diff --git a/Cargo.lock b/Cargo.lock
index 62d2a00605..9d8202ea46 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5026,6 +5026,22 @@ dependencies = [
  "trios-phi-schedule",
 ]
 
+[[package]]
+name = "trios-hybrid-broutput"
+version = "0.1.0"
+dependencies = [
+ "trios-hybrid-hy00",
+ "trios-hybrid-hy01",
+]
+
+[[package]]
+name = "trios-hybrid-hy00"
+version = "0.1.0"
+
+[[package]]
+name = "trios-hybrid-hy01"
+version = "0.1.0"
+
 [[package]]
 name = "trios-igla-race"
 version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 578a089ce0..cd5788896c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -65,6 +65,10 @@ members = [
     "vendor/tri-mcp/rings/SR-00",
     "vendor/tri-mcp/rings/SR-01",
     "vendor/tri-mcp/rings/SR-02",
+    # trios-hybrid — ring scaffold (issue #238)
+    "crates/trios-hybrid/rings/HY-00",
+    "crates/trios-hybrid/rings/HY-01",
+    "crates/trios-hybrid/rings/BR-OUTPUT",
 ]
 exclude = [
     "crates/trios-ext",
diff --git a/crates/trios-hybrid/AGENTS.md b/crates/trios-hybrid/AGENTS.md
new file mode 100644
index 0000000000..3897fa4604
--- /dev/null
+++ b/crates/trios-hybrid/AGENTS.md
@@ -0,0 +1,44 @@
+# AGENTS.md — trios-hybrid
+
+> AAIF-compliant (Linux Foundation Agentic AI Foundation)
+> MCP-compatible agent instructions
+
+## Identity
+
+- Crate: trios-hybrid
+- Tier: 2 (SILVER)
+- Status: Scaffolded (logic migration: TODO)
+- Repo: gHashTag/trios
+
+## What this crate does
+
+Existing logic in `src/`. The `rings/` directory contains scaffold packages
+for the future ring-isolation migration per issue #238.
+
+## Ring map
+
+| Ring | Package | Role | Sealed |
+|------|---------|------|--------|
+| HY-00 | trios-hybrid-hy-00 | runtime | No |
+| HY-01 | trios-hybrid-hy-01 | dispatch | No |
+| BR-OUTPUT | trios-hybrid-br-output | assembly | No |
+
+## Rules (ABSOLUTE)
+
+- Read repo `LAWS.md` and `CLAUDE.md` before any action
+- L-ARCH-001: After migration, logic lives in `rings/` — `src/lib.rs` becomes RE-EXPORT
+- R1–R5: Ring Isolation
+- R9: No cross-ring imports except via Cargo.toml
+- L6: Pure Rust only
+- L7: Experience line per merge
+
+## Migration plan
+
+1. Stub rings exist with passing tests (this PR)
+2. Future PR: extract types/logic from `src/` into appropriate rings
+3. `src/lib.rs` becomes thin re-export facade
+
+## You MAY NOT (until migration complete)
+
+- ❌ Add new logic to `rings/<ring>/src/lib.rs` beyond stub types
+- ❌ Cross-import rings without Cargo.toml declaration
diff --git a/crates/trios-hybrid/RING.md b/crates/trios-hybrid/RING.md
new file mode 100644
index 0000000000..3c4d226747
--- /dev/null
+++ b/crates/trios-hybrid/RING.md
@@ -0,0 +1,47 @@
+# RING — trios-hybrid
+
+## Identity
+
+| Field | Value |
+|-------|-------|
+| Metal | 🥈 Silver (Tier 2) |
+| Type | Crate (scaffold — logic migration: TODO) |
+| Sealed | No |
+
+## Purpose
+
+Scaffold for ring-isolation architecture (issue #238).
+Current logic lives in `src/` — rings are organizational placeholders for future migration.
+
+## Ring Structure (L-ARCH-001)
+
+```
+crates/trios-hybrid/
+├── src/                ← existing logic (untouched)
+├── rings/
+│   ├── HY-00/             ← runtime
+│   ├── HY-01/             ← dispatch
+│   ├── BR-OUTPUT/             ← assembly
+└── RING.md, AGENTS.md
+```
+
+## Dependency Flow
+
+```
+BR-OUTPUT
+    ↓
+  HY-00   HY-01 
+```
+
+No ring imports a sibling at the same level. Logic-bearing rings (non-BR) are independent.
+
+## Anchor
+
+`phi^2 + phi^-2 = 3 · TRINITY · NEVER STOP`
+
+## Laws
+
+- L-ARCH-001: Only `rings/` contains logic (after migration)
+- R1–R5: Ring Isolation
+- L6: Pure Rust only
+- R9: Ring isolation (no cross-ring imports except via Cargo.toml)
diff --git a/crates/trios-hybrid/rings/BR-OUTPUT/AGENTS.md b/crates/trios-hybrid/rings/BR-OUTPUT/AGENTS.md
new file mode 100644
index 0000000000..5c894b151a
--- /dev/null
+++ b/crates/trios-hybrid/rings/BR-OUTPUT/AGENTS.md
@@ -0,0 +1,38 @@
+# AGENTS.md — BR-OUTPUT (trios-hybrid)
+
+> AAIF-compliant | MCP-compatible
+
+## Identity
+
+- Ring: BR-OUTPUT
+- Package: trios-hybrid-broutput
+- Role: assembly (scaffold — logic migration: TODO)
+
+## What this ring does (target)
+
+Owns assembly logic for trios-hybrid after migration.
+Currently a stub with a marker type and metadata constants.
+
+## Rules (ABSOLUTE)
+
+- R1: Sibling rings may not be imported without Cargo.toml declaration
+- R9: Ring isolation
+- L6: Pure Rust only
+
+## You MAY
+
+- ✅ Add types/methods within this ring's scope (assembly)
+- ✅ Add unit tests
+- ✅ Migrate code from `crates/trios-hybrid/src/` matching this ring's scope
+
+## You MAY NOT
+
+- ❌ Import sibling rings without Cargo.toml dep
+- ❌ Add I/O or async without explicit approval (check parent crate's policy)
+
+## Build
+
+```bash
+cargo check -p trios-hybrid-broutput
+cargo test  -p trios-hybrid-broutput
+```
diff --git a/crates/trios-hybrid/rings/BR-OUTPUT/Cargo.toml b/crates/trios-hybrid/rings/BR-OUTPUT/Cargo.toml
new file mode 100644
index 0000000000..b5950f3a0f
--- /dev/null
+++ b/crates/trios-hybrid/rings/BR-OUTPUT/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "trios-hybrid-broutput"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dmitrii Vasilev"]
+license = "MIT"
+description = "BR-OUTPUT — assembly (scaffold for trios-hybrid, issue #238)"
+publish = false
+
+[dependencies]
+trios-hybrid-hy00 = { path = "../HY-00" }
+trios-hybrid-hy01 = { path = "../HY-01" }
diff --git a/crates/trios-hybrid/rings/BR-OUTPUT/README.md b/crates/trios-hybrid/rings/BR-OUTPUT/README.md
new file mode 100644
index 0000000000..bb62ac2986
--- /dev/null
+++ b/crates/trios-hybrid/rings/BR-OUTPUT/README.md
@@ -0,0 +1,16 @@
+# BR-OUTPUT — assembly
+
+Ring scaffold for **trios-hybrid** (issue #238).
+
+- Package: `trios-hybrid-broutput`
+- Status: Scaffolded
+- Logic migration: TODO
+
+## Build
+
+```bash
+cargo check -p trios-hybrid-broutput
+cargo test  -p trios-hybrid-broutput
+```
+
+Anchor: `phi^2 + phi^-2 = 3`
diff --git a/crates/trios-hybrid/rings/BR-OUTPUT/TASK.md b/crates/trios-hybrid/rings/BR-OUTPUT/TASK.md
new file mode 100644
index 0000000000..28e31c20e1
--- /dev/null
+++ b/crates/trios-hybrid/rings/BR-OUTPUT/TASK.md
@@ -0,0 +1,17 @@
+# TASK — BR-OUTPUT (trios-hybrid)
+
+## Status: Scaffolded (logic migration: TODO)
+
+## Completed
+
+- [x] Ring directory created
+- [x] `Cargo.toml` registered as workspace member
+- [x] Stub `BrOutputScope` / assembly type with metadata constants
+- [x] At least one passing unit test
+
+## Open
+
+- [ ] Migrate assembly logic from `crates/trios-hybrid/src/` into this ring
+- [ ] Define public API surface for BR-OUTPUT
+- [ ] Add integration tests covering migrated behavior
+- [ ] Update `crates/trios-hybrid/src/lib.rs` to re-export from this ring
diff --git a/crates/trios-hybrid/rings/BR-OUTPUT/src/lib.rs b/crates/trios-hybrid/rings/BR-OUTPUT/src/lib.rs
new file mode 100644
index 0000000000..586fdc80fa
--- /dev/null
+++ b/crates/trios-hybrid/rings/BR-OUTPUT/src/lib.rs
@@ -0,0 +1,32 @@
+//! BR-OUTPUT — assembly ring for trios-hybrid
+//!
+//! Scaffold (issue #238). Logic migration: TODO.
+//! Assembles sibling rings into a unified facade.
+
+/// Marker type for the trios-hybrid assembly facade.
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub struct HybridAssembly;
+
+impl HybridAssembly {
+    pub fn new() -> Self {
+        Self
+    }
+
+    /// Anchor invariant: phi^2 + phi^-2 = 3
+    pub const TRINITY_ANCHOR: &'static str = "phi^2 + phi^-2 = 3";
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn assembly_constructs() {
+        let _a = HybridAssembly::new();
+    }
+
+    #[test]
+    fn anchor_is_set() {
+        assert_eq!(HybridAssembly::TRINITY_ANCHOR, "phi^2 + phi^-2 = 3");
+    }
+}
diff --git a/crates/trios-hybrid/rings/HY-00/AGENTS.md b/crates/trios-hybrid/rings/HY-00/AGENTS.md
new file mode 100644
index 0000000000..73e3097b9e
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-00/AGENTS.md
@@ -0,0 +1,38 @@
+# AGENTS.md — HY-00 (trios-hybrid)
+
+> AAIF-compliant | MCP-compatible
+
+## Identity
+
+- Ring: HY-00
+- Package: trios-hybrid-hy00
+- Role: runtime (scaffold — logic migration: TODO)
+
+## What this ring does (target)
+
+Owns runtime logic for trios-hybrid after migration.
+Currently a stub with a marker type and metadata constants.
+
+## Rules (ABSOLUTE)
+
+- R1: Sibling rings may not be imported without Cargo.toml declaration
+- R9: Ring isolation
+- L6: Pure Rust only
+
+## You MAY
+
+- ✅ Add types/methods within this ring's scope (runtime)
+- ✅ Add unit tests
+- ✅ Migrate code from `crates/trios-hybrid/src/` matching this ring's scope
+
+## You MAY NOT
+
+- ❌ Import sibling rings without Cargo.toml dep
+- ❌ Add I/O or async without explicit approval (check parent crate's policy)
+
+## Build
+
+```bash
+cargo check -p trios-hybrid-hy00
+cargo test  -p trios-hybrid-hy00
+```
diff --git a/crates/trios-hybrid/rings/HY-00/Cargo.toml b/crates/trios-hybrid/rings/HY-00/Cargo.toml
new file mode 100644
index 0000000000..bd2c275097
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-00/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "trios-hybrid-hy00"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dmitrii Vasilev"]
+license = "MIT"
+description = "HY-00 — runtime (scaffold for trios-hybrid, issue #238)"
+publish = false
+
+[dependencies]
diff --git a/crates/trios-hybrid/rings/HY-00/README.md b/crates/trios-hybrid/rings/HY-00/README.md
new file mode 100644
index 0000000000..e76916274f
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-00/README.md
@@ -0,0 +1,16 @@
+# HY-00 — runtime
+
+Ring scaffold for **trios-hybrid** (issue #238).
+
+- Package: `trios-hybrid-hy00`
+- Status: Scaffolded
+- Logic migration: TODO
+
+## Build
+
+```bash
+cargo check -p trios-hybrid-hy00
+cargo test  -p trios-hybrid-hy00
+```
+
+Anchor: `phi^2 + phi^-2 = 3`
diff --git a/crates/trios-hybrid/rings/HY-00/TASK.md b/crates/trios-hybrid/rings/HY-00/TASK.md
new file mode 100644
index 0000000000..115ac2bac7
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-00/TASK.md
@@ -0,0 +1,17 @@
+# TASK — HY-00 (trios-hybrid)
+
+## Status: Scaffolded (logic migration: TODO)
+
+## Completed
+
+- [x] Ring directory created
+- [x] `Cargo.toml` registered as workspace member
+- [x] Stub `Hy00Scope` / assembly type with metadata constants
+- [x] At least one passing unit test
+
+## Open
+
+- [ ] Migrate runtime logic from `crates/trios-hybrid/src/` into this ring
+- [ ] Define public API surface for HY-00
+- [ ] Add integration tests covering migrated behavior
+- [ ] Update `crates/trios-hybrid/src/lib.rs` to re-export from this ring
diff --git a/crates/trios-hybrid/rings/HY-00/src/lib.rs b/crates/trios-hybrid/rings/HY-00/src/lib.rs
new file mode 100644
index 0000000000..fe2592f7de
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-00/src/lib.rs
@@ -0,0 +1,27 @@
+//! HY-00 — runtime (scaffold)
+//!
+//! Scaffold ring for trios-hybrid (issue #238). Logic migration: TODO.
+
+/// Marker for HY-00 ring scope (runtime).
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub struct Hy00Scope;
+
+impl Hy00Scope {
+    pub const RING: &'static str = "HY-00";
+    pub const PURPOSE: &'static str = "runtime";
+
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn scope_metadata() {
+        assert_eq!(Hy00Scope::RING, "HY-00");
+        assert_eq!(Hy00Scope::PURPOSE, "runtime");
+    }
+}
diff --git a/crates/trios-hybrid/rings/HY-01/AGENTS.md b/crates/trios-hybrid/rings/HY-01/AGENTS.md
new file mode 100644
index 0000000000..a000bb8694
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-01/AGENTS.md
@@ -0,0 +1,38 @@
+# AGENTS.md — HY-01 (trios-hybrid)
+
+> AAIF-compliant | MCP-compatible
+
+## Identity
+
+- Ring: HY-01
+- Package: trios-hybrid-hy01
+- Role: dispatch (scaffold — logic migration: TODO)
+
+## What this ring does (target)
+
+Owns dispatch logic for trios-hybrid after migration.
+Currently a stub with a marker type and metadata constants.
+
+## Rules (ABSOLUTE)
+
+- R1: Sibling rings may not be imported without Cargo.toml declaration
+- R9: Ring isolation
+- L6: Pure Rust only
+
+## You MAY
+
+- ✅ Add types/methods within this ring's scope (dispatch)
+- ✅ Add unit tests
+- ✅ Migrate code from `crates/trios-hybrid/src/` matching this ring's scope
+
+## You MAY NOT
+
+- ❌ Import sibling rings without Cargo.toml dep
+- ❌ Add I/O or async without explicit approval (check parent crate's policy)
+
+## Build
+
+```bash
+cargo check -p trios-hybrid-hy01
+cargo test  -p trios-hybrid-hy01
+```
diff --git a/crates/trios-hybrid/rings/HY-01/Cargo.toml b/crates/trios-hybrid/rings/HY-01/Cargo.toml
new file mode 100644
index 0000000000..cfe99184a6
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-01/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "trios-hybrid-hy01"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dmitrii Vasilev"]
+license = "MIT"
+description = "HY-01 — dispatch (scaffold for trios-hybrid, issue #238)"
+publish = false
+
+[dependencies]
diff --git a/crates/trios-hybrid/rings/HY-01/README.md b/crates/trios-hybrid/rings/HY-01/README.md
new file mode 100644
index 0000000000..4a038b39c5
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-01/README.md
@@ -0,0 +1,16 @@
+# HY-01 — dispatch
+
+Ring scaffold for **trios-hybrid** (issue #238).
+
+- Package: `trios-hybrid-hy01`
+- Status: Scaffolded
+- Logic migration: TODO
+
+## Build
+
+```bash
+cargo check -p trios-hybrid-hy01
+cargo test  -p trios-hybrid-hy01
+```
+
+Anchor: `phi^2 + phi^-2 = 3`
diff --git a/crates/trios-hybrid/rings/HY-01/TASK.md b/crates/trios-hybrid/rings/HY-01/TASK.md
new file mode 100644
index 0000000000..fbb9244097
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-01/TASK.md
@@ -0,0 +1,17 @@
+# TASK — HY-01 (trios-hybrid)
+
+## Status: Scaffolded (logic migration: TODO)
+
+## Completed
+
+- [x] Ring directory created
+- [x] `Cargo.toml` registered as workspace member
+- [x] Stub `Hy01Scope` / assembly type with metadata constants
+- [x] At least one passing unit test
+
+## Open
+
+- [ ] Migrate dispatch logic from `crates/trios-hybrid/src/` into this ring
+- [ ] Define public API surface for HY-01
+- [ ] Add integration tests covering migrated behavior
+- [ ] Update `crates/trios-hybrid/src/lib.rs` to re-export from this ring
diff --git a/crates/trios-hybrid/rings/HY-01/src/lib.rs b/crates/trios-hybrid/rings/HY-01/src/lib.rs
new file mode 100644
index 0000000000..91ef4f2e75
--- /dev/null
+++ b/crates/trios-hybrid/rings/HY-01/src/lib.rs
@@ -0,0 +1,27 @@
+//! HY-01 — dispatch (scaffold)
+//!
+//! Scaffold ring for trios-hybrid (issue #238). Logic migration: TODO.
+
+/// Marker for HY-01 ring scope (dispatch).
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub struct Hy01Scope;
+
+impl Hy01Scope {
+    pub const RING: &'static str = "HY-01";
+    pub const PURPOSE: &'static str = "dispatch";
+
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn scope_metadata() {
+        assert_eq!(Hy01Scope::RING, "HY-01");
+        assert_eq!(Hy01Scope::PURPOSE, "dispatch");
+    }
+}