diff --git a/lib/canvas/capabilities/headless-executor.ts b/lib/canvas/capabilities/headless-executor.ts
index ff85cde59..98f746608 100644
--- a/lib/canvas/capabilities/headless-executor.ts
+++ b/lib/canvas/capabilities/headless-executor.ts
@@ -10,6 +10,7 @@ import {
 } from "@/lib/ai/rmbg/service";
 import type { CanvasCapabilityClientCommand } from "@/lib/canvas/capabilities/client-command";
 import type { CanvasCapabilityTarget } from "@/lib/canvas/capabilities/context";
+import { resolveCanvasRuntimeEndpoint } from "@/lib/canvas/capabilities/internal-endpoint";
 import { generateCanvasImage } from "@/lib/canvas/generate-image";
 import { requestLongTaskResult } from "@/lib/client/long-task";
 import {
@@ -55,7 +56,7 @@ async function postRuntimeEndpoint(params: {
   requestUrl: string;
   timeoutMs?: number;
 }) {
-  const response = await fetch(new URL(params.path, params.requestUrl), {
+  const response = await fetch(resolveCanvasRuntimeEndpoint(params.path, params.requestUrl), {
     method: "POST",
     headers: {
       "Content-Type": "application/json",
@@ -80,7 +81,7 @@ async function postRuntimeFormData(params: {
   requestUrl: string;
   timeoutMs?: number;
 }) {
-  const response = await fetch(new URL(params.path, params.requestUrl), {
+  const response = await fetch(resolveCanvasRuntimeEndpoint(params.path, params.requestUrl), {
     method: "POST",
     headers: getCookieHeaders(params.requestHeaders),
     body: params.formData,
@@ -233,7 +234,7 @@ async function executeForTarget(
 
   if (command.capabilityId === "image.enhance") {
     const result = await requestLongTaskResult({
-      endpoint: new URL("/api/enhance", params.requestUrl).toString(),
+      endpoint: resolveCanvasRuntimeEndpoint("/api/enhance", params.requestUrl),
       payload: {
         imageUrl: target.sourceImageUrl,
         prompt: prompt || "图像增强处理",
@@ -258,7 +259,10 @@ async function executeForTarget(
 
   if (command.capabilityId === "image.remove_watermark") {
     const result = await requestLongTaskResult({
-      endpoint: new URL("/api/watermark-remove", params.requestUrl).toString(),
+      endpoint: resolveCanvasRuntimeEndpoint(
+        "/api/watermark-remove",
+        params.requestUrl
+      ),
       payload: { image_url: target.sourceImageUrl },
       timeoutMs: 20 * 60 * 1000,
       headers: getCookieHeaders(params.requestHeaders),
diff --git a/lib/canvas/capabilities/internal-endpoint.ts b/lib/canvas/capabilities/internal-endpoint.ts
new file mode 100644
index 000000000..d83a39691
--- /dev/null
+++ b/lib/canvas/capabilities/internal-endpoint.ts
@@ -0,0 +1,32 @@
+type CanvasRuntimeEndpointOptions = {
+  internalOrigin?: string;
+  port?: string;
+};
+
+function normalizeInternalOrigin(value: string) {
+  const url = new URL(value);
+  url.pathname = "/";
+  url.search = "";
+  url.hash = "";
+  return url.toString();
+}
+
+export function resolveCanvasRuntimeEndpoint(
+  path: string,
+  requestUrl: string,
+  options: CanvasRuntimeEndpointOptions = {}
+) {
+  const configuredOrigin = String(
+    options.internalOrigin ?? process.env.CANVAS_RUNTIME_INTERNAL_ORIGIN ?? ""
+  ).trim();
+  if (configuredOrigin) {
+    return new URL(path, normalizeInternalOrigin(configuredOrigin)).toString();
+  }
+
+  const port = String(options.port ?? process.env.PORT ?? "").trim();
+  if (/^\d{1,5}$/.test(port) && Number(port) > 0 && Number(port) <= 65_535) {
+    return new URL(path, `http://127.0.0.1:${port}`).toString();
+  }
+
+  return new URL(path, requestUrl).toString();
+}
diff --git a/lib/canvas/capabilities/task-queue.ts b/lib/canvas/capabilities/task-queue.ts
index aaafdc786..413d5ccc9 100644
--- a/lib/canvas/capabilities/task-queue.ts
+++ b/lib/canvas/capabilities/task-queue.ts
@@ -20,7 +20,11 @@ export async function enqueueCanvasCapabilityExecution<T>(params: {
   const state = getQueueState();
   const previous = state.tails.get(params.projectId) || Promise.resolve();
   const execution = previous.catch(() => undefined).then(params.execute);
-  const tail = execution.finally(() => {
+  const settledExecution = execution.then(
+    () => undefined,
+    () => undefined
+  );
+  const tail = settledExecution.finally(() => {
     if (state.tails.get(params.projectId) === tail) {
       state.tails.delete(params.projectId);
     }
diff --git a/playwright.helpers.config.ts b/playwright.helpers.config.ts
index 7fbcc6b96..6862b52e1 100644
--- a/playwright.helpers.config.ts
+++ b/playwright.helpers.config.ts
@@ -11,6 +11,7 @@ export default defineConfig({
     /routes\/canvas-entry-performance\.test\.ts/,
     /routes\/settings-visual-consistency\.test\.ts/,
     /routes\/canvas-scale-adjust-intent\.test\.ts/,
+    /routes\/canvas-runtime-internal-endpoint\.test\.ts/,
     /routes\/model-classification\.test\.ts/,
   ],
   fullyParallel: true,
diff --git a/tests/routes/canvas-runtime-internal-endpoint.test.ts b/tests/routes/canvas-runtime-internal-endpoint.test.ts
new file mode 100644
index 000000000..f3404a0e6
--- /dev/null
+++ b/tests/routes/canvas-runtime-internal-endpoint.test.ts
@@ -0,0 +1,55 @@
+import { expect, test } from "@playwright/test";
+
+import { resolveCanvasRuntimeEndpoint } from "@/lib/canvas/capabilities/internal-endpoint";
+import {
+  enqueueCanvasCapabilityExecution,
+  getCanvasCapabilityQueueDepth,
+} from "@/lib/canvas/capabilities/task-queue";
+
+test.describe("canvas runtime internal endpoints", () => {
+  test("uses the local HTTP listener for server-internal capability calls", () => {
+    expect(
+      resolveCanvasRuntimeEndpoint(
+        "/api/enhance",
+        "https://ai.yydd.ai/api/canvas/canvas-1/capabilities",
+        { port: "3125" }
+      )
+    ).toBe("http://127.0.0.1:3125/api/enhance");
+    expect(
+      resolveCanvasRuntimeEndpoint(
+        "/api/enhance",
+        "https://ai.yydd.ai/api/canvas/canvas-1/capabilities",
+        { internalOrigin: "http://canvas-runtime:3000/base" }
+      )
+    ).toBe("http://canvas-runtime:3000/api/enhance");
+  });
+
+  test("falls back to the incoming origin without an internal listener", () => {
+    expect(
+      resolveCanvasRuntimeEndpoint(
+        "/api/enhance",
+        "https://ai.yydd.ai/api/canvas/canvas-1/capabilities",
+        { port: "invalid" }
+      )
+    ).toBe("https://ai.yydd.ai/api/enhance");
+  });
+
+  test("continues the project queue after a failed capability execution", async () => {
+    await expect(
+      enqueueCanvasCapabilityExecution({
+        projectId: "failed-capability-project",
+        execute: async () => {
+          throw new Error("expected capability failure");
+        },
+      })
+    ).rejects.toThrow("expected capability failure");
+
+    await expect(
+      enqueueCanvasCapabilityExecution({
+        projectId: "failed-capability-project",
+        execute: async () => "recovered",
+      })
+    ).resolves.toBe("recovered");
+    expect(getCanvasCapabilityQueueDepth("failed-capability-project")).toBe(0);
+  });
+});