diff --git a/crates/trios-sacred/AGENTS.md b/crates/trios-sacred/AGENTS.md
new file mode 100644
index 0000000000..6447c5c070
--- /dev/null
+++ b/crates/trios-sacred/AGENTS.md
@@ -0,0 +1,21 @@
+# AGENTS.md — trios-sacred
+
+> AAIF-compliant | MCP-compatible
+
+- Crate: trios-sacred (Gold)
+- Repo: gHashTag/trios
+
+## Ring map
+
+| Ring | Package | Role |
+|------|---------|------|
+| SC-00 | trios-sacred-sc00 | geometry primitives |
+| SC-01 | trios-sacred-sc01 | sacred ratios |
+| BR-OUTPUT | trios-sacred-br-output | assembly |
+
+## Rules
+
+- L-ARCH-001 future logic in rings/
+- R9: no sibling imports
+- L6: pure Rust
+- Anchor: phi^2 + phi^-2 = 3
diff --git a/crates/trios-sacred/RING.md b/crates/trios-sacred/RING.md
new file mode 100644
index 0000000000..7c7175a878
--- /dev/null
+++ b/crates/trios-sacred/RING.md
@@ -0,0 +1,44 @@
+# RING — trios-sacred (Gold Crate)
+
+## Identity
+
+| Field | Value |
+|-------|-------|
+| Metal | 🥇 Gold |
+| Type | Crate |
+| Sealed | No |
+
+## Purpose
+
+Sacred geometry primitives — geometric shapes anchored on phi, and ratio
+helpers (golden ratio, sqrt(2), sqrt(3), pi). Foundational for
+trinity-aligned spatial reasoning.
+
+## Ring Structure (L-ARCH-001)
+
+```
+crates/trios-sacred/
+├── src/lib.rs          ← preserved (FFI to zig-sacred-geometry)
+└── rings/
+    ├── SC-00/          ← geometry primitives (Vec2, Triangle, Circle)
+    ├── SC-01/          ← sacred ratios (phi, sqrt2, sqrt3, pi)
+    └── BR-OUTPUT/      ← assembly + router
+```
+
+## Dependency Flow
+
+```
+BR-OUTPUT
+    ↓
+  SC-01 → SC-00
+```
+
+R9: rings cannot import siblings.
+
+## Laws
+
+- L-ARCH-001: Future logic in `rings/`
+- R1–R5: Ring Isolation
+- R9: No sibling imports
+- L6: Pure Rust only
+- Anchor: `phi^2 + phi^-2 = 3`
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/AGENTS.md b/crates/trios-sacred/rings/BR-OUTPUT/AGENTS.md
new file mode 100644
index 0000000000..10db9c69f5
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/AGENTS.md
@@ -0,0 +1,3 @@
+# AGENTS.md — BR-OUTPUT (trios-sacred)
+
+May import SC-00, SC-01. L6: pure Rust.
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/Cargo.lock b/crates/trios-sacred/rings/BR-OUTPUT/Cargo.lock
new file mode 100644
index 0000000000..c6461d4bbe
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/Cargo.lock
@@ -0,0 +1,22 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "trios-sacred-br-output"
+version = "0.1.0"
+dependencies = [
+ "trios-sacred-sc00",
+ "trios-sacred-sc01",
+]
+
+[[package]]
+name = "trios-sacred-sc00"
+version = "0.1.0"
+
+[[package]]
+name = "trios-sacred-sc01"
+version = "0.1.0"
+dependencies = [
+ "trios-sacred-sc00",
+]
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/Cargo.toml b/crates/trios-sacred/rings/BR-OUTPUT/Cargo.toml
new file mode 100644
index 0000000000..43c44fc377
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "trios-sacred-br-output"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dmitrii Vasilev"]
+license = "MIT"
+description = "BR-OUTPUT — assembly for trios-sacred"
+publish = false
+
+[dependencies]
+trios-sacred-sc00 = { path = "../SC-00" }
+trios-sacred-sc01 = { path = "../SC-01" }
+
+[workspace]
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/README.md b/crates/trios-sacred/rings/BR-OUTPUT/README.md
new file mode 100644
index 0000000000..cfcdfae524
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/README.md
@@ -0,0 +1,3 @@
+# BR-OUTPUT — trios-sacred
+
+Re-exports SC-00 + SC-01.
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/RING.md b/crates/trios-sacred/rings/BR-OUTPUT/RING.md
new file mode 100644
index 0000000000..8b5bf827ff
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/RING.md
@@ -0,0 +1,3 @@
+# RING — BR-OUTPUT (trios-sacred)
+
+Top of ring graph. Imports SC-00, SC-01.
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/TASK.md b/crates/trios-sacred/rings/BR-OUTPUT/TASK.md
new file mode 100644
index 0000000000..f34dc4300f
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/TASK.md
@@ -0,0 +1,8 @@
+# TASK — BR-OUTPUT (trios-sacred)
+
+## Status: SCAFFOLDED
+- [x] Re-export SC-00, SC-01
+- [x] `Sacred::anchor()`
+
+## Open
+- [ ] MCP tools
diff --git a/crates/trios-sacred/rings/BR-OUTPUT/src/lib.rs b/crates/trios-sacred/rings/BR-OUTPUT/src/lib.rs
new file mode 100644
index 0000000000..d18f5bb2df
--- /dev/null
+++ b/crates/trios-sacred/rings/BR-OUTPUT/src/lib.rs
@@ -0,0 +1,28 @@
+//! BR-OUTPUT — trios-sacred assembly
+
+pub use trios_sacred_sc00::{Circle, Triangle, Vec2};
+pub use trios_sacred_sc01::{scale_phi, PHI, PI, SQRT2, SQRT3};
+
+pub struct Sacred;
+
+impl Sacred {
+    pub const fn anchor() -> f64 {
+        3.0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn anchor_const() {
+        assert_eq!(Sacred::anchor(), 3.0);
+    }
+
+    #[test]
+    fn rings_link() {
+        let v = scale_phi(Vec2::new(1.0, 1.0));
+        assert!((v.x - PHI).abs() < 1e-12);
+    }
+}
diff --git a/crates/trios-sacred/rings/SC-00/AGENTS.md b/crates/trios-sacred/rings/SC-00/AGENTS.md
new file mode 100644
index 0000000000..b229dde7bf
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/AGENTS.md
@@ -0,0 +1,7 @@
+# AGENTS.md — SC-00
+
+- Ring: SC-00
+- Package: trios-sacred-sc00
+- R1: no imports from SC-01, BR-OUTPUT
+- R9: no sibling imports
+- L6: pure Rust
diff --git a/crates/trios-sacred/rings/SC-00/Cargo.lock b/crates/trios-sacred/rings/SC-00/Cargo.lock
new file mode 100644
index 0000000000..7c93679304
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "trios-sacred-sc00"
+version = "0.1.0"
diff --git a/crates/trios-sacred/rings/SC-00/Cargo.toml b/crates/trios-sacred/rings/SC-00/Cargo.toml
new file mode 100644
index 0000000000..27be57a4a4
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "trios-sacred-sc00"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dmitrii Vasilev"]
+license = "MIT"
+description = "SC-00 — sacred geometry primitives"
+publish = false
+
+[workspace]
diff --git a/crates/trios-sacred/rings/SC-00/README.md b/crates/trios-sacred/rings/SC-00/README.md
new file mode 100644
index 0000000000..f598571951
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/README.md
@@ -0,0 +1,9 @@
+# SC-00 — sacred geometry primitives
+
+Bottom of the ring graph for trios-sacred.
+
+## API
+
+- `Vec2 { x, y }` with `dot`
+- `Triangle([Vec2; 3])`
+- `Circle { center, radius }`
diff --git a/crates/trios-sacred/rings/SC-00/RING.md b/crates/trios-sacred/rings/SC-00/RING.md
new file mode 100644
index 0000000000..f89f073a75
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/RING.md
@@ -0,0 +1,11 @@
+# RING — SC-00 (trios-sacred)
+
+| Metal | 🥈 Silver |
+| Package | trios-sacred-sc00 |
+
+Geometry primitives. Bottom of dependency graph.
+
+## Laws
+- R1: no SC-01/BR-OUTPUT
+- R9: no sibling imports
+- L6: pure Rust
diff --git a/crates/trios-sacred/rings/SC-00/TASK.md b/crates/trios-sacred/rings/SC-00/TASK.md
new file mode 100644
index 0000000000..aa22c38635
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/TASK.md
@@ -0,0 +1,12 @@
+# TASK — SC-00
+
+## Status: SCAFFOLDED
+
+## Completed
+- [x] Vec2, Triangle, Circle
+- [x] dot product test
+
+## Open
+- [ ] Migrate from `crates/trios-sacred/src/sacred/`
+- [ ] Add Pentagon (phi-anchored)
+- [ ] Add Hexagon, Vesica Piscis
diff --git a/crates/trios-sacred/rings/SC-00/src/lib.rs b/crates/trios-sacred/rings/SC-00/src/lib.rs
new file mode 100644
index 0000000000..2cbe1fa845
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-00/src/lib.rs
@@ -0,0 +1,40 @@
+//! SC-00 — sacred geometry primitives
+//!
+//! Bottom of the ring graph for trios-sacred.
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct Vec2 {
+    pub x: f64,
+    pub y: f64,
+}
+
+impl Vec2 {
+    pub const fn new(x: f64, y: f64) -> Self {
+        Self { x, y }
+    }
+
+    pub fn dot(self, other: Vec2) -> f64 {
+        self.x * other.x + self.y * other.y
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct Triangle(pub [Vec2; 3]);
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct Circle {
+    pub center: Vec2,
+    pub radius: f64,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn vec2_dot() {
+        let a = Vec2::new(1.0, 0.0);
+        let b = Vec2::new(0.0, 1.0);
+        assert_eq!(a.dot(b), 0.0);
+    }
+}
diff --git a/crates/trios-sacred/rings/SC-01/AGENTS.md b/crates/trios-sacred/rings/SC-01/AGENTS.md
new file mode 100644
index 0000000000..56184a9dc1
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/AGENTS.md
@@ -0,0 +1,7 @@
+# AGENTS.md — SC-01
+
+- Package: trios-sacred-sc01
+- R1: no BR-OUTPUT imports
+- R9: no sibling imports
+- May import SC-00 only
+- L6: pure Rust
diff --git a/crates/trios-sacred/rings/SC-01/Cargo.lock b/crates/trios-sacred/rings/SC-01/Cargo.lock
new file mode 100644
index 0000000000..90aa6fc375
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/Cargo.lock
@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "trios-sacred-sc00"
+version = "0.1.0"
+
+[[package]]
+name = "trios-sacred-sc01"
+version = "0.1.0"
+dependencies = [
+ "trios-sacred-sc00",
+]
diff --git a/crates/trios-sacred/rings/SC-01/Cargo.toml b/crates/trios-sacred/rings/SC-01/Cargo.toml
new file mode 100644
index 0000000000..fbdf3814de
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "trios-sacred-sc01"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dmitrii Vasilev"]
+license = "MIT"
+description = "SC-01 — sacred ratios (phi, sqrt2, sqrt3, pi)"
+publish = false
+
+[dependencies]
+trios-sacred-sc00 = { path = "../SC-00" }
+
+[workspace]
diff --git a/crates/trios-sacred/rings/SC-01/README.md b/crates/trios-sacred/rings/SC-01/README.md
new file mode 100644
index 0000000000..d501ea98c5
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/README.md
@@ -0,0 +1,3 @@
+# SC-01 — sacred ratios
+
+phi, sqrt2, sqrt3, pi. Depends on SC-00 for `Vec2` scaling.
diff --git a/crates/trios-sacred/rings/SC-01/RING.md b/crates/trios-sacred/rings/SC-01/RING.md
new file mode 100644
index 0000000000..4e12211082
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/RING.md
@@ -0,0 +1,11 @@
+# RING — SC-01
+
+Sacred ratios (phi, sqrt2, sqrt3, pi).
+
+## Dependencies
+- SC-00
+
+## Laws
+- R1: no BR-OUTPUT
+- R9: no sibling imports
+- L6: pure Rust
diff --git a/crates/trios-sacred/rings/SC-01/TASK.md b/crates/trios-sacred/rings/SC-01/TASK.md
new file mode 100644
index 0000000000..2df32bc988
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/TASK.md
@@ -0,0 +1,12 @@
+# TASK — SC-01
+
+## Status: SCAFFOLDED
+
+## Completed
+- [x] PHI, SQRT2, SQRT3, PI
+- [x] scale_phi
+- [x] phi anchor test
+
+## Open
+- [ ] Migrate phi-engine from legacy `src/phi-engine/`
+- [ ] Add Beal-conjecture search helpers from FFI
diff --git a/crates/trios-sacred/rings/SC-01/src/lib.rs b/crates/trios-sacred/rings/SC-01/src/lib.rs
new file mode 100644
index 0000000000..58b8c1d8d4
--- /dev/null
+++ b/crates/trios-sacred/rings/SC-01/src/lib.rs
@@ -0,0 +1,32 @@
+//! SC-01 — sacred ratios
+//!
+//! phi (golden ratio), sqrt(2), sqrt(3), pi.
+
+use trios_sacred_sc00::Vec2;
+
+pub const PHI: f64 = 1.618_033_988_749_894_8;
+pub const SQRT2: f64 = std::f64::consts::SQRT_2;
+pub const SQRT3: f64 = 1.732_050_807_568_877_2;
+pub const PI: f64 = std::f64::consts::PI;
+
+/// Scale a Vec2 by phi.
+pub fn scale_phi(v: Vec2) -> Vec2 {
+    Vec2::new(v.x * PHI, v.y * PHI)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn phi_anchor() {
+        let lhs = PHI * PHI + (1.0 / PHI) * (1.0 / PHI);
+        assert!((lhs - 3.0).abs() < 1e-12);
+    }
+
+    #[test]
+    fn scale_phi_works() {
+        let v = scale_phi(Vec2::new(1.0, 0.0));
+        assert!((v.x - PHI).abs() < 1e-12);
+    }
+}