    webrtc
    sans-io
    networking
    media
    Download zip
    Version
    0.0.1
    License
    MIT OR Apache-2.0
    Repository
    Last updated
    16 hours ago
    Downloads
    2

    Dependencies

    #rtc.mbt

    rtc.mbt is an experimental, native MoonBit implementation of a Sans-I/O WebRTC stack. Its compatibility target is the fixed webrtc-rs/rtc snapshot recorded in UPSTREAM.md.

    The first supported platform is Linux x86_64 with the native backend and OpenSSL 3.x libcrypto.so.3. CI additionally verifies the exact OpenSSL 3.0.2-0ubuntu1.25 Ubuntu build in a digest- and archive-snapshot-pinned environment documented in docs/ci-crypto-environment.md.

    #What is implemented

    The stack includes:

    • SDP/JSEP offer, answer, provisional answer, rollback, glare handling, perfect negotiation, BUNDLE, trickle ICE, ICE restart, RTP media sections, RTX, RID, simulcast, and SSRC groups;
    • STUN, mDNS query/gather, host/srflx/prflx/relay ICE, TURN over UDP/TCP/TLS, and active/passive ICE TCP;
    • DTLS 1.2 with ECDSA, RSA, and PSK authentication across the eleven pinned cipher suites, EMS, replay protection, certificate fingerprints, and use_srtp;
    • SRTP/SRTCP for AES-CM and AEAD profiles;
    • SCTP association setup, fragmentation, SACK/retransmission, partial reliability, unordered delivery, stream reset, flow control, and DCEP DataChannels;
    • RTP/RTCP codecs, packetizers/depacketizers, NACK, TWCC, RTX, reports, interceptors, encoded transforms, tracks/transceivers, simulcast controls, media helpers, and detailed statistics.

    The fixed Rust webrtc 0.14.0 peer and Playwright Chromium 149.0.7827.55 exchange reliable and partial/unordered DataChannels plus Opus audio and VP8 video RTP over SRTP with MoonBit in both offerer and answerer roles. A Linux x86_64 coturn 4.14.0-r0 image is pinned by digest and carries a relay-only MoonBit DataChannel in CI.

    #Sans-I/O boundary

    The core never opens sockets or reads system time. Applications inject IoEvent, InboundDatagram, RtcMessage, and explicit monotonic timestamps, then drain:

    • poll_io_action for UDP and TCP/TLS connect/listen/read/write/close work;
    • poll_message and poll_event for application output;
    • poll_timeout for the next protocol deadline.

    The clock mapping is explicit and deterministic:

    ///|
    test "inject a deterministic clock sample" {
      let monotonic = @rtc.Instant::from_milliseconds(42L)
      let wall = @rtc.WallTime::from_unix_nanoseconds(1700000000000000000L)
      let sample = @rtc.ClockSample::new(monotonic~, wall~)
      assert_eq(sample.monotonic().as_milliseconds(), 42L)
      assert_eq(sample.wall().as_unix_nanoseconds(), 1700000000000000000L)
    }

    runtime/async is the official bounded-queue adapter. It manages UDP sockets, TCP listeners and streams, TURN TLS legs, timers, cancellation, and output backpressure while preserving the same core contract. Its bounded priority lane keeps protocol control traffic, timers, flushing, and cancellation live when application output is temporarily full.

    Run the complete in-memory example:

    moon run --target native examples/sans_io_datachannel

    The schema-free WebSocket signaling relay is in examples/websocket_signaling. Signaling, media capture, codecs, rendering, and device integration intentionally remain application concerns.

    #Development and acceptance

    The upstream audit expects --upstream to point to a webrtc-rs/rtc checkout at the commit recorded in UPSTREAM.md.

    moon fmt --check
moon check --target native --warn-list +73
moon test --target native
scripts/test-rust-interop
scripts/test-chromium-interop
scripts/test-coturn-interop
scripts/audit-upstream.mjs \
  --upstream /path/to/webrtc-rs-rtc \
  --write-ledger docs/upstream-coverage.json
moon bench --release --target native --no-parallelize
moon info

    The ASan entry point is scripts/run-asan.mjs. The performance gate is scripts/bench-gate.mjs. Its committed benchmarks/baseline.json binds the fixed workloads and 20 raw samples to clean commit 29f4ff26dcb507715a0bfdacd58a0a3b48f3c776. See benchmarks/README.md.

    The generated per-item upstream inventory is docs/upstream-coverage.json. Public interfaces are reviewed through every pkg.generated.mbti; DTLS record ciphers, PRF/key schedule helpers, crypto providers, parsers, and replay state remain internal.

    The project is dual-licensed under MIT or Apache-2.0. It remains pre-1.0 while the reviewed public API is intentionally experimental.

    CandidateType

    source

    ClockSample

    source

    CodecCapability

    source

    ConnectionId

    source

    Context

    source

    DataChannel

    source

    DataChannelConfig

    source

    DataChannelMessage

    source

    DataChannelState

    source

    Direction

    source

    Duration

    source

    EcnCodepoint

    source

    EncodedFrameContext

    source

    EncodedTransform

    source

    EncodedTransformPipeline

    source

    IceCandidate

    source

    IceConnectionState

    source

    IceGatheringState

    source

    IceRole

    source

    IceTransportPolicy

    source

    InboundDatagram

    source

    Instant

    source

    IoAction

    source

    IoEvent

    source

    IpAddress

    source

    ListenerId

    source

    ManualClock

    source

    MediaKind

    source

    MediaTrack

    source

    OutboundDatagram

    source

    Pipeline

    source

    RtpEncodingParameters

    source

    RtpParameters

    source

    RtpReceiver

    source

    RtpSender

    source

    RtpTransceiver

    source

    SdpType

    source

    SessionDescription

    source

    SignalingState

    source

    SocketAddress

    source

    Stage

    source

    TcpCandidateType

    source

    TransceiverDirection

    source

    TransformDirection

    source

    TransportContext

    source

    TransportProtocol

    source

    TurnTransport

    source

    WallTime

    source

    RtcError

    source

    ActiveRtcListener

    source
    type ActiveRtcListener

    ActiveRtcStream

    source
    type ActiveRtcStream

    CandidatePairStats

    source
    pub(all) struct CandidatePairStats {
      id : String
      local_candidate : 
    IceCandidate
      remote_candidate : 
    IceCandidate
      priority : UInt64
      state : 
    CandidatePairState
      nominated : Bool
      selected : Bool
    } derive(Eq, 
    Debug    )

    CodecStats

    source
    pub(all) struct CodecStats {
      id : String
      payload_type : Byte
      mime_type : String
      clock_rate : UInt
      channels : UInt16
      fmtp : String
    } derive(Eq, 
    Debug    )

    Configuration

    source
    pub struct Configuration {
      ice_servers : Array[IceServer]
      ice_transport_policy : 
    IceTransportPolicy
      mdns_mode : 
    Mode
      host_candidates : Array[
    IceCandidate    ]
      sctp_port : UInt16
      max_message_size : UInt64
      command_capacity : Int
      event_capacity : Int
      message_capacity : Int
      settings : Settings
      interceptor_pipeline : 
    Pipeline
      encoded_transform_pipeline : 
    EncodedTransformPipeline
    }

    Configuration::command_capacity

    source
    fn Configuration::command_capacity(self : Configuration) -> Int

    Configuration::encoded_transform_pipeline

    source

    Configuration::event_capacity

    source
    fn Configuration::event_capacity(self : Configuration) -> Int

    Configuration::host_candidates

    source

    Configuration::ice_servers

    source
    fn Configuration::ice_servers(self : Configuration) -> Array[IceServer]

    Configuration::ice_transport_policy

    source

    Configuration::interceptor_pipeline

    source

    Configuration::max_message_size

    source
    fn Configuration::max_message_size(self : Configuration) -> UInt64

    Configuration::mdns_mode

    source

    Configuration::message_capacity

    source
    fn Configuration::message_capacity(self : Configuration) -> Int

    Configuration::new

    source
    fn Configuration::new(ice_servers? : Array[IceServer], ice_transport_policy? : 
    IceTransportPolicy    , mdns_mode? : 
    Mode    , host_candidates? : Array[
    IceCandidate    ], sctp_port? : UInt16, max_message_size? : UInt64, command_capacity? : Int, event_capacity? : Int, message_capacity? : Int, settings? : Settings, interceptor_pipeline? : 
    Pipeline    , encoded_transform_pipeline? : 
    EncodedTransformPipeline    ) -> Configuration raise RtcError

    Configuration::sctp_port

    source
    fn Configuration::sctp_port(self : Configuration) -> UInt16

    Configuration::settings

    source
    fn Configuration::settings(self : Configuration) -> Settings

    DataChannelStats

    source
    pub(all) struct DataChannelStats {
      id : String
      stream_id : 
    StreamId
      label : String
      protocol : String
      state : 
    DataChannelState
      buffered_amount : UInt64
    } derive(Eq, 
    Debug    )

    DetailedStatsReport

    source
    pub(all) struct DetailedStatsReport {
      timestamp : 
    WallTime
      codecs : Array[CodecStats]
      outbound_rtp : Array[RtpStreamStats]
      inbound_rtp : Array[RtpStreamStats]
      candidate_pairs : Array[CandidatePairStats]
      data_channels : Array[DataChannelStats]
      transport : TransportStats
    } derive(Eq, 
    Debug    )

    IceServer

    source
    pub(all) struct IceServer {
      urls : Array[String]
      username : String?
      credential : String?
    } derive(Eq, 
    Debug    )

    IceServer::credential

    source
    fn IceServer::credential(self : IceServer) -> String?

    IceServer::new

    source
    fn IceServer::new(urls~ : Array[String], username? : String, credential? : String) -> IceServer raise RtcError

    IceServer::urls

    source
    fn IceServer::urls(self : IceServer) -> Array[String]

    IceServer::username

    source
    fn IceServer::username(self : IceServer) -> String?

    LocalMediaSection

    source
    type LocalMediaSection

    OfferCollisionPolicy

    source
    pub(all) enum OfferCollisionPolicy {
      Polite
      Impolite
    } derive(Eq, 
    Debug    )

    PeerConnection

    source
    pub struct PeerConnection {
      configuration : Configuration
      clock_sample : 
    ClockSample
      signaling : 
    SignalingStateMachine
      identity : 
    CertificateIdentity
      local_credentials : 
    IceCredentials
      session_id : UInt64
      session_version : UInt64
      tie_breaker : UInt64
      events : 
    Queue    [PeerEvent]
      messages : 
    Queue    [RtcMessage]
      outbound : 
    Queue    [
    OutboundDatagram    ]
      io_actions : 
    Queue    [
    IoAction    ]
      pending_streams : Array[PendingRtcStream]
      active_streams : Array[ActiveRtcStream]
      active_listeners : Array[ActiveRtcListener]
      next_connection_id : UInt64
      next_listener_id : UInt64
      local_transport_candidates : Array[
    IceCandidate    ]
      local_advertised_candidates : Array[
    IceCandidate    ]
      srflx_gatherers : Array[
    SrflxGatherer    ]
      turn_allocations : Array[
    Allocation    ]
      pending_relay_datagrams : Array[PendingRelayDatagram]
      remote_candidates : Array[
    IceCandidate    ]
      mdns_resolver : 
    Resolver
      pending_mdns_candidates : Map[
    QueryId    , 
    IceCandidate    ]
      state : PeerConnectionState
      gathering_state : 
    IceGatheringState
      data_manager : 
    Manager    ?
      ice_agent : 
    IceAgent    ?
      dtls_endpoint : 
    Endpoint    ?
      data_transport : 
    Transport    ?
      local_media_sections : Array[LocalMediaSection]
      remote_media_sections : Array[RemoteMediaSection]
      outbound_srtp : 
    Context    ?
      inbound_srtp : 
    Context    ?
      media_started : Bool
      rtcp_sender_ssrc : UInt
      next_rtcp_report : 
    Instant    ?
      next_transport_sequence : UInt16
      remote_twcc_recorder : 
    TwccRecorder    ?
      data_channel_buffered_amount_low_thresholds : Map[
    StreamId    , UInt64]
      transport_started : Bool
      ice_restart_pending : Bool
      dtls_started : Bool
      data_started : Bool
      closing : Bool
      bytes_sent : UInt64
      bytes_received : UInt64
      packets_sent : UInt64
      packets_received : UInt64
      data_channels_opened : UInt
      data_channels_closed : UInt
    }

    PeerConnection::add_ice_candidate

    source

    PeerConnection::add_track

    source

    PeerConnection::add_transceiver

    source

    PeerConnection::close

    source

    PeerConnection::close_data_channel

    source

    PeerConnection::connection_state

    source
    fn PeerConnection::connection_state(self : PeerConnection) -> PeerConnectionState

    PeerConnection::create_answer

    source

    PeerConnection::create_data_channel

    source

    PeerConnection::create_offer

    source

    PeerConnection::create_pranswer

    source

    PeerConnection::data_channel_buffered_amount

    source
    fn PeerConnection::data_channel_buffered_amount(self : PeerConnection, channel_id : 
    StreamId    ) -> UInt64

    PeerConnection::data_channel_buffered_amount_low_threshold

    source
    fn PeerConnection::data_channel_buffered_amount_low_threshold(self : PeerConnection, channel_id : 
    StreamId    ) -> UInt64

    PeerConnection::detailed_stats

    source

    PeerConnection::driver_command_capacity

    source
    fn PeerConnection::driver_command_capacity(self : PeerConnection) -> Int

    PeerConnection::driver_event_capacity

    source
    fn PeerConnection::driver_event_capacity(self : PeerConnection) -> Int

    PeerConnection::driver_message_capacity

    source
    fn PeerConnection::driver_message_capacity(self : PeerConnection) -> Int

    PeerConnection::driver_receive_mtu

    source
    fn PeerConnection::driver_receive_mtu(self : PeerConnection) -> Int

    PeerConnection::handle_datagram

    source

    PeerConnection::handle_io_event

    source

    PeerConnection::handle_mdns_datagram

    source

    PeerConnection::handle_message

    source
    fn PeerConnection::handle_message(self : PeerConnection, message : RtcMessage, now : 
    Instant    ) -> Unit raise RtcError

    PeerConnection::handle_timeout

    source

    PeerConnection::local_description

    source

    PeerConnection::local_host_candidates

    source

    PeerConnection::local_track_encodings

    source

    PeerConnection::local_track_payload_type

    source
    fn PeerConnection::local_track_payload_type(self : PeerConnection, track_id : String) -> Byte?

    PeerConnection::local_track_ssrc

    source
    fn PeerConnection::local_track_ssrc(self : PeerConnection, track_id : String) -> UInt?

    PeerConnection::new

    source

    PeerConnection::poll_datagram

    source

    PeerConnection::poll_event

    source
    fn PeerConnection::poll_event(self : PeerConnection) -> PeerEvent?

    PeerConnection::poll_io_action

    source

    PeerConnection::poll_message

    source
    fn PeerConnection::poll_message(self : PeerConnection) -> RtcMessage?

    PeerConnection::poll_timeout

    source

    PeerConnection::remote_description

    source

    PeerConnection::remove_track

    source
    fn PeerConnection::remove_track(self : PeerConnection, track_id : String, now : 
    Instant    ) -> Unit raise RtcError

    PeerConnection::restart_ice

    source

    PeerConnection::rollback

    source

    PeerConnection::set_data_channel_buffered_amount_low_threshold

    source
    fn PeerConnection::set_data_channel_buffered_amount_low_threshold(self : PeerConnection, channel_id : 
    StreamId    , threshold : UInt64) -> Unit raise RtcError

    PeerConnection::set_local_description

    source

    PeerConnection::set_remote_description

    source

    PeerConnection::set_remote_description_perfect

    source

    PeerConnection::set_sender_encodings

    source

    PeerConnection::signaling_state

    source

    PeerConnection::stats

    source

    PeerConnection::transceivers

    source

    PeerConnectionState

    source
    pub(all) enum PeerConnectionState {
      New
      Connecting
      Connected
      Disconnected
      Failed
      Closed
    } derive(Eq, 
    Debug    )

    PeerEvent

    source

    PendingRelayDatagram

    source
    type PendingRelayDatagram

    PendingRtcStream

    source
    type PendingRtcStream

    RemoteMediaSection

    source
    type RemoteMediaSection

    RtcMessage

    source

    RtcStreamOwner

    source
    type RtcStreamOwner derive(Eq, 
    Debug    )

    RtpStreamStats

    source
    pub(all) struct RtpStreamStats {
      id : String
      track_id : String
      kind : 
    MediaKind
      outbound : Bool
      ssrc : UInt
      rid : String?
      codec_id : String
      packets : UInt64
      bytes : UInt64
      packets_lost : UInt64
      jitter : UInt64
      retransmitted_packets : UInt64
      retransmitted_bytes : UInt64
      active : Bool
    } derive(Eq, 
    Debug    )

    Settings

    source
    pub struct Settings {
      ice_credentials : 
    IceCredentials    ?
      ice_check_interval : 
    Duration
      ice_initial_rto : 
    Duration
      ice_reliable_timeout : 
    Duration
      ice_max_retransmissions : Int
      ice_disconnected_timeout : 
    Duration
      ice_failed_timeout : 
    Duration
      ice_keepalive_interval : 
    Duration
      mdns_retry_interval : 
    Duration
      mdns_query_timeout : 
    Duration
      mdns_local_name : String?
      answering_dtls_role : 
    Role    ?
      verify_peer_fingerprint : Bool
      dtls_certificate_key_type : 
    CertificateKeyType
      dtls_cipher_suites : Array[
    CipherSuite    ]
      dtls_psk : Bytes?
      dtls_psk_identity : Bytes?
      dtls_srtp_profiles : Array[
    SrtpProtectionProfile    ]
      dtls_flight_interval : 
    Duration
      dtls_mtu : Int
      dtls_replay_window : Int
      srtp_replay_window : Int
      srtcp_replay_window : Int
      sctp_max_payload_size : Int
      sctp_send_buffer_size : UInt64
      sctp_receive_buffer_size : UInt
      sctp_initial_rto : 
    Duration
      receive_mtu : Int
      ignore_rid_pause_for_recv : Bool
      write_ssrc_attributes_for_simulcast : Bool
    }

    Settings::answering_dtls_role

    source
    fn Settings::answering_dtls_role(self : Settings) -> 
    Role    ?

    Settings::dtls_certificate_key_type

    source

    Settings::dtls_cipher_suites

    source

    Settings::dtls_flight_interval

    source

    Settings::dtls_mtu

    source
    fn Settings::dtls_mtu(self : Settings) -> Int

    Settings::dtls_psk

    source
    fn Settings::dtls_psk(self : Settings) -> Bytes?

    Settings::dtls_psk_identity

    source
    fn Settings::dtls_psk_identity(self : Settings) -> Bytes?

    Settings::dtls_replay_window

    source
    fn Settings::dtls_replay_window(self : Settings) -> Int

    Settings::dtls_srtp_profiles

    source

    Settings::ice_check_interval

    source

    Settings::ice_credentials

    source

    Settings::ice_disconnected_timeout

    source

    Settings::ice_failed_timeout

    source

    Settings::ice_initial_rto

    source

    Settings::ice_keepalive_interval

    source

    Settings::ice_max_retransmissions

    source
    fn Settings::ice_max_retransmissions(self : Settings) -> Int

    Settings::ice_reliable_timeout

    source

    Settings::ignore_rid_pause_for_recv

    source
    fn Settings::ignore_rid_pause_for_recv(self : Settings) -> Bool

    Settings::mdns_local_name

    source
    fn Settings::mdns_local_name(self : Settings) -> String?

    Settings::mdns_query_timeout

    source

    Settings::mdns_retry_interval

    source

    Settings::new

    source
    fn Settings::new(ice_credentials? : 
    IceCredentials    , ice_check_interval? : 
    Duration    , ice_initial_rto? : 
    Duration    , ice_reliable_timeout? : 
    Duration    , ice_max_retransmissions? : Int, ice_disconnected_timeout? : 
    Duration    , ice_failed_timeout? : 
    Duration    , ice_keepalive_interval? : 
    Duration    , mdns_retry_interval? : 
    Duration    , mdns_query_timeout? : 
    Duration    , mdns_local_name? : String, answering_dtls_role? : 
    Role    , verify_peer_fingerprint? : Bool, dtls_certificate_key_type? : 
    CertificateKeyType    , dtls_cipher_suites? : Array[
    CipherSuite    ], dtls_psk? : Bytes, dtls_psk_identity? : Bytes, dtls_srtp_profiles? : Array[
    SrtpProtectionProfile    ], dtls_flight_interval? : 
    Duration    , dtls_mtu? : Int, dtls_replay_window? : Int, srtp_replay_window? : Int, srtcp_replay_window? : Int, sctp_max_payload_size? : Int, sctp_send_buffer_size? : UInt64, sctp_receive_buffer_size? : UInt, sctp_initial_rto? : 
    Duration    , receive_mtu? : Int, ignore_rid_pause_for_recv? : Bool, write_ssrc_attributes_for_simulcast? : Bool) -> Settings raise RtcError

    Settings::receive_mtu

    source
    fn Settings::receive_mtu(self : Settings) -> Int

    Settings::sctp_initial_rto

    source

    Settings::sctp_max_payload_size

    source
    fn Settings::sctp_max_payload_size(self : Settings) -> Int

    Settings::sctp_receive_buffer_size

    source
    fn Settings::sctp_receive_buffer_size(self : Settings) -> UInt

    Settings::sctp_send_buffer_size

    source
    fn Settings::sctp_send_buffer_size(self : Settings) -> UInt64

    Settings::srtcp_replay_window

    source
    fn Settings::srtcp_replay_window(self : Settings) -> Int

    Settings::srtp_replay_window

    source
    fn Settings::srtp_replay_window(self : Settings) -> Int

    Settings::verify_peer_fingerprint

    source
    fn Settings::verify_peer_fingerprint(self : Settings) -> Bool

    Settings::write_ssrc_attributes_for_simulcast

    source
    fn Settings::write_ssrc_attributes_for_simulcast(self : Settings) -> Bool

    StatsReport

    source
    pub(all) struct StatsReport {
      timestamp : 
    WallTime
      bytes_sent : UInt64
      bytes_received : UInt64
      packets_sent : UInt64
      packets_received : UInt64
      packets_lost : UInt64
      data_channels_opened : UInt
      data_channels_closed : UInt
    } derive(Eq, 
    Debug    )

    TransportStats

    source
    pub(all) struct TransportStats {
      id : String
      ice_state : 
    IceConnectionState
      dtls_state : 
    State    ?
      selected_candidate_pair_id : String?
      bytes_sent : UInt64
      bytes_received : UInt64
      packets_sent : UInt64
      packets_received : UInt64
    } derive(Eq, 
    Debug    )

    Source Files

    Powered by MoonBit

    Site sourceReport issuePackagesBuild queueSkillsStatistics

    © 2026 mooncakes.io