From 93c2bf6143dc6970f562379c4ac4f67a625df56b Mon Sep 17 00:00:00 2001
From: chaodu-agent <chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 06:40:09 -0400
Subject: [PATCH 1/8] refactor(cp): make openab-cp proto usable without the
 server

Split openab-cp into an always-compiled `proto` module and a default
`server` feature (config, registry, policy, router, events, WS server,
binary), so runtime clients can depend on the wire contract with
default-features = false without linking axum/tokio. Adds
proto::MIN_RUNTIME_FRAME_BYTES and rejects CP configs whose
max_frame_bytes is below it.

Carried from #1528 (commit 9455b50). Also fixes #1528 round-3 finding 7
(bail! string had a literal run of spaces; test now asserts the exact
message) and gates tests/ws_lifecycle.rs on `server` so
`cargo test --no-default-features` runs the proto tests.

Part 1 of 3 re-landing #1528; see openabdev/openab-pty#77.

Verified on macmini (M4, rustc 1.99.1), clean copy of this tree:
- cargo metadata --locked: ok; Cargo.lock unchanged vs origin/main
- cargo build -p openab-cp --locked: ok
- cargo test -p openab-cp --locked: 142 unit + 9 ws_lifecycle passed
- cargo check -p openab-cp --no-default-features --locked: ok
- cargo test -p openab-cp --no-default-features --locked: 16 proto passed
- cargo tree -p openab-cp --no-default-features -e normal: no axum/tokio/hyper
- cargo clippy -p openab-cp --all-targets -- -D warnings: clean
  (default and --no-default-features)
- cargo fmt -p openab-cp --check: clean
- Docker dummy-layer sim (manifests + empty lib.rs, no openab-cp main.rs):
  cargo metadata --locked and root cargo check --locked ok
- CI parity: cargo check --workspace, clippy --workspace [--features
  unified] -D warnings, test -p openab-gateway --features acp (417),
  test -p openab-core --features acp-mcp acp_mcp:: (5) / acp::pool:: (24),
  test --features acp (42), build --features unified: all ok
- cargo test --workspace: all pass except openab-core
  secrets::tests::resolve_exec_nonzero_exit, which spawns /bin/false;
  macOS has only /usr/bin/false. openab-core is untouched here; CI is Linux.
---
 crates/openab-cp/Cargo.toml      | 61 ++++++++++++++++++++++++++------
 crates/openab-cp/cp.toml.example |  2 ++
 crates/openab-cp/src/config.rs   | 23 ++++++++++++
 crates/openab-cp/src/lib.rs      | 19 ++++++++++
 crates/openab-cp/src/proto.rs    |  4 +++
 5 files changed, 99 insertions(+), 10 deletions(-)

diff --git a/crates/openab-cp/Cargo.toml b/crates/openab-cp/Cargo.toml
index 86ca5e30c..17ad2aa08 100644
--- a/crates/openab-cp/Cargo.toml
+++ b/crates/openab-cp/Cargo.toml
@@ -6,19 +6,60 @@ license = "MIT"
 description = "OpenAB Agent Control Plane — registry, router, and policy for direct inter-agent delegation"
 
 [dependencies]
-tokio = { version = "1", features = ["full"] }
-axum = { version = "0.8", features = ["ws"] }
-futures-util = "0.3"
+# --- wire types (always compiled) ---
+# `proto` is the shared contract between the CP and every runtime that speaks
+# to it, so it must be usable WITHOUT the server: runtime clients (the OAB
+# runtime in `openab-core`, from the follow-up runtime-client PR) depend on
+# this crate with `default-features = false` purely for these types, and must
+# not inherit axum/tokio/hyper through that edge (the runtime image would
+# otherwise grow a whole HTTP server it never binds).
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-toml = "0.8"
-tracing = "0.1"
-tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-anyhow = "1"
 chrono = { version = "0.4", features = ["serde"] }
-parking_lot = "0.12"
-clap = { version = "4", features = ["derive"] }
-subtle = "2"
+
+# --- server-only (feature `server`, on by default) ---
+tokio = { version = "1", features = ["full"], optional = true }
+axum = { version = "0.8", features = ["ws"], optional = true }
+futures-util = { version = "0.3", optional = true }
+toml = { version = "0.8", optional = true }
+tracing = { version = "0.1", optional = true }
+tracing-subscriber = { version = "0.3", features = ["env-filter"], optional = true }
+anyhow = { version = "1", optional = true }
+parking_lot = { version = "0.12", optional = true }
+clap = { version = "4", features = ["derive"], optional = true }
+subtle = { version = "2", optional = true }
+
+[features]
+# Default: the full control plane (config, registry, policy, router, events,
+# WebSocket server) plus the `openab-cp` binary. Turning it off leaves only
+# `proto` — the wire contract — which is what runtime clients need.
+default = ["server"]
+server = [
+    "dep:tokio",
+    "dep:axum",
+    "dep:futures-util",
+    "dep:toml",
+    "dep:tracing",
+    "dep:tracing-subscriber",
+    "dep:anyhow",
+    "dep:parking_lot",
+    "dep:clap",
+    "dep:subtle",
+]
+
+# The binary IS the server; without the feature there is nothing for it to
+# start, so it is skipped instead of failing to compile.
+[[bin]]
+name = "openab-cp"
+path = "src/main.rs"
+required-features = ["server"]
+
+# The lifecycle tests drive the real WebSocket server, so they only exist
+# with it; without this, `cargo test --no-default-features` cannot build.
+[[test]]
+name = "ws_lifecycle"
+path = "tests/ws_lifecycle.rs"
+required-features = ["server"]
 
 [dev-dependencies]
 # WebSocket client for the end-to-end admission/lifecycle tests. Same version
diff --git a/crates/openab-cp/cp.toml.example b/crates/openab-cp/cp.toml.example
index f4ea04ddc..cb8fdfa54 100644
--- a/crates/openab-cp/cp.toml.example
+++ b/crates/openab-cp/cp.toml.example
@@ -23,6 +23,8 @@ max_deadline_secs = 1800
 max_result_bytes = 262144
 
 # Transport-level cap on inbound WebSocket messages (enforced pre-parse).
+# Must remain at least 1048576 bytes for the bundled runtime client; larger
+# values are allowed, while smaller values are rejected during validation.
 max_frame_bytes = 1048576
 
 # Delegation prompts larger than this are rejected.
diff --git a/crates/openab-cp/src/config.rs b/crates/openab-cp/src/config.rs
index a7fd7b6f9..be4d27088 100644
--- a/crates/openab-cp/src/config.rs
+++ b/crates/openab-cp/src/config.rs
@@ -307,6 +307,14 @@ impl CpConfig {
         if self.write_timeout_secs == 0 {
             bail!("write_timeout_secs must be greater than 0");
         }
+        if self.max_frame_bytes < crate::proto::MIN_RUNTIME_FRAME_BYTES {
+            bail!(
+                "max_frame_bytes ({}) is below the bundled runtime minimum ({}) — \
+                 raise it or use a protocol-compatible client with a smaller negotiated ceiling",
+                self.max_frame_bytes,
+                crate::proto::MIN_RUNTIME_FRAME_BYTES
+            );
+        }
         // A budget that cannot hold one maximum-size frame would refuse every
         // enqueue and disconnect every peer the moment a large frame is routed
         // to it.
@@ -614,6 +622,21 @@ lease_expiry_secs = 30
         }
     }
 
+    #[test]
+    fn frame_limit_cannot_undercut_the_bundled_runtime_contract() {
+        let cfg: CpConfig = toml::from_str("max_frame_bytes = 1048575").unwrap();
+        let err = cfg.validate().unwrap_err().to_string();
+        assert_eq!(
+            err,
+            concat!(
+                "max_frame_bytes (1048575) is below the bundled runtime minimum (1048576) — ",
+                "raise it or use a protocol-compatible client with a smaller negotiated ceiling"
+            )
+        );
+        let cfg: CpConfig = toml::from_str("max_frame_bytes = 1048576").unwrap();
+        cfg.validate().unwrap();
+    }
+
     #[test]
     fn resource_bounds_default_and_are_validated() {
         // The byte budget, the global in-flight ceiling, and the default
diff --git a/crates/openab-cp/src/lib.rs b/crates/openab-cp/src/lib.rs
index 2ffefece0..48baade90 100644
--- a/crates/openab-cp/src/lib.rs
+++ b/crates/openab-cp/src/lib.rs
@@ -5,11 +5,30 @@
 //! register over WebSocket; the CP authenticates them against config-bound
 //! identities, enforces delegation policy authoritatively, and routes
 //! `cp/delegate` / `cp/delegate_result` frames between them.
+//!
+//! ## Crate layout: `proto` vs the `server` feature
+//!
+//! [`proto`] is the wire contract and is ALWAYS compiled. Everything else —
+//! config, registry, policy, router, observer fan-out, and the WebSocket
+//! server — sits behind the default `server` feature, together with the axum
+//! and tokio dependencies it needs.
+//!
+//! That split exists so the OAB runtime (`openab-core`) can depend on this
+//! crate with `default-features = false` to speak the protocol without
+//! linking an HTTP server it never binds. Anything a runtime client needs
+//! belongs in `proto`; anything that only the hub does must stay behind the
+//! feature.
 
+#[cfg(feature = "server")]
 pub mod config;
+#[cfg(feature = "server")]
 pub mod events;
+#[cfg(feature = "server")]
 pub mod policy;
 pub mod proto;
+#[cfg(feature = "server")]
 pub mod registry;
+#[cfg(feature = "server")]
 pub mod router;
+#[cfg(feature = "server")]
 pub mod server;
diff --git a/crates/openab-cp/src/proto.rs b/crates/openab-cp/src/proto.rs
index 5e70b984b..acf57b97b 100644
--- a/crates/openab-cp/src/proto.rs
+++ b/crates/openab-cp/src/proto.rs
@@ -37,6 +37,10 @@ use serde_json::Value;
 /// Wire protocol version. Carried in `cp/register`; the CP rejects
 /// registrations with a version it does not support.
 pub const PROTOCOL_VERSION: u32 = 1;
+/// Minimum frame ceiling supported by the bundled runtime client. The server
+/// may configure a larger value, but a smaller one would let an otherwise
+/// valid runtime result disconnect the whole worker connection.
+pub const MIN_RUNTIME_FRAME_BYTES: usize = 1024 * 1024;
 
 // --- JSON-RPC envelopes ---
 

From 3fbe4022ecea5e69c45eb3802971b8d9af20c3d9 Mon Sep 17 00:00:00 2001
From: chaodu-agent <chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 06:49:48 -0400
Subject: [PATCH 2/8] test(cp): exercise the queue-vs-frame rule above the
 frame floor

Review opus5-F1: the max_frame_bytes floor ran before the
max_outbound_queue_bytes <= max_frame_bytes check, so the case
queue=4096/frame=8192 was rejected by the floor and the strictly-below
branch of the queue rule went untested. Replace it with
queue=1048576/frame=2097152 and assert the expected error text for every
rejection case instead of a bare is_err().

Review opus5-F2: proto.rs and cp.toml.example now say the runtime client
lands in a follow-up PR instead of describing it as already bundled.

Verified on macmini (M4), clean copy of this tree:
- cargo fmt -p openab-cp --check: clean
- cargo build -p openab-cp --locked: ok
- cargo test -p openab-cp --locked: 142 unit + 9 ws_lifecycle passed
- cargo check -p openab-cp --no-default-features --locked: ok
- cargo test -p openab-cp --no-default-features --locked: 16 proto passed
- cargo clippy -p openab-cp --all-targets -- -D warnings: clean
  (default and --no-default-features)
- cargo clippy --workspace -- -D warnings, cargo check --workspace: ok
- Cargo.lock unchanged vs origin/main
---
 crates/openab-cp/cp.toml.example |  5 +++--
 crates/openab-cp/src/config.rs   | 24 ++++++++++++++++++------
 crates/openab-cp/src/proto.rs    |  7 ++++---
 3 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/crates/openab-cp/cp.toml.example b/crates/openab-cp/cp.toml.example
index cb8fdfa54..baa22dec0 100644
--- a/crates/openab-cp/cp.toml.example
+++ b/crates/openab-cp/cp.toml.example
@@ -23,8 +23,9 @@ max_deadline_secs = 1800
 max_result_bytes = 262144
 
 # Transport-level cap on inbound WebSocket messages (enforced pre-parse).
-# Must remain at least 1048576 bytes for the bundled runtime client; larger
-# values are allowed, while smaller values are rejected during validation.
+# Must be at least 1048576 bytes, the minimum the runtime client (landing in
+# a follow-up PR) requires; larger values are allowed, smaller values are
+# rejected during validation.
 max_frame_bytes = 1048576
 
 # Delegation prompts larger than this are rejected.
diff --git a/crates/openab-cp/src/config.rs b/crates/openab-cp/src/config.rs
index be4d27088..4499cead5 100644
--- a/crates/openab-cp/src/config.rs
+++ b/crates/openab-cp/src/config.rs
@@ -659,16 +659,28 @@ default_max_delegated_sessions_cap = 3",
         assert_eq!(explicit.max_inflight_delegations, 32);
         assert_eq!(explicit.default_max_delegated_sessions_cap, 3);
 
-        for bad in [
-            "max_inflight_delegations = 0",
-            "default_max_delegated_sessions_cap = 0",
+        for (bad, why) in [
+            ("max_inflight_delegations = 0", "max_inflight_delegations"),
+            (
+                "default_max_delegated_sessions_cap = 0",
+                "default_max_delegated_sessions_cap",
+            ),
             // Equal to max_frame_bytes is not enough: one maximum-size frame
             // must fit, or the connection is unusable.
-            "max_outbound_queue_bytes = 1048576",
-            "max_outbound_queue_bytes = 4096\nmax_frame_bytes = 8192",
+            (
+                "max_outbound_queue_bytes = 1048576",
+                "must exceed max_frame_bytes",
+            ),
+            // Strictly below, with a frame ceiling above the runtime floor so
+            // the queue rule (not the floor) is what rejects it.
+            (
+                "max_outbound_queue_bytes = 1048576\nmax_frame_bytes = 2097152",
+                "must exceed max_frame_bytes",
+            ),
         ] {
             let cfg: CpConfig = toml::from_str(bad).unwrap();
-            assert!(cfg.validate().is_err(), "{bad} must be rejected");
+            let err = cfg.validate().expect_err(bad).to_string();
+            assert!(err.contains(why), "{bad}: unexpected error {err:?}");
         }
     }
 
diff --git a/crates/openab-cp/src/proto.rs b/crates/openab-cp/src/proto.rs
index acf57b97b..1802c95bc 100644
--- a/crates/openab-cp/src/proto.rs
+++ b/crates/openab-cp/src/proto.rs
@@ -37,9 +37,10 @@ use serde_json::Value;
 /// Wire protocol version. Carried in `cp/register`; the CP rejects
 /// registrations with a version it does not support.
 pub const PROTOCOL_VERSION: u32 = 1;
-/// Minimum frame ceiling supported by the bundled runtime client. The server
-/// may configure a larger value, but a smaller one would let an otherwise
-/// valid runtime result disconnect the whole worker connection.
+/// Minimum frame ceiling the runtime client (landing in the follow-up PR)
+/// will require. The server may configure a larger value, but a smaller one
+/// would let an otherwise valid runtime result disconnect the whole worker
+/// connection.
 pub const MIN_RUNTIME_FRAME_BYTES: usize = 1024 * 1024;
 
 // --- JSON-RPC envelopes ---

From 98626dcda8f518d9f64f6aa0d3e992fe73c7e0b0 Mon Sep 17 00:00:00 2001
From: chaodu-agent <chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 11:02:30 +0000
Subject: [PATCH 3/8] fix(review): defer max_frame_bytes floor enforcement to
 the runtime-client PR

Keep MIN_RUNTIME_FRAME_BYTES in proto as the shared constant, but drop the
CpConfig::validate() rejection and its test: nothing in this PR consumes the
floor, and the error text promised a frame-size negotiation the protocol does
not have. The check lands with the runtime client in PR B.
---
 crates/openab-cp/cp.toml.example |  3 ---
 crates/openab-cp/src/config.rs   | 26 +-------------------------
 crates/openab-cp/src/proto.rs    |  4 +++-
 3 files changed, 4 insertions(+), 29 deletions(-)

diff --git a/crates/openab-cp/cp.toml.example b/crates/openab-cp/cp.toml.example
index baa22dec0..f4ea04ddc 100644
--- a/crates/openab-cp/cp.toml.example
+++ b/crates/openab-cp/cp.toml.example
@@ -23,9 +23,6 @@ max_deadline_secs = 1800
 max_result_bytes = 262144
 
 # Transport-level cap on inbound WebSocket messages (enforced pre-parse).
-# Must be at least 1048576 bytes, the minimum the runtime client (landing in
-# a follow-up PR) requires; larger values are allowed, smaller values are
-# rejected during validation.
 max_frame_bytes = 1048576
 
 # Delegation prompts larger than this are rejected.
diff --git a/crates/openab-cp/src/config.rs b/crates/openab-cp/src/config.rs
index 4499cead5..f78015256 100644
--- a/crates/openab-cp/src/config.rs
+++ b/crates/openab-cp/src/config.rs
@@ -307,14 +307,6 @@ impl CpConfig {
         if self.write_timeout_secs == 0 {
             bail!("write_timeout_secs must be greater than 0");
         }
-        if self.max_frame_bytes < crate::proto::MIN_RUNTIME_FRAME_BYTES {
-            bail!(
-                "max_frame_bytes ({}) is below the bundled runtime minimum ({}) — \
-                 raise it or use a protocol-compatible client with a smaller negotiated ceiling",
-                self.max_frame_bytes,
-                crate::proto::MIN_RUNTIME_FRAME_BYTES
-            );
-        }
         // A budget that cannot hold one maximum-size frame would refuse every
         // enqueue and disconnect every peer the moment a large frame is routed
         // to it.
@@ -622,21 +614,6 @@ lease_expiry_secs = 30
         }
     }
 
-    #[test]
-    fn frame_limit_cannot_undercut_the_bundled_runtime_contract() {
-        let cfg: CpConfig = toml::from_str("max_frame_bytes = 1048575").unwrap();
-        let err = cfg.validate().unwrap_err().to_string();
-        assert_eq!(
-            err,
-            concat!(
-                "max_frame_bytes (1048575) is below the bundled runtime minimum (1048576) — ",
-                "raise it or use a protocol-compatible client with a smaller negotiated ceiling"
-            )
-        );
-        let cfg: CpConfig = toml::from_str("max_frame_bytes = 1048576").unwrap();
-        cfg.validate().unwrap();
-    }
-
     #[test]
     fn resource_bounds_default_and_are_validated() {
         // The byte budget, the global in-flight ceiling, and the default
@@ -671,8 +648,7 @@ default_max_delegated_sessions_cap = 3",
                 "max_outbound_queue_bytes = 1048576",
                 "must exceed max_frame_bytes",
             ),
-            // Strictly below, with a frame ceiling above the runtime floor so
-            // the queue rule (not the floor) is what rejects it.
+            // Strictly below max_frame_bytes.
             (
                 "max_outbound_queue_bytes = 1048576\nmax_frame_bytes = 2097152",
                 "must exceed max_frame_bytes",
diff --git a/crates/openab-cp/src/proto.rs b/crates/openab-cp/src/proto.rs
index 1802c95bc..2e9454838 100644
--- a/crates/openab-cp/src/proto.rs
+++ b/crates/openab-cp/src/proto.rs
@@ -40,7 +40,9 @@ pub const PROTOCOL_VERSION: u32 = 1;
 /// Minimum frame ceiling the runtime client (landing in the follow-up PR)
 /// will require. The server may configure a larger value, but a smaller one
 /// would let an otherwise valid runtime result disconnect the whole worker
-/// connection.
+/// connection. Not enforced yet: CP config validation starts rejecting
+/// smaller `max_frame_bytes` values in the same follow-up PR, together with
+/// the client that relies on it. The protocol has no frame-size negotiation.
 pub const MIN_RUNTIME_FRAME_BYTES: usize = 1024 * 1024;
 
 // --- JSON-RPC envelopes ---

From 1a3171280b0d112001a6768f8ec6dba4ce864a1e Mon Sep 17 00:00:00 2001
From: chaodu-agent <274062505+chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 11:05:34 +0000
Subject: [PATCH 4/8] fix(review): document Cargo feature unification for the
 openab-cp proto split

The no-server guarantee holds only when nothing else in the same build
enables the server feature; cargo build --workspace does, through the
openab-cp binary. The tokio-tungstenite dev-dependency is test-only and
never reaches downstream crates.
---
 crates/openab-cp/Cargo.toml | 7 +++++++
 crates/openab-cp/src/lib.rs | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/crates/openab-cp/Cargo.toml b/crates/openab-cp/Cargo.toml
index 17ad2aa08..4e57f685c 100644
--- a/crates/openab-cp/Cargo.toml
+++ b/crates/openab-cp/Cargo.toml
@@ -13,6 +13,13 @@ description = "OpenAB Agent Control Plane — registry, router, and policy for d
 # this crate with `default-features = false` purely for these types, and must
 # not inherit axum/tokio/hyper through that edge (the runtime image would
 # otherwise grow a whole HTTP server it never binds).
+#
+# Caveat: Cargo unifies features per build. If anything else in the same build
+# enables `server` (for example `cargo build --workspace`, which also builds
+# the `openab-cp` binary), the runtime is compiled against the server deps
+# too. The guarantee holds when the runtime package is built on its own.
+# `tokio-tungstenite` under [dev-dependencies] is test-only and never reaches
+# downstream crates.
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 chrono = { version = "0.4", features = ["serde"] }
diff --git a/crates/openab-cp/src/lib.rs b/crates/openab-cp/src/lib.rs
index 48baade90..99efdbb7c 100644
--- a/crates/openab-cp/src/lib.rs
+++ b/crates/openab-cp/src/lib.rs
@@ -18,6 +18,11 @@
 //! linking an HTTP server it never binds. Anything a runtime client needs
 //! belongs in `proto`; anything that only the hub does must stay behind the
 //! feature.
+//!
+//! Cargo unifies features per build, so this only keeps the server out of a
+//! build that does not also enable `server` somewhere else (a
+//! `cargo build --workspace` does, through the `openab-cp` binary). 
+//! Build the runtime package on its own to get the server-free graph.
 
 #[cfg(feature = "server")]
 pub mod config;

From 9c1166270f1563d681c6bf4a8147db64b705a26f Mon Sep 17 00:00:00 2001
From: chaodu-agent <274062505+chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 11:05:42 +0000
Subject: [PATCH 5/8] fix(review): drop trailing whitespace in openab-cp lib
 docs

---
 crates/openab-cp/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/openab-cp/src/lib.rs b/crates/openab-cp/src/lib.rs
index 99efdbb7c..d387ba884 100644
--- a/crates/openab-cp/src/lib.rs
+++ b/crates/openab-cp/src/lib.rs
@@ -21,7 +21,7 @@
 //!
 //! Cargo unifies features per build, so this only keeps the server out of a
 //! build that does not also enable `server` somewhere else (a
-//! `cargo build --workspace` does, through the `openab-cp` binary). 
+//! `cargo build --workspace` does, through the `openab-cp` binary).
 //! Build the runtime package on its own to get the server-free graph.
 
 #[cfg(feature = "server")]

From 0916de60b02ad5bb82d37f4ece05f113f43300a2 Mon Sep 17 00:00:00 2001
From: chaodu-agent <274062505+chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 11:14:53 +0000
Subject: [PATCH 6/8] fix(review): CI-check the openab-cp proto-only build

--workspace always enables openab-cp's default server feature, so no CI
step built the configuration runtime clients depend on. Add clippy and
test for openab-cp with --no-default-features, and fail if a server
dependency appears in its normal dependency graph (-e normal leaves out
the test-only tokio-tungstenite dev-dependency).
---
 .github/workflows/ci.yml | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f8d65f39e..91fa56616 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -93,6 +93,22 @@ jobs:
         run: cargo test --features acp
       - name: cargo build (unified)
         run: cargo build --features unified
+      # `--workspace` always enables openab-cp's default `server` feature, so nothing above ever
+      # builds the proto-only configuration that runtime clients depend on. Build, lint and test
+      # it on its own, then fail if a server dependency leaks into its normal dependency graph.
+      # `-e normal` leaves out the test-only `tokio-tungstenite` dev-dependency.
+      - name: openab-cp (proto only, no default features)
+        run: |
+          set -euo pipefail
+          cargo clippy -p openab-cp --no-default-features --all-targets -- -D warnings
+          cargo test -p openab-cp --no-default-features
+          leaked=$(cargo tree -p openab-cp --no-default-features -e normal --prefix none \
+            | grep -E '^(tokio|axum|hyper|tower|tracing|clap|toml) ' || true)
+          if [ -n "$leaked" ]; then
+            echo "::error::openab-cp proto-only build pulls in server dependencies:"
+            echo "$leaked"
+            exit 1
+          fi
 
   operator:
     needs: changes

From 9837a1a0ccff02bcb65c4ebdc6ee291ec705feb3 Mon Sep 17 00:00:00 2001
From: chaodu-agent <274062505+chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 09:21:15 -0400
Subject: [PATCH 7/8] fix(review): make the openab-cp proto-only leak check
 fail closed

- cargo tree's output is captured on its own, so a failing cargo tree
  aborts the step under set -e, and an output without the openab-cp root
  line fails explicitly instead of reading as "no leak" (opus5-F2).
- The denylist is now the ten optional deps the `server` feature gates
  plus axum's hyper/tower transitives (opus5-F3).

Verified on macmini (scratch copy, rust stable):
- the extracted CI step script (clippy -D warnings, cargo test
  --no-default-features: 16 passed, tree check): exit 0
- pattern against the default-features tree matches all ten server deps
- cargo tree on a bad package aborts the step before the grep
---
 .github/workflows/ci.yml | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 91fa56616..6caeffcf7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -96,14 +96,21 @@ jobs:
       # `--workspace` always enables openab-cp's default `server` feature, so nothing above ever
       # builds the proto-only configuration that runtime clients depend on. Build, lint and test
       # it on its own, then fail if a server dependency leaks into its normal dependency graph.
-      # `-e normal` leaves out the test-only `tokio-tungstenite` dev-dependency.
+      # `-e normal` leaves out the test-only `tokio-tungstenite` dev-dependency. The pattern is
+      # the `server` feature's optional deps (crates/openab-cp/Cargo.toml) plus axum's hyper/tower.
       - name: openab-cp (proto only, no default features)
         run: |
           set -euo pipefail
           cargo clippy -p openab-cp --no-default-features --all-targets -- -D warnings
           cargo test -p openab-cp --no-default-features
-          leaked=$(cargo tree -p openab-cp --no-default-features -e normal --prefix none \
-            | grep -E '^(tokio|axum|hyper|tower|tracing|clap|toml) ' || true)
+          tree=$(cargo tree -p openab-cp --no-default-features -e normal --prefix none)
+          if ! printf '%s\n' "$tree" | grep -q '^openab-cp '; then
+            echo "::error::cargo tree did not list openab-cp; the leak check cannot run"
+            exit 1
+          fi
+          leaked=$(printf '%s\n' "$tree" \
+            | grep -E '^(tokio|axum|futures-util|toml|tracing|tracing-subscriber|anyhow|parking_lot|clap|subtle|hyper|tower) ' \
+            || true)
           if [ -n "$leaked" ]; then
             echo "::error::openab-cp proto-only build pulls in server dependencies:"
             echo "$leaked"

From f0b33a9a07a4efdd3864b98cf33f377a0a47fa1d Mon Sep 17 00:00:00 2001
From: chaodu-agent <chaodu-agent@users.noreply.github.com>
Date: Fri, 30 Oct 2026 14:53:21 -0400
Subject: [PATCH 8/8] fix(cp): fail the proto leak check closed and drop the
 unused frame floor constant

- ci.yml: read the server-only denylist from the optional deps in
  crates/openab-cp/Cargo.toml instead of a hand-written list. Fail when
  that list is empty, when cargo tree errors or prints nothing, and when
  openab-cp is missing from the tree. The step has no || true.
- proto.rs: remove MIN_RUNTIME_FRAME_BYTES. Nothing consumes it in this
  PR (review NIT F2). The constant and its max_frame_bytes floor move to
  the runtime-client PR.

Checks on macmini, scratch copy of this commit (--locked):
- CI step script run verbatim: clippy -D warnings, cargo test
  --no-default-features (16 proto tests), leak check exit 0.
- Leak check against a fake cargo: leaked futures-util -> exit 1; empty
  tree -> exit 1; failing cargo tree -> exit 101; clean tree -> exit 0.
- Default: clippy --all-targets -D warnings clean; cargo test (141 unit,
  9 integration) passed.
- cargo fmt -p openab-cp --check clean.
---
 .github/workflows/ci.yml      | 35 +++++++++++++++++++++++++++--------
 crates/openab-cp/src/proto.rs |  7 -------
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6caeffcf7..77bef73a4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -96,24 +96,43 @@ jobs:
       # `--workspace` always enables openab-cp's default `server` feature, so nothing above ever
       # builds the proto-only configuration that runtime clients depend on. Build, lint and test
       # it on its own, then fail if a server dependency leaks into its normal dependency graph.
-      # `-e normal` leaves out the test-only `tokio-tungstenite` dev-dependency. The pattern is
-      # the `server` feature's optional deps (crates/openab-cp/Cargo.toml) plus axum's hyper/tower.
+      # `-e normal` leaves out the test-only `tokio-tungstenite` dev-dependency. The denylist is
+      # read from the optional dependencies in crates/openab-cp/Cargo.toml (every dep that the
+      # `server` feature turns on), so it cannot drift from the manifest. Any failure stops the step.
       - name: openab-cp (proto only, no default features)
         run: |
           set -euo pipefail
           cargo clippy -p openab-cp --no-default-features --all-targets -- -D warnings
           cargo test -p openab-cp --no-default-features
+          server_deps=$(python3 -c '
+          import tomllib
+          with open("crates/openab-cp/Cargo.toml", "rb") as f:
+              manifest = tomllib.load(f)
+          for name, spec in manifest.get("dependencies", {}).items():
+              if isinstance(spec, dict) and spec.get("optional"):
+                  print(name)
+          ')
+          if [ -z "$server_deps" ]; then
+            echo "::error::Cargo.toml lists no optional server dependencies; the leak check would be empty"
+            exit 1
+          fi
           tree=$(cargo tree -p openab-cp --no-default-features -e normal --prefix none)
-          if ! printf '%s\n' "$tree" | grep -q '^openab-cp '; then
+          if [ -z "$tree" ]; then
+            echo "::error::cargo tree printed nothing; the leak check cannot run"
+            exit 1
+          fi
+          if ! grep -q '^openab-cp ' <<< "$tree"; then
             echo "::error::cargo tree did not list openab-cp; the leak check cannot run"
             exit 1
           fi
-          leaked=$(printf '%s\n' "$tree" \
-            | grep -E '^(tokio|axum|futures-util|toml|tracing|tracing-subscriber|anyhow|parking_lot|clap|subtle|hyper|tower) ' \
-            || true)
+          leaked=""
+          while read -r dep; do
+            if grep -q "^${dep} " <<< "$tree"; then
+              leaked="$leaked $dep"
+            fi
+          done <<< "$server_deps"
           if [ -n "$leaked" ]; then
-            echo "::error::openab-cp proto-only build pulls in server dependencies:"
-            echo "$leaked"
+            echo "::error::openab-cp proto-only build pulls in server dependencies:$leaked"
             exit 1
           fi
 
diff --git a/crates/openab-cp/src/proto.rs b/crates/openab-cp/src/proto.rs
index 2e9454838..5e70b984b 100644
--- a/crates/openab-cp/src/proto.rs
+++ b/crates/openab-cp/src/proto.rs
@@ -37,13 +37,6 @@ use serde_json::Value;
 /// Wire protocol version. Carried in `cp/register`; the CP rejects
 /// registrations with a version it does not support.
 pub const PROTOCOL_VERSION: u32 = 1;
-/// Minimum frame ceiling the runtime client (landing in the follow-up PR)
-/// will require. The server may configure a larger value, but a smaller one
-/// would let an otherwise valid runtime result disconnect the whole worker
-/// connection. Not enforced yet: CP config validation starts rejecting
-/// smaller `max_frame_bytes` values in the same follow-up PR, together with
-/// the client that relies on it. The protocol has no frame-size negotiation.
-pub const MIN_RUNTIME_FRAME_BYTES: usize = 1024 * 1024;
 
 // --- JSON-RPC envelopes ---