diff --git a/api-report/apps/api/src/modules/trace/contract.d.ts b/api-report/apps/api/src/modules/trace/contract.d.ts
index ba4d8a8..c3970d1 100644
--- a/api-report/apps/api/src/modules/trace/contract.d.ts
+++ b/api-report/apps/api/src/modules/trace/contract.d.ts
@@ -76,6 +76,8 @@ export type TraceService = {
         workflowId?: string;
         nodeId?: string;
         output?: Record<string, unknown>;
+        /** 非放行终态的原因 —— 有它就把这一段标成错,时间轴上一眼看出哪儿坏了 */
+        error?: string;
     }): Promise<void>;
     endWorkflow(input: {
         workflowId: string;
diff --git a/apps/api/src/app/wiring/engines.ts b/apps/api/src/app/wiring/engines.ts
index 890b1be..6e7eaca 100644
--- a/apps/api/src/app/wiring/engines.ts
+++ b/apps/api/src/app/wiring/engines.ts
@@ -991,8 +991,24 @@ export function wireEngines(deps: EngineWiringDeps): EngineWiring {
   const tracedProcess: ProcessService = {
     ...process,
     async onTaskTerminal(taskId, terminal, ports) {
-      // 节点 span 先收(这一步办完了),再让流程往下走 —— 时间轴上不倒序
-      await deps.trace.endNode({ taskId, output: { terminal } });
+      /*
+       * 节点 span 先收(这一步办完了),再让流程往下走 —— 时间轴上不倒序。
+       * **非放行终态标成错**:blocked / exhausted / 失败都要在时间轴上看得出来,
+       * 收成一条无害的「已结束」等于把事故藏起来(实测:落地失败的那几单,
+       * 观测面上与走完的单长得一模一样)。原因从任务上现读。
+       */
+      const failed = terminal !== 'released';
+      const reason = failed
+        ? await task
+            .get(taskId as TaskId)
+            .then((t) => JSON.stringify(t.reason ?? terminal))
+            .catch(() => terminal)
+        : undefined;
+      await deps.trace.endNode({
+        taskId,
+        output: { terminal },
+        ...(reason === undefined ? {} : { error: `${terminal}:${reason}` }),
+      });
       const state = await process.onTaskTerminal(taskId, terminal, ports);
       return state;
     },
diff --git a/apps/api/src/modules/task/__tests__/landing-failure.test.ts b/apps/api/src/modules/task/__tests__/landing-failure.test.ts
new file mode 100644
index 0000000..92d3c81
--- /dev/null
+++ b/apps/api/src/modules/task/__tests__/landing-failure.test.ts
@@ -0,0 +1,138 @@
+/**
+ * 放行落地**失败**的收场 —— 实测抓到的一条真事故(2026-07-29)。
+ *
+ * 症状:点了通过,任务却以 `exhausted` 收场,界面上什么都看不到。
+ * 机理:`land()` 抛错(草稿与正式版并发冲突)→ 异常穿到推进器 → 推进器写一行
+ * stderr 就 break;而这一拍**已经把 runtime 落回 running、已经扣了一步预算** ——
+ * 两秒后又来一次,一直空转到 steps 触顶(实测 3 步的活跑了 40 步)。
+ * 真正的原因只在服务端 stderr 里刷屏,任务记忆、界面、trace 上一个字都没有。
+ *
+ * 定的规矩:**落地失败是终态,不是可重试的中间态** —— 就地落 `blocked`,
+ * 原因写进任务记忆(人读得到),推进器再也不会来推它。
+ */
+import { describe, expect, it } from 'vitest';
+import type { TaskId } from '@contracts';
+import type { Task } from '../contract.ts';
+import { createTaskService } from '../internal/usecase/task-service.ts';
+import type { TaskServiceDeps } from '../internal/usecase/task-service.ts';
+
+const TASK = 't-1' as TaskId;
+
+type Harness = {
+  service: ReturnType<typeof createTaskService>;
+  readonly memories: Array<{ kind: string; title: string }>;
+  readonly landCalls: number[];
+  task: Task;
+};
+
+/** 谱已走完、放行通过 —— 只在「落地这一下」上做文章 */
+function harness(land: () => Promise<never> | Promise<{ converged: boolean; emittedPorts: string[]; ledgerRowsMerged: number; facts: unknown }>): Harness {
+  const memories: Harness['memories'] = [];
+  const landCalls: number[] = [];
+  const h: Harness = { service: undefined as never, memories, landCalls, task: undefined as never };
+  h.task = {
+    id: TASK,
+    activityId: 'a-1',
+    paradigm: 'flow',
+    ownerId: 's-1' as Task['ownerId'],
+    title: '占位活动',
+    runtime: 'running',
+    envelope: { activityId: 'a-1', packageVersion: '0.7.0' },
+    data: {},
+    caps: { steps: 40, tokens: 200000, humanCalls: 2, activeMinutes: 60 },
+    used: { steps: 3, tokens: 0, activeMs: 100, humanCalls: 1 },
+    startedAt: '2026-07-29T00:00:00.000Z',
+  };
+
+  const deps: TaskServiceDeps = {
+    store: {
+      get: async () => h.task,
+      update: async (_id, patch) => {
+        h.task = { ...h.task, ...patch };
+        return h.task;
+      },
+      addConsumption: async () => h.task.used,
+      lastProgressAt: async () => new Date('2026-07-29T00:00:01.000Z'),
+      markProgress: async () => undefined,
+      listByOwner: async () => [],
+      insert: async () => undefined,
+    },
+    activities: {
+      load: async () => ({
+        paradigm: 'flow' as const,
+        caps: h.task.caps,
+        envelope: {},
+        inputSchema: {},
+        businessModel: {},
+        stallAfter: 'PT30M',
+      }),
+    },
+    schemas: { validate: () => ({ ok: true, errors: [] }) },
+    engines: {
+      // 谱走完 + 放行通过 —— 接下来就该落地
+      flow: { load: async () => undefined, advance: async () => ({ status: 'finished', released: true, selectedPorts: {} }), onEvent: async () => ({ status: 'running' }) },
+      loop: { load: async () => undefined, advance: async () => ({ status: 'running' }), onEvent: async () => ({ status: 'running' }) },
+    },
+    memory: {
+      append: async (input) => {
+        memories.push({ kind: input.kind, title: input.title });
+      },
+      hasHistory: async () => true,
+      seal: async () => undefined,
+      distill: async () => undefined,
+    },
+    landing: {
+      land: async () => {
+        landCalls.push(landCalls.length + 1);
+        return land();
+      },
+    } as TaskServiceDeps['landing'],
+    listeners: { hasArmedListener: async () => false },
+    persistence: { hasDrafts: async () => false, hasRuntimeState: async () => true },
+    events: { publishTerminal: async () => undefined, publishControl: async () => undefined },
+    notifier: { notify: async () => undefined },
+    interaction: { setPhase: async () => undefined },
+    clock: { now: () => new Date('2026-07-29T00:00:02.000Z') },
+    ids: { next: () => 'x' },
+  };
+
+  h.service = createTaskService(deps);
+  return h;
+}
+
+describe('放行落地失败 —— 是终态,不是可重试的中间态', () => {
+  it('land 抛错:落 blocked 终态,原因进任务记忆(不再空转)', async () => {
+    const h = harness(async () => {
+      throw new Error('草稿与正式版并发冲突:2 处字段已被他单改动');
+    });
+
+    const out = await h.service.tick(TASK);
+    expect(out.task.terminal, '落地失败即终态').toBe('blocked');
+    expect(String(out.task.reason)).toContain('放行落地失败');
+    expect(String(out.task.reason)).toContain('并发冲突');
+
+    // 原因要人读得到 —— 从前只写 stderr,界面上一个字都没有
+    const said = h.memories.find((m) => m.title.includes('放行落地失败'));
+    expect(said, '任务记忆里要有一条说清为什么').toBeDefined();
+    expect(said!.title).toContain('并发冲突');
+  });
+
+  it('终态之后不再被推 —— 空转到预算耗尽的那条路断了', async () => {
+    const h = harness(async () => {
+      throw new Error('落地炸了');
+    });
+
+    await h.service.tick(TASK);
+    expect(h.landCalls).toHaveLength(1);
+    // 推进器只推 runtime==='running' 的任务;落了终态就再也不会来
+    expect(h.task['runtime']).toBe('terminal');
+    expect(h.task['terminal']).toBe('blocked');
+  });
+
+  it('落地成功照旧 released —— 修的是失败那条路,别误伤正常路', async () => {
+    const h = harness(async () => ({ converged: true, emittedPorts: ['intake'], ledgerRowsMerged: 2, facts: {} }));
+    const out = await h.service.tick(TASK);
+    expect(out.task.terminal).toBe('released');
+    expect(h.memories.some((m) => m.title.includes('落地收敛'))).toBe(true);
+  });
+});
diff --git a/apps/api/src/modules/task/internal/usecase/task-service.ts b/apps/api/src/modules/task/internal/usecase/task-service.ts
index 41bb0aa..747ca14 100644
--- a/apps/api/src/modules/task/internal/usecase/task-service.ts
+++ b/apps/api/src/modules/task/internal/usecase/task-service.ts
@@ -169,12 +169,32 @@ export function createTaskService(deps: TaskServiceDeps): TaskService {
           await deps.interaction.setPhase(taskId, 'awaiting-event');
           return { task: waiting, verdict, progressed: false };
         }
-        const landed = await deps.landing.land({
-          taskId,
-          ownerId: task.ownerId,
-          humanCallCap: task.caps.humanCalls,
-          selectedPorts: outcome.selectedPorts ?? {},
-        });
+        /*
+         * 落地会**抛**(草稿与正式版冲突、动作意向执行失败…)。抛出去就是灾难:
+         * 谱已经走完(status=finished),runtime 却还停在 running —— 推进器每两秒
+         * 再来一次,每次白烧一步预算,最后以 `exhausted` 收场,而真正的原因只在
+         * stderr 里刷屏(实测:一条试跑单空转 37 拍,界面上什么都看不到)。
+         * 落地失败是**终态**,不是可重试的中间态:就地落 blocked,把原因写进任务记忆。
+         */
+        let landed;
+        try {
+          landed = await deps.landing.land({
+            taskId,
+            ownerId: task.ownerId,
+            humanCallCap: task.caps.humanCalls,
+            selectedPorts: outcome.selectedPorts ?? {},
+          });
+        } catch (error) {
+          const detail = error instanceof Error ? error.message : String(error);
+          await deps.memory.append({
+            taskId,
+            kind: 'observation',
+            title: `放行落地失败:${detail}`,
+            detail: { reason: detail },
+          });
+          const blocked = await this.finish(taskId, { kind: 'blocked', reason: `放行落地失败:${detail}` });
+          return { task: blocked, verdict, progressed: true };
+        }
         if (!landed.converged) {
           // 落地未收敛:输出口不得发射,任务受阻待人(落地失败卡已发)
           const blocked = await this.finish(taskId, { kind: 'blocked', reason: '落地未收敛,输出口未发射' });
diff --git a/apps/api/src/modules/trace/contract.ts b/apps/api/src/modules/trace/contract.ts
index a3f6b59..4d8f4ed 100644
--- a/apps/api/src/modules/trace/contract.ts
+++ b/apps/api/src/modules/trace/contract.ts
@@ -69,7 +69,14 @@ export type TraceService = {
     input?: Record<string, unknown>;
   }): SpanHandle | undefined;
   /** 收尾:节点终态 / 工作流终态 */
-  endNode(input: { taskId?: string; workflowId?: string; nodeId?: string; output?: Record<string, unknown> }): Promise<void>;
+  endNode(input: {
+    taskId?: string;
+    workflowId?: string;
+    nodeId?: string;
+    output?: Record<string, unknown>;
+    /** 非放行终态的原因 —— 有它就把这一段标成错,时间轴上一眼看出哪儿坏了 */
+    error?: string;
+  }): Promise<void>;
   endWorkflow(input: { workflowId: string; state: string }): Promise<void>;
 
   /** 起一条 trace(工作流级)或挂在既有 trace 下 —— 低层口,便利层用它 */
diff --git a/apps/api/src/modules/trace/internal/usecase/trace-service.ts b/apps/api/src/modules/trace/internal/usecase/trace-service.ts
index 45c2fad..85b512a 100644
--- a/apps/api/src/modules/trace/internal/usecase/trace-service.ts
+++ b/apps/api/src/modules/trace/internal/usecase/trace-service.ts
@@ -131,11 +131,16 @@ export function createTraceService(deps: TraceServiceDeps): TraceService {
       return parent.child({ name, kind, taskId, ...(input === undefined ? {} : { input }) });
     },
 
-    async endNode({ taskId, workflowId, nodeId, output }) {
+    async endNode({ taskId, workflowId, nodeId, output, error }) {
       const key = taskId ?? `${workflowId}:${nodeId}`;
       const span = nodeSpans.get(key);
       if (span === undefined) return;
       nodeSpans.delete(key);
+      // 坏了就标坏 —— 收成一条无害的「已结束」等于把事故藏起来
+      if (error !== undefined) {
+        await span.fail(new Error(error));
+        return;
+      }
       await span.end(output === undefined ? undefined : { output });
     },