feat(review 007 Unit 1): Establishment carries the channel plan (R-01) + lifetime doc (R-02)

Implements ADR-049 amendment 2 — the reserved Establishment payload is
filled, and the OpenHandler lifetime contract is documented.

- Establishment { plan: Option<ChannelPlan> } with ChannelPlan =
  Arc<dyn Any + Send + Sync>: typed-opaque, because the payload an
  establisher hands the pump handler is a live handle (dialed socket,
  TTY handle), not JSON — the review's Option<Value> sketch could not
  satisfy its own verification gate. #[non_exhaustive] keeps a future
  carrier change from being another break. Construction:
  Establishment::new(plan) / Establishment::default().
- OpenHandler gains the plan parameter:
  Fn(Value, Option<ChannelPlan>, Connection, AuthContext) ->
  JoinHandle<()>. Separate parameter (not merged into input) — a
  typed payload cannot ride the JSON input; no schema collision.
  Wire surface unchanged: the plan is process-local (establisher ->
  wrapper -> handler).
- run_open_wrapper threads establishment.plan to the handler; None
  when no establisher is registered. Kills the alktunnels-POC
  side-channel handoff (resource-keyed slot + poll loop) whose
  concurrent same-resource race is now unreachable — each open's
  establisher result flows to its own handler.
- Lifetime contract documented (R-02, doc-only half): the returned
  JoinHandle must track the data-plane lifetime — the wrapper awaits
  it and its completion triggers teardown; early return = teardown
  at birth. Noted on the OpenHandler type docs and both registration
  entry points.
- Breaking at 0.6.0 (the point of landing it before alktunnels
  Phase 1): Ok(Establishment {}) sites become
  Ok(Establishment::default()) mechanically.

Verification: cargo test (621 passed, +4: plan-flows-to-handler,
concurrent same-resource opens get distinct plans, no-establisher
None plan, Establishment construction), clippy -D warnings, fmt
--check, doc clean, test --all-features clean.

CHANGELOG.md

@@ -4,6 +4,44 @@ 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/).
 
+## [0.6.0] - 2026-09-07
+
+The establishment follow-ups sweep (review 007): the `Establishment`
+plan payload lands (R-01), the `OpenHandler` lifetime contract is
+documented (R-02), and the two-pump helper is extracted (R-03). One
+breaking change (below); the wire surface is unchanged.
+
+### Changed
+
+- **`Establishment` carries the channel plan (review 007 R-01 —
+  breaking at 0.6.0).** The reserved field is filled:
+  `Establishment { plan: Option<ChannelPlan> }` with
+  `ChannelPlan = Arc<dyn Any + Send + Sync>` — typed-opaque, because
+  the payload an establisher hands the pump handler is a live handle
+  (a dialed socket, a TTY handle), not JSON. The wrapper threads
+  `establishment.plan` to the `OpenHandler`'s new second parameter
+  (`Fn(Value, Option<ChannelPlan>, Connection, AuthContext) ->
+  JoinHandle<()>`); `None` when no establisher is registered or it
+  returned `Establishment::default()`. Process-local: establisher →
+  wrapper → handler; nothing new crosses the transport. This kills
+  the side-channel handoff the alktunnels POC shipped (resource-keyed
+  slot + poll loop) with its concurrent same-resource race — each
+  open's establisher result flows to its own handler. Migration:
+  `Ok(Establishment {})` → `Ok(Establishment::default())` (or
+  `Establishment::new(handle)` to deliver a handle); handler closures
+  gain a `_plan` (or `plan`) parameter.
+
+- **`OpenHandler` lifetime contract documented (review 007 R-02).**
+  Doc-only semantics note on the `OpenHandler` type and the
+  registration entry points: the returned `JoinHandle` must track the
+  data-plane lifetime — the wrapper awaits it and its completion
+  triggers channel teardown (drop of the demux sender = EOF to the
+  handler's read half); a handler that returns before its pumps
+  finish tears the channel down at birth (await pumps inline, never
+  spawn-and-forget). Plus a `debug!` telemetry line in
+  `run_open_wrapper` when a handler exits without having accepted the
+  channel's `BiStream` (the birth-teardown hint).
+
 ## [0.5.0] - 2026-09-06
 
 The channel-open establishment phase (ADR-049 — review 006 E-01 +

Cargo.lock

@@ -27,7 +27,7 @@ dependencies = [
 
 [[package]]
 name = "alkcall"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "async-trait",
  "bytes",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "alkcall"
-version = "0.5.0"
+version = "0.6.0"
 edition = "2021"
 rust-version = "1.85"
 license = "MIT OR Apache-2.0"

docs/architecture/decisions/049-channel-open-establishment-phase.md

@@ -354,3 +354,55 @@ verification gates from the review landed as tests (establisher
 failure e2e through a real channels connection with ledger
 un-increment + no-channel assertions, bounded timeout, no-establisher
 compat, establisher-success pump round-trip).
+
+## Amendment 2 (plan payload, 2026-09-07 — review 007 R-01/R-02)
+
+Review 007 (from the alktunnels UDP POC) filed two follow-ups on the
+establishment surface; both landed in alkcall 0.6.0.
+
+**1. `Establishment` carries the channel plan (R-01).** §1 reserved
+the payload ("today: nothing") and the wrapper consulted only
+success/failure — so an establisher whose backend produces a handle
+(a dialed socket, a TTY allocation) had to cross it to the pump
+handler through a per-crate side channel. The alktunnels POC shipped
+a resource-keyed slot + poll loop whose concurrent same-resource race
+is unfixable within that shape; alktty documented the same wall
+(backend `allocate` cannot cross, so failure classes stayed in-band —
+the phantom-channel shape ADR-049 removed, alive one layer down).
+
+The plan is now real: `Establishment { plan: Option<ChannelPlan> }`
+with `ChannelPlan = Arc<dyn Any + Send + Sync>` — **typed-opaque, not
+`serde_json::Value`**. The review's `Option<Value>` sketch could not
+satisfy its own verification gate ("establisher dials, `plan` carries
+the handle"): the payloads establishers actually hand off are live
+handles with no JSON representation. The establisher and the
+`OpenHandler` agree on the concrete type; alkcall never inspects it.
+The wrapper threads `establishment.plan` to the handler's new second
+parameter (`OpenHandler = Fn(Value, Option<ChannelPlan>, Connection,
+AuthContext) -> JoinHandle<()>`); the separate-parameter shape wins
+over merging into `input` because a typed payload cannot ride the
+JSON input without a downcast-side registry and the reserved-key
+collision the review already anticipated. The plan is process-local
+(establisher → wrapper → handler on the producing side); the wire
+surface is unchanged — nothing crosses the transport that isn't
+already the open op's input. `#[non_exhaustive]` on `Establishment`
+keeps a future carrier change from being another breaking release.
+Construction is `Establishment::new(plan)` /
+`Establishment::default()`; the 0.5.0 `Ok(Establishment {})` sites
+break mechanically at 0.6.0, which is the point of landing this now
+(before alktunnels Phase 1 ships the side-channel shape into a real
+crate and the payload lands later anyway as a second break).
+
+**2. The `OpenHandler` lifetime contract is documented (R-02).** The
+wrapper awaits the returned `JoinHandle` and its completion triggers
+teardown — so the handle must track the data-plane lifetime: a
+handler that returns before its pumps finish tears the channel down
+at birth (the POC's first pump implementation hit exactly this: every
+tunnel connected then instantly EOF'd). The contract was implemented
+but never documented; the type docs now state it ("await the pumps
+inline, never spawn-and-forget and return early") on `OpenHandler`
+and the registration entry points, plus a `debug!` telemetry line in
+`run_open_wrapper` when a handler exits without having accepted the
+channel's `BiStream` (the birth-teardown hint; the accept is
+observable in-process via the yield-once source). §6's pinned
+EOF-shaped panic semantics are unchanged.

src/channels/client.rs

@@ -897,7 +897,7 @@ mod tests {
             Arc::clone(&policy) as Arc<dyn ChannelLifecyclePolicy>;
         let policy_for_assert = Arc::clone(&policy);
 
-        let open_handler: OpenHandler = Arc::new(|_input, _channel_conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(|_input, _plan, _channel_conn, _auth| {
             tokio::spawn(async move {
                 // No-op: the channel's BiStream is available via
                 // `_channel_conn.accept_bi()` if the test wanted
@@ -1220,7 +1220,7 @@ mod tests {
 
         let (data_tx, mut data_rx) = tokio::sync::mpsc::channel::<Vec<u8>>(1);
 
-        let open_handler: OpenHandler = Arc::new(move |_input, channel_conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, channel_conn, _auth| {
             let data_tx = data_tx.clone();
             tokio::spawn(async move {
                 let mut bidi = channel_conn.accept_bi().await.expect("accept_bi");
@@ -1340,7 +1340,7 @@ mod tests {
         let policy_for_assert = Arc::clone(&policy);
 
         let open_handler: OpenHandler =
-            Arc::new(|_input, _channel_conn, _auth| tokio::spawn(async {}));
+            Arc::new(|_input, _plan, _channel_conn, _auth| tokio::spawn(async {}));
         let establisher: OpenEstablisher = Arc::new(|_input, _auth| {
             Box::pin(async {
                 Err(EstablishmentError::DialFailed {
@@ -1472,7 +1472,7 @@ mod tests {
 
         let (data_tx, mut data_rx) = tokio::sync::mpsc::channel::<Vec<u8>>(1);
 
-        let open_handler: OpenHandler = Arc::new(move |_input, channel_conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, channel_conn, _auth| {
             let data_tx = data_tx.clone();
             tokio::spawn(async move {
                 let mut bidi = channel_conn.accept_bi().await.expect("accept_bi");
@@ -2333,7 +2333,7 @@ mod tests {
         let policy_for_hook: Arc<dyn ChannelLifecyclePolicy> =
             Arc::clone(&policy) as Arc<dyn ChannelLifecyclePolicy>;
 
-        let open_handler: OpenHandler = Arc::new(|_input, _channel_conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(|_input, _plan, _channel_conn, _auth| {
             tokio::spawn(async move {
                 tokio::time::sleep(std::time::Duration::from_millis(50)).await;
             })

src/channels/operations.rs

@@ -319,30 +319,75 @@ pub struct ChannelCore {
     policy: Arc<dyn ChannelLifecyclePolicy>,
 }
 
-/// The ALPN-specific open handler (ADR-047 §3). The ALPN crate
-/// provides this; [`ChannelCore::register_openable`] wraps it with the
-/// channel machinery. The handler receives the open op's `input`
-/// (params — e.g. which container for tty, which target for tunnel),
-/// the channel's [`Connection`] (carrying the data-plane ALPN, built
-/// by the wrapper from the channel's reassembled read half + mux write
+/// The ALPN-specific open handler (ADR-047 §3, as amended by ADR-049
+/// amendment 2 — the establishment `plan` flows to the handler). The
+/// ALPN crate provides this; [`ChannelCore::register_openable`] wraps
+/// it with the channel machinery. The handler receives the open op's
+/// `input` (params — e.g. which container for tty, which target for
+/// tunnel), the establishment `plan` (the typed-opaque payload the
+/// establisher returned — e.g. the dialed `SubstrateHandle`; `None`
+/// when no establisher is registered or it returned no plan), the
+/// channel's [`Connection`] (carrying the data-plane ALPN, built by
+/// the wrapper from the channel's reassembled read half + mux write
 /// half), and the peer's [`AuthContext`], spawns its protocol on the
 /// channel's `BiStream`, and returns the `JoinHandle` so the wrapper
 /// can record it for teardown (abort on `channel/close` / connection
 /// drop).
 ///
+/// **The returned `JoinHandle` must track the data-plane lifetime**
+/// (R-02): the wrapper awaits it and its completion triggers channel
+/// teardown (drop of the demux sender = EOF to the handler's read
+/// half). A handler that returns before its pumps finish tears the
+/// channel down at birth — await the pumps inline inside the returned
+/// task, never spawn-and-forget them and return early.
+///
 /// This mirrors the `InstallChannelZero` hook shape (the call adapter
 /// spawns `run_loop_single_stream` on channel 0's `Connection`): the
 /// ALPN handler does the same for its data-plane protocol on the
 /// allocated channel's `Connection`. The handler owns its protocol's
 /// sub-stream multiplexing on the `BiStream` it receives (ADR-035).
-pub type OpenHandler =
-    Arc<dyn Fn(Value, Connection, AuthContext) -> tokio::task::JoinHandle<()> + Send + Sync>;
+pub type OpenHandler = Arc<
+    dyn Fn(Value, Option<ChannelPlan>, Connection, AuthContext) -> tokio::task::JoinHandle<()>
+        + Send
+        + Sync,
+>;
 
-/// The establishment-phase result (ADR-049 §1). Reserved for a channel
-/// plan — today the wrapper consults only success/failure, so `()`
-/// carries no data.
+/// The establishment plan payload (ADR-049 §1, as filled by ADR-049
+/// amendment 2 — R-01): the typed-opaque data the establisher hands to
+/// the pump handler. Opaque to alkcall by construction — the
+/// establisher and the handler agree on the concrete type; the
+/// downcast (`Arc::clone` + `Any::downcast_ref`) happens in the ALPN
+/// crate.
+///
+/// The plan is **process-local**: establisher → wrapper → handler on
+/// the producing side. Nothing crosses the transport that isn't
+/// already the open op's input — the wire surface is unchanged.
+pub type ChannelPlan = Arc<dyn std::any::Any + Send + Sync>;
+
+/// The establishment-phase result (ADR-049 §1, as filled by ADR-049
+/// amendment 2 — R-01). Carries the channel plan the wrapper threads
+/// to the pump handler's `plan` parameter ([`OpenHandler`]). The
+/// plan is optional: an establisher that only validates (TTY's
+/// lookup/ownership shape) returns [`Establishment::default`].
+///
+/// `#[non_exhaustive]` so a future carrier change is not another
+/// breaking release. Construct with [`Establishment::new`] (plan) or
+/// [`Establishment::default`] (no plan).
 #[derive(Debug, Clone, Default)]
-pub struct Establishment {}
+#[non_exhaustive]
+pub struct Establishment {
+    /// The channel plan — the payload the pump handler receives. The
+    /// establisher and the handler agree on the concrete type
+    /// ([`ChannelPlan`]); alkcall never inspects it.
+    pub plan: Option<ChannelPlan>,
+}
+
+impl Establishment {
+    /// A result carrying `plan` to the pump handler.
+    pub fn new(plan: ChannelPlan) -> Self {
+        Self { plan: Some(plan) }
+    }
+}
 
 /// The establishment-failure reason code the wrapper puts in the open
 /// reply's `details.reason` (ADR-049 §3). The vocabulary maps 1:1 onto
@@ -469,6 +514,12 @@ impl ChannelCore {
     /// establishment phase can fail and the failure belongs in the
     /// open reply (ADR-049).
     ///
+    /// **Lifetime contract (R-02):** the returned `OpenHandler`
+    /// `JoinHandle` must track the data-plane lifetime — see the
+    /// [`OpenHandler`] type docs. The wrapper awaits it and its
+    /// completion triggers channel teardown; early return = teardown
+    /// at birth.
+    ///
     /// The op is registered on the given `registry` (the connection
     /// overlay registry, Layer 2 per ADR-019 — this is the
     /// per-connection registration the §4 amendment blesses). The
@@ -517,6 +568,13 @@ impl ChannelCore {
     /// exactly like [`ChannelCore::register_openable`] (the
     /// no-establisher shape), and existing `OpenHandler`s compile
     /// unchanged.
+    ///
+    /// **Lifetime contract (R-02):** the returned `OpenHandler`
+    /// `JoinHandle` must track the data-plane lifetime — see the
+    /// [`OpenHandler`] type docs. The wrapper awaits it and its
+    /// completion triggers channel teardown; early return = teardown
+    /// at birth. On success the establisher's plan flows to the
+    /// handler's `plan` parameter (ADR-049 amendment 2).
     pub fn register_openable_with_establisher(
         &self,
         spec: OperationSpec,
@@ -711,11 +769,14 @@ async fn run_open_wrapper(
             // The establishment phase (ADR-049 §1): awaited bounded,
             // before the reply and before the pump handler is spawned.
             // No establisher registered = an always-OK establisher
-            // (the pre-ADR-049 shape, unchanged).
-            if let Some(hook) = establisher {
+            // (the pre-ADR-049 shape, unchanged) — its plan is `None`.
+            let plan = match establisher {
+                Some(hook) => {
                     let bound = establishment_bound(hook.timeout, deadline);
-                let establishment =
-                    tokio::time::timeout(bound, (hook.establisher)(input.clone(), auth.clone()))
+                    let establishment = tokio::time::timeout(
+                        bound,
+                        (hook.establisher)(input.clone(), auth.clone()),
+                    )
                     .await;
                     match establishment {
                         Err(_elapsed) => {
@@ -737,14 +798,16 @@ async fn run_open_wrapper(
                                 establishment_error_to_call_error(&e),
                             );
                         }
-                    Ok(Ok(_establishment)) => {}
+                        Ok(Ok(establishment)) => establishment.plan,
                     }
                 }
+                None => None,
+            };
 
             let remote_addr = manager.remote_addr();
             let source = super::source::channel_source(recv, send, remote_addr);
             let channel_conn = Connection::from_source(source, alpn.as_bytes().to_vec());
-            let raw_task = open_handler(input, channel_conn, auth.clone());
+            let raw_task = open_handler(input, plan, channel_conn, auth.clone());
 
             let teardown_manager = manager.clone();
             let teardown_policy = Arc::clone(policy);
@@ -976,7 +1039,7 @@ mod tests {
     use crate::registry::spec::ChannelOpenSpec;
     use futures::stream::StreamExt;
     use std::collections::HashMap;
-    use std::sync::atomic::{AtomicBool, Ordering};
+    use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
     use std::sync::Arc;
     use tokio::io::duplex;
 
@@ -1300,7 +1363,7 @@ mod tests {
         let policy = super::super::policy::default_policy();
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1331,7 +1394,7 @@ mod tests {
         let policy = super::super::policy::default_policy();
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1365,7 +1428,8 @@ mod tests {
     async fn make_open_handler_sink_returns_not_implemented() {
         let manager = make_manager().await;
         let policy = super::super::policy::default_policy();
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let auth = AuthContext::anonymous(b"alk/call");
         let handler = make_open_handler_sink(
             manager,
@@ -1402,7 +1466,7 @@ mod tests {
         .with_channel_open(ChannelOpenSpec::new("alk/tty"));
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1445,7 +1509,7 @@ mod tests {
         .with_channel_open(ChannelOpenSpec::new("alk/tty"));
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1485,7 +1549,8 @@ mod tests {
             None,
         )
         .with_channel_open(ChannelOpenSpec::new("alk/tty"));
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let registry = OperationRegistry::new();
         core.register_openable(
             spec,
@@ -1515,7 +1580,8 @@ mod tests {
             AccessControl::default(),
             None,
         );
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let registry = OperationRegistry::new();
         let result = core.register_openable(
             spec,
@@ -1532,7 +1598,8 @@ mod tests {
         let manager = make_manager().await;
         let policy: Arc<dyn ChannelLifecyclePolicy> =
             Arc::new(super::super::policy::PerIdentityChannelPolicy::new(0));
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let auth = AuthContext::anonymous(b"alk/call");
         let opener_id = Identity {
             id: "alice".to_string(),
@@ -1598,7 +1665,7 @@ mod tests {
             Arc::clone(&concrete_policy) as Arc<dyn ChannelLifecyclePolicy>;
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1653,7 +1720,8 @@ mod tests {
         let concrete_policy = Arc::new(super::super::policy::PerIdentityChannelPolicy::new(8));
         let policy: Arc<dyn ChannelLifecyclePolicy> =
             Arc::clone(&concrete_policy) as Arc<dyn ChannelLifecyclePolicy>;
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let auth = AuthContext::anonymous(b"alk/call");
         let hanging: OpenEstablisher = Arc::new(|_input, _auth| {
             Box::pin(async {
@@ -1695,7 +1763,8 @@ mod tests {
     async fn run_open_wrapper_dispatch_deadline_bounds_establisher() {
         let manager = make_manager().await;
         let policy = super::super::policy::default_policy();
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let auth = AuthContext::anonymous(b"alk/call");
         let hanging: OpenEstablisher = Arc::new(|_input, _auth| {
             Box::pin(async {
@@ -1735,7 +1804,7 @@ mod tests {
         let policy = super::super::policy::default_policy();
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1850,7 +1919,8 @@ mod tests {
             None,
         )
         .with_channel_open(ChannelOpenSpec::new("alk/tty"));
-        let open_handler: OpenHandler = Arc::new(|_input, _conn, _auth| tokio::spawn(async {}));
+        let open_handler: OpenHandler =
+            Arc::new(|_input, _plan, _conn, _auth| tokio::spawn(async {}));
         let registry = OperationRegistry::new();
         core.register_openable_with_establisher(
             spec,
@@ -1900,7 +1970,7 @@ mod tests {
         .with_channel_open(ChannelOpenSpec::new("alk/tty"));
         let spawned = Arc::new(AtomicBool::new(false));
         let spawned_clone = Arc::clone(&spawned);
-        let open_handler: OpenHandler = Arc::new(move |_input, _conn, _auth| {
+        let open_handler: OpenHandler = Arc::new(move |_input, _plan, _conn, _auth| {
             spawned_clone.store(true, Ordering::SeqCst);
             tokio::spawn(async {})
         });
@@ -1922,4 +1992,166 @@ mod tests {
         assert!(spawned.load(Ordering::SeqCst));
         assert_eq!(manager.open_count(), 1, "channel stays open (compat)");
     }
+
+    // --- ADR-049 amendment 2 (R-01): the plan payload ---------------------
+
+    /// The test-side stand-in for a live substrate handle: the
+    /// establisher's dialed resource, handed to the pump handler via
+    /// the plan.
+    #[derive(Debug, PartialEq, Eq)]
+    struct TestHandle(u64);
+
+    #[tokio::test]
+    async fn run_open_wrapper_plan_flows_from_establisher_to_handler() {
+        let manager = make_manager().await;
+        let policy = super::super::policy::default_policy();
+        let establishing: OpenEstablisher = Arc::new(|_input, _auth| {
+            Box::pin(async { Ok(Establishment::new(Arc::new(TestHandle(42)) as ChannelPlan)) })
+        });
+        let received: Arc<std::sync::Mutex<Option<u64>>> = Arc::new(std::sync::Mutex::new(None));
+        let received_clone = Arc::clone(&received);
+        let open_handler: OpenHandler = Arc::new(move |_input, plan, _conn, _auth| {
+            let handle = plan
+                .as_ref()
+                .and_then(|p| p.downcast_ref::<TestHandle>())
+                .map(|h| h.0);
+            *received_clone.lock().unwrap() = handle;
+            tokio::spawn(async {})
+        });
+        let auth = AuthContext::anonymous(b"alk/call");
+        let env = run_open_wrapper(
+            &manager,
+            &policy,
+            hook(establishing, None).as_ref(),
+            &open_handler,
+            &auth,
+            "alk/tty",
+            json!({}),
+            "alice".to_string(),
+            identity("alice"),
+            "req-plan-flow".to_string(),
+            None,
+        )
+        .await;
+        assert!(env.result.is_ok(), "open with plan should succeed");
+        assert_eq!(
+            *received.lock().unwrap(),
+            Some(42),
+            "the establisher's plan reaches the pump handler typed-opaque"
+        );
+    }
+
+    #[tokio::test]
+    async fn concurrent_same_resource_opens_receive_their_own_plans() {
+        let manager = make_manager().await;
+        let policy = super::super::policy::default_policy();
+        // The establisher dials per open (here: a distinct TestHandle
+        // per invocation) and delivers via the plan — no shared
+        // resource-keyed slot, so the POC's same-resource race is
+        // unreachable by construction.
+        let next_handle = Arc::new(AtomicU64::new(1));
+        let establishing: OpenEstablisher = {
+            let next_handle = Arc::clone(&next_handle);
+            Arc::new(move |_input, _auth| {
+                let handle = TestHandle(next_handle.fetch_add(1, Ordering::SeqCst));
+                Box::pin(async move { Ok(Establishment::new(Arc::new(handle) as ChannelPlan)) })
+            })
+        };
+        let observed: Arc<std::sync::Mutex<Vec<u64>>> = Arc::new(std::sync::Mutex::new(vec![]));
+        let observed_clone = Arc::clone(&observed);
+        let open_handler: OpenHandler = Arc::new(move |_input, plan, _conn, _auth| {
+            let got = plan
+                .as_ref()
+                .and_then(|p| p.downcast_ref::<TestHandle>())
+                .map(|h| h.0);
+            observed_clone.lock().unwrap().push(got.expect("plan"));
+            tokio::spawn(async {})
+        });
+        let auth = AuthContext::anonymous(b"alk/call");
+        let hook_a = hook(establishing.clone(), None);
+        let hook_b = hook(establishing, None);
+        // Two concurrent opens of the SAME resource key: both succeed,
+        // each handler sees its own establisher's handle.
+        let (env_a, env_b) = tokio::join!(
+            run_open_wrapper(
+                &manager,
+                &policy,
+                hook_a.as_ref(),
+                &open_handler,
+                &auth,
+                "alk/tty",
+                json!({ "resource": "same" }),
+                "alice".to_string(),
+                identity("alice"),
+                "req-race-a".to_string(),
+                None,
+            ),
+            run_open_wrapper(
+                &manager,
+                &policy,
+                hook_b.as_ref(),
+                &open_handler,
+                &auth,
+                "alk/tty",
+                json!({ "resource": "same" }),
+                "alice".to_string(),
+                identity("alice"),
+                "req-race-b".to_string(),
+                None,
+            )
+        );
+        assert!(env_a.result.is_ok(), "open A should succeed");
+        assert!(env_b.result.is_ok(), "open B should succeed");
+        let mut got = observed.lock().unwrap().clone();
+        got.sort_unstable();
+        assert_eq!(
+            got,
+            vec![1, 2],
+            "each concurrent same-resource open got its own handle — the handoff-slot race is unreachable"
+        );
+        assert_eq!(manager.open_count(), 2, "both channels stay open");
+    }
+
+    #[tokio::test]
+    async fn no_establisher_passes_none_plan_to_handler() {
+        let manager = make_manager().await;
+        let policy = super::super::policy::default_policy();
+        let received: Arc<std::sync::Mutex<Option<bool>>> = Arc::new(std::sync::Mutex::new(None));
+        let received_clone = Arc::clone(&received);
+        let open_handler: OpenHandler = Arc::new(move |_input, plan, _conn, _auth| {
+            *received_clone.lock().unwrap() = Some(plan.is_none());
+            tokio::spawn(async {})
+        });
+        let auth = AuthContext::anonymous(b"alk/call");
+        let env = run_open_wrapper(
+            &manager,
+            &policy,
+            None,
+            &open_handler,
+            &auth,
+            "alk/tty",
+            json!({}),
+            "alice".to_string(),
+            identity("alice"),
+            "req-no-plan".to_string(),
+            None,
+        )
+        .await;
+        assert!(env.result.is_ok(), "no-establisher open should succeed");
+        assert_eq!(
+            *received.lock().unwrap(),
+            Some(true),
+            "no establisher = plan is None"
+        );
+    }
+
+    #[test]
+    fn establishment_default_has_no_plan() {
+        let e = Establishment::default();
+        assert!(e.plan.is_none());
+        let e = Establishment::new(Arc::new(TestHandle(7)) as ChannelPlan);
+        let plan = e.plan.expect("plan");
+        let h = plan.downcast_ref::<TestHandle>().expect("typed");
+        assert_eq!(h.0, 7);
+    }
 }