ADR-085 records the actual workspace scope: the mono-repo is the core networking toolkit (substrate: core, tls, call, channels; deployment shapes: hub, worker; foundational handlers: tty, http, ssh, tunnel, socks5, fs, sftp; vault). Consumer repos (docker, agent) are separate repos depending on the published core crates. The overview's crate graph had been describing the wrong scope since ADR-003 — a flat ~12-crate workspace including DNS/messaging/NAPI while omitting channels, hub, worker, and tls. This stale scope was a causal factor in the 'assembly layer' hedging pattern: when the overview implies everything lives in one repo but the architecture needs a hub/worker composition layer not in the graph, the gap gets filled with 'assembly layer' as an escape hatch. The overview is rewritten to match the real boundary. TLS spec review fixes (from architecture review): - C3: hub/worker/hub-worker terminology pointers (tls README + endpoint.md) - W1: server-only statement + OQ-64 (client-side TLS helper, deferred) - W2: ACME task lifecycle semantics (returns immediately, no first-cert await) - W3: remove stale EndpointError::TlsConfig variant - W4: update stale ALPN section for two-config hub - W5: add alknet-tls to hub dep graph (assembly-layer dep) - W6: trim inline rationale -> point to ADR-084 - W7: ADR-084 status dependency note New open questions: - OQ-62: ALPN list sharing for two-config hub (open, high) - OQ-63: TlsError shape (open, high) - OQ-64: client-side TLS helper (deferred, blocked on OQ-55)
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OQ-62: Does a Hub Pass the Same ALPN List to Both TlsServerConfigs?
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Origin:
docs/architecture/crates/tls/README.md(the "WhatAlknetEndpointdoes after the refactor" section describes a hub holding twoTlsServerConfigs — raw key + X.509/ACME — but does not state whether each receives the same ALPN list or different lists);docs/architecture/crates/core/endpoint.md(the ALPN section previously stated "both connection sources advertise the same set of ALPNs," which is stale under the two-config hub model). -
Status: open
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Door type: one-way (the ALPN list each
TlsServerConfigadvertises is baked into therustls::ServerConfigat construction; changing it after the hub is deployed is a config+restart, but the pattern — same-list vs split-list — sets the assembly-layer wiring shape that downstream consumers copy) -
Priority: high (the hub is the first two-config consumer; its wiring sets the pattern, and an implementer cannot write the hub's assembly code without this decided)
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Resolution: Not yet decided. The two plausible options:
Option A — same list (union) to both configs. Both
TlsServerConfigs receiveregistry.alpn_strings()verbatim. The raw-key QUIC listener advertisesh2/http/1.1(browsers can't connect to a raw-key listener anyway, so the advertisement is harmless dead negotiation). The X.509 TCP+TLS listener advertisesalknet/call(a native client connecting over TCP+TLS with an X.509 client cert can use it). Simplest wiring; no split logic; every transport can serve every ALPN.Option B — split list, transport-appropriate. The raw-key config gets the native ALPNs (
alknet/call,alknet/channels,alknet/tty); the X.509/ACME config gets the union includingh2/http/1.1(browser ALPNs that only make sense over TCP+TLS with a domain cert). The assembly layer filtersregistry.alpn_strings()by which transports can serve each ALPN. More logic; cleaner advertisement (no browser ALPNs on a raw-key listener).The question is whether the "harmless dead negotiation" in Option A is acceptable or whether the cleaner advertisement in Option B is worth the split logic. This needs a decision before the hub's assembly code is written — it is not guessable from the existing specs, and guessing produces a wiring shape that downstream consumers copy.
Note: this is distinct from the iroh path. Iroh takes its ALPN list from
iroh::Endpoint::builder().alpns()at construction, set by the assembly layer fromregistry.alpn_strings(). Iroh uses raw keys only, so it gets the native ALPN set regardless of which option is chosen for the quinn/TCP+TLS pair. -
Cross-references: ADR-082 (
TlsServerConfig::newtakesalpns: &[Vec<u8>]— the caller decides), ADR-083 (the assembly layer builds transports; ALPN-list construction is its job), OQ-64 (client-side TLS helper — related but orthogonal; this OQ is server-side advertisement)