diff --git a/crates/apps/tahuantinsuyu/src/shell.rs b/crates/apps/tahuantinsuyu/src/shell.rs
index 7fccb5e..61ceeb9 100644
--- a/crates/apps/tahuantinsuyu/src/shell.rs
+++ b/crates/apps/tahuantinsuyu/src/shell.rs
@@ -118,20 +118,23 @@ impl Shell {
                 let age = current_age_years(&chart.birth_data);
                 self.current_chart = Some(chart.clone());
                 self.current_offset_minutes = 0;
-                // Inicializar la edad objetivo del módulo de progresión
-                // con la edad actual del sujeto, así el slider arranca
-                // "donde corresponde" si el usuario lo activa.
-                let prog_entry = self
-                    .module_configs
-                    .entry("progression".into())
-                    .or_insert_with(|| serde_json::json!({}));
-                if let serde_json::Value::Object(map) = prog_entry {
-                    map.insert("target_age_years".into(), serde_json::json!(age));
+                // Inicializar la edad objetivo de los módulos basados
+                // en edad con la edad actual del sujeto, así sus
+                // sliders arrancan donde corresponde al activarse.
+                for module_id in ["progression", "solar_arc"] {
+                    let entry = self
+                        .module_configs
+                        .entry(module_id.into())
+                        .or_insert_with(|| serde_json::json!({}));
+                    if let serde_json::Value::Object(map) = entry {
+                        map.insert("target_age_years".into(), serde_json::json!(age));
+                    }
                 }
                 self.render_current(cx);
                 self.panel.update(cx, |p, cx| {
                     p.set_active_kind(Some(chart.kind), cx);
                     p.set_slider("progression", "target_age_years", age, cx);
+                    p.set_slider("solar_arc", "target_age_years", age, cx);
                 });
             }
             TreeSelection::Contact(id) => {
@@ -192,16 +195,35 @@ impl Shell {
             requests.push(PipelineRequest::Transit);
         }
         if module_enabled(&self.module_configs, "progression") {
-            if let Some(chart) = self.current_chart.as_ref() {
-                let age = current_age_years(&chart.birth_data);
-                requests.push(PipelineRequest::SecondaryProgression {
-                    target_age_years: age,
-                });
-            }
+            let age = self.module_age_or_current("progression");
+            requests.push(PipelineRequest::SecondaryProgression {
+                target_age_years: age,
+            });
+        }
+        if module_enabled(&self.module_configs, "solar_arc") {
+            let age = self.module_age_or_current("solar_arc");
+            requests.push(PipelineRequest::SolarArc {
+                target_age_years: age,
+            });
         }
         requests
     }
 
+    /// Lee `target_age_years` del módulo o cae a la edad actual del
+    /// sujeto (calculada desde la fecha de nacimiento y el reloj).
+    fn module_age_or_current(&self, module_id: &str) -> f64 {
+        self.module_configs
+            .get(module_id)
+            .and_then(|c| c.get("target_age_years"))
+            .and_then(|v| v.as_f64())
+            .unwrap_or_else(|| {
+                self.current_chart
+                    .as_ref()
+                    .map(|c| current_age_years(&c.birth_data))
+                    .unwrap_or(0.0)
+            })
+    }
+
     fn render_current(&mut self, cx: &mut Context<Self>) {
         let Some(chart) = self.current_chart.as_ref() else {
             return;
diff --git a/crates/modules/tahuantinsuyu/tahuantinsuyu-canvas/src/lib.rs b/crates/modules/tahuantinsuyu/tahuantinsuyu-canvas/src/lib.rs
index c265dbd..b7e663f 100644
--- a/crates/modules/tahuantinsuyu/tahuantinsuyu-canvas/src/lib.rs
+++ b/crates/modules/tahuantinsuyu/tahuantinsuyu-canvas/src/lib.rs
@@ -535,16 +535,17 @@ fn render_wheel(
         }
     }
 
-    // Planet glyphs: natal (en `bodies`) y progresada (en `progression`,
-    // con alpha + tamaño un poco distintos para diferenciarlos).
+    // Planet glyphs: natal (en `bodies`) + overlays en sus rings
+    // (progression, solar_arc) con alpha + tamaño más chico para
+    // diferenciarse visualmente del natal.
     if visible.get(&LayerKind::Bodies).copied().unwrap_or(true) {
         for layer in &render.layers {
             if matches!(layer.kind, LayerKind::Bodies) {
-                let is_prog = layer.module_id == "progression";
-                let ring = if is_prog { radii.progression } else { radii.bodies };
-                let alpha = if is_prog { 0.85 } else { 1.0 };
-                let font_size = if is_prog { 14.0 } else { 18.0 };
-                let box_size = if is_prog { 20.0 } else { 24.0 };
+                let is_natal = layer.module_id == "natal";
+                let ring = radii.body_ring(&layer.module_id);
+                let alpha = if is_natal { 1.0 } else { 0.85 };
+                let font_size = if is_natal { 18.0 } else { 14.0 };
+                let box_size = if is_natal { 24.0 } else { 20.0 };
                 for g in &layer.glyphs {
                     let (x, y) = polar_to_screen(g.deg, asc, rot_offset, ring);
                     let color = with_alpha(planet_color(palette, &g.symbol), alpha);
@@ -683,15 +684,17 @@ struct Radii {
     sign_outer: f32,
     sign_inner: f32,
     /// Anillo de glifos de tránsito (cuando el overlay está activo).
-    /// Vive entre `sign_inner` y `houses_outer`; queda vacío cuando no
-    /// hay capa Outer con module_id = "transit".
     transits: f32,
     houses_outer: f32,
     houses_inner: f32,
     bodies: f32,
-    /// Anillo interno con cuerpos progresados (cuando hay overlay de
-    /// progresión secundaria). Queda vacío sino.
+    /// Anillo interno con cuerpos progresados (overlay opcional).
     progression: f32,
+    /// Anillo más interno con cuerpos dirigidos por Solar Arc (overlay
+    /// opcional). Si tanto progression como solar_arc están activos,
+    /// progression va afuera (más cerca de bodies natales) y solar_arc
+    /// adentro (entre progression y aspects).
+    solar_arc: f32,
     aspects: f32,
 }
 
@@ -705,18 +708,28 @@ impl Radii {
             houses_inner: r * 0.66,
             bodies: r * 0.58,
             progression: r * 0.48,
-            aspects: r * 0.38,
+            solar_arc: r * 0.40,
+            aspects: r * 0.32,
+        }
+    }
+
+    /// Radio del ring de cuerpos según el `module_id` del Layer.
+    fn body_ring(&self, module_id: &str) -> f32 {
+        match module_id {
+            "progression" => self.progression,
+            "solar_arc" => self.solar_arc,
+            _ => self.bodies,
         }
     }
 
     /// Resuelve qué radios corresponden a una capa de aspectos según el
-    /// `module_id`: natal-natal en `aspects`, cross-aspects con
-    /// tránsito desde `bodies` a `transits`, cross con progresión desde
-    /// `bodies` a `progression`.
+    /// `module_id`: natal-natal en `aspects`, cross con cada overlay
+    /// desde `bodies` (extremo natal) al ring del módulo.
     fn aspect_endpoints(&self, module_id: &str) -> (f32, f32) {
         match module_id {
             "transit" => (self.bodies, self.transits),
             "progression" => (self.bodies, self.progression),
+            "solar_arc" => (self.bodies, self.solar_arc),
             _ => (self.aspects, self.aspects),
         }
     }
@@ -876,16 +889,14 @@ fn paint_wheel(
         }
     }
 
-    // 4. Dots de cuerpos: natal en `bodies`, progresada en `progression`.
+    // 4. Dots de cuerpos: natal en `bodies`, overlays en sus rings
+    // específicos (progression, solar_arc).
     if show(LayerKind::Bodies) {
         let dot_r = (radii.sign_outer * 0.018).max(2.0);
         for layer in layers {
             if matches!(layer.kind, LayerKind::Bodies) {
-                let ring = match layer.module_id.as_str() {
-                    "progression" => radii.progression,
-                    _ => radii.bodies,
-                };
-                let alpha = if layer.module_id == "progression" { 0.85 } else { 1.0 };
+                let ring = radii.body_ring(&layer.module_id);
+                let alpha = if layer.module_id == "natal" { 1.0 } else { 0.85 };
                 for g in &layer.glyphs {
                     let color = with_alpha(planet_color(palette, &g.symbol), alpha);
                     let (x, y) = polar_to_screen(g.deg, ascendant_deg, rot_offset_deg, ring);
@@ -895,27 +906,33 @@ fn paint_wheel(
         }
     }
 
-    // Si hay progresión, dibujar anillo guía sutil delimitando su slot.
-    let prog_active = layers
-        .iter()
-        .any(|l| matches!(l.kind, LayerKind::Bodies) && l.module_id == "progression");
-    if prog_active {
-        stroke_circle(
-            window,
-            cx,
-            cy,
-            radii.progression + radii.sign_outer * 0.03,
-            0.5,
-            with_alpha(palette.house_cusp, 0.35),
-        );
-        stroke_circle(
-            window,
-            cx,
-            cy,
-            radii.progression - radii.sign_outer * 0.03,
-            0.5,
-            with_alpha(palette.house_cusp, 0.35),
-        );
+    // Anillos guía para los overlays internos (progression, solar_arc).
+    let guide_inset = radii.sign_outer * 0.03;
+    for (module_id, ring) in [
+        ("progression", radii.progression),
+        ("solar_arc", radii.solar_arc),
+    ] {
+        let active = layers
+            .iter()
+            .any(|l| matches!(l.kind, LayerKind::Bodies) && l.module_id == module_id);
+        if active {
+            stroke_circle(
+                window,
+                cx,
+                cy,
+                ring + guide_inset,
+                0.5,
+                with_alpha(palette.house_cusp, 0.35),
+            );
+            stroke_circle(
+                window,
+                cx,
+                cy,
+                ring - guide_inset,
+                0.5,
+                with_alpha(palette.house_cusp, 0.35),
+            );
+        }
     }
 
     // 5. Outer ring (transit overlay): anillo guía + dots de transit.
diff --git a/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/bridge.rs b/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/bridge.rs
index 480f48c..cb9a1ae 100644
--- a/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/bridge.rs
+++ b/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/bridge.rs
@@ -9,9 +9,9 @@ use std::sync::OnceLock;
 use std::time::Instant;
 
 use eternal_astrology::{
-    find_aspects, find_synastry_aspects, secondary_progression, Aspect, AspectKind as EAspectKind,
-    BirthData, BodySet, ChartConfig, HouseSystem as EHouseSystem, NatalChart, OrbTable,
-    Zodiac as EZodiac,
+    find_aspects, find_synastry_aspects, secondary_progression, solar_arc_true, Aspect,
+    AspectKind as EAspectKind, BirthData, BodySet, ChartConfig, HouseSystem as EHouseSystem,
+    NatalChart, OrbTable, Zodiac as EZodiac,
 };
 use eternal_sky::{Ayanamsha, Body, EphemerisSession, Instant as ESInstant, Observer, SessionConfig};
 
@@ -258,6 +258,9 @@ pub fn compose(
             crate::PipelineRequest::SecondaryProgression { target_age_years } => {
                 build_progression_overlay(&natal, *target_age_years, &mut render)?;
             }
+            crate::PipelineRequest::SolarArc { target_age_years } => {
+                build_solar_arc_overlay(&natal, *target_age_years, &mut render)?;
+            }
         }
     }
 
@@ -398,6 +401,71 @@ fn build_progression_overlay(
     Ok(())
 }
 
+/// Helper: agrega al `RenderModel` las capas del overlay de Solar Arc
+/// (método true-progressed-Sun por default). Cada cuerpo natal se
+/// desplaza por el mismo arco — preserva las relaciones angulares y
+/// las posiciones relativas en casas se mantienen.
+fn build_solar_arc_overlay(
+    natal: &NatalChart,
+    target_age_years: f64,
+    render: &mut RenderModel,
+) -> Result<(), EngineError> {
+    let session = session()?;
+    let arc = solar_arc_true(natal, session, target_age_years)
+        .map_err(|e| EngineError::Eternal(format!("solar_arc_true: {:?}", e)))?;
+    let directed = &arc.directed;
+
+    let glyphs: Vec<Glyph> = directed
+        .placements
+        .iter()
+        .map(|p| Glyph {
+            deg: p.longitude.longitude_deg() as f32,
+            symbol: body_symbol(p.body).into(),
+            annotation: Some(format!("{:.1}°", p.longitude.degree_in_sign_decimal())),
+            retrograde: p.longitude_rate_rad_per_day < 0.0,
+            house: Some(p.house_number),
+        })
+        .collect();
+    render.layers.push(Layer {
+        module_id: "solar_arc".into(),
+        kind: LayerKind::Bodies,
+        ring: 0.43,
+        z: 8,
+        geometry: Geometry::GlyphsOnly,
+        glyphs,
+    });
+
+    let cross = find_synastry_aspects(
+        natal,
+        directed,
+        &OrbTable::modern_western(),
+        EAspectKind::MAJORS,
+    );
+    let cross_lines: Vec<LineSeg> = cross
+        .iter()
+        .filter_map(|a| {
+            let natal_p = natal.placement(a.person_a_body)?;
+            let dir_p = directed.placement(a.person_b_body)?;
+            let opacity = orb_to_opacity(a.orb_abs_deg(), a.kind);
+            Some(LineSeg {
+                from_deg: natal_p.longitude.longitude_deg() as f32,
+                to_deg: dir_p.longitude.longitude_deg() as f32,
+                kind: aspect_kind_id(a.kind).into(),
+                opacity: opacity * 0.7,
+            })
+        })
+        .collect();
+    render.layers.push(Layer {
+        module_id: "solar_arc".into(),
+        kind: LayerKind::Aspects,
+        ring: 0.0,
+        z: 9,
+        geometry: Geometry::Lines(cross_lines),
+        glyphs: Vec::new(),
+    });
+    Ok(())
+}
+
 // =====================================================================
 // NatalChart → RenderModel
 // =====================================================================
diff --git a/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/lib.rs b/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/lib.rs
index 25d18c9..d235767 100644
--- a/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/lib.rs
+++ b/crates/modules/tahuantinsuyu/tahuantinsuyu-engine/src/lib.rs
@@ -173,8 +173,14 @@ pub enum PipelineRequest {
         /// `SystemTime::now`.
         target_age_years: f64,
     },
-    // ── Fase 8 ──────────────────────────────────────────────────────
-    // SolarArc { target_year: i32 },
+    /// `module_id = "solar_arc"` — Solar Arc dirigido (default = "true
+    /// progressed Sun"): cada cuerpo y cada cusp natal se desplazan por
+    /// el mismo arco ≈ 1° por año de vida. Anillo interno bien adentro
+    /// + cross aspects natal × dirigida.
+    SolarArc {
+        target_age_years: f64,
+    },
+    // ── Fase 10 ─────────────────────────────────────────────────────
     // Synastry { partner: tahuantinsuyu_model::ChartId },
 }
 
diff --git a/crates/modules/tahuantinsuyu/tahuantinsuyu-modules/src/lib.rs b/crates/modules/tahuantinsuyu/tahuantinsuyu-modules/src/lib.rs
index a857895..2981335 100644
--- a/crates/modules/tahuantinsuyu/tahuantinsuyu-modules/src/lib.rs
+++ b/crates/modules/tahuantinsuyu/tahuantinsuyu-modules/src/lib.rs
@@ -125,6 +125,7 @@ impl Registry {
         r.register(Box::new(natal::NatalModule));
         r.register(Box::new(transit::TransitModule));
         r.register(Box::new(progression::ProgressionModule));
+        r.register(Box::new(solar_arc::SolarArcModule));
         r
     }
 
@@ -332,6 +333,59 @@ pub mod progression {
     }
 }
 
+// =====================================================================
+// SolarArcModule — Solar Arc dirigido (true progressed Sun)
+// =====================================================================
+
+pub mod solar_arc {
+    use super::*;
+
+    /// Cada planeta y cusp natal se desplaza por el mismo arco
+    /// (≈ 1° por año de vida, calculado como el delta del Sol
+    /// progresado secundario). Anillo interno bien adentro + cross
+    /// aspects natal × dirigida.
+    pub struct SolarArcModule;
+
+    impl Module for SolarArcModule {
+        fn id(&self) -> &'static str {
+            "solar_arc"
+        }
+        fn label(&self) -> &'static str {
+            "Solar Arc"
+        }
+        fn description(&self) -> &'static str {
+            "Dirección por arco solar — uniforme, ≈1°/año."
+        }
+        fn applies_to(&self, kind: ChartKind) -> bool {
+            matches!(kind, ChartKind::Natal)
+        }
+        fn enabled_by_default(&self) -> bool {
+            false
+        }
+        fn controls(&self) -> Vec<Control> {
+            vec![
+                Control::Toggle {
+                    key: "enabled".into(),
+                    label: "Activar".into(),
+                    default: false,
+                    hotkey: None,
+                },
+                Control::Slider {
+                    key: "target_age_years".into(),
+                    label: "Edad objetivo (años)".into(),
+                    min: 0.0,
+                    max: 120.0,
+                    step: 0.25,
+                    default: 30.0,
+                },
+            ]
+        }
+        fn compute_layers(&self, _chart: &Chart, _cfg: &serde_json::Value) -> Vec<Layer> {
+            Vec::new()
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -342,9 +396,9 @@ mod tests {
         assert!(r.find("natal").is_some());
         assert!(r.find("transit").is_some());
         assert!(r.find("progression").is_some());
-        // Natal kind tiene 3 módulos aplicables: natal + transit + progression.
-        assert_eq!(r.for_kind(ChartKind::Natal).len(), 3);
-        // Synastry kind no tiene módulos hoy.
+        assert!(r.find("solar_arc").is_some());
+        // Natal kind tiene 4 módulos: natal + transit + progression + solar_arc.
+        assert_eq!(r.for_kind(ChartKind::Natal).len(), 4);
         assert!(r.for_kind(ChartKind::Synastry).is_empty());
     }
 }