Prune the channels spec to reflect the stream-unification resolution
(docs/research/stream-unification/findings.md): the channels wire format
goes from 9 bytes to 8 bytes, the channels layer no longer carries a
stream_type concept, into_sub_streams() is removed, and TTY always uses
its 5-byte format (carried transparently in the channels payload).
ADR-093 is the umbrella decision (the channels-layer consequence of
ADR-092's BiStream handler leaf): every channel is a BiStream, the
handler owns its sub-stream multiplexing, the channels layer routes by
channel_id only. Amends ADR-071 (8-byte header, no stream_type),
ADR-074 (into_sub_streams removed, accept_bi yields BiStream), reverses
ADR-077 (TTY always 5-byte), and the channels-facing clauses of
ADR-072/073/075/076/080/081. Adds ADR-092 forward-reference note
(into_sub_streams preservation subsequently reversed by ADR-093) and
the missing ADR-092 cross-reference on ADR-070.
Adds OQ-68 (add/strip API shape — built-in vs utility; the contract is
decided in ADR-093, the function surface is open; two-way door, low
priority, decision-ready when the channels crate's implementation
begins).
Rewrites the 7 channels spec docs (README, overview, channels-wire,
channels-connection, channels-adapter, channel-operations, channel-client)
to describe the post-amendment shape as current, with the 8-byte header,
the add/strip composition, single accept_bi accessor, BiStream per
channel, and TTY-always-5-byte.
Touch-up cross-references in hub README, client README, ADR-085, and
the OQ-45/47/65 question files (TTY-internal stream_type 3 →
STREAM_CTRL_IN; channels 9-byte → 8-byte).
ADR-070 made Connection hold Box<dyn BidiStreamSource> so downstream
crates can add connection shapes without editing core. The trait and
three built-in impls landed, but the public constructor that lets a
downstream crate construct a Connection from its own BidiStreamSource
impl was never added — the source field is private with no from_source
constructor. The channels POC update surfaced this when it tried to
use the trait directly and found no way to build a Connection from a
ChannelBidiStreamSource.
This is a gap in the ADR-070 implementation, not a new decision. ADR-070
§Consequences says 'the channels crate implements ChannelBidiStreamSource
in its own crate and constructs Connection from it' — the constructor for
that path is what was missing.
- ADR-070: add from_source to the Constructors table + reword the
downstream-crates paragraph to make the two paths explicit
(from_source for custom impls; from_quinn/from_iroh/from_stream for
built-in impls)
- core-types.md: add from_source to the impl Connection block, the
built-in implementations table, and the design-decisions table entry
- tasks/core/connection-from-source-constructor.md: the implementation
task (one constructor + one test, scope narrow, risk low)
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