ADR-083 revised: TCP+TLS moves from an external sibling loop calling
public dispatch to a first-class owned transport via
with_tcp_tls(listener, acceptor), running inside run() alongside the
quinn and iroh accept loops. The endpoint owns all its accept loops;
shutdown() stops them all. The multi-owner shutdown problem (OQ-61)
does not arise — dissolved.
The reason TCP+TLS was structurally excluded (ADR-010 Am. 1: the
endpoint built transports internally, TCP+TLS couldn't fit) is gone
after ADR-083 — the endpoint no longer builds transports; it runs
accept loops on whatever it's given. TCP+TLS is a listener transport,
same shape as quinn and iroh. ADR-010 Amendment 2 supersedes Am. 1's
struct-level exclusion.
dispatch stays public — but for genuinely external shapes (SSH channels,
future WebTransport streams), which are connection-internal multiplexing,
not listener transports. The listener-vs-multiplexing distinction is now
explicit.
OQ-60 resolved: the TCP+TLS loop lives in alknet-core behind a tcp
feature (owned by the endpoint); builder functions are inlined by the
assembly layer. A alknet-transport crate was rejected — it would contain
only trivial builders; the real component (the loop) is in core. Hub-
specific composition lives in the hub crate; transport runtimes that any
node might need live in core.
Updated: ADR-010 (Amendment 2), ADR-082 (TCP+TLS loop location), ADR-083
(revised), core/endpoint.md (struct + dispatch + shutdown), hub/README.md
(transport table + assembly example + stale sibling references),
tls/README.md (endpoint section + TCP+TLS loop location + references),
open-questions.md (OQ-60 resolved, OQ-61 dissolved).
Review: zero critical issues, five warnings fixed (stale hub README
prose, stale core endpoint.md struct/dispatch listings, stale ADR-082
TCP+TLS loop location, stale TLS README reference entry, hub front-matter
date).
The hub README predates channels (2026-07-09) and was built on the
call-protocol-directly-over-QUIC model: 'One QUIC connection per peer
carrying the call protocol,' CallClient::connect as the dial path,
QUIC as the only transport. The channels crate replaced that substrate
(ADR-071/079/080), and the hub's primary use case (worker provisioning
on docker/vast.ai/runpod) requires TCP+TLS for registration and QUIC
or TCP+TLS for the ongoing session — coexisting on one hub, not as
alternatives.
Rewrite:
- Multi-transport stated as decided: 'A hub MUST support TCP+TLS and
QUIC endpoints simultaneously.' TCP+TLS accept loop (ADR-010 Am. 1)
lives in the hub, shares the HandlerRegistry with the quinn endpoint.
- Channels substrate: the hub uses ChannelsAdapter/ChannelClient
(from_connection primary, connect_quic convenience — ADR-080),
not CallClient/CallAdapter directly. One channels connection per
peer; CallAdapter runs on channel 0 (ADR-072).
- Transport-agnostic dial/accept: dial_worker_connection takes a
Connection (one-way door); connect_quic_worker is a two-way-door
convenience. supervise_worker takes a dial closure, not a SocketAddr.
- Identity over transports: fingerprint path (QUIC+raw-key,
X.509 client cert) via resolve_from_fingerprint; bearer-token path
(TCP+TLS no client cert, WebTransport, WebSocket) via
resolve_from_token on the call first frame. Both resolve to the
same PeerEntry (ADR-030/034).
- Worker registration flow (6 steps): provision → token → download →
key gen → HTTP POST over TCP+TLS → channels connect. Step 4 is HTTP
on HttpAdapter; step 6 is channels over QUIC or TCP+TLS. The hub
creates a mixed-fingerprint PeerEntry (ADR-034 §3) at registration.
- OQ-58: worker registration flow — enrollment-token model,
endpoint shape, register_worker API. Open (decision-ready, not
blocked), one-way door, high priority.
- ADR-081: fix stale references to channels-hub/channels-worker
sub-crates (the ADR's Decision says they don't exist; the References
section said they did).
Review (architecture-reviewer): 3 critical (ADR-081 stale refs;
bearer-token extraction flow; assembly example QUIC-only +
unspecced into_connection), 7 warnings (registration 'or'→'both',
channel/control translation, OQ-52 interim, HubError variant naming,
RegistrationError definition, X.509-client-cert prose, adapter
ownership phrasing), 5 suggestions. All criticals and warnings #4/#7/#8
addressed; #5/#6/#9/#10 addressed; #11-15 noted as optional.
The channels concept (docs/research/alknet-channels/phase-0-findings.md)
was developed in a separate session and is research-phase, not
architecture. The hub spec was inadvertently built assuming a channel
model that doesn't exist yet.
Changes:
- Remove all channels references from hub README (subtitle, channel
model section, channel management bullet, channel proxying section,
'does NOT do' bullet, references)
- Remove OQ-55 (channel/open operation) — channels research has its
own question tracking (OQ-CH-01 through OQ-CH-07)
- Hub spec now describes what it actually provides: peer lifecycle,
aggregated operation env, service discovery. One QUIC connection
per peer carrying the call protocol. No channels, no future
multiplexing, no research references.
- Replace on_worker_connected() post-hoc call with WorkerConnectedCallback
that fires inside CallAdapter::handle(). handle() blocks until disconnect
— there is no 'after handle accepts' point for the assembly layer to
hook into. The callback carries both on_connected (from_call + attach_peer)
and on_disconnected (detach_peer + drop channels).
- Add CallAdapter::with_worker_connected_callback(callback) builder method.
- Consolidate duplicate WorkerConnectedCallback struct definitions.
- Fix channel role: 'channel proxying' → 'channel management'. The hub
tracks channels; it does not proxy streams. What the caller does with
the resulting channel is the assembly layer's business.
- Resolve OQ-54: callback is the committed design. Update OQ file and
open-questions.md table.
Replace the 'future strategies' section with the channel model:
- Channel 0 is the call protocol — the universal control plane. Handles
operation discovery (from_call), operation routing (invoke_peer),
service discovery, and channel negotiation (channel/open, channel/close,
channel/list).
- Channels 1..N carry any ALPN as data planes. Opened via channel/open on
the call protocol. Each channel is a bidirectional QUIC stream, wrapped
as Connection::from_bidi (ADR-065), and handed to the same
ProtocolHandler::handle() that handles dedicated connections. The
handler does not know it's on a multiplexed channel.
- Channel negotiation is symmetric — either side can open a channel.
Same pattern as from_call: bidirectional, symmetric, negotiated over
the call protocol.
- The hub's role for channels 1..N is transparent stream proxying. The
hub does not interpret the protocol; the client and worker speak the
ALPN directly.
- Hub struct gains channel tracking (PeerId → ChannelId → ChannelInfo).
HubError gains ChannelAlreadyOpen, ChannelNotFound, ChannelOpenFailed.
- New OQ-55: channel/open operation spec (deferred to call-protocol
implementation phase).
- Replace .unwrap() with .expect() in spec pseudocode; remove .unwrap()
from ADR-067 prose. Specs describe intent, not implementation details.
- Remove 'ownership reaping' from hub's 'does NOT do' list. Ownership
is an alknet-docker concern, not a hub concern. The other agent's
hedging leaked into the spec; removed.
- Restructure hub README: separate core peer lifecycle (protocol-agnostic)
from call-protocol strategy (first strategy). Add extension points
section for future tty/blobs/custom strategies. A QUIC connection can
multiplex multiple protocols over separate streams; the hub's core
manages the connection, each strategy manages its own protocol-specific
state. The call-protocol strategy handles the majority of real-world
use cases; the architecture keeps the door open for others.
Three ADRs addressing gaps surfaced by the first hub consumer (alkapi):
- ADR-067: Aggregated peer-env wiring — Dispatcher::with_aggregated_env hook
so compose_root_env reads a shared PeerCompositeEnv across all calls,
not a fresh per-call one. The hub-defining gap (alkapi OQ-08 / G.1).
- ADR-068: PeerCompositeEnv::peer_operations override — adds
list_operation_names() to OperationEnv, overrides on OverlayOperationEnv
and PeerCompositeEnv. Fixes services/list-peers returning empty operation
lists for non-local peers (alkapi G.6).
- ADR-069: from_call is a manual free function, not auto-wired — reverses
the aspirational OQ-27 resolution to match the implementation. Cleans
the 'v1 default' hedging language in ADR-017 and client-and-adapters.md
(alkapi G.4).
New crate spec: alknet-hub — reusable hub pattern (aggregated env,
connection lifecycle, worker supervision with backoff, service discovery).
Spec fixes: builder API drift (with_local/with_local_streaming separation),
ScopedOperationEnv → ScopedPeerEnv type name, OQ count 51→54.
Three new OQs: OQ-52 (wait_for_close), OQ-53 (backoff defaults),
OQ-54 (inbound hook placement).