diff --git a/backend/packages/ai_engine/src/windup_ai_engine/impl/character_generator.py b/backend/packages/ai_engine/src/windup_ai_engine/impl/character_generator.py
index 2f194e8f..ff453e7d 100644
--- a/backend/packages/ai_engine/src/windup_ai_engine/impl/character_generator.py
+++ b/backend/packages/ai_engine/src/windup_ai_engine/impl/character_generator.py
@@ -25,8 +25,9 @@
     CharacterGeneratorPort,
     GeneratedAction,
     ProgressPort,
+    SequenceGeometry,
 )
-from windup_ai_engine.postprocess import align_bottom_center, frame_durations
+from windup_ai_engine.postprocess import FOOT_LINE, align_bottom_center, frame_durations
 from windup_ai_engine.prompt import PROMPT_VERSION
 from windup_ai_engine.slicing import (
     dead_frame_indices,
@@ -198,6 +199,7 @@ def _finish(
         return GeneratedAction(
             frames=[_png(im) for im in aligned],
             durations=frame_durations(action.action.value, len(aligned)),
+            geometry=_geometry_of(aligned[0], canvas),
             quality=quality,
             prompt_version=PROMPT_VERSION,
         )
@@ -263,3 +265,19 @@ def _lastmile(
             return align_bottom_center(imgs, ref_height=ref)
         cw, ch = canvas
         return align_bottom_center(imgs, cell=cw, cell_h=ch, ref_height=ref)
+
+
+def _geometry_of(frame: Image.Image, canvas: tuple[int, int] | None) -> SequenceGeometry:
+    """交付帧的落位几何。取自对齐那一步用的同一组常量,不另立一份。
+
+    ``canvas`` 为 None 时 ``_lastmile`` 走 ``align_bottom_center`` 的默认 cell,
+    所以这里也回落到实际交付帧的尺寸,而不是把 CELL 再抄一遍。
+    """
+    w, h = canvas if canvas else frame.size
+    return SequenceGeometry(
+        canvas_w=w,
+        canvas_h=h,
+        anchor_x=0.5,          # align_bottom_center 横向恒居中
+        anchor_y=FOOT_LINE,
+        foot_y=int(h * FOOT_LINE),
+    )
diff --git a/backend/packages/ai_engine/src/windup_ai_engine/ports/__init__.py b/backend/packages/ai_engine/src/windup_ai_engine/ports/__init__.py
index 45d8dd89..30f0cd61 100644
--- a/backend/packages/ai_engine/src/windup_ai_engine/ports/__init__.py
+++ b/backend/packages/ai_engine/src/windup_ai_engine/ports/__init__.py
@@ -233,6 +233,22 @@ class ActionQuality:
     """
 
 
+@dataclass(frozen=True)
+class SequenceGeometry:
+    """一组交付帧的落位几何:主体锚点与脚线,取自对齐那一步的实参。
+
+    ``anchor`` 用左上原点、y 轴向下的 0-1 归一化坐标,与前端导出契约同一口径;
+    ``foot_y`` 是同一条线的像素值,一并给出是因为消费方要按画布像素画,而
+    ``int(canvas_h * anchor_y)`` 的取整方式不该由每个消费方各自决定。
+    """
+
+    canvas_w: int
+    canvas_h: int
+    anchor_x: float
+    anchor_y: float
+    foot_y: int
+
+
 @dataclass
 class GeneratedAction:
     """一个动作的生成产物:对齐后的原地序列帧 + 逐帧时长 + 成色 + 提示词版本。
@@ -242,6 +258,10 @@ class GeneratedAction:
     """
 
     frames: list[bytes] = field(default_factory=list)   # RGBA PNG,按播放序
+    # 交付帧的落位几何。**报出来而不是让消费方按常数推**:脚线比例、画布尺寸都是
+    # 对齐那一步的实参,消费方抄一份常数过去就是第二真相源 —— 前端 export 正是这么
+    # 抄的(``FOOT_LINE_RATIO = 0.92``),而这边改了 FOOT_LINE 那边不会跟着变。
+    geometry: SequenceGeometry | None = field(default=None, kw_only=True)
     # 播放时序的**唯一**真相源。曾另有一个 fps 字段抄自入参,与本字段互相矛盾:
     # fps=20 宣称 50ms/帧,而 walk 这里给的是 125ms/帧 —— 同一段素材两个播放速度,
     # 取哪个看消费方心情(2026-08-10 机器审 P2)。逐帧 ms 严格更能表达(关键帧定格),
diff --git a/backend/packages/ai_engine/src/windup_ai_engine/postprocess/__init__.py b/backend/packages/ai_engine/src/windup_ai_engine/postprocess/__init__.py
index e69f0ec7..bd919c7e 100644
--- a/backend/packages/ai_engine/src/windup_ai_engine/postprocess/__init__.py
+++ b/backend/packages/ai_engine/src/windup_ai_engine/postprocess/__init__.py
@@ -11,7 +11,7 @@
     pixelate_frames,
     to_pixel_art,
 )
-from .pack import align_bottom_center, save_gif, sprite_sheet
+from .pack import FOOT_LINE, align_bottom_center, save_gif, sprite_sheet
 
 __all__ = [
     "to_pixel_art",
@@ -23,6 +23,7 @@
     "frame_durations",
     "DEFAULT_FPS_MS",
     "align_bottom_center",
+    "FOOT_LINE",
     "sprite_sheet",
     "save_gif",
 ]
diff --git a/backend/packages/app/src/windup_app/server/orchestrator/executor.py b/backend/packages/app/src/windup_app/server/orchestrator/executor.py
index 47fb6b16..7752594a 100644
--- a/backend/packages/app/src/windup_app/server/orchestrator/executor.py
+++ b/backend/packages/app/src/windup_app/server/orchestrator/executor.py
@@ -406,6 +406,17 @@ def _produce_action(
                 "quality": dataclasses.asdict(generated.quality),
                 "prompt_version": generated.prompt_version,
             }
+            # 落位几何随产物一起交出:消费方要把帧画到画布上、判角色有没有站在地上,
+            # 而这条线的比例是对齐那一步的实参。前端此前抄了一份 0.92 自己算 —— 两份
+            # 常数只要有一次不同步,角色就不站在地上,而没有任何一道会红。
+            if generated.geometry is not None:
+                g = generated.geometry
+                result["geometry"] = {
+                    "canvas_width": g.canvas_w,
+                    "canvas_height": g.canvas_h,
+                    "anchor": {"x": g.anchor_x, "y": g.anchor_y},
+                    "foot_y": g.foot_y,
+                }
             # master 为 None 时 review 按"没判"返回 None(三渲二路线没有可比的参照)。
             decision = quality_gate.review(
                 self._get_judge(), checked, master, _judged_action(input)
diff --git a/backend/packages/app/src/windup_app/server/orchestrator/model.py b/backend/packages/app/src/windup_app/server/orchestrator/model.py
index 25082871..fa356436 100644
--- a/backend/packages/app/src/windup_app/server/orchestrator/model.py
+++ b/backend/packages/app/src/windup_app/server/orchestrator/model.py
@@ -133,7 +133,9 @@ class CharacterActionOutput:
 
     前端拿到后写入 ``character_data.outfits[].actions[]``：
     ``action_type`` → ``CharacterAction.type``，
-    ``frames`` → ``CharacterAction.frames[]``。
+    ``frames`` + ``direction`` → ``CharacterAction.sequences[]``(一个方向一条,
+    镜像方向按 ``CharacterActionSequence`` 的校验只存来源关系、不存帧),
+    ``geometry`` → 导出契约的 ``anchor`` / ``footY``。
 
     ``quality`` / ``prompt_version`` 是引擎产出成色的账本(``ai_engine.ports.ActionQuality``
     的原样转录 + 提示词版本),不参与前端回填、只落库供后续对比——本层不据此判成败,
@@ -153,6 +155,9 @@ class CharacterActionOutput:
     quality: dict | None = None
     prompt_version: str | None = None
     direction: ActionDirection = ActionDirection.EAST
+    # 交付帧的落位几何(画布尺寸、主体锚点、脚线像素)。``None`` = 引擎没给,
+    # 不是"用默认值" —— 消费方要能区分这两者,才不会把缺省当成实测。
+    geometry: dict | None = None
 
 
 # -- 任务记录 ------------------------------------------------------------
diff --git a/backend/tests/test_render3d_route_and_assets.py b/backend/tests/test_render3d_route_and_assets.py
index d09f43c5..10b7aa00 100644
--- a/backend/tests/test_render3d_route_and_assets.py
+++ b/backend/tests/test_render3d_route_and_assets.py
@@ -600,3 +600,25 @@ def test_after_approval_it_proceeds_and_reuses_the_stored_model(tmp_path):
     gate.approve(OUTFIT)
     assert builder.ensure(OUTFIT, _png(), _NullProgress()) == b"RIGGED-bytes"
     assert (m.calls, r.calls) == (1, 1)
+
+
+def test_generated_action_reports_the_alignment_geometry_instead_of_a_constant():
+    """交付几何由引擎报出,不让消费方按常数推。
+
+    前端导出契约此前自带一份 ``FOOT_LINE_RATIO = 0.92`` 算 anchor 与 footY。
+    两份常数只要有一次不同步,角色就不站在地上,而帧数、时长、成色全都正常 ——
+    没有任何一道会红。所以这条钉的是"报出来了",而且报的值必须来自
+    ``postprocess.FOOT_LINE`` 本身,不是用例里再抄一遍的字面量。
+    """
+    from windup_ai_engine.postprocess import FOOT_LINE
+
+    canvas = (256, 320)
+    out = _real_generator(_FakeRenderer()).generate_rendered(
+        _card(), _spec(), b"RIGGED", _NullProgress(), canvas=canvas,
+    )
+    g = out.geometry
+    assert g is not None, "几何必须报出来,None 表示引擎没给"
+    assert (g.canvas_w, g.canvas_h) == canvas
+    assert g.anchor_x == 0.5
+    assert g.anchor_y == FOOT_LINE
+    assert g.foot_y == int(canvas[1] * FOOT_LINE)
diff --git a/frontend/src/entities/generation/api.ts b/frontend/src/entities/generation/api.ts
index ec2932b0..7188a5c1 100644
--- a/frontend/src/entities/generation/api.ts
+++ b/frontend/src/entities/generation/api.ts
@@ -21,6 +21,7 @@ import type {
   GenerationResult,
   GenerationType,
   ImageCandidateCount,
+  SequenceGeometry,
   TaskStatus,
 } from '.'
 import { isActionDirection, type ActionDirection } from '@/entities/character/directions'
@@ -302,15 +303,52 @@ function mapActionResult(
       throw new GenerationApiError('动作帧 index 必须从 0 开始连续排列', 200)
     }
   }
+  const geometry = actionGeometry(result.geometry)
   const mapped = {
     type: 'complete_animation',
     frames: orderedFrames,
+    ...(geometry === undefined ? {} : { geometry }),
   } as const
   return expectation.direction === undefined
     ? mapped
     : { ...mapped, direction: expectation.direction }
 }
 
+/**
+ * 解析交付帧的落位几何。缺失返回 undefined —— 旧任务没有这一段，而"没给"与
+ * "给了默认值"必须能被消费方区分开：把缺省读成实测，角色不站在地上时没有一处会报错。
+ * 给了就按结构严格校验，半个几何比没有更糟。
+ */
+function actionGeometry(value: unknown): SequenceGeometry | undefined {
+  if (value === undefined || value === null) return undefined
+  if (!isRecord(value)) throw new GenerationApiError('完整动画结果 geometry 不是对象', 200)
+  const anchor = value.anchor
+  if (!isRecord(anchor)) throw new GenerationApiError('完整动画结果 geometry.anchor 无效', 200)
+  const unit = (raw: unknown, field: string) => {
+    if (!Number.isFinite(raw) || (raw as number) < 0 || (raw as number) > 1) {
+      throw new GenerationApiError(`完整动画结果 ${field} 必须是 0-1 归一化值`, 200)
+    }
+    return raw as number
+  }
+  const positive = (raw: unknown, field: string) => {
+    if (!Number.isSafeInteger(raw) || (raw as number) <= 0) {
+      throw new GenerationApiError(`完整动画结果 ${field} 无效`, 200)
+    }
+    return raw as number
+  }
+  const canvasHeight = positive(value.canvas_height, 'geometry.canvas_height')
+  const footY = value.foot_y
+  if (!Number.isSafeInteger(footY) || (footY as number) < 0 || (footY as number) > canvasHeight) {
+    throw new GenerationApiError('完整动画结果 geometry.foot_y 超出画布', 200)
+  }
+  return {
+    canvasWidth: positive(value.canvas_width, 'geometry.canvas_width'),
+    canvasHeight,
+    anchor: { x: unit(anchor.x, 'geometry.anchor.x'), y: unit(anchor.y, 'geometry.anchor.y') },
+    footY: footY as number,
+  }
+}
+
 function mapResult(
   result: Record<string, unknown> | null,
   status: TaskStatus,
diff --git a/frontend/src/entities/generation/index.ts b/frontend/src/entities/generation/index.ts
index 242bdabc..e9671ee8 100644
--- a/frontend/src/entities/generation/index.ts
+++ b/frontend/src/entities/generation/index.ts
@@ -124,10 +124,22 @@ export interface FirstFrameGenerationResult {
   images: readonly GeneratedImage[]
 }
 
+/** 交付帧的落位几何，由后端按对齐时的实参报出。 */
+export interface SequenceGeometry {
+  canvasWidth: number
+  canvasHeight: number
+  /** 左上原点、y 轴向下的 0-1 归一化坐标。 */
+  anchor: { x: number; y: number }
+  /** 脚底线距画布顶部的像素值。 */
+  footY: number
+}
+
 export interface CompleteAnimationGenerationResult {
   type: 'complete_animation'
   direction?: ActionDirection
   frames: readonly GeneratedFrame[]
+  /** 旧任务没有这一段；缺失时消费方不能当成"用默认值"，只能明示回落。 */
+  geometry?: SequenceGeometry
 }
 
 export type GenerationResult =
diff --git a/frontend/src/entities/index.ts b/frontend/src/entities/index.ts
index ce8cb1bd..ea74d900 100644
--- a/frontend/src/entities/index.ts
+++ b/frontend/src/entities/index.ts
@@ -99,6 +99,7 @@ export type {
   GenerationResultFor,
   GenerationType,
   ImageCandidateCount,
+  SequenceGeometry,
   TaskStatus,
 } from './generation'
 export type { GenerationApiConfig, GenerationTransport } from './generation/api'
diff --git a/frontend/src/features/export-package/progressive-export.test.ts b/frontend/src/features/export-package/progressive-export.test.ts
index d06b5e05..99f0e99b 100644
--- a/frontend/src/features/export-package/progressive-export.test.ts
+++ b/frontend/src/features/export-package/progressive-export.test.ts
@@ -85,6 +85,44 @@ const run: WorkflowRun = {
   ],
 }
 
+/** 一条走到"完整动画已生成、尚未发布"的流程，几何相关用例共用。 */
+function actionRunFixture(base: WorkflowRun): WorkflowRun {
+  return {
+    ...base,
+    nodes: [
+      ...base.nodes,
+      {
+        id: 'walk-method',
+        type: 'action-generation-method',
+        status: 'passed',
+        phase: 'completed',
+        dependsOnNodeIds: ['walk-first'],
+        generations: [],
+        error: null,
+        method: 'video-cropping',
+      },
+      {
+        id: 'walk-full',
+        type: 'action-full-frame',
+        status: 'passed',
+        phase: 'completed',
+        dependsOnNodeIds: ['walk-method'],
+        generations: [{ taskId: 'generation-full', role: 'complete_animation' }],
+        error: null,
+      },
+      {
+        id: 'walk-review',
+        type: 'review',
+        status: 'active',
+        phase: 'reviewing',
+        dependsOnNodeIds: ['walk-full'],
+        generations: [],
+        error: null,
+      },
+    ],
+  }
+}
+
 describe('createProgressiveExportModel', () => {
   it('拒绝把其它 WorkflowRun 的完成度拼到当前角色', () => {
     expect(() =>
@@ -241,6 +279,66 @@ describe('createProgressiveExportModel', () => {
     })
   })
 
+  it('落位几何取后端报的那份，而不是前端自己按 0.92 算', () => {
+    const generation = {
+      id: 'generation-full',
+      projectId: project.id,
+      type: 'complete_animation',
+      status: 'completed',
+      error: null,
+      result: {
+        type: 'complete_animation',
+        frames: [{ index: 0, url: '/walk-0.png', durationMs: 100 }],
+        // 故意与 0.92 不同：若前端还在自己算，这条就会读出 spriteHeight*0.92
+        geometry: {
+          canvasWidth: project.spriteSize.width,
+          canvasHeight: project.spriteSize.height,
+          anchor: { x: 0.5, y: 0.8 },
+          footY: 32,
+        },
+      },
+    } satisfies Generation<'complete_animation'>
+
+    const model = createProgressiveExportModel({
+      project,
+      character,
+      outfitId: 'outfit-1',
+      run: actionRunFixture(run),
+      generations: [generation],
+    })
+
+    expect(model.actions[0]?.sequences[0]).toMatchObject({
+      anchor: { x: 0.5, y: 0.8 },
+      footY: 32,
+    })
+  })
+
+  it('后端没报几何时明示回落，不静默给 0', () => {
+    const generation = {
+      id: 'generation-full',
+      projectId: project.id,
+      type: 'complete_animation',
+      status: 'completed',
+      error: null,
+      result: {
+        type: 'complete_animation',
+        frames: [{ index: 0, url: '/walk-0.png', durationMs: 100 }],
+      },
+    } satisfies Generation<'complete_animation'>
+
+    const model = createProgressiveExportModel({
+      project,
+      character,
+      outfitId: 'outfit-1',
+      run: actionRunFixture(run),
+      generations: [generation],
+    })
+
+    const sequence = model.actions[0]?.sequences[0]
+    expect(sequence?.anchor).toEqual({ x: 0.5, y: 0.92 })
+    expect(sequence?.footY).toBe(Math.trunc(project.spriteSize.height * 0.92))
+  })
+
   it('同名但不同 ID 的已发布与生成中动作不会互相覆盖', () => {
     const withPublishedAction: Character = {
       ...character,
diff --git a/frontend/src/features/export-package/progressive-export.ts b/frontend/src/features/export-package/progressive-export.ts
index a489c351..e742c0d5 100644
--- a/frontend/src/features/export-package/progressive-export.ts
+++ b/frontend/src/features/export-package/progressive-export.ts
@@ -4,6 +4,7 @@ import type {
   Frame,
   Generation,
   Project,
+  SequenceGeometry,
   WorkflowActionInput,
   WorkflowRun,
 } from '@/entities'
@@ -16,7 +17,27 @@ import type {
   ExportPlaytest,
 } from './model'
 
-const FOOT_LINE_RATIO = 0.92
+/**
+ * 后端没报落位几何时的回落值（早于 geometry 上线的资产）。
+ *
+ * 这个数与后端 `postprocess.pack.FOOT_LINE` 是同一条线，抄一份在这里就是第二真相源 ——
+ * 所以只在缺 geometry 时用，能拿到就一律用后端报的那份。两份不同步的后果是角色不站在
+ * 地上，而帧数、时长、成色全都正常，没有任何一道会红。
+ */
+const FALLBACK_FOOT_LINE_RATIO = 0.92
+
+function sequenceGeometry(
+  geometry: SequenceGeometry | undefined,
+  spriteHeight: number,
+): { anchor: { x: number; y: number }; footY: number } {
+  if (geometry) {
+    return { anchor: geometry.anchor, footY: geometry.footY }
+  }
+  return {
+    anchor: { x: 0.5, y: FALLBACK_FOOT_LINE_RATIO },
+    footY: Math.trunc(spriteHeight * FALLBACK_FOOT_LINE_RATIO),
+  }
+}
 
 export interface CreateProgressiveExportModelInput {
   project: Project
@@ -63,8 +84,7 @@ function exportAction(action: Action, project: Project): ExportAction {
         direction: 'default',
         expectedFrameCount: action.frameCount,
         loop: action.loop,
-        anchor: { x: 0.5, y: FOOT_LINE_RATIO },
-        footY: Math.trunc(project.spriteSize.height * FOOT_LINE_RATIO),
+        ...sequenceGeometry(undefined, project.spriteSize.height),
         qualityStatus: 'passed',
         frames: exportFrames(action),
       },
@@ -186,8 +206,7 @@ function generatedActions(
             direction: 'default',
             expectedFrameCount: frames.length,
             loop: true,
-            anchor: { x: 0.5, y: FOOT_LINE_RATIO },
-            footY: Math.trunc(project.spriteSize.height * FOOT_LINE_RATIO),
+            ...sequenceGeometry(generation.result.geometry, project.spriteSize.height),
             qualityStatus: review?.status === 'passed' ? 'passed' : 'pending',
             frames,
           },