Session

QRSession owns the handshake state machine. One instance per node; it tracks every offer it made and every connection it accepted.

import { QRSession } from '@le-space/libp2p-webrtc-qr'

const session = new QRSession(node, { rtcConfiguration })

The two sides

// offering side
const offer = await session.createOffer()
const { peerId, connection, address, ageSeconds } = await session.acceptAnswer(reply)

// answering side
const answer = await session.acceptOffer(offer)
session.addEventListener('connect', e => e.detail.peerId)

acceptOffer returns as soon as the answer is signed, not when the connection is up — the offering peer cannot finish until it reads that answer. The connection completes afterwards and reports itself through connect, or error if it never does.

Options

option	default	meaning
rtcConfiguration	—	passed to RTCPeerConnection
compact	false	produce v3 short codes
iceGatheringTimeout	5000	stop waiting for candidates
connectionTimeout	30000	give up on connected
answerWaitTimeout	—	how long the answering side holds its side open
dialAttempts, dialRetryDelay, dialSettleDelay	—	retry shape while the peer attaches its muxer

Per call: createOffer({ compact }), acceptAnswer(text, { dial }).

Pass dial: false when you open your own protocol stream — otherwise the connection is dialled twice.

Methods, state, events

createOffer, acceptOffer, acceptAnswer	the handshake
dial, dialProtocol	after it
session.offers	pending offers, keyed by session id
session.inbound	connections built from an accepted offer
events	connect, error

session.offers and session.inbound together are every peer connection this session is responsible for — which is what a liveness readout has to iterate.

Diagnosing a failure

import { describeIce } from '@le-space/libp2p-webrtc-qr'

describeIce(peerConnection) // one line: both candidate sets and the ICE state

That string is what a failure message should carry. "Connection failed" without it cannot be acted on by anyone.