diff --git a/packages/gittensory-engine/README.md b/packages/gittensory-engine/README.md
index 7d576824bc..8845eb60ca 100644
--- a/packages/gittensory-engine/README.md
+++ b/packages/gittensory-engine/README.md
@@ -540,6 +540,7 @@ dashboard progress summaries:
 - `isPlanProgressComplete(plan)` — every step is `completed` or `skipped` (empty plans are not complete; mirrors `planProgress`'s `completed` status)
 - `resolvePlanOverallStatus(plan)` — coarse status (`pending` | `running` | `completed` | `failed` | `blocked`); mirrors `planProgress`'s `status`
 - `hasPlanReadySteps(plan)` — any step is runnable now (`pending` with satisfied dependencies; mirrors `nextReadySteps(plan).length > 0`)
+- `isPlanTerminated(plan)` — plan reached a terminal outcome (`failed` step or every step `completed`/`skipped`; empty plans are not terminated)
 
 ## Opportunity competition
 
diff --git a/packages/gittensory-engine/src/index.ts b/packages/gittensory-engine/src/index.ts
index 2c7784e92e..05ec54a5cf 100644
--- a/packages/gittensory-engine/src/index.ts
+++ b/packages/gittensory-engine/src/index.ts
@@ -150,6 +150,7 @@ export { isPlanBlocked } from "./plan-blocked.js";
 export { isPlanProgressComplete } from "./plan-progress-complete.js";
 export { resolvePlanOverallStatus, type PlanOverallStatus } from "./plan-overall-status.js";
 export { hasPlanReadySteps } from "./plan-ready.js";
+export { isPlanTerminated } from "./plan-terminated.js";
 export * from "./plan-templates.js";
 export * from "./portfolio/queue.js";
 export {
diff --git a/packages/gittensory-engine/src/plan-terminated.ts b/packages/gittensory-engine/src/plan-terminated.ts
new file mode 100644
index 0000000000..48fb46b502
--- /dev/null
+++ b/packages/gittensory-engine/src/plan-terminated.ts
@@ -0,0 +1,11 @@
+import type { PlanDag } from "./plan-export.js";
+import { hasPlanFailedSteps } from "./plan-failure.js";
+import { isPlanProgressComplete } from "./plan-progress-complete.js";
+
+/**
+ * Return whether the plan reached a terminal outcome: any step `failed`, or every step is `completed` or `skipped`.
+ * Empty plans are not terminated. Pure.
+ */
+export function isPlanTerminated(plan: PlanDag): boolean {
+  return hasPlanFailedSteps(plan) || isPlanProgressComplete(plan);
+}
diff --git a/test/unit/plan-terminated.test.ts b/test/unit/plan-terminated.test.ts
new file mode 100644
index 0000000000..84d9325276
--- /dev/null
+++ b/test/unit/plan-terminated.test.ts
@@ -0,0 +1,76 @@
+import { describe, expect, it } from "vitest";
+
+import { isPlanTerminated } from "../../packages/gittensory-engine/src/plan-terminated";
+import type { PlanStep } from "../../packages/gittensory-engine/src/plan-export";
+
+function step(over: Partial<PlanStep> & { id: string; title: string }): PlanStep {
+  return {
+    actionClass: undefined,
+    dependsOn: [],
+    status: "pending",
+    attempts: 0,
+    maxAttempts: 3,
+    lastError: null,
+    ...over,
+  };
+}
+
+describe("isPlanTerminated", () => {
+  it("returns false for an empty plan", () => {
+    expect(isPlanTerminated({ steps: [] })).toBe(false);
+  });
+
+  it("returns false while work is still in flight", () => {
+    expect(
+      isPlanTerminated({
+        steps: [
+          step({ id: "a", title: "Build", status: "running" }),
+          step({ id: "b", title: "Test", status: "pending" }),
+        ],
+      }),
+    ).toBe(false);
+  });
+
+  it("returns true when any step failed", () => {
+    expect(
+      isPlanTerminated({
+        steps: [
+          step({ id: "a", title: "Build", status: "completed" }),
+          step({ id: "b", title: "Deploy", status: "failed" }),
+        ],
+      }),
+    ).toBe(true);
+  });
+
+  it("returns true when every step is completed or skipped", () => {
+    expect(
+      isPlanTerminated({
+        steps: [
+          step({ id: "a", title: "Build", status: "completed" }),
+          step({ id: "b", title: "Deploy", status: "skipped" }),
+        ],
+      }),
+    ).toBe(true);
+  });
+
+  it("returns false for a blocked cyclic deadlock", () => {
+    expect(
+      isPlanTerminated({
+        steps: [
+          step({ id: "a", title: "A", dependsOn: ["b"] }),
+          step({ id: "b", title: "B", dependsOn: ["a"] }),
+        ],
+      }),
+    ).toBe(false);
+  });
+
+  it("is exported from the package barrel", async () => {
+    const barrel = await import("../../packages/gittensory-engine/src/index");
+    expect(typeof barrel.isPlanTerminated).toBe("function");
+    expect(
+      barrel.isPlanTerminated({
+        steps: [step({ id: "a", title: "A", status: "failed" })],
+      }),
+    ).toBe(true);
+  });
+});