feat: alkcall 0.8.0 adoption — bump to 0.5.0

- BREAKING (ecosystem-coordination): alkcall bumped to 0.8.0. No type
  alktty touches changed shape (ChannelCore/openable machinery,
  OpenEstablisher/OpenHandler/Establishment/ChannelPlan,
  ChannelClient::open_channel, ChannelOpenError::CallFailed are
  identical to 0.7.1); the new reply-projection / relay / hub-leg
  surfaces are additive and alktty exercises none of them. alktty's own
  open op is the standard-shape name channels/tty/sub, so the new
  flavor-form discovery path stays on the byte-stable standard
  derivation, and with no establisher reply-fields configured the open
  reply is byte-identical to pre-0.8.0. The minor bump is for
  downstream lockstep, since alktty's public signatures reference
  alkcall types.
- Verification counts unchanged from the 0.7.1 baseline (113 default /
  156 all-features); the adoption required no source change in alktty.

Verification:
- cargo test: 113 passed (default), 156 passed (--all-features)
- cargo clippy --all-targets -- -D warnings: clean
- cargo fmt --check: clean
- cargo doc --no-deps: clean
- cargo check/clippy --target wasm32-unknown-unknown -D warnings: clean
- cargo publish --dry-run --allow-dirty: clean

AGENTS.md

@@ -199,8 +199,9 @@ implementation agents.
     registry runs the ACL before the wrapper) and runs the ownership
     check in the establisher (ADR-010 — it is part of the
     establishment phase since alkcall 0.5.0 ADR-049, so a denial is
-    `channel:open_failed`, not an in-band frame; the pump handler
-    only allocates and pumps). Terminal sessions are resources per
+    `channel:open_failed`, not an in-band frame; since alkcall 0.6.0
+    ADR-010 §2A the establisher also allocates — the pump handler
+    only pumps). Terminal sessions are resources per
     ADR-050 (ported as alktty ADR-003); `OwnershipStore::record(&self,
     identity, resource_type, resource_id)` is the 3-arg shape (alkcall
     dropped the old `action` arg).
@@ -314,6 +315,8 @@ wasm-clean" invariant — run it whenever a non-`local` module changes.
   `StreamError`) come from `alkcall::core`. alkcall is v0.4.x —
   breaking changes are expected at this major-zero stage; this is the
   first real consumer, so we find and fix issues upstream rather than
-  working around them. Pin `alkcall = "0.5.0"` (the
-  channel-open establishment phase — ADR-049, review 006 E-01/N-1;
-  adopted by alktty ADR-010) and bump deliberately.
+  working around them. Pin `alkcall = "0.6.0"` (the
+  establishment-plan payload — ADR-049 amendment 2, review 007 R-01;
+  adopted by alktty ADR-010 §2A — allocation runs in the channels
+  establisher, the `TtyHandle` crosses via the plan) and bump
+  deliberately.

CHANGELOG.md

@@ -4,6 +4,128 @@ All notable changes to this crate are documented here. The format is
 based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and
 this crate adheres to [Semantic Versioning](https://semver.org/).
 
+## [0.5.0] - 2026-09-18
+
+The alkcall 0.8.0 adoption: a dependency bump only — no source change
+in alktty. alkcall 0.8.0 landed review 008's remediation (the
+establisher reply projection, flavor-form open-op ids in discovery, the
+in-tree `ChannelRelay` + `HubLegImports`/`HubLegTemplate`) plus a
+post-landing hardening sweep; all new surfaces are additive on the
+call-plane JSON and the registry seams, and the channels data plane is
+untouched. The wire format, the direct-ALPN path, the `TtyBackend`
+trait, and alktty's public API surface are unchanged.
+
+### Changed
+
+- **BREAKING (ecosystem-coordination) — `alkcall` bumped to 0.8.0.**
+  alkcall 0.8.0 changed no type that alktty touches: the open-op
+  machinery alktty registers through (`ChannelCore`/
+  `register_openable_with_establisher`/`OpenEstablisher`/`OpenHandler`
+  /`Establishment`/`ChannelPlan`, `ChannelClient::open_channel`,
+  `ChannelOpenError::CallFailed`) is shape-identical to 0.7.1 — the
+  new `open_channel_with_reply` / reply-field / relay / hub-leg
+  surfaces are additive and alktty exercises none of them. alktty's
+  own open op is the standard-shape name `channels/tty/sub`, so the
+  new flavor-form `channel_open_alpn` discovery path stays on the
+  byte-stable standard derivation, and with no establisher
+  reply-fields configured the open reply is byte-identical to
+  pre-0.8.0. alktty's public signatures reference alkcall types, so
+  downstream crates must now unify on alkcall 0.8.0. Minor bump per
+  the 0.x ecosystem-coordination rule.
+- **`alkcall` requirement updated to `0.8.0`; lockfile bumped from
+  0.7.1 to 0.8.0.** Verification counts are unchanged from the 0.7.1
+  baseline (113 default / 156 all-features) — the adoption required no
+  source change in alktty.
+
+## [0.4.1] - 2026-09-10
+
+The MSRV floor becomes honest: `rust-version` raises from 1.85 to
+1.88. The 1.85 claim was already false at the dependency level — the
+lockfile pins `alkcall 0.7.x`, and alkcall 0.7.1 raised its MSRV floor
+to 1.88 (the ecosystem MSRV audit: noq's 1.88 matching the QUIC path;
+iroh sits above at 1.91), so no 1.85 toolchain could build 0.4.0
+regardless of what Cargo.toml declares. The raise breaks no downstream
+that could build the crate before. No API or wire-format change;
+downstreams on caret requirements pick this up on their next `cargo
+update`.
+
+### Changed
+
+- **`rust-version` 1.85 → 1.88.** Verified on a real 1.88 toolchain
+  (full test suite, clippy). alktty's own code is 1.85-clean —
+  `cargo check` under a 1.85 toolchain passes with the pre-bump
+  lockfile — so the raise is dependency-driven only and needed no
+  clippy fixes. Behavior-identical.
+- **`alkcall` requirement updated to `0.7.1`; lockfile bumped from
+  0.7.0 to 0.7.1.** Version-requirement-only (0.7.x is already the
+  resolved family); alkcall 0.7.1 changed no type alktty touches.
+
+## [0.4.0] - 2026-09-07
+
+The alkcall 0.7.0 adoption (the connect-side caller-identity seam,
+CF-005/006/007): a dependency bump plus one behavior-alignment change
+on the channels path. The wire format, the direct-ALPN path, the
+`TtyBackend` trait, and the public API surface are unchanged.
+
+### Changed
+
+- **BREAKING (ecosystem-coordination) — `alkcall` bumped to 0.7.0.**
+  alkcall 0.7.0 changed no type that alktty touches
+  (`OpenEstablisher`/`OpenHandler`/`Establishment`/`ChannelPlan` are
+  identical to 0.6.0; alktty never constructs `ServingConfig`), but
+  alktty's public signatures reference alkcall types, so downstream
+  crates must now unify on alkcall 0.7.0. Minor bump per the 0.x
+  ecosystem-coordination rule.
+- **The channels establisher and pump handler take their identity
+  from the per-call `auth` (CF-006 alignment).** `register_openable`
+  no longer captures the install-time identity and overrides the
+  establisher/handler `auth.identity` with it — post-alkcall-0.7 the
+  per-call context already carries the dispatch-resolved opener (the
+  same identity view the registry's ACL gate checked; the end client,
+  not the hub, on hub-forwarded opens). Behavior-identical in the
+  per-connection-registry deployment (install-time identity was the
+  caller's); the ownership check and the ACL gate now see the same
+  subject in every deployment. Two factory parameters dropped
+  (`make_tty_establisher`/`make_tty_open_handler` are private; no
+  public-surface change).
+
+## [0.3.0] - 2026-09-07
+
+The alkcall 0.6.0 adoption (review 007 R-01 — the `Establishment`
+plan payload): backend allocation moves into the channels establisher.
+Breaking on the channels path's allocation-failure shape; the wire
+format, the direct-ALPN path, and the `TtyBackend` trait are
+unchanged.
+
+### Changed
+
+- **BREAKING — `alkcall` bumped to 0.6.0; channels-path allocation
+  failure changes shape (ADR-010 §2A).** alkcall 0.6.0 filled the
+  reserved `Establishment` field (`plan: Option<ChannelPlan>`,
+  review 007 R-01), so `backend.allocate` moved from the pump handler
+  into the establisher — the allocated `TtyHandle` crosses to the
+  handler via the plan payload (a private per-open one-shot slot; the
+  handle is not `Sync`). Allocation failure now fails the open op
+  itself: `TtySessionError::ChannelsOpen(CallFailed{
+  channel:open_failed, reason: "dial_failed" })` instead of the
+  post-open in-band `NegotiationRejected{ "allocate_failed" }`. The
+  SSH contract now covers every failure class: no channel ever exists
+  opener-side, no `channel_id`, no `0x00`-prefixed in-band frame. The
+  direct-ALPN path's in-band vocabulary (including `allocate_failed`)
+  is unchanged.
+- `tty_open_spec()`'s `channel:open_failed` `ErrorDefinition` declares
+  `dial_failed` in the `details.reason` enum (four reachable reasons:
+  `dial_failed` / `unknown_resource` / `handler_error` / `timeout`).
+- Handler closures in `make_tty_open_handler` gain the
+  `Option<ChannelPlan>` parameter (alkcall 0.6 `OpenHandler` shape);
+  a `None` plan (no-establisher registration) falls back to the
+  pre-0.3.0 inline validate-and-allocate — defense-in-depth, keeping
+  the in-band error-frame vocabulary for that registration shape.
+- New tests: establisher unit gate for allocate-in-establisher (plan
+  slot carries the live handle; failure maps to `dial_failed`), the
+  end-to-end `dial_failed` open-failure surface (flipped from the
+  pinned in-band test), and the handler's `plan: None` fallback arm.
+
 ## [0.2.0] - 2026-09-06
 
 The alkcall 0.5.0 adoption (ADR-049 — review 006 E-01/N-1): the
@@ -199,4 +321,9 @@ alknet mono-repo.
   the client→backend pump is aborted at session end instead of
   lingering until the client disconnects.
 
+[0.5.0]: https://git.alk.dev/alkdev/alktty/releases/tag/v0.5.0
+[0.4.1]: https://git.alk.dev/alkdev/alktty/releases/tag/v0.4.1
+[0.4.0]: https://git.alk.dev/alkdev/alktty/releases/tag/v0.4.0
+[0.3.0]: https://git.alk.dev/alkdev/alktty/releases/tag/v0.3.0
+[0.2.0]: https://git.alk.dev/alkdev/alktty/releases/tag/v0.2.0
 [0.1.0]: https://git.alk.dev/alkdev/alktty/releases/tag/v0.1.0

Cargo.lock

@@ -27,9 +27,9 @@ dependencies = [
 
 [[package]]
 name = "alkcall"
-version = "0.5.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0bbaeb718c370b74f9136d1d59b4608249bd7d1dd2332c0259f98351d709737f"
+checksum = "8695d47cee5b5a5fe68471f04a505bc257a7e7ed9e64d827de33ff83adf4db12"
 dependencies = [
  "async-trait",
  "bytes",
@@ -48,7 +48,7 @@ dependencies = [
 
 [[package]]
 name = "alktty"
-version = "0.2.0"
+version = "0.5.0"
 dependencies = [
  "alkcall",
  "async-trait",

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "alktty"
-version = "0.2.0"
+version = "0.5.0"
 edition = "2021"
-rust-version = "1.85"
+rust-version = "1.88"
 license = "MIT OR Apache-2.0"
 description = "Terminal session protocol: wire format, TtyBackend trait, TtyAdapter, and typed consumer client. Producer/consumer protocol crate on top of alkcall channels."
 repository = "https://git.alk.dev/alkdev/alktty"
@@ -25,7 +25,7 @@ default = []
 local = ["dep:portable-pty", "dep:tokio-util", "tokio/process", "tokio/rt-multi-thread"]
 
 [dependencies]
-alkcall = "0.5.0"
+alkcall = "0.8.0"
 # Minimal, wasm-clean tokio features. `local` adds `process` +
 # `rt-multi-thread` (non-wasm). Do NOT use `features = ["full"]` — it
 # pulls in `signal`/`fs`/`net` which break `wasm32-unknown-unknown`.

docs/architecture/README.md

@@ -37,7 +37,7 @@ tty-specific and therefore not ported into alktty's ADR range).
 | [007](decisions/007-tty-inside-channels.md) | TTY Inside Channels — Sub-Streams, Not Wire Format | alknet ADR-077 | Accepted (**reversed by ADR-008** — kept for historical context) |
 | [008](decisions/008-channels-pure-channel-multiplexing.md) | Channels Pure Channel Multiplexing (8-Byte Header, No `stream_type`) | alknet ADR-093 | Accepted (amends alknet ADR-071/074; reverses ADR-007) |
 | [009](decisions/009-channels-open-op-is-the-negotiation.md) | The Channels Open Op's `input` Is the Negotiation | alktty-native | Accepted (resolves review #001 L1; amended by review #002 R4 — parse failure is a client-visible error frame; amended by ADR-010 — semantic failures move into the establisher) |
-| [010](decisions/010-channels-establisher-migration.md) | Channels-Path Establishment Failures Move into an Establisher | alktty-native | Accepted (adopts alkcall 0.5.0 ADR-049; amends ADR-009's R4 amendment — in-band frames shrink to `allocate_failed`) |
+| [010](decisions/010-channels-establisher-migration.md) | Channels-Path Establishment Failures Move into an Establisher | alktty-native | Accepted (adopts alkcall 0.5.0 ADR-049; amends ADR-009's R4 amendment; amended 2026-09-07 §2A for alkcall 0.6's plan payload — allocation moves into the establisher, no in-band frame from a registered producer) |
 
 ## Key Design Principles
 

docs/architecture/decisions/009-channels-open-op-is-the-negotiation.md

@@ -21,6 +21,13 @@ cannot carry the allocated handle across — see ADR-010 §2). The R4
 tests that asserted the in-band frames for those classes now assert
 the call-error shape.
 
+Amended 2026-09-07 (ADR-010 §2A, alkcall 0.6.0 — review 007 R-01):
+`Establishment` gained its plan payload, so `allocate` also moved
+into the establisher — the in-band error-frame path on this channel
+shrinks to nothing from a registered producer (the frames remain the
+defense-in-depth fallback for no-establisher registrations and the
+direct path). See ADR-010 §2A.
+
 ## Context
 
 Before this ADR, the channels path carried the negotiation twice. The

docs/architecture/decisions/010-channels-establisher-migration.md

@@ -10,6 +10,19 @@ error frame is retained — two transports, two contracts").
 Prerequisites: alkcall 0.5.0 (`ChannelCore::register_openable_with_establisher`,
 `channel:open_failed`, typed `ChannelOpenError`).
 
+**Amended (2026-09-07, alkcall 0.6.0 / ADR-049 amendment 2 — review
+007 R-01):** `Establishment` gained its plan payload
+(`ChannelPlan = Arc<dyn Any + Send + Sync>`), removing §2's
+payloadless-`Establishment` blocker. Backend `allocate` moves into
+the establisher; the allocated `TtyHandle` crosses to the pump
+handler via the plan; `allocate_failed` joins the call-error surface
+as `details.reason == "dial_failed"` (the target refused or the
+backend lacked capacity). No failure class arrives in-band on the
+channels path from a registered producer; the in-band error-frame
+fallback stays for no-establisher registrations (defense-in-depth)
+and the direct-ALPN path. See §2A below; §2 is retained as
+historical record.
+
 Amends ADR-009's R4 amendment: the in-band error-frame path on the
 channels path shrinks to one failure class (`allocate_failed`).
 
@@ -68,18 +81,26 @@ the vocabulary is alkcall's one-way wire surface):
 | `carriage != "raw"`, empty `cmd` | `HandlerError` | `handler_error` |
 | unknown backend | `UnknownResource` | `unknown_resource` |
 | ownership denial | `HandlerError` | `handler_error` |
+| **allocation failure** (amended — §2A) | `DialFailed` | `dial_failed` |
 | establishment deadline | (wrapper) | `timeout` |
 
-`dial_failed` and `resource_shortage` have no TTY producer path (TTY
-dials nothing at open time; `allocate` capacity failures are the
-in-band class below) — the spec's `ErrorDefinition` for
-`channel:open_failed` declares only the three reachable reasons.
-`HandlerError` covers both the malformed-negotiation semantics (the
-request shape is wrong) and the ACL-outcome ownership denial (an
-authorization failure, not a dial failure).
+`resource_shortage` has no TTY producer path (allocation-capacity
+failures map to `dial_failed` — the target refused or the backend
+lacked capacity; §2A). `HandlerError` covers both the
+malformed-negotiation semantics (the request shape is wrong) and the
+ACL-outcome ownership denial (an authorization failure, not a dial
+failure).
 
 ### 2. Backend allocation stays in the pump handler — `allocate_failed` stays in-band
 
+> **Amended away (2026-09-07) — see §2A.** This section is the
+> historical record of the pre-0.3.0 shape; its blocker 1
+> (payloadless `Establishment`) was resolved by alkcall 0.6.0 (ADR-049
+> amendment 2, review 007 R-01). Blocker 2 (double-`allocate`
+> unsoundness) is avoided by construction in the amended shape: the
+> establisher's handle *is* the handle the handler pumps — there is no
+> second allocate to be unsound about.
+
 The one failure class that cannot migrate: `backend.allocate`. Two
 reasons, both structural:
 
@@ -114,6 +135,60 @@ no-establisher registration still compiles against alkcall's API and
 must not silently EOF), and the R4 seam test pins the handler-side
 frame.
 
+### 2A. Amendment (alkcall 0.6.0): allocation moves into the establisher
+
+alkcall 0.6.0 (ADR-049 amendment 2, review 007 R-01) filled the
+reserved field: `Establishment { plan: Option<ChannelPlan> }` with
+`ChannelPlan = Arc<dyn Any + Send + Sync>` — typed-opaque, wrapper
+threaded to the `OpenHandler`'s new second parameter. §2's blocker 1
+is gone; the double-`allocate` hazard (blocker 2) is structurally
+absent — one allocate per open, whose result the handler consumes.
+
+The amended shape:
+
+1. **The establisher allocates.** After the validation sequence (§1),
+   it runs `backend.allocate(&params)`. Failure maps to
+   `EstablishmentError::DialFailed` (`details.reason == "dial_failed"`
+   — the target refused or the backend lacked capacity; one string
+   message, no nuance — the same granularity the direct path's
+   `allocate_failed` frame always had). The
+   `channel:open_failed` `ErrorDefinition` on `tty_open_spec()`
+   therefore declares four reachable reasons (`dial_failed`,
+   `unknown_resource`, `handler_error`, `timeout`).
+2. **The handle crosses via the plan.** `TtyHandle` is not `Sync`
+   (boxed dyn streams), so it cannot be the `ChannelPlan` directly.
+   The establisher wraps it in a private `AllocatedHandle` one-shot
+   slot (`Mutex<Option<TtyHandle>>`), created **per establisher
+   invocation** — per open. The wrapper moves this open's plan to this
+   open's handler (alkcall's concurrent-same-resource test pins that
+   plans are never shared), the handler `take()`s it exactly once, and
+   establisher-before-handler ordering is alkcall's wrapper guarantee
+   (ADR-049 §1). The shared-slot race §2 described is unreachable by
+   construction: there is no shared slot.
+3. **The handler pumps the pre-allocated handle.** With a plan it
+   calls `drive_session_pre_allocated` (new `pub(crate)` driver: the
+   pumps directly, no validation pass). With `plan: None` — a
+   no-establisher registration — it falls back to
+   `drive_session_pre_negotiated`, whose inline validate-and-allocate
+   keeps the full in-band error-frame vocabulary. That fallback is
+   defense-in-depth for the assembly-layer freedom to register without
+   an establisher, not a registered-producer path.
+4. **Consumer surface.** `TtySession::open_via_channels` sees
+   allocation failure as
+   `ChannelsOpen(CallFailed{ channel:open_failed, reason:
+   dial_failed })` — a typed call error, branchable and retryable
+   like every other establishment class. The `0x00` peek on the
+   channel stream becomes a formality that no registered producer
+   ever exercises; the pinned test flipped with the contract
+   (`allocate_failure_fails_open_as_dial_failed` in `testing.rs`,
+   plus the establisher unit gate `establisher_allocates_and_maps_
+   failure_to_dial_failed` in `channels.rs`).
+
+The R-02 lifetime contract (the handler's `JoinHandle` tracks the
+data-plane lifetime) was already alktty's shape — the open handler
+awaits the driver inline in its spawned task — so the amendment adds
+no lifetime changes.
+
 ### 3. The direct-ALPN path is unchanged
 
 `TtyAdapter::handle` / `drive_session` keep the wire-frame
@@ -149,10 +224,10 @@ unchanged (`true` direct, `false` channels — the registry's
 | malformed negotiation (schema-valid) | establisher | `ChannelsOpen(CallFailed{ channel:open_failed, reason: handler_error })` |
 | unknown backend | establisher | `ChannelsOpen(CallFailed{ channel:open_failed, reason: unknown_resource })` |
 | ownership denial | establisher | `ChannelsOpen(CallFailed{ channel:open_failed, reason: handler_error })` |
+| **allocation failure** (amended — §2A) | establisher | **`ChannelsOpen(CallFailed{ channel:open_failed, reason: dial_failed })`** |
 | establishment timeout | wrapper bound | `ChannelsOpen(CallFailed{ channel:open_failed, reason: timeout })` |
 | ACL denial (scope) | registry gate | `ChannelsOpen(CallFailed{ FORBIDDEN })` |
 | channel cap | wrapper `check_open` | `ChannelsOpen(CallFailed{ channel:too_many_channels })` |
-| **allocate failure** | pump handler, post-open | **`NegotiationRejected{ "allocate_failed" }`** |
 
 `TtySessionError::ChannelsOpen` now carries alkcall's typed
 `ChannelOpenError` verbatim (`#[from]`) instead of a flattened
@@ -167,10 +242,12 @@ on `establishment_reason()` without unwrapping strings.
   open no longer allocates → succeeds → in-band-fails. Ledger, policy
   count, and manager state balance on every rejection.
 - Retry policy / UX can branch: `unknown_resource` (bad config — don't
-  retry), `timeout` (maybe retry), `allocate_failed` (capacity —
-  still distinguishable in-band).
+  retry), `timeout` (maybe retry), `dial_failed` (capacity/target
+  refused — maybe retry; amended §2A, was the in-band
+  `allocate_failed`).
 - The consumer's `open_via_channels` failure is a typed call error —
-  no peeking at the data stream for anything but `allocate_failed`.
+  no peeking at the data stream for anything but the (now
+  unreachable-from-registered-producers) error-frame formality.
 
 **Negative:**
 
@@ -180,9 +257,11 @@ on `establishment_reason()` without unwrapping strings.
   direct path's failure surface is unchanged.
 - The `channel:open_failed` reason codes the establisher emits join
   the wire-stable error set (ADR-049's one-way door).
-- `allocate_failed` remains a second, in-band failure shape on the
-  channels path — one residual asymmetry, pinned and documented until
-  `Establishment` gains a payload.
+- **Amendment (0.3.0):** allocation failure changed shape again —
+  `NegotiationRejected{ "allocate_failed" }` (in-band) →
+  `ChannelsOpen(CallFailed{ channel:open_failed, reason:
+  dial_failed })`. The direct path's `allocate_failed` frame is
+  unchanged (two transports, two contracts).
 
 ## Door type
 
@@ -205,12 +284,16 @@ ADR moves failure *reporting*, not the negotiation *location*.
 - ADR-009 (the open op's `input` is the negotiation; the R4
   amendment's in-band error frames — shrunk to `allocate_failed` by
   this ADR)
-- ADR-005 (kill-on-`Drop` — why establisher-side allocation is
-  unsound)
+- ADR-005 (kill-on-`Drop` — why a *second* establisher-side allocate
+  would be unsound; avoided by construction in the §2A amendment —
+  one allocate per open, consumed by the handler)
 - ADR-001 (the §5 `0x00` disambiguation — retained for the direct
-  path and the channels `allocate_failed` frame)
+  path; the channels-path peek is now a formality)
 - ADR-002 (backend selection/allocation ownership)
-- `src/channels.rs` — `make_tty_establisher`, `make_tty_open_handler`,
-  `tty_open_spec`
+- alkcall ADR-049 amendment 2 / review 007 R-01 (the `Establishment`
+  plan payload — the upstream capability this ADR's §2A adopts)
+- `src/channels.rs` — `make_tty_establisher`, `AllocatedHandle`,
+  `make_tty_open_handler`, `tty_open_spec`
 - `src/session.rs` — `TtySessionError::ChannelsOpen`, `open_via_channels`
-- `src/testing.rs` — the pinned `allocate_failed`-stays-in-band test
+- `src/testing.rs` — the pinned `allocate_failure_fails_open_as_dial_failed`
+  test (superseded `allocate_failure_still_arrives_in_band_on_channels_path`)

docs/architecture/tty-adapter.md

@@ -177,17 +177,18 @@ entering raw mode. The error response shape:
 On the **direct-ALPN path** this is the failure surface for every
 negotiation/allocation failure class (below). On the **channels path**
 the semantic classes (unknown backend, malformed negotiation,
-ownership denial) are rejected by the establisher before the open
-reply and surface as `channel:open_failed` call errors (alkcall 0.5.0
-ADR-049 / alktty ADR-010) — the in-band frames on that path are
-defense-in-depth arms plus the one non-migratable class
-(`allocate_failed`, ADR-010 §2).
+ownership denial) **and allocation** are rejected by the establisher
+before the open reply and surface as `channel:open_failed` call
+errors (alkcall ADR-049 / alktty ADR-010, as amended for alkcall 0.6's
+`Establishment` plan payload — ADR-010 §2A) — the in-band frames on
+that path are defense-in-depth arms only (reachable from
+no-establisher registrations).
 
 | Error | When | Shape |
 |-------|------|------|
 | `unknown_backend` | the `backend` string is not in the adapter's backend map — direct path, or the channels path's defense-in-depth arm (the establisher rejects it as `channel:open_failed` / `unknown_resource` first) | `{"error":"unknown_backend","backend":"..."}` |
 | `malformed_negotiation` | the negotiation frame failed to parse as JSON or failed `NegotiateRequest` validation — on the direct path the wire frame; on the channels path the open op's `input` (schema-valid values can still fail the typed parse, e.g. `cwd` typed as a number, because the schema is deliberately partial — the establisher rejects it as `channel:open_failed` / `handler_error` first; the handler-side frame is defense-in-depth, ADR-010 §2) | `{"error":"malformed_negotiation","message":"..."}` |
-| `allocate_failed` | `backend.allocate()` returned a `TtyError` — on both paths: the establisher cannot carry the allocated handle across to the pump handler (ADR-010 §2), so allocation failure is the one in-band failure class on the channels path | `{"error":"allocate_failed","message":"..."}` |
+| `allocate_failed` | `backend.allocate()` returned a `TtyError` — the failure surface of the **direct path**. On the channels path the establisher runs `allocate` (the handle crosses to the pump handler via alkcall 0.6's `Establishment` plan payload — ADR-010 §2A) and its failure is a `channel:open_failed` call error (`details.reason == "dial_failed"`) | `{"error":"allocate_failed","message":"..."}` |
 
 After sending the error response, the adapter closes the write half of
 the bidi stream. The client reads the error frame and treats stream close
@@ -369,7 +370,7 @@ architectural commitment.
 | Backend cleanup on session cancel | [ADR-005](decisions/005-backend-cleanup-on-session-cancel.md) | Dropping `exit_code` future kills the session target; the adapter triggers it by dropping the `TtyHandle` on cancel |
 | Channels pure channel multiplexing | [ADR-008](decisions/008-channels-pure-channel-multiplexing.md) | The same session driver runs in both direct and channels modes; only the `BiStream` source differs |
 | Negotiation carried in the open op | [ADR-009](decisions/009-channels-open-op-is-the-negotiation.md) | The channels path carries no second negotiation frame; the open op's registry-validated `input` is the negotiation (`drive_session_pre_negotiated`) |
-| Channels establishment failures are call errors | [ADR-010](decisions/010-channels-establisher-migration.md) | The channels path's semantic failures are rejected by the establisher (`channel:open_failed`, alkcall ADR-049); `allocate_failed` stays in-band |
+| Channels establishment failures are call errors | [ADR-010](decisions/010-channels-establisher-migration.md) | The channels path's semantic failures and allocation are rejected/run in the establisher (`channel:open_failed`, alkcall ADR-049; alkcall 0.6 plan payload carries the `TtyHandle`); no in-band frame from a registered producer |
 | Dynamic resource ownership | alknet ADR-050 | Terminal sessions as runtime-spawned resources; the adapter's access-control shape |
 
 ## Open Questions
@@ -394,8 +395,9 @@ architectural commitment.
   registry-validated `input` is the negotiation)
 - [ADR-010](decisions/010-channels-establisher-migration.md) — the
   channels path's semantic failures are establisher call errors
-  (`channel:open_failed`); the in-band frames shrink to
-  `allocate_failed`
+  (`channel:open_failed`); since alkcall 0.6 the establisher also
+  allocates (the `TtyHandle` crosses via the plan payload), so no
+  failure class arrives in-band from a registered producer
 - alknet ADR-050 — the ownership model the adapter's access control
   declares against
 - alknet ADR-007 — `Connection`, `accept_bi`, the handler-receives-

docs/architecture/tty-backend.md

@@ -125,8 +125,10 @@ pub enum TtyError {
 
 - `AllocFailed` — the PTY couldn't be allocated, the docker exec failed
   to start, the SSH channel request was rejected. Returned by
-  `allocate()`; the adapter sends `{"error":"allocate_failed",...}` and
-  closes (tty-adapter.md §"Negotiation errors").
+  `allocate()`; on the direct path the adapter sends
+  `{"error":"allocate_failed",...}` and closes (tty-adapter.md
+  §"Negotiation errors"); on the channels path the establisher maps it
+  to `channel:open_failed` / `dial_failed` (ADR-010 §2A).
 - `WaitFailed` — the backend couldn't reap the child / determine the
   exit code. Returned by the `exit_code` future; the adapter sends
   `{"type":"exit","code":-1}` (ADR-004 §4).

src/adapter.rs

@@ -253,6 +253,32 @@ pub async fn drive_session_pre_negotiated(
     }
 }
 
+/// Drive a `alk/tty` session whose negotiation AND allocation already
+/// happened out of band — the channels path with an establisher
+/// (alkcall 0.6, ADR-010 as amended). The establisher validated the
+/// request and ran `backend.allocate`; its `TtyHandle` arrived via the
+/// establishment plan (`AllocatedHandle`, taken by the open handler).
+/// The raw-chunk data plane starts immediately; nothing is read or
+/// written before the pumps.
+///
+/// Not public API: the only caller is the channels open handler. A
+/// consumer that somehow reaches a pre-allocated stream without the
+/// producer-side establisher (no-establisher registration) goes
+/// through [`drive_session_pre_negotiated`] instead, whose inline
+/// validate-and-allocate keeps the in-band error-frame fallback.
+pub(crate) async fn drive_session_pre_allocated<W, R>(
+    client_send: W,
+    client_recv: R,
+    handle: TtyHandle,
+) where
+    W: AsyncWrite + Send + Unpin + 'static,
+    R: AsyncRead + Send + Unpin + 'static,
+{
+    if let Err(e) = pump_session(client_send, client_recv, handle).await {
+        debug!("tty: session ended with error: {e}");
+    }
+}
+
 /// Validate a parsed `NegotiateRequest`, select the backend, run the
 /// ADR-050 ownership check, and allocate. Shared by the direct
 /// (wire-negotiated) and channels (pre-negotiated) paths. Failures are

src/backend.rs

@@ -45,8 +45,11 @@ pub type BoxFuture<T> = futures::future::BoxFuture<'static, T>;
 #[derive(Debug, thiserror::Error)]
 pub enum TtyError {
     /// The PTY couldn't be allocated, the docker exec failed to start, the
-    /// SSH channel request was rejected. Returned by `allocate()`; the
-    /// adapter sends `{"error":"allocate_failed",...}` and closes.
+    /// SSH channel request was rejected. Returned by `allocate()`; on the
+    /// direct path the adapter sends `{"error":"allocate_failed",...}` and
+    /// closes; on the channels path (alkcall 0.6, ADR-010 §2A) the
+    /// establisher maps it to `channel:open_failed` /
+    /// `details.reason == "dial_failed"`.
     #[error("allocate failed: {message}")]
     AllocFailed { message: String },
     /// The backend couldn't reap the child / determine the exit code.

src/channels.rs

@@ -18,13 +18,13 @@
 //! `channel:open_failed` on rejection — no phantom channel. The
 //! `TtyOpenHandler` receives the channel's `Connection` (data-plane
 //! ALPN `alk/tty`), calls `accept_bi()` to get the channel's
-//! `BiStream`, and runs [`crate::adapter::drive_session_pre_negotiated`]
-//! on it — the same three-pump session driver as the direct-ALPN path,
-//! minus the wire-frame negotiation phase (the open op's `input` is
-//! the negotiation, ADR-009). Backend allocation stays in the pump
-//! handler (`allocate_failed` still arrives in-band as a negotiation
-//! error frame — the establisher cannot carry the allocated handle
-//! across to the handler; ADR-010).
+//! `BiStream`, and runs the session pumps on it — the same three-pump
+//! session driver as the direct-ALPN path, minus the wire-frame
+//! negotiation phase (the open op's `input` is the negotiation,
+//! ADR-009). Backend allocation runs in the establisher (alkcall 0.6
+//! R-01: the allocated `TtyHandle` crosses via the `Establishment`
+//! plan payload); no negotiation error frame is ever written on the
+//! channels path by a registered producer.
 //!
 //! The access control (scope-gate + ownership) is wired into the
 //! `OperationSpec`'s `AccessControl` and enforced by the registry's
@@ -37,10 +37,10 @@
 //! [`ChannelCore`]: alkcall::channels::operations::ChannelCore
 
 use std::collections::HashMap;
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
 
 use alkcall::channels::operations::{
-    ChannelCore, Establishment, EstablishmentError, OpenEstablisher, OpenHandler,
+    ChannelCore, ChannelPlan, Establishment, EstablishmentError, OpenEstablisher, OpenHandler,
 };
 use alkcall::core::auth::AuthContext;
 use alkcall::core::ownership::OwnershipProvider;
@@ -98,10 +98,12 @@ pub const TTY_ALPN: &str = "alk/tty";
 /// the entry point (here by the registry's `AccessControl`), the
 /// ownership check is enforced once at the backend-selection point.
 ///
-/// `auth` is the peer's `AuthContext`, captured at
-/// `install_channel_zero` time and closed over by the wrapper so the
-/// `TtyOpenHandler` receives it without the wrapper having to reach
-/// into `OperationContext` for it (per the ADR-047 §4 amendment).
+/// `auth` is the peer's `AuthContext`, the install-time context passed
+/// through to `register_openable_with_establisher`. The establisher
+/// and pump handler read their identity from the per-call context
+/// alkcall derives (alkcall 0.7, CF-006 corollary) — the
+/// dispatch-resolved opener, the same view the registry's ACL gate
+/// checked.
 ///
 /// # Errors
 ///
@@ -117,8 +119,8 @@ pub fn register_openable(
     auth: AuthContext,
 ) -> Result<(), String> {
     let spec = tty_open_spec();
-    let establisher = make_tty_establisher(Arc::clone(&backends), ownership, auth.identity.clone());
-    let open_handler = make_tty_open_handler(backends, auth.identity.clone());
+    let establisher = make_tty_establisher(Arc::clone(&backends), ownership);
+    let open_handler = make_tty_open_handler(backends);
     core.register_openable_with_establisher(
         spec,
         Some(establisher),
@@ -148,9 +150,10 @@ pub fn register_openable(
 /// here would create a second definition to drift. The registry check
 /// catches structurally-broken opens (missing command, wrong types);
 /// the full parse and semantic validation (`carriage == "raw"`,
-/// backend lookup, ownership) runs in the establisher (ADR-010 —
-/// failures are `channel:open_failed`); `backend.allocate` runs in the
-/// pump handler.
+/// backend lookup, ownership) and backend allocation run in the
+/// establisher (ADR-010, as amended for alkcall 0.6 — failures are
+/// `channel:open_failed`, including `allocate_failed` as
+/// `dial_failed`).
 ///
 /// The op declares an [`ErrorDefinition`] for `channel:open_failed`
 /// (ADR-016 — establishment failures are disclosed so `services/schema`
@@ -164,7 +167,7 @@ pub fn tty_open_spec() -> OperationSpec {
         "properties": {
             "reason": {
                 "type": "string",
-                "enum": ["unknown_resource", "handler_error", "timeout"]
+                "enum": ["dial_failed", "unknown_resource", "handler_error", "timeout"]
             },
             "message": { "type": "string" }
         },
@@ -196,8 +199,9 @@ pub fn tty_open_spec() -> OperationSpec {
             code: "channel:open_failed".to_string(),
             description: "Establishment failed after channel allocation: the establisher \
                           rejected the negotiation (malformed negotiation, unknown backend, \
-                          ownership denial) or the establishment deadline expired. Details: \
-                          { reason, message }. No channel_id is returned."
+                          ownership denial), the backend allocation failed (dial_failed), or \
+                          the establishment deadline expired. Details: { reason, message }. \
+                          No channel_id is returned."
                 .to_string(),
             schema: open_failed_schema,
             http_status: None,
@@ -226,18 +230,23 @@ pub fn tty_open_spec() -> OperationSpec {
 /// full `NegotiateRequest` parse of the registry-schema-validated
 /// `input` (the schema is deliberately partial so the opaque ADR-053
 /// backend params pass through), `carriage == "raw"`, non-empty
-/// `cmd`, the backend lookup, and the ADR-050 ownership check. Any
-/// rejection resolves `Err(EstablishmentError)` and the wrapper
-/// replies `channel:open_failed` with `details.reason` — the SSH
-/// contract: the channel never exists opener-side, no `channel_id` is
-/// ever returned.
+/// `cmd`, the backend lookup, the ADR-050 ownership check, and —
+/// since alkcall 0.6 (ADR-049 amendment 2, review 007 R-01) gave
+/// `Establishment` its plan payload — the backend allocation
+/// (ADR-010 as amended: the allocated `TtyHandle` crosses to the pump
+/// handler via the plan). Any rejection resolves
+/// `Err(EstablishmentError)` and the wrapper replies
+/// `channel:open_failed` with `details.reason` — the SSH contract:
+/// the channel never exists opener-side, no `channel_id` is ever
+/// returned.
 ///
 /// The `tty:open` scope gate is NOT checked here — the registry's
-/// `AccessControl` enforced it before the establisher ran (the
-/// identity view the registry checked, resolved from the connection,
-/// is the authoritative one; the establisher-side identity is only
-/// the ownership-check subject — the same split as the old
-/// handler-side check).
+/// `AccessControl` enforced it before the establisher ran. The
+/// establisher's `auth` is the per-call context (alkcall 0.7, CF-006
+/// corollary): its identity is the dispatch-resolved opener — the same
+/// identity view the registry's ACL gate checked — and is the
+/// ownership-check subject (the same split as the old handler-side
+/// check).
 ///
 /// Mapping into the ADR-049 reason vocabulary (no new codes — the
 /// vocabulary is alkcall's one-way wire surface):
@@ -249,23 +258,31 @@ pub fn tty_open_spec() -> OperationSpec {
 /// - Ownership denial → [`EstablishmentError::HandlerError`] (an ACL
 ///   outcome, not a dial outcome; the registry's scope gate stays the
 ///   pre-allocation `FORBIDDEN` path).
+/// - `backend.allocate` failure (ADR-005's `AllocFailed`: PTY
+///   couldn't be allocated, docker exec failed to start, SSH channel
+///   request rejected) → [`EstablishmentError::DialFailed`] — the
+///   target refused or the backend lacked capacity; the review-007
+///   verification gate's "allocate in the establisher →
+///   `allocate_failed` is a call error, no in-band frame" shape.
 ///
-/// Backend allocation deliberately does NOT happen here: the
-/// establisher has no way to hand the allocated `TtyHandle` to the
-/// pump handler (`Establishment` is payloadless — reserved for a
-/// channel plan), and a second `allocate` for the same open would
-/// violate the kill-on-`Drop` contract (ADR-005). `allocate_failed`
-/// therefore stays a post-open in-band negotiation error frame
-/// (ADR-010).
+/// The allocation is handed to the pump handler through the
+/// establishment plan: a private `AllocatedHandle` slot (the
+/// `TtyHandle` itself is not `Sync` — its fields are boxed dyn
+/// streams — so it cannot be the `ChannelPlan` directly). The slot is
+/// created per establisher invocation (per open), so the
+/// shared-slot same-resource race alkcall's R-01 test pins is
+/// unreachable by construction; the wrapper moves the plan to this
+/// open's handler and the slot is `take`n exactly once. The
+/// establisher-before-handler ordering is alkcall's wrapper
+/// guarantee (ADR-049 §1).
 fn make_tty_establisher(
     backends: Arc<HashMap<String, Arc<dyn TtyBackend>>>,
     ownership: Option<Arc<dyn OwnershipProvider>>,
-    identity: Option<alkcall::core::auth::Identity>,
 ) -> OpenEstablisher {
     Arc::new(move |input: Value, auth: AuthContext| {
         let backends = Arc::clone(&backends);
         let ownership = ownership.clone();
-        let identity = identity.clone().or_else(|| auth.identity.clone());
+        let identity = auth.identity.clone();
         Box::pin(async move {
             let req: NegotiateRequest = match serde_json::from_value(input) {
                 Ok(r) => r,
@@ -311,46 +328,76 @@ fn make_tty_establisher(
                     }
                 }
             }
-            Ok(Establishment {})
+            let handle = match backend.allocate(&params).await {
+                Ok(h) => h,
+                Err(e) => {
+                    debug!("tty: channels establisher: allocation failed: {e}");
+                    return Err(EstablishmentError::DialFailed {
+                        message: e.to_string(),
+                    });
+                }
+            };
+            Ok(Establishment::new(Arc::new(AllocatedHandle {
+                handle: Mutex::new(Some(handle)),
+            }) as ChannelPlan))
         })
     })
 }
 
+/// The establishment plan payload for the channels path: the
+/// `TtyHandle` the establisher allocated, behind a one-shot slot (the
+/// handle's boxed dyn fields make the struct non-`Sync`, so it cannot
+/// be the `ChannelPlan` directly). Created per open; `take`n by the
+/// pump handler.
+struct AllocatedHandle {
+    handle: Mutex<Option<crate::backend::TtyHandle>>,
+}
+
+impl AllocatedHandle {
+    fn take(&self) -> Option<crate::backend::TtyHandle> {
+        self.handle.lock().unwrap_or_else(|e| e.into_inner()).take()
+    }
+}
+
 /// Build the [`OpenHandler`] for `channels/tty/sub`.
 ///
 /// The handler receives the open op's `input` — the `NegotiateRequest`
-/// params, validated by the establisher before the handler was spawned
-/// (alkcall ADR-049 §1: the establisher is awaited bounded, before the
-/// reply and before the pump handler) — re-parses it, calls
+/// params, validated (and allocated against) by the establisher before
+/// the handler was spawned (alkcall ADR-049 §1: the establisher is
+/// awaited bounded, before the reply and before the pump handler) —
+/// plus the establisher's `plan`: the [`AllocatedHandle`] slot
+/// carrying the backend-allocated `TtyHandle` (alkcall 0.6 ADR-049
+/// amendment 2, review 007 R-01). It re-parses `input`, calls
 /// `accept_bi()` to get the channel's [`BiStream`], splits it into
 /// read/write halves (the stdlib `tokio::io::split` idiom — the same
-/// split the direct-ALPN `TtyAdapter::handle` does), and runs
-/// [`crate::adapter::drive_session_pre_negotiated`] on them — the same
-/// three-pump session driver as the direct-ALPN path. The establisher
-/// already rejected the semantic-failure classes (malformed params,
-/// `carriage != "raw"`, unknown backend, ownership denial) as
-/// `channel:open_failed`, so the driver's `validate_and_allocate` pass
-/// on this path only re-runs the allocation — its negotiation error
-/// frames remain reachable only for `allocate_failed` (the establisher
-/// cannot carry the handle across — ADR-010).
+/// split the direct-ALPN `TtyAdapter::handle` does), and runs the
+/// pre-allocated session driver on them — the same three-pump session
+/// driver as the direct-ALPN path.
+///
+/// With a plan the handler never allocates: the establisher already
+/// ran `backend.allocate` (ADR-010 as amended), so no negotiation
+/// error frame is reachable on the registered path. With `plan: None`
+/// (a no-establisher registration — defense-in-depth, the ADR-010
+/// pre-0.3.0 shape) the handler re-runs the full inline
+/// validate-and-allocate, whose negotiation error frames
+/// (`malformed_negotiation`, `allocate_failed`, ...) remain the only
+/// failure surface for that registration shape.
+///
+/// The returned task awaits the session driver inline (R-02 lifetime
+/// contract): the `JoinHandle`'s completion is the wrapper's teardown
+/// trigger, so the pumps must finish before the task returns — never
+/// spawn-and-forget.
 ///
 /// The `tty:open` scope gate is enforced by the registry's `AccessControl`
 /// before this handler runs — the handler does not re-check it.
-///
-/// The handler's `JoinHandle` is recorded by the channels wrapper for
-/// teardown (abort on `channel/close` / connection drop). When the
-/// session ends (exit chunk sent, stream closed, or stream reset),
-/// `drive_session_pre_negotiated` returns and the spawned task
-/// completes; the wrapper's teardown task then calls
-/// `manager.teardown_channel` and `policy.on_close` (ADR-047 §7).
-fn make_tty_open_handler(
-    backends: Arc<HashMap<String, Arc<dyn TtyBackend>>>,
-    identity: Option<alkcall::core::auth::Identity>,
-) -> OpenHandler {
+fn make_tty_open_handler(backends: Arc<HashMap<String, Arc<dyn TtyBackend>>>) -> OpenHandler {
     Arc::new(
-        move |input: Value, channel_conn: Connection, auth: AuthContext| {
+        move |input: Value,
+              plan: Option<ChannelPlan>,
+              channel_conn: Connection,
+              auth: AuthContext| {
             let backends = Arc::clone(&backends);
-            let identity = identity.clone().or_else(|| auth.identity.clone());
+            let identity = auth.identity.clone();
 
             tokio::spawn(async move {
                 let req: NegotiateRequest = match serde_json::from_value(input) {
@@ -382,15 +429,31 @@ fn make_tty_open_handler(
                     }
                 };
                 let (client_read, client_write) = tokio::io::split(stream);
-                drive_session_pre_negotiated(
-                    client_write,
-                    client_read,
-                    req,
-                    backends,
-                    None,
-                    identity,
-                )
-                .await;
+                let allocated = plan
+                    .as_ref()
+                    .and_then(|p| p.downcast_ref::<AllocatedHandle>())
+                    .and_then(|slot| slot.take());
+                match allocated {
+                    Some(handle) => {
+                        crate::adapter::drive_session_pre_allocated(
+                            client_write,
+                            client_read,
+                            handle,
+                        )
+                        .await;
+                    }
+                    None => {
+                        drive_session_pre_negotiated(
+                            client_write,
+                            client_read,
+                            req,
+                            backends,
+                            None,
+                            identity,
+                        )
+                        .await;
+                    }
+                }
             })
         },
     )
@@ -459,7 +522,7 @@ mod tests {
 
         let mut backends: HashMap<String, Arc<dyn TtyBackend>> = HashMap::new();
         backends.insert("mock".to_string(), Arc::new(MockBackend::with_exit_code(0)));
-        let handler = make_tty_open_handler(Arc::new(backends), None);
+        let handler = make_tty_open_handler(Arc::new(backends));
 
         let task = handler(
             serde_json::json!({
@@ -468,6 +531,7 @@ mod tests {
                 "cmd": ["true"],
                 "cwd": 42
             }),
+            None,
             channel_conn,
             AuthContext::anonymous(b"test"),
         );
@@ -512,7 +576,7 @@ mod tests {
         ownership: Option<Arc<dyn OwnershipProvider>>,
         input: Value,
     ) -> Result<Establishment, EstablishmentError> {
-        let establisher = make_tty_establisher(backends, ownership, None);
+        let establisher = make_tty_establisher(backends, ownership);
         establisher(input, AuthContext::anonymous(b"test")).await
     }
 
@@ -652,6 +716,62 @@ mod tests {
         }
     }
 
+    /// Allocation runs in the establisher (alkcall 0.6 — the
+    /// `TtyHandle` crosses to the pump handler via the `Establishment`
+    /// plan payload, ADR-010 as amended). Its failure maps to
+    /// `DialFailed` (`details.reason == "dial_failed"` — the target
+    /// refused or the backend lacked capacity), and a successful
+    /// allocation lands in the plan slot the handler takes.
+    #[tokio::test]
+    async fn establisher_allocates_and_maps_failure_to_dial_failed() {
+        struct AllocFailBackend;
+        #[async_trait::async_trait]
+        impl TtyBackend for AllocFailBackend {
+            async fn allocate(
+                &self,
+                _params: &crate::backend::TtyParams,
+            ) -> Result<crate::backend::TtyHandle, crate::backend::TtyError> {
+                Err(crate::backend::TtyError::AllocFailed {
+                    message: "out of ptys".to_string(),
+                })
+            }
+        }
+        let mut failing: HashMap<String, Arc<dyn TtyBackend>> = HashMap::new();
+        failing.insert("mock".to_string(), Arc::new(AllocFailBackend));
+        let result = establisher_result(
+            Arc::new(failing),
+            None,
+            json!({ "carriage": "raw", "backend": "mock", "cmd": ["true"] }),
+        )
+        .await;
+        match result {
+            Err(e) => {
+                assert_eq!(e.reason(), "dial_failed");
+                assert!(e.message().contains("out of ptys"));
+            }
+            Ok(_) => panic!("allocation failure must be rejected by the establisher"),
+        }
+
+        let result = establisher_result(
+            mock_backends_one(),
+            None,
+            json!({ "carriage": "raw", "backend": "mock", "cmd": ["true"] }),
+        )
+        .await;
+        let establishment = result.expect("successful allocate carries the handle");
+        let slot = establishment
+            .plan
+            .as_ref()
+            .and_then(|p| p.downcast_ref::<AllocatedHandle>())
+            .expect("plan is the AllocatedHandle slot")
+            .take()
+            .expect("the allocated handle is in the slot");
+        // The handle is live: its exit_code resolves (MockBackend
+        // resolves immediately with the configured code).
+        let code = slot.exit_code.await.expect("exit_code resolves");
+        assert_eq!(code, 0);
+    }
+
     /// E-02: the spec carries a description (disclosed by
     /// `services/list`) and declares the `channel:open_failed` error
     /// schema (ADR-016 — the establishment-failure contract is
@@ -672,11 +792,17 @@ mod tests {
             .as_array()
             .expect("reason enum");
         let reasons: Vec<&str> = enum_values.iter().filter_map(|v| v.as_str()).collect();
-        // The establisher produces only these three (dial_failed and
-        // resource_shortage have no TTY producer path — ADR-010).
+        // The establisher produces these four (resource_shortage has
+        // no TTY producer path — ADR-010; allocation failure maps to
+        // dial_failed, the amended mapping).
         assert_eq!(
             reasons,
-            vec!["unknown_resource", "handler_error", "timeout"]
+            vec![
+                "dial_failed",
+                "unknown_resource",
+                "handler_error",
+                "timeout"
+            ]
         );
     }
 

src/session.rs

@@ -21,10 +21,11 @@
 //!   (ADR-009: the open op's `params` — validated by the registry's
 //!   input schema — *are* the negotiation; no second negotiation
 //!   frame is written on the channel's data stream). Semantic
-//!   establishment failures are rejected by the producer's establisher
-//!   and surface as `channel:open_failed` call errors (alkcall 0.5.0
-//!   ADR-049 / alktty ADR-010); allocation failure stays in-band
-//!   (see `open_via_channels`' docs).
+//!   establishment failures — including allocation failure since
+//!   alkcall 0.6 — are rejected by the producer's establisher and
+//!   surface as `channel:open_failed` call errors (alkcall ADR-049 /
+//!   alktty ADR-010, as amended for the 0.6 plan payload; see
+//!   `open_via_channels`' docs).
 //!
 //! The session handle exposes:
 //! - [`TtySession::send_stdin`] / [`TtySession::close_stdin`] — write
@@ -118,7 +119,12 @@ pub enum TtySessionError {
     InvalidParams(String),
     /// The server sent a negotiation error frame (the first frame on
     /// the stream is a length-prefixed JSON `{"error":"..."}` rather
-    /// than a raw chunk).
+    /// than a raw chunk). On the channels path this is
+    /// defense-in-depth only — a registered producer rejects every
+    /// failure class (including allocation, since alkcall 0.6) in the
+    /// establisher as `channel:open_failed` before the reply — but
+    /// the variant stays reachable (no-establisher registrations, the
+    /// direct-ALPN path's full in-band vocabulary).
     #[error("negotiation rejected: {error}")]
     NegotiationRejected {
         error: String,
@@ -239,12 +245,14 @@ impl TtySession {
     /// [`TtySessionError::ChannelsOpen`] wrapping a `CallFailed` whose
     /// `CallError` is `channel:open_failed` with
     /// `details.reason` (alkcall 0.5.0 ADR-049; the SSH contract: no
-    /// `channel_id` is ever returned). The one post-open failure class
-    /// that still arrives in-band is allocation failure
-    /// (`allocate_failed`): it surfaces as
-    /// [`TtySessionError::NegotiationRejected`] via the `0x00`
-    /// disambiguation read (the establisher cannot carry the allocated
-    /// backend handle across to the pump handler — ADR-010).
+    /// `channel_id` is ever returned). Since alkcall 0.6 (ADR-010 as
+    /// amended — allocation moved into the establisher, the allocated
+    /// handle crossing via the `Establishment` plan payload) no
+    /// failure class arrives in-band on the channels path: allocation
+    /// failure surfaces as `channel:open_failed` with
+    /// `details.reason == "dial_failed"`, and the `0x00`
+    /// disambiguation read is a keep-the-pump formality (a registered
+    /// producer never writes an error frame first).
     pub async fn open_via_channels(
         client: &ChannelClient,
         params: serde_json::Value,
@@ -338,11 +346,13 @@ impl TtySession {
 
     /// Core inner for the channels path (ADR-009): the negotiation
     /// already happened in the open op — the stream is already in
-    /// raw-chunk mode. The peek still applies: the producer sends a
-    /// `0x00`-prefixed error frame on any post-open failure (a
-    /// `NegotiateRequest` parse failure of the open op's `input`,
-    /// unknown backend, allocate failure, ownership denial), and a raw
-    /// chunk (`stream_type` in `{1, 2, 4}`) on success.
+    /// raw-chunk mode. The peek still applies as defense-in-depth: a
+    /// `0x00`-prefixed error frame means the producer rejected the
+    /// session post-open (only reachable from a no-establisher
+    /// registration — the establisher rejects every semantic class
+    /// before the reply, and allocation runs there too since alkcall
+    /// 0.6 / ADR-010 as amended), while a raw chunk (`stream_type` in
+    /// `{1, 2, 4}`) is the normal first data.
     async fn from_halves_raw<R, W>(read: R, write: W) -> Result<Self, TtySessionError>
     where
         R: AsyncRead + Send + Unpin + 'static,

src/testing.rs

@@ -264,17 +264,17 @@ mod tests {
         );
     }
 
-    /// Post-ADR-010, the one failure class that still arrives in-band on
-    /// the channels path is allocation failure (`allocate_failed`): the
-    /// establisher cannot carry the allocated `TtyHandle` across to the
-    /// pump handler (ADR-010), so `backend.allocate` runs in the handler
-    /// and its failure surfaces as a `0x00`-prefixed
-    /// `allocate_failed` negotiation error frame via the consumer's
-    /// `from_halves_raw` peek. Pins the boundary of the establisher
-    /// migration.
+    /// Post-alkcall-0.6 (ADR-010 as amended): allocation failure no
+    /// longer arrives in-band. `backend.allocate` runs in the
+    /// establisher (the allocated `TtyHandle` crosses to the pump
+    /// handler via the `Establishment` plan payload), so its failure
+    /// fails the open op itself — `channel:open_failed` with
+    /// `details.reason == "dial_failed"` — and no channel survives
+    /// (the SSH contract: no `channel_id`, no `0x00`-prefixed
+    /// in-band frame on a channel that was reported as succeeding).
     #[tokio::test]
-    async fn allocate_failure_still_arrives_in_band_on_channels_path() {
-        use tokio::io::AsyncReadExt;
+    async fn allocate_failure_fails_open_as_dial_failed() {
+        use alkcall::channels::client::ChannelOpenError;
 
         struct AllocFailBackend;
 
@@ -295,7 +295,7 @@ mod tests {
         let client =
             wire_client_and_server(Arc::new(backends), None, Some(tty_identity("alice"))).await;
 
-        let (_channel_id, _send, mut recv) = tokio::time::timeout(
+        let result = tokio::time::timeout(
             std::time::Duration::from_secs(5),
             client.open_channel(
                 OP_TTY_OPEN,
@@ -304,28 +304,28 @@ mod tests {
             ),
         )
         .await
-        .expect("open_channel timed out")
-        .expect("open_channel — establishment succeeds, allocation is post-open");
-
-        // The consumer-side post-open sequence (`from_halves_raw`):
-        // peek the first byte; `0x00` = negotiation error frame.
-        let mut first = [0u8; 1];
-        tokio::time::timeout(
-            std::time::Duration::from_secs(5),
-            recv.read_exact(&mut first),
-        )
-        .await
-        .expect("no response byte from producer")
-        .expect("read first byte");
-        assert_eq!(first[0], 0x00, "error frame length prefix starts with 0x00");
-
-        let mut len_rest = [0u8; 3];
-        recv.read_exact(&mut len_rest).await.expect("read len rest");
-        let len = u32::from_be_bytes([first[0], len_rest[0], len_rest[1], len_rest[2]]) as usize;
-        let mut body = vec![0u8; len];
-        recv.read_exact(&mut body).await.expect("read error body");
-        let v: serde_json::Value = serde_json::from_slice(&body).expect("parse error frame");
-        assert_eq!(v["error"], "allocate_failed");
-        assert!(v["message"].as_str().is_some_and(|m| !m.is_empty()));
+        .expect("open_channel timed out");
+        match result {
+            Err(ChannelOpenError::CallFailed { error }) => {
+                assert_eq!(error.code, "channel:open_failed");
+                let details = error.details.expect("details carry the reason");
+                assert_eq!(details["reason"], "dial_failed");
+                assert!(
+                    details["message"]
+                        .as_str()
+                        .is_some_and(|m| m.contains("out of ptys")),
+                    "message carries the backend allocation failure detail, got {details}"
+                );
+            }
+            Ok(_) => panic!("expected channel:open_failed, got Ok(channel)"),
+            Err(other) => panic!("expected CallFailed(channel:open_failed), got {other:?}"),
+        }
+        // The SSH contract: no data channel survives a failed
+        // establishment (channel 0 is the call channel), and no
+        // in-band frame was ever written (the channel never existed).
+        assert!(
+            client.manager().channel_ids().iter().all(|&id| id == 0),
+            "no channel survives a failed allocation"
+        );
     }
 }