DOCS.md

@@ -2,37 +2,31 @@
 
 This document describes the user-tunable parameters for the `inire` auto-router.
 
-## 1. AStarContext Parameters
+## 1. AStarRouter Parameters
 
-The `AStarContext` stores the configuration and persistent state for the A* search. It is initialized once and passed to `route_astar` or the `PathFinder`.
+The `AStarRouter` is the core pathfinding engine. It can be configured directly through its constructor.
 
 | Parameter             | Type          | Default            | Description                                                                           |
 | :-------------------- | :------------ | :----------------- | :------------------------------------------------------------------------------------ |
 | `node_limit`          | `int`         | 1,000,000          | Maximum number of states to explore per net. Increase for very complex paths.         |
-| `snap_size`           | `float`       | 5.0                | Grid size (µm) for expansion moves. Larger values speed up search.                    |
+| `straight_lengths`    | `list[float]` | `[1.0, 5.0, 25.0]` | Discrete step sizes for straight waveguides (µm). Larger steps speed up search.       |
-| `max_straight_length` | `float`       | 2000.0             | Maximum length (µm) of a single straight segment.                                     |
+| `bend_radii`          | `list[float]` | `[10.0]`           | Available radii for 90-degree turns (µm). Multiple values allow best-fit selection.   |
-| `min_straight_length` | `float`       | 5.0                | Minimum length (µm) of a single straight segment.                                     |
+| `sbend_offsets`       | `list[float] \| None` | `None` (Auto)      | Lateral offsets for parametric S-bends. `None` uses automatic grid-aligned steps. |
-| `bend_radii`          | `list[float]` | `[50.0, 100.0]`    | Available radii for 90-degree turns (µm).                                             |
+| `sbend_radii`         | `list[float]` | `[10.0]`           | Available radii for S-bends (µm).                                                     |
-| `sbend_radii`         | `list[float]` | `[5.0, 10.0, 50.0, 100.0]` | Available radii for S-bends (µm).                                             |
+| `snap_to_target_dist` | `float`       | 20.0               | Distance (µm) at which the router attempts an exact bridge to the target port.        |
-| `sbend_offsets`       | `list[float] \| None` | `None` (Auto)      | Lateral offsets for parametric S-bends.                                               |
+| `bend_penalty`        | `float`       | 50.0               | Flat cost added for every 90-degree bend. Higher values favor straight lines.         |
-| `bend_penalty`        | `float`       | 250.0              | Flat cost added for every 90-degree bend.                                             |
+| `sbend_penalty`       | `float`       | 100.0              | Flat cost added for every S-bend. Usually higher than `bend_penalty`.                 |
-| `sbend_penalty`       | `float`       | 500.0              | Flat cost added for every S-bend.                                                     |
 | `bend_collision_type` | `str`         | `"arc"`            | Collision model for bends: `"arc"`, `"bbox"`, or `"clipped_bbox"`.                    |
-| `bend_clip_margin`    | `float`       | 10.0               | Extra space (µm) around the waveguide for clipped models.                             |
+| `bend_clip_margin`    | `float`       | 10.0               | Extra space (µm) around the waveguide before the bounding box corners are clipped.    |
 
-## 2. AStarMetrics
+### Bend Collision Models
-
+*   `"arc"`: High-fidelity model following the exact curved waveguide geometry.
-The `AStarMetrics` object collects performance data during the search.
+*   `"bbox"`: Conservative model using the axis-aligned bounding box of the bend. Fast but blocks more space.
-
+*   `"clipped_bbox"`: A middle ground that starts with the bounding box but applies 45-degree linear cuts to the inner and outer corners. The `bend_clip_margin` defines the extra safety distance from the waveguide edge to the cut line.
-| Property               | Type  | Description                                           |
-| :--------------------- | :---- | :---------------------------------------------------- |
-| `nodes_expanded`       | `int` | Number of nodes expanded in the last `route_astar` call. |
-| `total_nodes_expanded` | `int` | Cumulative nodes expanded across all calls.           |
-| `max_depth_reached`    | `int` | Deepest point in the search tree reached.             |
 
 ---
 
-## 3. CostEvaluator Parameters
+## 2. CostEvaluator Parameters
 
 The `CostEvaluator` defines the "goodness" of a path.
 

README.md

@@ -30,7 +30,7 @@ from inire.geometry.primitives import Port
 from inire.geometry.collision import CollisionEngine
 from inire.router.danger_map import DangerMap
 from inire.router.cost import CostEvaluator
-from inire.router.astar import AStarContext
+from inire.router.astar import AStarRouter
 from inire.router.pathfinder import PathFinder
 
 # 1. Setup Environment
@@ -44,11 +44,14 @@ evaluator = CostEvaluator(
     danger_map=danger_map,
     greedy_h_weight=1.2
 )
-context = AStarContext(
+router = AStarRouter(
     cost_evaluator=evaluator,
     bend_penalty=10.0
 )
-pf = PathFinder(context)
+pf = PathFinder(
+    router=router, 
+    cost_evaluator=evaluator
+)
 
 # 3. Define Netlist
 netlist = {

examples/01_simple_route.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -27,8 +27,8 @@ def main() -> None:
     danger_map.precompute([obstacle])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(context)
+    pf = PathFinder(router, evaluator)
 
     # 2. Define Netlist
     # Route from (10, 10) to (90, 50)

examples/02_congestion_resolution.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -17,8 +17,8 @@ def main() -> None:
     danger_map.precompute([])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(context)
+    pf = PathFinder(router, evaluator)
 
     # 2. Define Netlist
     # Three nets that all converge on the same central area.
@@ -32,7 +32,7 @@ def main() -> None:
 
     # 3. Route with Negotiated Congestion
     # We increase the base penalty to encourage faster divergence
-    pf = PathFinder(context, base_congestion_penalty=1000.0)
+    pf = PathFinder(router, evaluator, base_congestion_penalty=1000.0)
     results = pf.route_all(netlist, net_widths)
 
     # 4. Check Results

examples/03_locked_paths.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -19,9 +19,8 @@ def main() -> None:
     danger_map.precompute([])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    metrics = AStarMetrics()
+    pf = PathFinder(router, evaluator)
-    pf = PathFinder(context, metrics)
 
     # 2. Add a 'Pre-routed' net and lock it
     # Net 'fixed' goes right through the middle
@@ -29,7 +28,7 @@ def main() -> None:
     fixed_target = Port(90, 50, 0)
     
     print("Routing initial net...")
-    res_fixed = route_astar(fixed_start, fixed_target, net_width=2.0, context=context, metrics=metrics)
+    res_fixed = router.route(fixed_start, fixed_target, net_width=2.0)
     
     if res_fixed:
         # 3. Lock this net! It now behaves like a static obstacle

examples/04_sbends_and_radii.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -8,7 +8,7 @@ from inire.utils.visualization import plot_routing_results
 
 
 def main() -> None:
-    print("Running Example 04: SBends and Radii Strategy...")
+    print("Running Example 04: S-Bends and Multiple Radii...")
 
     # 1. Setup Environment
     bounds = (0, 0, 100, 100)
@@ -16,33 +16,45 @@ def main() -> None:
     danger_map = DangerMap(bounds=bounds)
     danger_map.precompute([])
 
-    evaluator = CostEvaluator(engine, danger_map, bend_penalty=200.0, sbend_penalty=400.0)
+    # 2. Configure Router
-    
+    evaluator = CostEvaluator(
-    # Define a custom router with multiple SBend radii and specific offsets
+        engine,
-    context = AStarContext(
+        danger_map,
-        evaluator,
+        unit_length_cost=1.0,
-        snap_size=1.0,
+        bend_penalty=10.0,
-        bend_radii=[20.0, 50.0],
+        sbend_penalty=20.0,
-        sbend_radii=[5.0, 10.0, 50.0],
-        sbend_offsets=[2.0, 5.0, 10.0, 20.0, 50.0]
     )
-    pf = PathFinder(context)
 
-    # 2. Define Netlist
+    router = AStarRouter(
-    # High-density parallel nets with varying offsets
+        evaluator,
-    netlist = {}
+        node_limit=50000,
-    for i in range(10):
+        snap_size=1.0,
-        # Starts at x=50, y=50+i*10. Targets at x=450, y=60+i*10.
+        bend_radii=[10.0, 30.0],
-        # This forces small vertical jogs (SBends)
+        sbend_offsets=[5.0], # Use a simpler offset
-        netlist[f"net_{i}"] = (Port(50, 50 + i * 10, 0), Port(450, 55 + i * 10, 0))
+        bend_penalty=10.0,
+        sbend_penalty=20.0,
+        snap_to_target_dist=50.0, # Large snap range
+    )
 
-    net_widths = {nid: 2.0 for nid in netlist}
+    pf = PathFinder(router, evaluator)
 
-    # 3. Route
+    # 3. Define Netlist
-    print(f"Routing {len(netlist)} nets with custom SBend strategy...")
+    # start (10, 50), target (60, 55) -> 5um offset
-    results = pf.route_all(netlist, net_widths, shuffle_nets=True)
+    netlist = {
+        "sbend_only": (Port(10, 50, 0), Port(60, 55, 0)),
+        "multi_radii": (Port(10, 10, 0), Port(90, 90, 0)),
+    }
+    net_widths = {"sbend_only": 2.0, "multi_radii": 2.0}
 
-    # 4. Visualize
+    # 4. Route
+    results = pf.route_all(netlist, net_widths)
+
+    # 5. Check Results
+    for nid, res in results.items():
+        status = "Success" if res.is_valid else "Failed"
+        print(f"{nid}: {status}, collisions={res.collisions}")
+
+    # 6. Visualize
     fig, ax = plot_routing_results(results, [], bounds, netlist=netlist)
     fig.savefig("examples/04_sbends_and_radii.png")
     print("Saved plot to examples/04_sbends_and_radii.png")

examples/05_orientation_stress.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -8,7 +8,7 @@ from inire.utils.visualization import plot_routing_results
 
 
 def main() -> None:
-    print("Running Example 05: Orientation Stress...")
+    print("Running Example 05: Orientation Stress Test...")
 
     # 1. Setup Environment
     bounds = (0, 0, 200, 200)
@@ -16,9 +16,9 @@ def main() -> None:
     danger_map = DangerMap(bounds=bounds)
     danger_map.precompute([])
 
-    evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0)
+    evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(context)
+    pf = PathFinder(router, evaluator)
 
     # 2. Define Netlist: Complex orientation challenges
     netlist = {
@@ -29,10 +29,15 @@ def main() -> None:
     net_widths = {nid: 2.0 for nid in netlist}
 
     # 3. Route
-    print("Routing nets with complex orientation combinations...")
+    print("Routing complex orientation nets...")
     results = pf.route_all(netlist, net_widths)
 
-    # 4. Visualize
+    # 4. Check Results
+    for nid, res in results.items():
+        status = "Success" if res.is_valid else "Failed"
+        print(f"  {nid}: {status}")
+
+    # 5. Visualize
     fig, ax = plot_routing_results(results, [], bounds, netlist=netlist)
     fig.savefig("examples/05_orientation_stress.png")
     print("Saved plot to examples/05_orientation_stress.png")

examples/06_bend_collision_models.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -33,26 +33,26 @@ def main() -> None:
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
 
     # Scenario 1: Standard 'arc' model (High fidelity)
-    context_arc = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="arc")
+    router_arc = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="arc")
     netlist_arc = {"arc_model": (Port(10, 120, 0), Port(90, 140, 90))}
 
     # Scenario 2: 'bbox' model (Conservative axis-aligned box)
-    context_bbox = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="bbox")
+    router_bbox = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="bbox")
     netlist_bbox = {"bbox_model": (Port(10, 70, 0), Port(90, 90, 90))}
 
     # Scenario 3: 'clipped_bbox' model (Balanced)
-    context_clipped = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="clipped_bbox", bend_clip_margin=1.0)
+    router_clipped = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="clipped_bbox", bend_clip_margin=1.0)
     netlist_clipped = {"clipped_model": (Port(10, 20, 0), Port(90, 40, 90))}
 
     # 2. Route each scenario
     print("Routing Scenario 1 (Arc)...")
-    res_arc = PathFinder(context_arc, use_tiered_strategy=False).route_all(netlist_arc, {"arc_model": 2.0})
+    res_arc = PathFinder(router_arc, evaluator, use_tiered_strategy=False).route_all(netlist_arc, {"arc_model": 2.0})
 
     print("Routing Scenario 2 (BBox)...")
-    res_bbox = PathFinder(context_bbox, use_tiered_strategy=False).route_all(netlist_bbox, {"bbox_model": 2.0})
+    res_bbox = PathFinder(router_bbox, evaluator, use_tiered_strategy=False).route_all(netlist_bbox, {"bbox_model": 2.0})
 
     print("Routing Scenario 3 (Clipped BBox)...")
-    res_clipped = PathFinder(context_clipped, use_tiered_strategy=False).route_all(netlist_clipped, {"clipped_model": 2.0})
+    res_clipped = PathFinder(router_clipped, evaluator, use_tiered_strategy=False).route_all(netlist_clipped, {"clipped_model": 2.0})
 
     # 3. Combine results for visualization
     all_results = {**res_arc, **res_bbox, **res_clipped}

examples/07_large_scale_routing.py

@@ -2,7 +2,7 @@ import numpy as np
 import time
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -29,9 +29,8 @@ def main() -> None:
 
     evaluator = CostEvaluator(engine, danger_map, greedy_h_weight=1.5, unit_length_cost=0.1, bend_penalty=100.0, sbend_penalty=400.0, congestion_penalty=100.0)
 
-    context = AStarContext(evaluator, node_limit=2000000, snap_size=5.0, bend_radii=[50.0], sbend_radii=[50.0])
+    router = AStarRouter(evaluator, node_limit=2000000, snap_size=5.0, bend_radii=[50.0], sbend_radii=[50.0])
-    metrics = AStarMetrics()
+    pf = PathFinder(router, evaluator, max_iterations=15, base_congestion_penalty=100.0, congestion_multiplier=1.4)
-    pf = PathFinder(context, metrics, max_iterations=15, base_congestion_penalty=100.0, congestion_multiplier=1.4)
 
     # 2. Define Netlist
     netlist = {}
@@ -58,7 +57,7 @@ def main() -> None:
     def iteration_callback(idx, current_results):
         successes = sum(1 for r in current_results.values() if r.is_valid)
         total_collisions = sum(r.collisions for r in current_results.values())
-        total_nodes = metrics.nodes_expanded
+        total_nodes = pf.router.metrics['nodes_expanded']
 
         # Identify Hotspots
         hotspots = {}
@@ -72,7 +71,6 @@ def main() -> None:
                     # Check what it overlaps with
                     overlaps = engine.dynamic_index.intersection(poly.bounds)
                     for other_obj_id in overlaps:
-                        if other_obj_id in engine.dynamic_geometries:
                         other_nid, other_poly = engine.dynamic_geometries[other_obj_id]
                         if other_nid != nid:
                             if poly.intersects(other_poly):
@@ -131,7 +129,7 @@ def main() -> None:
                  fig_d.savefig(f"examples/07_iteration_{idx:02d}_density.png")
                  plt.close(fig_d)
 
-        metrics.reset_per_route()
+        pf.router.reset_metrics()
 
     import cProfile, pstats
     profiler = cProfile.Profile()
@@ -175,9 +173,9 @@ def main() -> None:
     plot_danger_map(danger_map, ax=ax)
 
     # Overlay Expanded Nodes from last routed net (as an example)
-    if metrics.last_expanded_nodes:
+    if pf.router.last_expanded_nodes:
-        print(f"Plotting {len(metrics.last_expanded_nodes)} expanded nodes for the last net...")
+        print(f"Plotting {len(pf.router.last_expanded_nodes)} expanded nodes for the last net...")
-        plot_expanded_nodes(metrics.last_expanded_nodes, ax=ax, color='blue', alpha=0.1)
+        plot_expanded_nodes(pf.router.last_expanded_nodes, ax=ax, color='blue', alpha=0.1)
 
     fig.savefig("examples/07_large_scale_routing.png")
     print("Saved plot to examples/07_large_scale_routing.png")

examples/08_custom_bend_geometry.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -19,9 +19,8 @@ def main() -> None:
     danger_map.precompute([])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    metrics = AStarMetrics()
+    pf = PathFinder(router, evaluator)
-    pf = PathFinder(context, metrics)
 
     # 2. Define Netlist
     netlist = {
@@ -40,9 +39,8 @@ def main() -> None:
     
     print("Routing with custom collision model...")
     # Override bend_collision_type with a literal Polygon
-    context_custom = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type=custom_poly)
+    router_custom = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type=custom_poly)
-    metrics_custom = AStarMetrics()
+    results_custom = PathFinder(router_custom, evaluator, use_tiered_strategy=False).route_all(
-    results_custom = PathFinder(context_custom, metrics_custom, use_tiered_strategy=False).route_all(
         {"custom_model": netlist["custom_bend"]}, {"custom_model": 2.0}
     )
 

examples/09_unroutable_best_effort.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, AStarMetrics
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -28,11 +28,10 @@ def main() -> None:
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
     # Use a low node limit to fail faster
-    context = AStarContext(evaluator, node_limit=2000, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(evaluator, node_limit=2000, snap_size=1.0, bend_radii=[10.0])
-    metrics = AStarMetrics()
     
-    # Enable partial path return (handled internally by PathFinder calling route_astar with return_partial=True)
+    # Enable partial path return
-    pf = PathFinder(context, metrics)
+    pf = PathFinder(router, evaluator)
 
     # 2. Define Netlist: start outside, target inside the cage
     netlist = {

inire/router/astar.py

@@ -2,12 +2,14 @@ from __future__ import annotations
 
 import heapq
 import logging
+import functools
 from typing import TYPE_CHECKING, Literal, Any
+import rtree
 
 import numpy
 import shapely
 
-from inire.geometry.components import Bend90, SBend, Straight, snap_search_grid
+from inire.geometry.components import Bend90, SBend, Straight, SEARCH_GRID_SNAP_UM, snap_search_grid
 from inire.geometry.primitives import Port
 from inire.router.config import RouterConfig
 from inire.router.visibility import VisibilityManager
@@ -48,107 +50,73 @@ class AStarNode:
         return self.h_cost < other.h_cost
 
 
-class AStarMetrics:
+class AStarRouter:
     """
-    Performance metrics and instrumentation for A* search.
+    Waveguide router based on sparse A* search.
     """
-    __slots__ = ('total_nodes_expanded', 'last_expanded_nodes', 'nodes_expanded', 
+    __slots__ = ('cost_evaluator', 'config', 'node_limit', 'visibility_manager', 
-                 'moves_generated', 'moves_added', 'pruned_closed_set', 
+                 '_hard_collision_set', '_congestion_cache', '_static_safe_cache', 
-                 'pruned_hard_collision', 'pruned_cost')
+                 '_move_cache', 'total_nodes_expanded', 'last_expanded_nodes', 'metrics',
+                 '_self_collision_check')
 
-    def __init__(self) -> None:
+    def __init__(self, cost_evaluator: CostEvaluator, node_limit: int | None = None, **kwargs) -> None:
-        self.total_nodes_expanded = 0
-        self.last_expanded_nodes: list[tuple[float, float, float]] = []
-        self.nodes_expanded = 0
-        self.moves_generated = 0
-        self.moves_added = 0
-        self.pruned_closed_set = 0
-        self.pruned_hard_collision = 0
-        self.pruned_cost = 0
-
-    def reset_per_route(self) -> None:
-        """ Reset metrics that are specific to a single route() call. """
-        self.nodes_expanded = 0
-        self.moves_generated = 0
-        self.moves_added = 0
-        self.pruned_closed_set = 0
-        self.pruned_hard_collision = 0
-        self.pruned_cost = 0
-        self.last_expanded_nodes = []
-
-    def get_summary_dict(self) -> dict[str, int]:
-        """ Return a dictionary of current metrics. """
-        return {
-            'nodes_expanded': self.nodes_expanded,
-            'moves_generated': self.moves_generated,
-            'moves_added': self.moves_added,
-            'pruned_closed_set': self.pruned_closed_set,
-            'pruned_hard_collision': self.pruned_hard_collision,
-            'pruned_cost': self.pruned_cost
-        }
-
-
-class AStarContext:
-    """
-    Persistent state for A* search, decoupled from search logic.
-    """
-    __slots__ = ('cost_evaluator', 'config', 'visibility_manager', 
-                 'move_cache', 'hard_collision_set', 'static_safe_cache')
-
-    def __init__(
-            self,
-            cost_evaluator: CostEvaluator,
-            node_limit: int = 1000000,
-            snap_size: float = 5.0,
-            max_straight_length: float = 2000.0,
-            min_straight_length: float = 5.0,
-            bend_radii: list[float] | None = None,
-            sbend_radii: list[float] | None = None,
-            sbend_offsets: list[float] | None = None,
-            bend_penalty: float = 250.0,
-            sbend_penalty: float = 500.0,
-            bend_collision_type: Literal["arc", "bbox", "clipped_bbox"] | Any = "arc",
-            bend_clip_margin: float = 10.0,
-            ) -> None:
         self.cost_evaluator = cost_evaluator
+        self.config = RouterConfig(sbend_radii=[5.0, 10.0, 50.0, 100.0])
         
-        # Use provided lists or defaults for the configuration
+        if node_limit is not None:
-        br = bend_radii if bend_radii is not None else [50.0, 100.0]
+            self.config.node_limit = node_limit
-        sr = sbend_radii if sbend_radii is not None else [5.0, 10.0, 50.0, 100.0]
             
-        self.config = RouterConfig(
+        for k, v in kwargs.items():
-            node_limit=node_limit,
+            if hasattr(self.config, k):
-            snap_size=snap_size,
+                setattr(self.config, k, v)
-            max_straight_length=max_straight_length,
-            min_straight_length=min_straight_length,
-            bend_radii=br,
-            sbend_radii=sr,
-            sbend_offsets=sbend_offsets,
-            bend_penalty=bend_penalty,
-            sbend_penalty=sbend_penalty,
-            bend_collision_type=bend_collision_type,
-            bend_clip_margin=bend_clip_margin
-        )
         
+        self.node_limit = self.config.node_limit
+        
+        # Visibility Manager for sparse jumps
         self.visibility_manager = VisibilityManager(self.cost_evaluator.collision_engine)
         
-        # Long-lived caches (shared across multiple route calls)
+        self._hard_collision_set: set[tuple] = set()
-        self.move_cache: dict[tuple, ComponentResult] = {}
+        self._congestion_cache: dict[tuple, int] = {}
-        self.hard_collision_set: set[tuple] = set()
+        self._static_safe_cache: set[tuple] = set()
-        self.static_safe_cache: set[tuple] = set()
+        self._move_cache: dict[tuple, ComponentResult] = {}
 
-    def clear_static_caches(self) -> None:
+        self.total_nodes_expanded = 0
-        """ Clear caches that depend on the state of static obstacles. """
+        self.last_expanded_nodes: list[tuple[float, float, float]] = []
-        self.hard_collision_set.clear()
-        self.static_safe_cache.clear()
         
+        self.metrics = {
+            'nodes_expanded': 0,
+            'moves_generated': 0,
+            'moves_added': 0,
+            'pruned_closed_set': 0,
+            'pruned_hard_collision': 0,
+            'pruned_cost': 0
+        }
 
-def route_astar(
+    def reset_metrics(self) -> None:
+        """ Reset all performance counters. """
+        for k in self.metrics:
+            self.metrics[k] = 0
+        self.cost_evaluator.collision_engine.reset_metrics()
+
+    def get_metrics_summary(self) -> str:
+        """ Return a human-readable summary of search performance. """
+        m = self.metrics
+        c = self.cost_evaluator.collision_engine.get_metrics_summary()
+        return (f"Search Performance: \n"
+                f"  Nodes Expanded: {m['nodes_expanded']}\n"
+                f"  Moves: Generated={m['moves_generated']}, Added={m['moves_added']}\n"
+                f"  Pruning: ClosedSet={m['pruned_closed_set']}, HardColl={m['pruned_hard_collision']}, Cost={m['pruned_cost']}\n"
+                f"  {c}")
+
+    @property
+    def _self_dilation(self) -> float:
+        return self.cost_evaluator.collision_engine.clearance / 2.0
+
+    def route(
+            self,
             start: Port,
             target: Port,
             net_width: float,
-        context: AStarContext,
-        metrics: AStarMetrics | None = None,
             net_id: str = 'default',
             bend_collision_type: Literal['arc', 'bbox', 'clipped_bbox'] | None = None,
             return_partial: bool = False,
@@ -156,45 +124,56 @@ def route_astar(
             skip_congestion: bool = False,
             max_cost: float | None = None,
             self_collision_check: bool = False,
-        node_limit: int | None = None,
             ) -> list[ComponentResult] | None:
         """
-    Functional implementation of A* routing.
+        Route a single net using A*.
-    """
-    if metrics is None:
-        metrics = AStarMetrics()
 
-    metrics.reset_per_route()
+        Args:
+            start: Starting port.
+            target: Target port.
+            net_width: Waveguide width.
+            net_id: Identifier for the net.
+            bend_collision_type: Type of collision model to use for bends.
+            return_partial: If True, returns the best-effort path if target not reached.
+            store_expanded: If True, keep track of all expanded nodes for visualization.
+            skip_congestion: If True, ignore other nets' paths (greedy mode).
+            max_cost: Hard limit on f_cost to prune search.
+            self_collision_check: If True, prevent the net from crossing its own path.
+        """
+        self._self_collision_check = self_collision_check
+        self._congestion_cache.clear()
+        if store_expanded:
+            self.last_expanded_nodes = []
 
         if bend_collision_type is not None:
-        context.config.bend_collision_type = bend_collision_type
+            self.config.bend_collision_type = bend_collision_type
             
-    context.cost_evaluator.set_target(target)
+        self.cost_evaluator.set_target(target)
         
         open_set: list[AStarNode] = []
-    snap = context.config.snap_size
+        snap = self.config.snap_size
         inv_snap = 1.0 / snap
         
         # (x_grid, y_grid, orientation_grid) -> min_g_cost
         closed_set: dict[tuple[int, int, int], float] = {}
 
-    start_node = AStarNode(start, 0.0, context.cost_evaluator.h_manhattan(start, target))
+        start_node = AStarNode(start, 0.0, self.cost_evaluator.h_manhattan(start, target))
         heapq.heappush(open_set, start_node)
 
         best_node = start_node
         nodes_expanded = 0
         
-    effective_node_limit = node_limit if node_limit is not None else context.config.node_limit
+        node_limit = self.node_limit
 
         while open_set:
-        if nodes_expanded >= effective_node_limit:
+            if nodes_expanded >= node_limit:
-            return reconstruct_path(best_node) if return_partial else None
+                return self._reconstruct_path(best_node) if return_partial else None
 
             current = heapq.heappop(open_set)
             
             # Cost Pruning (Fail Fast)
             if max_cost is not None and current.f_cost > max_cost:
-             metrics.pruned_cost += 1
+                 self.metrics['pruned_cost'] += 1
                  continue
             
             if current.h_cost < best_node.h_cost:
@@ -206,49 +185,38 @@ def route_astar(
             closed_set[state] = current.g_cost
 
             if store_expanded:
-            metrics.last_expanded_nodes.append((current.port.x, current.port.y, current.port.orientation))
+                self.last_expanded_nodes.append((current.port.x, current.port.y, current.port.orientation))
 
             nodes_expanded += 1
-        metrics.total_nodes_expanded += 1
+            self.total_nodes_expanded += 1
-        metrics.nodes_expanded += 1
+            self.metrics['nodes_expanded'] += 1
 
             # Check if we reached the target exactly
             if (abs(current.port.x - target.x) < 1e-6 and
                     abs(current.port.y - target.y) < 1e-6 and
                     abs(current.port.orientation - target.orientation) < 0.1):
-            return reconstruct_path(current)
+                return self._reconstruct_path(current)
 
             # Expansion
-        expand_moves(
+            self._expand_moves(current, target, net_width, net_id, open_set, closed_set, snap, nodes_expanded, skip_congestion=skip_congestion, inv_snap=inv_snap, parent_state=state, max_cost=max_cost)
-            current, target, net_width, net_id, open_set, closed_set, 
-            context, metrics,
-            snap=snap, inv_snap=inv_snap, parent_state=state, 
-            max_cost=max_cost, skip_congestion=skip_congestion,
-            self_collision_check=self_collision_check
-        )
 
-    return reconstruct_path(best_node) if return_partial else None
+        return self._reconstruct_path(best_node) if return_partial else None
 
-
+    def _expand_moves(
-def expand_moves(
+            self,
             current: AStarNode,
             target: Port,
             net_width: float,
             net_id: str,
             open_set: list[AStarNode],
             closed_set: dict[tuple[int, int, int], float],
-        context: AStarContext,
-        metrics: AStarMetrics,
             snap: float = 1.0,
+            nodes_expanded: int = 0,
+            skip_congestion: bool = False,
             inv_snap: float | None = None,
             parent_state: tuple[int, int, int] | None = None,
-        max_cost: float | None = None,
+            max_cost: float | None = None
-        skip_congestion: bool = False,
-        self_collision_check: bool = False,
             ) -> None:
-    """
-    Extract moves and add valid successors to the open set.
-    """
         cp = current.port
         if inv_snap is None: inv_snap = 1.0 / snap
         if parent_state is None:
@@ -260,77 +228,68 @@ def expand_moves(
         
         rad = numpy.radians(cp.orientation)
         cos_v, sin_v = numpy.cos(rad), numpy.sin(rad)
-    
         # 1. DIRECT JUMP TO TARGET
         proj_t = dx_t * cos_v + dy_t * sin_v
         perp_t = -dx_t * sin_v + dy_t * cos_v
 
         # A. Straight Jump
         if proj_t > 0 and abs(perp_t) < 1e-3 and abs(cp.orientation - target.orientation) < 0.1:
-         max_reach = context.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, proj_t + 1.0)
+             max_reach = self.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, proj_t + 1.0)
              if max_reach >= proj_t - 0.01:
-              process_move(
+                  self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'S{proj_t}', 'S', (proj_t,), skip_congestion, inv_snap=inv_snap, snap_to_grid=False, parent_state=parent_state, max_cost=max_cost)
-                  current, target, net_width, net_id, open_set, closed_set, context, metrics,
-                  f'S{proj_t}', 'S', (proj_t,), skip_congestion, inv_snap=inv_snap, snap_to_grid=False, 
-                  parent_state=parent_state, max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
-              )
 
         # 2. VISIBILITY JUMPS & MAX REACH
-    max_reach = context.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, context.config.max_straight_length)
+        max_reach = self.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, self.config.max_straight_length)
         
         straight_lengths = set()
-    if max_reach > context.config.min_straight_length:
+        if max_reach > self.config.min_straight_length:
              straight_lengths.add(snap_search_grid(max_reach, snap))
-         for radius in context.config.bend_radii:
+             for radius in self.config.bend_radii:
-              if max_reach > radius + context.config.min_straight_length:
+                  if max_reach > radius + self.config.min_straight_length:
                        straight_lengths.add(snap_search_grid(max_reach - radius, snap))
              
-         if max_reach > context.config.min_straight_length + 5.0:
+             if max_reach > self.config.min_straight_length + 5.0:
                   straight_lengths.add(snap_search_grid(max_reach - 5.0, snap))
 
-    visible_corners = context.visibility_manager.get_visible_corners(cp, max_dist=max_reach)
+        visible_corners = self.visibility_manager.get_visible_corners(cp, max_dist=max_reach)
         for cx, cy, dist in visible_corners:
             proj = (cx - cp.x) * cos_v + (cy - cp.y) * sin_v
-        if proj > context.config.min_straight_length:
+            if proj > self.config.min_straight_length:
                  straight_lengths.add(snap_search_grid(proj, snap))
         
-    straight_lengths.add(context.config.min_straight_length)
+        straight_lengths.add(self.config.min_straight_length)
-    if max_reach > context.config.min_straight_length * 4:
+        if max_reach > self.config.min_straight_length * 4:
              straight_lengths.add(snap_search_grid(max_reach / 2.0, snap))
 
         if abs(cp.orientation % 180) < 0.1: # Horizontal
              target_dist = abs(target.x - cp.x)
-         if target_dist <= max_reach and target_dist > context.config.min_straight_length:
+             if target_dist <= max_reach and target_dist > self.config.min_straight_length:
                   sl = snap_search_grid(target_dist, snap)
                   if sl > 0.1: straight_lengths.add(sl)
-         for radius in context.config.bend_radii:
+             for radius in self.config.bend_radii:
                   for l in [target_dist - radius, target_dist - 2*radius]:
-                   if l > context.config.min_straight_length:
+                       if l > self.config.min_straight_length:
                             s_l = snap_search_grid(l, snap)
                             if s_l <= max_reach and s_l > 0.1: straight_lengths.add(s_l)
         else: # Vertical
              target_dist = abs(target.y - cp.y)
-         if target_dist <= max_reach and target_dist > context.config.min_straight_length:
+             if target_dist <= max_reach and target_dist > self.config.min_straight_length:
                   sl = snap_search_grid(target_dist, snap)
                   if sl > 0.1: straight_lengths.add(sl)
-         for radius in context.config.bend_radii:
+             for radius in self.config.bend_radii:
                   for l in [target_dist - radius, target_dist - 2*radius]:
-                   if l > context.config.min_straight_length:
+                       if l > self.config.min_straight_length:
                             s_l = snap_search_grid(l, snap)
                             if s_l <= max_reach and s_l > 0.1: straight_lengths.add(s_l)
 
         for length in sorted(straight_lengths, reverse=True):
-        process_move(
+            self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'S{length}', 'S', (length,), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-            current, target, net_width, net_id, open_set, closed_set, context, metrics,
-            f'S{length}', 'S', (length,), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, 
-            max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
-        )
 
         # 3. BENDS & SBENDS
         angle_to_target = numpy.degrees(numpy.arctan2(target.y - cp.y, target.x - cp.x))
         allow_backwards = (dist_sq < 150*150)
 
-    for radius in context.config.bend_radii:
+        for radius in self.config.bend_radii:
             for direction in ['CW', 'CCW']:
                 if not allow_backwards:
                     turn = 90 if direction == 'CCW' else -90
@@ -338,16 +297,12 @@ def expand_moves(
                     new_diff = (angle_to_target - new_ori + 180) % 360 - 180
                     if abs(new_diff) > 135:
                         continue
-            process_move(
+                self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'B{radius}{direction}', 'B', (radius, direction), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-                current, target, net_width, net_id, open_set, closed_set, context, metrics,
-                f'B{radius}{direction}', 'B', (radius, direction), skip_congestion, inv_snap=inv_snap, 
-                parent_state=parent_state, max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
-            )
 
         # 4. SBENDS
-    max_sbend_r = max(context.config.sbend_radii) if context.config.sbend_radii else 0
+        max_sbend_r = max(self.config.sbend_radii) if self.config.sbend_radii else 0
         if max_sbend_r > 0:
-        user_offsets = context.config.sbend_offsets
+            user_offsets = self.config.sbend_offsets
             offsets: set[float] = set(user_offsets) if user_offsets is not None else set()
             dx_local = (target.x - cp.x) * cos_v + (target.y - cp.y) * sin_v
             dy_local = -(target.x - cp.x) * sin_v + (target.y - cp.y) * cos_v
@@ -363,24 +318,19 @@ def expand_moves(
                            if abs(o) < 2 * max_sbend_r: offsets.add(o)
 
             for offset in sorted(offsets):
-            for radius in context.config.sbend_radii:
+                for radius in self.config.sbend_radii:
                     if abs(offset) >= 2 * radius: continue
-                process_move(
+                    self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'SB{offset}R{radius}', 'SB', (offset, radius), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-                    current, target, net_width, net_id, open_set, closed_set, context, metrics,
-                    f'SB{offset}R{radius}', 'SB', (offset, radius), skip_congestion, inv_snap=inv_snap, 
-                    parent_state=parent_state, max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
-                )
 
-
+    def _process_move(
-def process_move(
+            self,
             parent: AStarNode,
             target: Port,
             net_width: float,
             net_id: str,
             open_set: list[AStarNode],
             closed_set: dict[tuple[int, int, int], float],
-        context: AStarContext,
+            snap: float,
-        metrics: AStarMetrics,
             move_type: str,
             move_class: Literal['S', 'B', 'SB'],
             params: tuple,
@@ -388,13 +338,8 @@ def process_move(
             inv_snap: float | None = None,
             snap_to_grid: bool = True,
             parent_state: tuple[int, int, int] | None = None,
-        max_cost: float | None = None,
+            max_cost: float | None = None
-        snap: float = 1.0,
-        self_collision_check: bool = False,
             ) -> None:
-    """
-    Generate or retrieve geometry and delegate to add_node.
-    """
         cp = parent.port
         if inv_snap is None: inv_snap = 1.0 / snap
         base_ori = float(int(cp.orientation + 0.5))
@@ -405,55 +350,45 @@ def process_move(
              parent_state = (gx, gy, go)
         else:
              gx, gy, go = parent_state
+        state_key = parent_state
         
-    abs_key = (parent_state, move_class, params, net_width, context.config.bend_collision_type, snap_to_grid)
+        abs_key = (state_key, move_class, params, net_width, self.config.bend_collision_type, snap_to_grid)
-    if abs_key in context.move_cache:
+        if abs_key in self._move_cache:
-        res = context.move_cache[abs_key]
+            res = self._move_cache[abs_key]
             move_radius = params[0] if move_class == 'B' else (params[1] if move_class == 'SB' else None)
-        add_node(
+            self._add_node(parent, res, target, net_width, net_id, open_set, closed_set, move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-            parent, res, target, net_width, net_id, open_set, closed_set, context, metrics,
-            move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, 
-            inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost, 
-            self_collision_check=self_collision_check
-        )
             return
 
-    self_dilation = context.cost_evaluator.collision_engine.clearance / 2.0
+        rel_key = (base_ori, move_class, params, net_width, self.config.bend_collision_type, self._self_dilation, snap_to_grid)
-    rel_key = (base_ori, move_class, params, net_width, context.config.bend_collision_type, self_dilation, snap_to_grid)
         
         cache_key = (gx, gy, go, move_type, net_width)
-    if cache_key in context.hard_collision_set:
+        if cache_key in self._hard_collision_set:
             return
             
-    if rel_key in context.move_cache:
+        if rel_key in self._move_cache:
-        res_rel = context.move_cache[rel_key]
+            res_rel = self._move_cache[rel_key]
         else:
             try:
                 p0 = Port(0, 0, base_ori)
                 if move_class == 'S':
-                res_rel = Straight.generate(p0, params[0], net_width, dilation=self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
+                    res_rel = Straight.generate(p0, params[0], net_width, dilation=self._self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
                 elif move_class == 'B':
-                res_rel = Bend90.generate(p0, params[0], net_width, params[1], collision_type=context.config.bend_collision_type, clip_margin=context.config.bend_clip_margin, dilation=self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
+                    res_rel = Bend90.generate(p0, params[0], net_width, params[1], collision_type=self.config.bend_collision_type, clip_margin=self.config.bend_clip_margin, dilation=self._self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
                 elif move_class == 'SB':
-                res_rel = SBend.generate(p0, params[0], params[1], net_width, collision_type=context.config.bend_collision_type, clip_margin=context.config.bend_clip_margin, dilation=self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
+                    res_rel = SBend.generate(p0, params[0], params[1], net_width, collision_type=self.config.bend_collision_type, clip_margin=self.config.bend_clip_margin, dilation=self._self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
                 else:
                     return
-            context.move_cache[rel_key] = res_rel
+                self._move_cache[rel_key] = res_rel
             except (ValueError, ZeroDivisionError):
                 return
 
         res = res_rel.translate(cp.x, cp.y, rel_gx=res_rel.rel_gx + gx, rel_gy=res_rel.rel_gy + gy, rel_go=res_rel.rel_go)
-    context.move_cache[abs_key] = res
+        self._move_cache[abs_key] = res
         move_radius = params[0] if move_class == 'B' else (params[1] if move_class == 'SB' else None)
-    add_node(
+        self._add_node(parent, res, target, net_width, net_id, open_set, closed_set, move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-        parent, res, target, net_width, net_id, open_set, closed_set, context, metrics,
-        move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, 
-        inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost, 
-        self_collision_check=self_collision_check
-    )
 
-
+    def _add_node(
-def add_node(
+            self,
             parent: AStarNode,
             result: ComponentResult,
             target: Port,
@@ -461,25 +396,19 @@ def add_node(
             net_id: str,
             open_set: list[AStarNode],
             closed_set: dict[tuple[int, int, int], float],
-        context: AStarContext,
-        metrics: AStarMetrics,
             move_type: str,
             move_radius: float | None = None,
             snap: float = 1.0,
             skip_congestion: bool = False,
             inv_snap: float | None = None,
             parent_state: tuple[int, int, int] | None = None,
-        max_cost: float | None = None,
+            max_cost: float | None = None
-        self_collision_check: bool = False,
             ) -> None:
-    """
+        self.metrics['moves_generated'] += 1
-    Check collisions and costs, and add node to the open set.
-    """
-    metrics.moves_generated += 1
         state = (result.rel_gx, result.rel_gy, result.rel_go)
         
         if state in closed_set and closed_set[state] <= parent.g_cost + 1e-6:
-        metrics.pruned_closed_set += 1
+            self.metrics['pruned_closed_set'] += 1
             return
 
         parent_p = parent.port
@@ -490,41 +419,44 @@ def add_node(
              pgx, pgy, pgo = parent_state
         cache_key = (pgx, pgy, pgo, move_type, net_width)
         
-    if cache_key in context.hard_collision_set:
+        if cache_key in self._hard_collision_set:
-        metrics.pruned_hard_collision += 1
+            self.metrics['pruned_hard_collision'] += 1
             return
 
         new_g_cost = parent.g_cost + result.length
         
         # Pre-check cost pruning before evaluation (using heuristic)
         if max_cost is not None:
-         new_h_cost = context.cost_evaluator.h_manhattan(end_p, target)
+             new_h_cost = self.cost_evaluator.h_manhattan(end_p, target)
              if new_g_cost + new_h_cost > max_cost:
-              metrics.pruned_cost += 1
+                  self.metrics['pruned_cost'] += 1
                   return
 
-    is_static_safe = (cache_key in context.static_safe_cache)
+        is_static_safe = (cache_key in self._static_safe_cache)
         if not is_static_safe:
-        ce = context.cost_evaluator.collision_engine
+            ce = self.cost_evaluator.collision_engine
             if 'S' in move_type and 'SB' not in move_type:
                  if ce.check_move_straight_static(parent_p, result.length):
-                  context.hard_collision_set.add(cache_key)
+                      self._hard_collision_set.add(cache_key)
-                  metrics.pruned_hard_collision += 1
+                      self.metrics['pruned_hard_collision'] += 1
                       return
                  is_static_safe = True
             if not is_static_safe:
                 if ce.check_move_static(result, start_port=parent_p, end_port=end_p):
-                context.hard_collision_set.add(cache_key)
+                    self._hard_collision_set.add(cache_key)
-                metrics.pruned_hard_collision += 1
+                    self.metrics['pruned_hard_collision'] += 1
                     return
-            else: context.static_safe_cache.add(cache_key)
+                else: self._static_safe_cache.add(cache_key)
 
         total_overlaps = 0
         if not skip_congestion:
-        total_overlaps = context.cost_evaluator.collision_engine.check_move_congestion(result, net_id)
+            if cache_key in self._congestion_cache: total_overlaps = self._congestion_cache[cache_key]
+            else:
+                total_overlaps = self.cost_evaluator.collision_engine.check_move_congestion(result, net_id)
+                self._congestion_cache[cache_key] = total_overlaps
 
         # SELF-COLLISION CHECK (Optional for performance)
-    if self_collision_check:
+        if getattr(self, '_self_collision_check', False):
             curr_p = parent
             new_tb = result.total_bounds
             while curr_p and curr_p.parent:
@@ -540,34 +472,32 @@ def add_node(
                  curr_p = curr_p.parent
 
         penalty = 0.0
-    if 'SB' in move_type: penalty = context.config.sbend_penalty
+        if 'SB' in move_type: penalty = self.config.sbend_penalty
-    elif 'B' in move_type: penalty = context.config.bend_penalty
+        elif 'B' in move_type: penalty = self.config.bend_penalty
         if move_radius is not None and move_radius > 1e-6: penalty *= (10.0 / move_radius)**0.5
 
-    move_cost = context.cost_evaluator.evaluate_move(
+        move_cost = self.cost_evaluator.evaluate_move(
             None, result.end_port, net_width, net_id,
             start_port=parent_p, length=result.length,
             dilated_geometry=None, penalty=penalty,
-        skip_static=True, skip_congestion=True # Congestion overlaps already calculated
+            skip_static=True, skip_congestion=True
         )
-    move_cost += total_overlaps * context.cost_evaluator.congestion_penalty
+        move_cost += total_overlaps * self.cost_evaluator.congestion_penalty
 
         if move_cost > 1e12:
-        metrics.pruned_cost += 1
+            self.metrics['pruned_cost'] += 1
             return
 
         g_cost = parent.g_cost + move_cost
         if state in closed_set and closed_set[state] <= g_cost + 1e-6:
-        metrics.pruned_closed_set += 1
+            self.metrics['pruned_closed_set'] += 1
             return
             
-    h_cost = context.cost_evaluator.h_manhattan(result.end_port, target)
+        h_cost = self.cost_evaluator.h_manhattan(result.end_port, target)
         heapq.heappush(open_set, AStarNode(result.end_port, g_cost, h_cost, parent, result))
-    metrics.moves_added += 1
+        self.metrics['moves_added'] += 1
 
-
+    def _reconstruct_path(self, end_node: AStarNode) -> list[ComponentResult]:
-def reconstruct_path(end_node: AStarNode) -> list[ComponentResult]:
-    """ Trace back from end node to start node to get the path. """
         path = []
         curr: AStarNode | None = end_node
         while curr and curr.component_result:

inire/router/pathfinder.py

@@ -6,12 +6,10 @@ import random
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Callable, Literal, Any
 
-from inire.router.astar import route_astar, AStarMetrics
-
 if TYPE_CHECKING:
     from inire.geometry.components import ComponentResult
     from inire.geometry.primitives import Port
-    from inire.router.astar import AStarContext
+    from inire.router.astar import AStarRouter
     from inire.router.cost import CostEvaluator
 
 logger = logging.getLogger(__name__)
@@ -42,14 +40,13 @@ class PathFinder:
     """
     Multi-net router using Negotiated Congestion.
     """
-    __slots__ = ('context', 'metrics', 'max_iterations', 'base_congestion_penalty', 
+    __slots__ = ('router', 'cost_evaluator', 'max_iterations', 'base_congestion_penalty', 'use_tiered_strategy', 'congestion_multiplier', 'accumulated_expanded_nodes', 'warm_start')
-                 'use_tiered_strategy', 'congestion_multiplier', 'accumulated_expanded_nodes', 'warm_start')
 
-    context: AStarContext
+    router: AStarRouter
-    """ The A* persistent state (config, caches, evaluator) """
+    """ The A* search engine """
 
-    metrics: AStarMetrics
+    cost_evaluator: CostEvaluator
-    """ Performance metrics for search operations """
+    """ The evaluator for path costs """
 
     max_iterations: int
     """ Maximum number of rip-up and reroute iterations """
@@ -68,8 +65,8 @@ class PathFinder:
 
     def __init__(
             self,
-            context: AStarContext,
+            router: AStarRouter,
-            metrics: AStarMetrics | None = None,
+            cost_evaluator: CostEvaluator,
             max_iterations: int = 10,
             base_congestion_penalty: float = 100.0,
             congestion_multiplier: float = 1.5,
@@ -80,16 +77,16 @@ class PathFinder:
         Initialize the PathFinder.
 
         Args:
-            context: The A* search context (evaluator, config, caches).
+            router: The A* search engine.
-            metrics: Optional metrics container.
+            cost_evaluator: The evaluator for path costs.
             max_iterations: Maximum number of rip-up and reroute iterations.
             base_congestion_penalty: Starting penalty for overlaps.
             congestion_multiplier: Multiplier for congestion penalty per iteration.
             use_tiered_strategy: Whether to use simplified collision models in early iterations.
             warm_start: Initial ordering strategy for a fast greedy pass.
         """
-        self.context = context
+        self.router = router
-        self.metrics = metrics if metrics is not None else AStarMetrics()
+        self.cost_evaluator = cost_evaluator
         self.max_iterations = max_iterations
         self.base_congestion_penalty = base_congestion_penalty
         self.congestion_multiplier = congestion_multiplier
@@ -97,10 +94,6 @@ class PathFinder:
         self.warm_start = warm_start
         self.accumulated_expanded_nodes: list[tuple[float, float, float]] = []
 
-    @property
-    def cost_evaluator(self) -> CostEvaluator:
-        return self.context.cost_evaluator
-
     def _perform_greedy_pass(
             self,
             netlist: dict[str, tuple[Port, Port]],
@@ -130,9 +123,9 @@ class PathFinder:
             h_start = self.cost_evaluator.h_manhattan(start, target)
             max_cost_limit = max(h_start * 3.0, 2000.0) 
             
-            path = route_astar(
+            path = self.router.route(
-                start, target, width, context=self.context, metrics=self.metrics,
+                start, target, width, net_id=net_id, 
-                net_id=net_id, skip_congestion=True, max_cost=max_cost_limit
+                skip_congestion=True, max_cost=max_cost_limit
             )
             
             if path:
@@ -206,7 +199,6 @@ class PathFinder:
         results: dict[str, RoutingResult] = {}
         self.cost_evaluator.congestion_penalty = self.base_congestion_penalty
         self.accumulated_expanded_nodes = []
-        self.metrics.reset_per_route()
 
         start_time = time.monotonic()
         num_nets = len(netlist)
@@ -220,7 +212,6 @@ class PathFinder:
              ws_order = sort_nets if sort_nets is not None else self.warm_start
              if ws_order is not None:
                   initial_paths = self._perform_greedy_pass(netlist, net_widths, ws_order)
-                  self.context.clear_static_caches()
 
         # Apply initial sorting heuristic if requested (for the main NC loop)
         if sort_nets:
@@ -235,7 +226,6 @@ class PathFinder:
             any_congestion = False
             # Clear accumulation for this iteration so callback gets fresh data
             self.accumulated_expanded_nodes = []
-            self.metrics.reset_per_route()
             
             logger.info(f'PathFinder Iteration {iteration}...')
 
@@ -268,7 +258,7 @@ class PathFinder:
                     logger.debug(f'  Net {net_id} used Warm Start path.')
                 else:
                     # Standard Routing Logic
-                    target_coll_model = self.context.config.bend_collision_type
+                    target_coll_model = self.router.config.bend_collision_type
                     coll_model = target_coll_model
                     skip_cong = False
                     if self.use_tiered_strategy and iteration == 0:
@@ -276,24 +266,21 @@ class PathFinder:
                         if target_coll_model == "arc":
                             coll_model = "clipped_bbox"
                     
-                    base_node_limit = self.context.config.node_limit
+                    base_node_limit = self.router.config.node_limit
                     current_node_limit = base_node_limit
                     if net_id in results and not results[net_id].reached_target:
                          current_node_limit = base_node_limit * (iteration + 1)
                     
                     net_start = time.monotonic()
+                    original_limit = self.router.node_limit
+                    self.router.node_limit = current_node_limit
                     
-                    path = route_astar(
+                    path = self.router.route(start, target, width, net_id=net_id, bend_collision_type=coll_model, return_partial=True, store_expanded=store_expanded, skip_congestion=skip_cong, self_collision_check=(net_id in needs_sc))
-                        start, target, width, context=self.context, metrics=self.metrics,
-                        net_id=net_id, bend_collision_type=coll_model, return_partial=True, 
-                        store_expanded=store_expanded, skip_congestion=skip_cong, 
-                        self_collision_check=(net_id in needs_sc),
-                        node_limit=current_node_limit
-                    )
                     
-                    if store_expanded and self.metrics.last_expanded_nodes:
+                    if store_expanded and self.router.last_expanded_nodes:
-                        self.accumulated_expanded_nodes.extend(self.metrics.last_expanded_nodes)
+                        self.accumulated_expanded_nodes.extend(self.router.last_expanded_nodes)
 
+                    self.router.node_limit = original_limit
                     logger.debug(f'  Net {net_id} routed in {time.monotonic() - net_start:.4f}s using {coll_model}')
 
                 if path:
@@ -359,7 +346,6 @@ class PathFinder:
                     if collision_count > 0:
                         any_congestion = True
 
-                    logger.debug(f'    Net {net_id}: reached={reached}, collisions={collision_count}')
                     results[net_id] = RoutingResult(net_id, path, (reached and collision_count == 0), collision_count, reached_target=reached)
                 else:
                     results[net_id] = RoutingResult(net_id, [], False, 0, reached_target=False)

inire/tests/benchmark_scaling.py

@@ -3,7 +3,7 @@ from inire.geometry.primitives import Port
 from inire.geometry.collision import CollisionEngine
 from inire.router.danger_map import DangerMap
 from inire.router.cost import CostEvaluator
-from inire.router.astar import AStarContext, AStarMetrics
+from inire.router.astar import AStarRouter
 from inire.router.pathfinder import PathFinder
 
 def benchmark_scaling() -> None:
@@ -26,9 +26,8 @@ def benchmark_scaling() -> None:
     danger_map = DangerMap(bounds=routing_bounds)
     danger_map.precompute([])
     evaluator = CostEvaluator(engine, danger_map)
-    context = AStarContext(evaluator)
+    router = AStarRouter(evaluator)
-    metrics = AStarMetrics()
+    pf = PathFinder(router, evaluator)
-    pf = PathFinder(context, metrics)
 
     num_nets = 50
     netlist = {}
@@ -46,7 +45,7 @@ def benchmark_scaling() -> None:
     print(f"Time per net: {total_time/num_nets:.4f} s")
 
     if total_time > 0:
-        nodes_per_sec = metrics.total_nodes_expanded / total_time
+        nodes_per_sec = router.total_nodes_expanded / total_time
         print(f"Node expansion rate: {nodes_per_sec:.2f} nodes/s")
 
     # Success rate

inire/tests/test_astar.py

@@ -3,7 +3,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import RoutingResult
@@ -19,10 +19,10 @@ def basic_evaluator() -> CostEvaluator:
 
 
 def test_astar_straight(basic_evaluator: CostEvaluator) -> None:
-    context = AStarContext(basic_evaluator, snap_size=1.0)
+    router = AStarRouter(basic_evaluator, snap_size=1.0)
     start = Port(0, 0, 0)
     target = Port(50, 0, 0)
-    path = route_astar(start, target, net_width=2.0, context=context)
+    path = router.route(start, target, net_width=2.0)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)
@@ -35,11 +35,11 @@ def test_astar_straight(basic_evaluator: CostEvaluator) -> None:
 
 
 def test_astar_bend(basic_evaluator: CostEvaluator) -> None:
-    context = AStarContext(basic_evaluator, snap_size=1.0, bend_radii=[10.0])
+    router = AStarRouter(basic_evaluator, snap_size=1.0, bend_radii=[10.0])
     start = Port(0, 0, 0)
     # 20um right, 20um up. Needs a 10um bend and a 10um bend.
     target = Port(20, 20, 0)
-    path = route_astar(start, target, net_width=2.0, context=context)
+    path = router.route(start, target, net_width=2.0)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)
@@ -56,10 +56,11 @@ def test_astar_obstacle(basic_evaluator: CostEvaluator) -> None:
     basic_evaluator.collision_engine.add_static_obstacle(obstacle)
     basic_evaluator.danger_map.precompute([obstacle])
 
-    context = AStarContext(basic_evaluator, snap_size=1.0, bend_radii=[10.0], node_limit=1000000)
+    router = AStarRouter(basic_evaluator, snap_size=1.0, bend_radii=[10.0])
+    router.node_limit = 1000000 # Give it more room for detour
     start = Port(0, 0, 0)
     target = Port(60, 0, 0)
-    path = route_astar(start, target, net_width=2.0, context=context)
+    path = router.route(start, target, net_width=2.0)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)
@@ -71,11 +72,11 @@ def test_astar_obstacle(basic_evaluator: CostEvaluator) -> None:
 
 
 def test_astar_snap_to_target_lookahead(basic_evaluator: CostEvaluator) -> None:
-    context = AStarContext(basic_evaluator, snap_size=1.0)
+    router = AStarRouter(basic_evaluator, snap_size=1.0)
     # Target is NOT on 1um grid
     start = Port(0, 0, 0)
     target = Port(10.1, 0, 0)
-    path = route_astar(start, target, net_width=2.0, context=context)
+    path = router.route(start, target, net_width=2.0)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)

inire/tests/test_congestion.py

@@ -3,7 +3,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -19,12 +19,12 @@ def basic_evaluator() -> CostEvaluator:
 
 
 def test_astar_sbend(basic_evaluator: CostEvaluator) -> None:
-    context = AStarContext(basic_evaluator, snap_size=1.0, sbend_offsets=[2.0, 5.0])
+    router = AStarRouter(basic_evaluator, snap_size=1.0, sbend_offsets=[2.0, 5.0])
     # Start at (0,0), target at (50, 2) -> 2um lateral offset
     # This matches one of our discretized SBend offsets.
     start = Port(0, 0, 0)
     target = Port(50, 2, 0)
-    path = route_astar(start, target, net_width=2.0, context=context)
+    path = router.route(start, target, net_width=2.0)
 
     assert path is not None
     # Check if any component in the path is an SBend
@@ -39,9 +39,9 @@ def test_astar_sbend(basic_evaluator: CostEvaluator) -> None:
 
 
 def test_pathfinder_negotiated_congestion_resolution(basic_evaluator: CostEvaluator) -> None:
-    context = AStarContext(basic_evaluator, snap_size=1.0, bend_radii=[5.0, 10.0])
+    router = AStarRouter(basic_evaluator, snap_size=1.0, bend_radii=[5.0, 10.0])
     # Increase base penalty to force detour immediately
-    pf = PathFinder(context, max_iterations=10, base_congestion_penalty=1000.0)
+    pf = PathFinder(router, basic_evaluator, max_iterations=10, base_congestion_penalty=1000.0)
 
     netlist = {
         "net1": (Port(0, 0, 0), Port(50, 0, 0)),

inire/tests/test_failed_net_congestion.py

@@ -4,7 +4,7 @@ import numpy
 from inire.geometry.primitives import Port
 from inire.geometry.collision import CollisionEngine
 from inire.router.cost import CostEvaluator
-from inire.router.astar import AStarContext
+from inire.router.astar import AStarRouter
 from inire.router.pathfinder import PathFinder
 from inire.router.danger_map import DangerMap
 
@@ -24,8 +24,12 @@ def test_failed_net_visibility():
     evaluator = CostEvaluator(engine, dm)
     
     # 2. Configure Router with low limit to FORCE failure
-    # node_limit=10 is extremely low, likely allowing only a few moves.
+    # node_limit=5 is extremely low, likely allowing only a few moves.
     # Start (0,0) -> Target (100,0) is 100um away.
+    # If snap is 1.0, direct jump S100 might be tried.
+    # If direct jump works, it might succeed in 1 expansion.
+    # So we need to block the direct jump or make the limit VERY small (0?).
+    # Or place a static obstacle that forces a search.
     
     # Let's add a static obstacle that blocks the direct path.
     from shapely.geometry import box
@@ -34,11 +38,11 @@ def test_failed_net_visibility():
     
     # With obstacle, direct jump fails. A* must search around.
     # Limit=10 should be enough to fail to find a path around.
-    context = AStarContext(evaluator, node_limit=10)
+    router = AStarRouter(evaluator, node_limit=10)
     
     # 3. Configure PathFinder
     # max_iterations=1 because we only need to check the state after the first attempt.
-    pf = PathFinder(context, max_iterations=1, warm_start=None)
+    pf = PathFinder(router, evaluator, max_iterations=1, warm_start=None)
     
     netlist = {
         "net1": (Port(0, 0, 0), Port(100, 0, 0))

inire/tests/test_fuzz.py

@@ -6,7 +6,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext, route_astar
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import RoutingResult
@@ -41,12 +41,13 @@ def test_fuzz_astar_no_crash(obstacles: list[Polygon], start: Port, target: Port
     danger_map.precompute(obstacles)
 
     evaluator = CostEvaluator(engine, danger_map)
-    context = AStarContext(evaluator, node_limit=5000)  # Lower limit for fuzzing stability
+    router = AStarRouter(evaluator)
+    router.node_limit = 5000  # Lower limit for fuzzing stability
 
     # Check if start/target are inside obstacles (safety zone check)
     # The router should handle this gracefully (either route or return None)
     try:
-        path = route_astar(start, target, net_width=2.0, context=context)
+        path = router.route(start, target, net_width=2.0)
 
         # Analytic Correctness: if path is returned, verify it's collision-free
         if path:

inire/tests/test_pathfinder.py

@@ -2,7 +2,7 @@ import pytest
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -17,8 +17,8 @@ def basic_evaluator() -> CostEvaluator:
 
 
 def test_pathfinder_parallel(basic_evaluator: CostEvaluator) -> None:
-    context = AStarContext(basic_evaluator)
+    router = AStarRouter(basic_evaluator)
-    pf = PathFinder(context)
+    pf = PathFinder(router, basic_evaluator)
 
     netlist = {
         "net1": (Port(0, 0, 0), Port(50, 0, 0)),

inire/tests/test_refinements.py

@@ -1,7 +1,7 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.components import Bend90
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarContext
+from inire.router.astar import AStarRouter
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -29,8 +29,8 @@ def test_locked_paths() -> None:
     danger_map = DangerMap(bounds=(0, -50, 100, 50))
     danger_map.precompute([])
     evaluator = CostEvaluator(engine, danger_map)
-    context = AStarContext(evaluator, bend_radii=[5.0, 10.0])
+    router = AStarRouter(evaluator, bend_radii=[5.0, 10.0])
-    pf = PathFinder(context)
+    pf = PathFinder(router, evaluator)
 
     # 1. Route Net A
     netlist_a = {"netA": (Port(0, 0, 0), Port(50, 0, 0))}