The earlier specs claimed alknet-tty reuses alknet-call's
FrameFramedReader/FrameFramedWriter 'framing utility' (ADR-052 §6,
ADR-003 Am. 1). A pre-implementation sanity check found this was
unsound: FrameFramedReader::read_frame() is hardcoded to deserialize
EventEnvelope — the length-prefix read and the type-specific deserialize
are one entangled call, not a separable utility. alknet-tty's
negotiation payload is a NegotiateRequest, not an EventEnvelope, so the
claimed reuse did not exist in a usable form.
ADR-057: alknet-tty implements its own ~30-line length-prefixed
framing directly on tokio AsyncRead/AsyncWrite. The format coincides
with alknet-call's framing by convention (both are length-prefixed
JSON); the implementations are independent. alknet-tty depends on
alknet-core only — no alknet-call dependency. The ~30 lines of framing
is an idiom, not a domain abstraction worth a cross-crate dependency.
Updates:
- ADR-003 Amendment 2: clarifies alknet-tty does not depend on
alknet-call; the Am. 1 protocol-foundation exception remains for
alknet-http/agent/napi (actual type reuse), not alknet-tty.
- ADR-052 §6: framing is self-contained in alknet-tty; format coincides
by convention, not by code reuse.
- overview.md: dependency block drops alknet-call; new 'Why no
alknet-call dependency' subsection explains the unsound-reuse finding.
- tty-wire.md, tty-backend.md, tty README, crates/tty/README.md,
top-level README: ADR tables, Design Decisions tables, and dependency
edges updated to reflect alknet-core-only dependency.
- ADR-053, ADR-054: References updated to ADR-003 Am. 2 + ADR-057.
Grounded in the alknet-docker POC (seed codec) and the alknet-tty POC
(2026-07-05, validated the control channel, the local-PTY blocking→async
bridge, and the signal-delivery contract).
Four ADRs:
- ADR-052: wire format — alknet/tty ALPN, two-carriage (JSON negotiation
then raw chunks), fixed channel set 0-3, control as JSON, negotiation-
error framing disambiguation
- ADR-053: TtyBackend trait + TtyHandle — the backend inversion point;
exit_code as a Future; REQ-TTY-01 (backends need not be natively async)
- ADR-054: local backend as alknet-tty-local sibling crate behind a
feature re-export; PTY vs pipe per-session; runner pattern preserved
- ADR-055: exit code on a stream_type 3 control chunk; "exit chunk is
last" invariant; adapter owns the ordering
Five component specs (crates/tty/): README, overview, tty-wire, tty-
backend, tty-adapter, tty-local. The docker/SSH backends are future
crates (out of scope); the trait shape is committed so they can be
built against it.
Five OQs (OQ-43…47): two resolved (TtyControl Clone, stdin closure),
two deferred(scope) (terminal modes, runner API surface), one open
low-risk (flow control).
Zero critical issues from a general-subagent architecture review;
warnings addressed (inline rationale trimmed to ADR refs, TtyError and
StdinCmd defined, framing disambiguation documented, missing ADRs added
to index tables).
glm-5.2