reactor-webrtc (Python)

Python bindings for the reactor-webrtc WebRTC engine, built with PyO3 and distributed as a self-contained wheel — no separate native library required at runtime.

Installation

pip install reactor-webrtc

Requires Python ≥ 3.10.

Quick start

PeerConnection's signaling methods are natively awaitable, so this runs inside an asyncio event loop:

import asyncio
import reactor_webrtc as rw

async def main():
    factory = rw.PeerConnectionFactory()

    obs = rw.PeerConnectionObserver()
    obs.on_ice_candidate = lambda c: relay_to_peer(c)
    obs.on_connection_state_change = lambda s: print("state:", s)

    config = rw.RtcConfiguration(ice_servers=[
        rw.IceServer(urls=["stun:stun.l.google.com:19302"]),
        # A turn:/turns: entry needs both credentials, or libwebrtc rejects the
        # whole configuration.
        rw.IceServer(urls=["turn:turn.example.com:3478"], username="alice", password="secret"),
    ])
    pc = factory.create_peer_connection(config, obs)

    offer = await pc.create_offer()
    await pc.set_local_description(offer)

    # Exchange offer.sdp with the remote peer via your signaling channel, then:
    # await pc.set_remote_description(remote_answer)
    # await pc.add_ice_candidate(candidate)

asyncio.run(main())

Audio

# Headless / server: push PCM programmatically (synthetic ADM, default)
factory = rw.PeerConnectionFactory()
factory.push_audio_frame(pcm_bytes, sample_rate=48000, channels=1)

# Desktop client: real mic + AEC3 + noise suppression
factory = rw.PeerConnectionFactory(
    platform_adm=True,
    echo_canceller=True,
    noise_suppression=True,
)

Pre-encoded video

factory, video = rw.PeerConnectionFactory.with_encoded_video_track(
    "camera", width=1280, height=720
)
pc = factory.create_peer_connection(config, obs)
tx = video.add_transceiver(pc, rw.TransceiverDirection.SendOnly)

# From your encoder thread:
video.push_encoded_frame(
    data=h264_annex_b,
    is_key_frame=True,
    width=1280, height=720,
)

Receiving media

obs = rw.PeerConnectionObserver()

def on_track(kind, track):
    if kind == rw.MediaKind.Video:
        track.on_video_frame(lambda bgra, w, h: display(bgra, w, h))
    elif kind == rw.MediaKind.Audio:
        track.on_audio_frame(lambda pcm, sr, ch, n: play(pcm))

obs.on_track = on_track

Stats

report = await pc.get_stats()
for pair in report.candidate_pairs:
    print(pair.state, f"{pair.current_round_trip_time_s * 1000:.1f}ms")

API reference

Class Description
PeerConnectionFactory Entry point; creates peer connections and tracks
PeerConnection SDP offer/answer, ICE, tracks, data channels, stats
PeerConnectionObserver Callbacks: state, ICE candidate, track, data channel
RtcConfiguration ICE servers, ICE transport type, gathering policy
IceServer A STUN or TURN server entry
IceCandidate A trickled ICE candidate
SessionDescription SDP offer or answer (kind, sdp, ice_ufrags, with_ice_credentials, declares_frame_metadata, with_frame_metadata)
FrameMetadata Per-frame frame_id, timestamp, user_data
FrameMetadataGate What the remote declared about per-frame metadata
Track Local (push frames) or remote (attach sink) media track
EncodedVideoTrack Push pre-encoded video (H.264 Annex-B, VP8, VP9, …)
Transceiver RTP m-section: mid, kind, set_track, set_direction, set_sender_transform, set_receiver_transform
DataChannel SCTP data channel: send, on_message, on_open, …
StatsReport inbound_rtp, outbound_rtp, candidate_pairs
FrameMetadata, FrameAction, EncodedFrame, FrameTransform Per-frame metadata trailers and custom encoded-frame transforms — see docs/frame-metadata.md
Enum Values
PeerConnectionState New, Connecting, Connected, Disconnected, Failed, Closed
IceGatheringState New, Gathering, Complete
TransceiverDirection SendRecv, SendOnly, RecvOnly, Inactive
MediaKind Audio, Video
DataChannelState Connecting, Open, Closing, Closed
IceCandidatePairState Waiting, InProgress, Failed, Succeeded, Cancelled
String-valued field Values
RtcConfiguration.ice_transport_type all (default), relay, no_host, none
RtcConfiguration.continual_gathering_policy once (default), continually
RtcConfiguration.bundle_policy Balanced (default), MaxBundle, MaxCompat
RtcConfiguration.tcp_candidate_policy Disabled (default), Enabled

RtcConfiguration also takes a min_port/max_port pair (UDP port range), ice_connection_receiving_timeout_ms, and ice_check_interval_strong_connectivity_ms; PeerConnection.set_bitrate sets congestion-control bitrate limits after the connection is created. All covered in docs/configuration.md.

Per-frame metadata

Arbitrary bytes can ride alongside each encoded video frame, in a protobuf trailer appended to the payload:

video.push_video_frame(bgra, 320, 240, user_data=b"anything you like")

def on_frame(bgra, w, h, meta):
    if meta is not None:
        print(meta.frame_id, meta.timestamp, meta.user_data)

track.on_video_frame(on_frame)

That only works if the far end strips the trailer before its decoder sees it, so support is negotiated in the SDP and you do not have to do anything for it:

  • create_offer advertises the capability as one session-level a=x-reactor-frame-metadata:1 (rw.FRAME_METADATA_ATTRIBUTE, rw.FRAME_METADATA_VERSION).
  • create_answer mirrors an offer that asked for it.
  • set_remote_description arms pc.frame_metadata_gate() and, when it is open, installs the embed and strip transforms on the video transceivers. The sender transform still checks the gate per frame, so a renegotiation that drops support stops the trailers.

A peer that has never heard of the attribute ignores it, the gate stays closed, and user_data is silently dropped rather than corrupting that peer's decode. Read pc.frame_metadata_gate().is_open() if you want to know whether the peer agreed.

Read the declaration from the signalled SDP string, not from pc.remoteDescription or its equivalents: libwebrtc and browsers both discard a= lines they do not recognise while parsing.

A FrameTransform of your own composes with the metadata step rather than displacing it — the library owns libwebrtc's single transformer slot per sender/receiver and runs both. Your callback goes first in both directions, so it sees exactly the bytes that traverse the network.

To keep frame metadata out of a connection entirely:

config = rw.RtcConfiguration(frame_metadata=False)

No a=extmap, no mirroring, no transforms, and user_data is dropped — the connection is indistinguishable from one built before the capability existed.

Choosing your own ICE credentials

libwebrtc generates the ICE ufrag and password itself and offers no setter. If something upstream needs to recognise a session by its ufrag — an edge relay that demultiplexes on it, say — substitute the credentials in the description before setting it locally:

answer = await pc.create_answer()
answer = answer.with_ice_credentials(my_ufrag, my_password)
await pc.set_local_description(answer)

answer.ice_ufrags()  # ["<my_ufrag>", ...] — one per m-section

The local description is what libwebrtc reads the transport's ICE parameters from, so the substituted values are the ones that end up on the wire.

Two things to get right:

  • Order. Setting the local description is what creates the transport and starts gathering, so substituting afterwards acts on nothing.
  • Renegotiation. Changing the credentials between generations is an ICE restart (RFC 8445 §9). On a renegotiation that is not meant to restart ICE, pass the values the session already uses.

Raises if a value is outside RFC 8445's ranges (ufrag 4–256 characters, password 22–256) or contains anything outside ice-char — which is also what stops a newline in a credential from injecting an SDP line.

Thread safety

PeerConnection's signaling methods (create_offer, create_answer, set_local_description, set_remote_description, add_ice_candidate, get_stats) plus set_bitrate are natively awaitable — await them directly, no asyncio.to_thread()/executor wrapping needed. They still take a few milliseconds to resolve while the WebRTC engine responds, but that wait happens off the event loop thread, so it never blocks other coroutines.

Every other method (add_track, add_transceiver, transceivers, create_data_channel, and everything on Track/Transceiver/DataChannel) is a fast synchronous call with no native round-trip, and stays a plain function call — no await.

Callbacks fire on WebRTC internal threads with the GIL acquired; keep them fast.

License

Apache-2.0. Upstream WebRTC is BSD-3-Clause + the WebRTC patent grant.

Project links

Data verified by PyPI on Aug 11, 2026
Data provided by the project maintainers, verified at the time the release was uploaded to PyPI.

Key dates

PyPI data
Data sourced directly from PyPI's database.
  • Released:
Newer release available (0.14.0)

Owner

PyPI data
Data sourced directly from PyPI's database.

GitHub Statistics

Data verified by PyPI on Aug 11, 2026
The GitHub source repository was provided by the project maintainers and verified by PyPI at the time of upload. Stars, forks, and open issues/PRs are derived from that repository and have not been independently verified.

License

Apache Software License (Apache-2.0)

Requires

Python >=3.10

Classifiers

Report project as malware

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distributions

No source distribution files available for this release.See tutorial on generating distribution archives.

Built Distributions

If you're not sure about the file name format, learn more about wheel file names.

reactor_webrtc-0.7.2-cp310-abi3-win_amd64.whl (8.0 MB view details)

Uploaded CPython 3.10+Windows x86-64

reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_x86_64.whl (9.1 MB view details)

Uploaded CPython 3.10+manylinux: glibc 2.34+ x86-64

reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_aarch64.whl (8.5 MB view details)

Uploaded CPython 3.10+manylinux: glibc 2.34+ ARM64

reactor_webrtc-0.7.2-cp310-abi3-macosx_13_0_x86_64.whl (8.3 MB view details)

Uploaded CPython 3.10+macOS 13.0+ x86-64

reactor_webrtc-0.7.2-cp310-abi3-macosx_11_0_arm64.whl (7.3 MB view details)

Uploaded CPython 3.10+macOS 11.0+ ARM64

File details

Details for the file reactor_webrtc-0.7.2-cp310-abi3-win_amd64.whl.

File metadata

File hashes

Hashes for reactor_webrtc-0.7.2-cp310-abi3-win_amd64.whl
Algorithm Hash digest
SHA256 e3488e3f963141421dc535550255a413ec77dbec3faf5d9c4280a0dcc33fba1f
MD5 46f57d796299c6b7b577a0567253e022
BLAKE2b-256 7562bd7dcde4c5df9ff738b6b0d5974dc43012315ac30140581f898de0c63d07

See more details on using hashes here.

Provenance

The following attestation bundles were made for reactor_webrtc-0.7.2-cp310-abi3-win_amd64.whl:

Publisher: publish.yml on reactor-team/reactor-webrtc

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_x86_64.whl.

File metadata

File hashes

Hashes for reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_x86_64.whl
Algorithm Hash digest
SHA256 c2d2f4be74224a1b4e9cfe2d83c2dd013352f5d0e65a5743d7e6ed5acbc8745f
MD5 1f576cf755cb38cd74d86aee8224776b
BLAKE2b-256 c9fbe0461c214475c211f67eecc7711753f548024411d11a35b99e14a3096240

See more details on using hashes here.

Provenance

The following attestation bundles were made for reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_x86_64.whl:

Publisher: publish.yml on reactor-team/reactor-webrtc

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_aarch64.whl.

File metadata

File hashes

Hashes for reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_aarch64.whl
Algorithm Hash digest
SHA256 54a4742c995b2fd12870830a528ff9782317c09926abdc25b652f8d0fa4bae69
MD5 bae22bda41fce5d5fdbcbfb2d63d6bcc
BLAKE2b-256 38f701ab6a9792063e6b6972719ff6d4982f95486b76b3966ab8f21535555917

See more details on using hashes here.

Provenance

The following attestation bundles were made for reactor_webrtc-0.7.2-cp310-abi3-manylinux_2_34_aarch64.whl:

Publisher: publish.yml on reactor-team/reactor-webrtc

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file reactor_webrtc-0.7.2-cp310-abi3-macosx_13_0_x86_64.whl.

File metadata

File hashes

Hashes for reactor_webrtc-0.7.2-cp310-abi3-macosx_13_0_x86_64.whl
Algorithm Hash digest
SHA256 14c4c46dd9ed7170b1956173f32fb4ed482103be7a494d33c1f5353b50754388
MD5 c3dce387ff1fb6cfc38359a6b8ff7d2d
BLAKE2b-256 289a995f79776ee231aeb6127308f6ec267804b9de1a59596c7599aa9e2a7742

See more details on using hashes here.

Provenance

The following attestation bundles were made for reactor_webrtc-0.7.2-cp310-abi3-macosx_13_0_x86_64.whl:

Publisher: publish.yml on reactor-team/reactor-webrtc

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file reactor_webrtc-0.7.2-cp310-abi3-macosx_11_0_arm64.whl.

File metadata

File hashes

Hashes for reactor_webrtc-0.7.2-cp310-abi3-macosx_11_0_arm64.whl
Algorithm Hash digest
SHA256 093ca3c249c6cc3eb3848c6042072b706743b48843d1cee8e852f50cffada61f
MD5 08676284de6dd28f9d162ce04506d12a
BLAKE2b-256 f9224cb8f75b0c0cc4ef4eb5a47d54506b805b79d31efad7164060f759c21f57

See more details on using hashes here.

Provenance

The following attestation bundles were made for reactor_webrtc-0.7.2-cp310-abi3-macosx_11_0_arm64.whl:

Publisher: publish.yml on reactor-team/reactor-webrtc

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

0.14.0

5 files

0.13.0

5 files

0.12.1

5 files

0.12.0

5 files

0.11.0

5 files

0.10.0

5 files

0.9.0

5 files

0.8.0

5 files

This release

0.7.2 This release

5 files

0.7.1

5 files

0.7.0

5 files

0.6.0

5 files

0.5.0

5 files

0.4.2

5 files

0.4.1

5 files

0.4.0

5 files

0.3.0

4 files

0.2.0

4 files

0.1.0

4 files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page