The channels path no longer carries a second negotiation frame on the
channel's data stream (ADR-009). The open op's registry-validated
input IS the negotiation:
- producer: make_tty_open_handler parses the open op's input into a
NegotiateRequest and drives the new drive_session_pre_negotiated
(same three-pump driver as drive_session, minus the wire-frame
negotiation phase; validate/allocate factored into
validate_and_allocate, shared by both paths). Post-open failures
(unknown backend, allocate_failed, ownership denial) still go to the
client as a 0x00-prefixed negotiation error frame, so the consumer's
M1 disambiguation read applies unchanged. The tty:open scope gate is
enforced by the registry's AccessControl (not re-checked in the
handler).
- consumer: open_via_channels parses params locally (fail-fast before
a channel is allocated), opens the channel, and starts raw-chunk
mode directly (from_halves_raw — no negotiation write; the
0x00-error-frame peek retained).
- tty_open_spec's input schema is now the partial NegotiateRequest
shape (carriage/backend/cmd required; backend params stay free-form
— raw JSON Schema is permissive on unknown keys).
Prerequisites landed upstream: alkcall 0.4.0 enforces
OperationSpec.input_schema at dispatch (the registry check this design
leans on never existed before); alkcall 0.4.1 parks early-arrival
chunks for un-adopted channels instead of dropping them — the open
response / producer's-first-write race was silently losing the first
chunks (found by L3's test; the session never resolved).
L3: open_via_channels + from_bidi_stream_via now covered end-to-end
(5 session tests + pre-negotiated adapter test + shared-harness tests
in the new crate::testing module; the channels harness moved there so
session tests share it).
Verification: cargo test 93 lib (default), 116 lib + 19 integration
(--all-features); clippy -D warnings native + wasm clean; fmt clean;
doc 0 warnings; wasm check clean.
Update the remediation plan with a resolution section and per-finding
status. Nine findings resolved in commit 9944153; L1, L3, L6, N4, N6
remain open.
The previous BAST document modeled the JSON payloads (NegotiateRequest,
ControlMessage and its resize/signal/eof/exit variants, TerminalParams)
as BAST struct/union definitions with uint16/int32 fields. That was a
category error: BAST describes binary data layouts, and per the BAST
format spec itself, "a BAST document cannot validate a JSON payload."
The control and negotiation payloads on the wire are UTF-8 JSON text
serialized via serde_json, not struct-encoded binary — the uint16/int32
field widths implied a binary encoding that does not exist on the wire
and would have misled any generated validator.
The rewrite keeps only the genuinely-binary framing layer:
- ChunkHeader (5-byte: stream_type u8 + length u32 BE)
- StreamType enum (name->index table; documented deviation: on-wire
is uint8, not BAST's standard u32 enum index)
- Chunk (header + length-prefixed bytes payload)
- NegotiationFrame (4-byte BE length prefix + UTF-8 JSON body,
modeled as bytes since the body's JSON interpretation is above the
BAST layer)
The JSON shapes (NegotiateRequest, ControlMessage, TerminalParams)
remain specified in tty-wire.md and implemented by the Rust source
(src/negotiation.rs, src/control.rs), which are the source of truth
for those payloads. Cross-references in tty-wire.md, overview.md, and
README.md updated to reflect the simplified scope.
The drift-detection test (project plan "Risk: BAST schema drift")
still works unchanged — it asserts the StreamType enum values match
wire.rs's STREAM_* constants, and that enum is retained.
Docs-only change; no Rust source changes.
Verification:
- cargo test --all-features -> 122 tests pass (unchanged)
- cargo clippy --all-targets --all-features -- -D warnings -> clean
- cargo fmt --check -> clean
- cargo doc --no-deps -> no new warnings (9 pre-existing rustdoc link
warnings in src/, unchanged)
- BAST JSON block parses as valid JSON (4 : ChunkHeader,
StreamType, Chunk, NegotiationFrame)
Port the alknet-tty architecture docs into alktty and add the BAST
document for the alk/tty wire format. Docs-only; no Rust source
changes.
Spec docs (docs/architecture/, flat layout — single-crate repo):
- overview.md — crate purpose, two-carriage model, deps, ALPN,
backend location map, feature gates
- tty-wire.md — 5-byte chunk codec, control channel split
(STREAM_CTRL_IN=3 / STREAM_CTRL_OUT=4), sentinels
- tty-backend.md — TtyBackend trait, TtyHandle, TtyControl,
REQ-TTY-01 (backends need not be natively async)
- tty-adapter.md — TtyAdapter, three-pump driver, exit-chunk
ordering (ADR-004), cancel cleanup (ADR-005), access control
- tty-local.md — LocalTtyBackend (local feature module), PTY +
pipe modes, REQ-TTY-02 (signal forwarding to process group)
- README.md — architecture index
ADRs (docs/architecture/decisions/, renumbered 001..008 from
alknet 052,053,054,055,056,057,077,093 in order):
- 001 wire format + two-carriage model (incl. Phase 7 control-
channel split amendment)
- 002 TtyBackend trait + TtyHandle
- 003 local backend placement (records both the alknet sibling-
crate decision and the alktty single-crate consolidation behind
a local feature)
- 004 exit code on a control chunk
- 005 backend cleanup on session cancel
- 006 self-contained negotiation framing
- 007 tty inside channels (reversed by 008; kept for historical
context with reversal notice)
- 008 channels pure channel multiplexing (reverses 007; TTY
always uses its 5-byte format)
BAST document (docs/architecture/tty-bast.md):
- Normative JSON spec for the alk/tty wire format, conforming to
the BAST meta-schema at https://alk.dev/bast/v1/schema
- 5-byte chunk header (struct, big-endian: stream_type uint8,
length uint32) + StreamType enum (Stdin=0..CtrlOut=4)
- ControlMessage union (field-name discriminator on type:
resize/signal/eof/exit) with documented deviation that on-wire
control payloads are UTF-8 JSON, not BAST's binary union
encoding
- NegotiationFrame (4-byte BE length + UTF-8 JSON body) +
NegotiateRequest / TerminalParams JSON shapes
- StreamType enum deviation noted: on-wire uint8, not BAST's
standard u32 enum index (chunk header is 5 bytes, not 8)
- alktty does not depend on alktype; the hand-rolled wire.rs is
the runtime codec, the BAST is the human-readable contract
AGENTS.md: fixed the ADR mapping table to match the plan's 8-to-8
mapping (the previous table substituted ADR-050 for 054, relabeled
056 as control-message split, dropped 077, and added a new
control-split ADR at 006 — inconsistent with both the plan and the
prose). ADR-050 (dynamic resource ownership) is an alkcall/alknet-
core ADR, not tty-specific, and is not ported; the Phase 7 control
split stays as an amendment inside ADR-001, mirroring alknet.
Verification (all pass, no Rust source changed):
- cargo test (80 passed)
- cargo test --all-features (103 passed)
- cargo clippy --all-targets -- -D warnings (clean)
- cargo fmt --check (clean)
- cargo check --target wasm32-unknown-unknown (clean)
- cargo clippy --target wasm32-unknown-unknown -- -D warnings
(clean)
- cargo doc --no-deps: 9 pre-existing intra-doc-link warnings in
src/session.rs and src/channels.rs (untouched by this commit;
not introduced here)
- BAST JSON parses; StreamType indices match wire.rs constants
(0=Stdin..4=CtrlOut)
- all markdown cross-reference links resolve
The default crate (no features) must compile to wasm32-unknown-unknown
so the downstream TS/Python adapter story works — a wasm-compiled
alktty is the protocol layer for a sandboxed adapter. The local feature
is inherently non-wasm (portable-pty + tokio::process need a real OS)
and enabling it on wasm is a build error by design.
Cargo.toml:
- tokio: drop features = ["full"], use the wasm-clean subset alkcall
uses (rt, sync, io-util, macros) with default-features = false
- local feature adds tokio/process + tokio/rt-multi-thread
- document the wasm constraint in the [features] comment
Plan:
- Decision 1: add WASM target subsection recording the constraint
- Phase 0: mark the tokio feature split as done
- Risks: add WASM-target-regression risk with a cargo-check CI mitigation
Reflect what actually landed since the 2026-08-14 draft:
- alkcall 0.1.1: alk/tty + alk/channels ALPN rename (no public API change)
- alkcall Identity.resources now HashMap<String, Vec<String>>
- alkcall OwnershipProvider::owns gained action arg; OwnershipStore::record lost it
- alktype 0.2.0: kind-based BAST format (schema doc artifact, not a runtime dep)
Fold alknet-tty-local into the single crate as the feature-gated local
module (pty.rs + pipe.rs + backend.rs) — the cyclic-dep workaround it
required in the alknet mono-repo doesn't apply to a single crate.
Add Decision 7 (BAST schema as documentation artifact), Phase 0
(scaffold hygiene), Phase 4 BAST-schema step, OQ-6, and a BAST-drift
risk with a cheap test mitigation.
Cargo.toml: bump alkcall 0.1.0 -> 0.1.1; add futures = 0.3 as a direct
dep so the BoxFuture alias doesn't ride on a transitive.
glm-5.3-flash
deepseek-v4-pro
glm-5.2