The channels protocol is transport-agnostic by design (ADR-071 substrate
modes; ADR-065 unwound the server-side QUIC-welding via
Connection::from_stream/from_bidi). ADR-080 had welded the client-side
one-way-door API to QUIC and masked it as a deferral ('QUIC-only
initially', 'can be generalized later') — anti-patterns #8/#9/#11
(door-type-as-deferral + resolved-with-escape-hatch). 'Can be
generalized later' meant 'can be rewritten later' — the expensive
reversal the one-way-door classification exists to prevent.
Fix: split the constructor surface.
- from_connection(connection: Connection) — transport-agnostic primary,
one-way door. Mirrors server-side ChannelsAdapter::handle(Connection)
and the existing CallClient::spawn_dispatch pattern.
- connect_quic(addr, credentials) — QUIC convenience, two-way door,
additive. Future connect_tcp_tls / connect_webtransport join it
without touching the one-way-door surface.
OQ-55 reframed: the deferred thing is the shared dial+TLS seam
(AlknetClient), not a QUIC-welded client API. The client take-over APIs
(CallClient::spawn_dispatch, ChannelClient::from_connection) are
transport-agnostic and decided; only the shared dial across transports
is blocked on a second transport's dial existing.
Files:
- decisions/080-channelclient.md: amendment section, Decision code
block, Transport-agnostic by construction (replaces QUIC-only
initially), Consequences, Door type, subscribe_resources added to
Decision block (was referenced by Door type but missing)
- crates/channels/channel-client.md: from_connection primary API,
Transport-agnostic by construction section, OQ-55 relationship
- crates/channels/overview.md, crates/channels/README.md,
crates/core/README.md, README.md, open-questions.md,
questions/055-...md: cross-reference summaries aligned
Three core-crate changes surfaced by the alknet-channels POC:
- ADR-070: extract BidiStreamSource trait so Connection holds
Box<dyn BidiStreamSource> instead of a closed ConnectionKind enum;
downstream crates (channels, future transports) implement the trait
to add connection shapes without editing core. Public Connection API
preserved verbatim. REQ-CORE-02 (close() params clippy warning under
--no-default-features) folded in — the signature stays on the trait,
non-QUIC impls ignore the args.
- OQ-55: AlknetClient / client establishment extraction deferred(scope).
Blocked on a second *transport's* real client (not a second QUIC
client) — extracting a QUIC-shaped connector now would bake QUIC in
as the establishment shape, the same welding ADR-065 unwound on the
server side. Each crate builds its own client standalone for now.
- core-types.md / auth.md / overview.md / README indexes updated to
reflect ADR-070 and OQ-55. Architecture review: zero critical issues.
- tasks/core/bidistreamsource-trait.md: the implementation task (Parts
1-3: BidiStreamSource refactor, close() fix, AuthContext::anonymous).
glm-5.2