diff --git a/src/lib/lane-config.test.ts b/src/lib/lane-config.test.ts
new file mode 100644
index 0000000..2d06318
--- /dev/null
+++ b/src/lib/lane-config.test.ts
@@ -0,0 +1,174 @@
+import { afterEach, describe, expect, it } from "vitest";
+import {
+  getBacklogLane,
+  getClaimableLanes,
+  getConfiguredLanes,
+  getLaneById,
+  getLaneIds,
+  isClaimableLane,
+  isValidLane,
+  resetLaneConfig,
+  setLaneConfig,
+} from "./lane-config";
+
+describe("lane-config defaults", () => {
+  it("returns three default lanes", () => {
+    const lanes = getConfiguredLanes();
+    expect(lanes).toHaveLength(3);
+    expect(lanes.map((l) => l.id)).toEqual(["normal", "escalated", "backlog"]);
+  });
+
+  it("normal and escalated are claimable, backlog is not", () => {
+    expect(isClaimableLane("normal")).toBe(true);
+    expect(isClaimableLane("escalated")).toBe(true);
+    expect(isClaimableLane("backlog")).toBe(false);
+  });
+
+  it("getClaimableLanes returns only claimable lanes", () => {
+    const claimable = getClaimableLanes();
+    expect(claimable).toHaveLength(2);
+    expect(claimable.map((l) => l.id)).toEqual(["normal", "escalated"]);
+  });
+
+  it("getBacklogLane returns the non-claimable lane", () => {
+    const backlog = getBacklogLane();
+    expect(backlog).toBeDefined();
+    expect(backlog?.id).toBe("backlog");
+    expect(backlog?.claimable).toBe(false);
+  });
+
+  it("isValidLane returns correct values for defaults", () => {
+    expect(isValidLane("normal")).toBe(true);
+    expect(isValidLane("escalated")).toBe(true);
+    expect(isValidLane("backlog")).toBe(true);
+    expect(isValidLane("unknown")).toBe(false);
+  });
+
+  it("getLaneById returns the lane or undefined", () => {
+    expect(getLaneById("normal")?.title).toBe("Normal");
+    expect(getLaneById("nonexistent")).toBeUndefined();
+  });
+
+  it("getLaneIds returns all configured ids", () => {
+    expect(getLaneIds()).toEqual(["normal", "escalated", "backlog"]);
+  });
+
+  it("returns a deep copy (mutations do not leak)", () => {
+    const lanes = getConfiguredLanes();
+    lanes[0].id = "mutated";
+    expect(getConfiguredLanes()[0].id).toBe("normal");
+  });
+});
+
+describe("lane-config custom config", () => {
+  afterEach(() => {
+    resetLaneConfig();
+  });
+
+  it("accepts a single claimable lane plus backlog", () => {
+    setLaneConfig({
+      lanes: [
+        { id: "default", title: "Default", claimable: true },
+        { id: "backlog", title: "Backlog", claimable: false },
+      ],
+    });
+
+    expect(getConfiguredLanes()).toHaveLength(2);
+    expect(isClaimableLane("default")).toBe(true);
+    expect(isClaimableLane("backlog")).toBe(false);
+    expect(getBacklogLane()?.id).toBe("backlog");
+  });
+
+  it("accepts multiple claimable lanes plus backlog", () => {
+    setLaneConfig({
+      lanes: [
+        { id: "fast", title: "Fast Lane", claimable: true },
+        { id: "slow", title: "Slow Lane", claimable: true },
+        { id: "parked", title: "Parked", claimable: false },
+      ],
+    });
+
+    expect(getClaimableLanes()).toHaveLength(2);
+    expect(isClaimableLane("fast")).toBe(true);
+    expect(isClaimableLane("slow")).toBe(true);
+    expect(isClaimableLane("parked")).toBe(false);
+    expect(getBacklogLane()?.id).toBe("parked");
+  });
+
+  it("rejects empty lane array", () => {
+    expect(() => setLaneConfig({ lanes: [] })).toThrow(
+      "Lane config must contain at least one lane",
+    );
+  });
+
+  it("rejects duplicate lane ids", () => {
+    expect(() =>
+      setLaneConfig({
+        lanes: [
+          { id: "a", title: "A", claimable: true },
+          { id: "a", title: "A dup", claimable: false },
+        ],
+      }),
+    ).toThrow("Duplicate lane id: a");
+  });
+
+  it("rejects empty lane id", () => {
+    expect(() =>
+      setLaneConfig({ lanes: [{ id: "", title: "X", claimable: true }] }),
+    ).toThrow("Lane id must be a non-empty string");
+  });
+
+  it("rejects missing title", () => {
+    // @ts-expect-error — testing runtime validation
+    expect(() => setLaneConfig({ lanes: [{ id: "x", claimable: true }] })).toThrow(
+      'Lane "x" must have a non-empty title',
+    );
+  });
+
+  it("rejects all non-claimable lanes", () => {
+    expect(() =>
+      setLaneConfig({
+        lanes: [
+          { id: "a", title: "A", claimable: false },
+          { id: "b", title: "B", claimable: false },
+        ],
+      }),
+    ).toThrow("Lane config must contain at least one claimable lane");
+  });
+
+  it("supports optional fields (description, color, defaultAgent)", () => {
+    setLaneConfig({
+      lanes: [
+        {
+          id: "custom",
+          title: "Custom",
+          claimable: true,
+          description: "A custom lane",
+          color: "#ff0000",
+          defaultAgent: "custom-agent",
+        },
+        { id: "backlog", title: "Backlog", claimable: false },
+      ],
+    });
+
+    const lane = getLaneById("custom");
+    expect(lane?.description).toBe("A custom lane");
+    expect(lane?.color).toBe("#ff0000");
+    expect(lane?.defaultAgent).toBe("custom-agent");
+  });
+});
+
+describe("lane-config reset", () => {
+  it("resetLaneConfig restores defaults", () => {
+    setLaneConfig({
+      lanes: [
+        { id: "only", title: "Only", claimable: true },
+      ],
+    });
+    expect(getConfiguredLanes()).toHaveLength(1);
+
+    resetLaneConfig();
+    expect(getConfiguredLanes()).toHaveLength(3);
+    expect(getLaneIds()).toEqual(["normal", "escalated", "backlog"]);
+  });
+});
diff --git a/src/lib/lane-config.ts b/src/lib/lane-config.ts
new file mode 100644
index 0000000..7c80a71
--- /dev/null
+++ b/src/lib/lane-config.ts
@@ -0,0 +1,181 @@
+/**
+ * Central lane configuration module.
+ *
+ * Provides a typed, configurable lane model so that all lane consumers go
+ * through one helper instead of scattered string unions and constants.
+ *
+ * The default config preserves current behavior (normal / escalated / backlog).
+ */
+
+// ─── Types ────────────────────────────────────────────────────────────────────
+
+/**
+ * A single lane definition.
+ */
+export interface LaneConfig {
+  /** Unique identifier (e.g. "normal", "escalated", "backlog") */
+  id: string;
+  /** Display title */
+  title: string;
+  /** Whether workers may claim issues in this lane */
+  claimable: boolean;
+  /** Optional human-readable description */
+  description?: string;
+  /** Optional hex color for UI rendering */
+  color?: string;
+  /** Default agent that handles this lane (optional) */
+  defaultAgent?: string;
+}
+
+/**
+ * Full lane configuration set.
+ */
+export interface LaneConfigSet {
+  lanes: LaneConfig[];
+}
+
+// ─── Defaults ─────────────────────────────────────────────────────────────────
+
+/**
+ * Default lane configuration — equivalent to current behavior.
+ *
+ * - `normal`: claimable, standard worker lane
+ * - `escalated`: claimable, requires higher-judgment model support
+ * - `backlog`: non-claimable, needs grooming before work can start
+ */
+const DEFAULT_LANE_CONFIG: LaneConfigSet = {
+  lanes: [
+    {
+      id: "normal",
+      title: "Normal",
+      claimable: true,
+      description: "Standard execution lane for concrete, scoped implementation work.",
+      color: "#3b82f6",
+    },
+    {
+      id: "escalated",
+      title: "Escalated",
+      claimable: true,
+      description: "Requires higher-judgment model support (architecture, design, cross-service).",
+      color: "#f97316",
+    },
+    {
+      id: "backlog",
+      title: "Backlog",
+      claimable: false,
+      description: "Needs grooming before work can start. Not directly claimable.",
+      color: "#6b7280",
+    },
+  ],
+};
+
+// ─── Config State ─────────────────────────────────────────────────────────────
+
+let laneConfigSet: LaneConfigSet = DEFAULT_LANE_CONFIG;
+
+/**
+ * Override the lane configuration (e.g. from environment or custom config file).
+ *
+ * Validates that every lane has a unique, non-empty id and that at least one
+ * claimable lane exists. Throws on invalid config.
+ */
+export function setLaneConfig(config: LaneConfigSet): void {
+  validateLaneConfigSet(config);
+  laneConfigSet = config;
+}
+
+/**
+ * Reset to the default lane configuration.
+ */
+export function resetLaneConfig(): void {
+  laneConfigSet = DEFAULT_LANE_CONFIG;
+}
+
+// ─── Public Helpers ───────────────────────────────────────────────────────────
+
+/**
+ * Return all configured lanes (deep copy).
+ */
+export function getConfiguredLanes(): LaneConfig[] {
+  return laneConfigSet.lanes.map((lane) => ({ ...lane }));
+}
+
+/**
+ * Return only claimable lanes.
+ */
+export function getClaimableLanes(): LaneConfig[] {
+  return getConfiguredLanes().filter((lane) => lane.claimable);
+}
+
+/**
+ * Return the non-claimable "backlog" fallback lane, if configured.
+ * Returns `undefined` when no non-claimable lane exists.
+ */
+export function getBacklogLane(): LaneConfig | undefined {
+  return getConfiguredLanes().find((lane) => !lane.claimable);
+}
+
+/**
+ * Check whether a lane id is configured.
+ */
+export function isValidLane(id: string): boolean {
+  return getConfiguredLanes().some((lane) => lane.id === id);
+}
+
+/**
+ * Check whether a lane id is both configured and claimable.
+ */
+export function isClaimableLane(id: string): boolean {
+  return getConfiguredLanes().some((lane) => lane.id === id && lane.claimable);
+}
+
+/**
+ * Look up a lane by id. Returns `undefined` when not found.
+ */
+export function getLaneById(id: string): LaneConfig | undefined {
+  return getConfiguredLanes().find((lane) => lane.id === id);
+}
+
+/**
+ * Return all configured lane ids.
+ */
+export function getLaneIds(): string[] {
+  return getConfiguredLanes().map((lane) => lane.id);
+}
+
+// ─── Validation ───────────────────────────────────────────────────────────────
+
+/**
+ * Validate a LaneConfigSet and throw on errors.
+ */
+function validateLaneConfigSet(config: LaneConfigSet): void {
+  if (!Array.isArray(config.lanes) || config.lanes.length === 0) {
+    throw new Error("Lane config must contain at least one lane");
+  }
+
+  const ids = new Set<string>();
+
+  for (const lane of config.lanes) {
+    if (typeof lane.id !== "string" || lane.id.trim().length === 0) {
+      throw new Error(`Lane id must be a non-empty string, got: ${JSON.stringify(lane.id)}`);
+    }
+
+    if (ids.has(lane.id)) {
+      throw new Error(`Duplicate lane id: ${lane.id}`);
+    }
+    ids.add(lane.id);
+
+    if (typeof lane.title !== "string" || lane.title.trim().length === 0) {
+      throw new Error(`Lane "${lane.id}" must have a non-empty title`);
+    }
+
+    if (typeof lane.claimable !== "boolean") {
+      throw new Error(`Lane "${lane.id}" must have a boolean claimable field`);
+    }
+  }
+
+  const hasClaimable = config.lanes.some((l) => l.claimable);
+  if (!hasClaimable) {
+    throw new Error("Lane config must contain at least one claimable lane");
+  }
+}