diff --git a/config/knip.config.ts b/config/knip.config.ts
index 2a6c73ecc41d..953cb181c532 100644
--- a/config/knip.config.ts
+++ b/config/knip.config.ts
@@ -52,6 +52,7 @@ const repositoryScriptEntries = [
   "scripts/e2e/lib/release-user-journey/clickclack-fixture.mjs!",
   "scripts/e2e/lib/release-user-journey/write-clickclack-plugin.mjs!",
   "scripts/e2e/lib/run-with-pty.mjs!",
+  "scripts/e2e/lib/sandbox-browser-sidecar/scenario.mjs!",
   "scripts/e2e/lib/upgrade-survivor/probe-gateway.mjs!",
   "scripts/embedded-run-abort-leak.ts!",
   "scripts/fixtures/packed-plugin-sdk-type-smoke.ts!",
diff --git a/package.json b/package.json
index b0437aab8bfb..cae3e523951d 100644
--- a/package.json
+++ b/package.json
@@ -1709,6 +1709,7 @@
     "test:docker:agents-delete-shared-workspace": "bash scripts/e2e/agents-delete-shared-workspace-docker.sh",
     "test:docker:all": "node scripts/test-docker-all.mjs",
     "test:docker:browser-cdp-snapshot": "bash scripts/e2e/browser-cdp-snapshot-docker.sh",
+    "test:docker:sandbox-browser-sidecar": "bash scripts/e2e/sandbox-browser-sidecar-docker.sh",
     "test:docker:bundled-plugin-install-uninstall": "bash scripts/e2e/bundled-plugin-install-uninstall-docker.sh",
     "test:docker:cleanup": "bash scripts/test-cleanup-docker.sh",
     "test:docker:commitments-safety": "bash scripts/e2e/commitments-safety-docker.sh",
diff --git a/scripts/check-docker-e2e-boundaries.mjs b/scripts/check-docker-e2e-boundaries.mjs
index 4f52dbd51462..b0e03e3af784 100644
--- a/scripts/check-docker-e2e-boundaries.mjs
+++ b/scripts/check-docker-e2e-boundaries.mjs
@@ -47,13 +47,43 @@ function walk(dir, out = []) {
   return out;
 }
 
+function findRelativeModuleSpecifiers(text) {
+  const specifiers = new Set();
+  for (const pattern of [
+    /(?:\bfrom\s*|\bimport\s*\()\s*["']([^"']+)["']/gu,
+    /\bimport\s*["']([^"']+)["']/gu,
+  ]) {
+    for (const match of text.matchAll(pattern)) {
+      const specifier = match[1];
+      if (specifier?.startsWith(".")) {
+        specifiers.add(specifier);
+      }
+    }
+  }
+  return [...specifiers];
+}
+
+function isPathWithin(parent, candidate) {
+  const relative = path.relative(parent, candidate);
+  return (
+    relative === "" ||
+    (!path.isAbsolute(relative) && !relative.startsWith(`..${path.sep}`) && relative !== "..")
+  );
+}
+
 for (const relativePath of walk("scripts/e2e")) {
   if (!/\.(?:sh|ts|mjs|js)$/u.test(relativePath)) {
     continue;
   }
   const text = readText(relativePath);
-  if (/from\s+["']\.\.\/\.\.\/src\//u.test(text) || /import\(["']\.\.\/\.\.\/src\//u.test(text)) {
-    errors.push(`${relativePath}: Docker E2E harness must import built dist, not ../../src`);
+  const sourceImport = findRelativeModuleSpecifiers(text).find((specifier) => {
+    const resolved = path.resolve(ROOT_DIR, path.dirname(relativePath), specifier);
+    return isPathWithin(path.join(ROOT_DIR, "src"), resolved);
+  });
+  if (sourceImport) {
+    errors.push(
+      `${relativePath}: Docker E2E harness must import package exports, not ${sourceImport}`,
+    );
   }
   if (/-v\s+["']?\$ROOT_DIR:\/app(?::|["'\s]|$)/u.test(text)) {
     errors.push(`${relativePath}: do not mount the repo root as /app in Docker E2E`);
diff --git a/scripts/code-mode-model-matrix.ts b/scripts/code-mode-model-matrix.ts
index df7fe1d62751..98f39a8d659d 100644
--- a/scripts/code-mode-model-matrix.ts
+++ b/scripts/code-mode-model-matrix.ts
@@ -14,7 +14,7 @@ import {
   validateQaEvidenceSummaryJson,
   type QaEvidenceStatus,
   type QaEvidenceSummaryJson,
-} from "../extensions/qa-lab/api.ts";
+} from "../extensions/qa-lab/api.js";
 import type { AgentExecEnvelope } from "../src/commands/agent-exec.ts";
 import { previewForDevToolLog, redactJsonValueForDevToolLog } from "./lib/dev-tooling-safety.ts";
 
@@ -401,12 +401,14 @@ async function canonicalizeExistingPathPrefix(value: string): Promise<string> {
 
 async function runtimeArtifactDirectories(repoRoot: string, outputDir: string): Promise<string[]> {
   const packagesRoot = path.join(repoRoot, "packages");
-  const packageEntries = await fs.readdir(packagesRoot, { withFileTypes: true }).catch((error: unknown) => {
-    if ((error as NodeJS.ErrnoException).code === "ENOENT") {
-      return [];
-    }
-    throw error;
-  });
+  const packageEntries = await fs
+    .readdir(packagesRoot, { withFileTypes: true })
+    .catch((error: unknown) => {
+      if ((error as NodeJS.ErrnoException).code === "ENOENT") {
+        return [];
+      }
+      throw error;
+    });
   const artifacts = [
     path.join(repoRoot, "dist"),
     ...packageEntries
diff --git a/scripts/e2e/lib/sandbox-browser-sidecar/scenario.mjs b/scripts/e2e/lib/sandbox-browser-sidecar/scenario.mjs
new file mode 100644
index 000000000000..581430c30f19
--- /dev/null
+++ b/scripts/e2e/lib/sandbox-browser-sidecar/scenario.mjs
@@ -0,0 +1,247 @@
+import assert from "node:assert/strict";
+import { execFile } from "node:child_process";
+import fs from "node:fs/promises";
+import http from "node:http";
+import path from "node:path";
+import { promisify } from "node:util";
+import { resolveSandboxContext } from "openclaw/plugin-sdk/agent-harness-runtime";
+
+const execFileAsync = promisify(execFile);
+
+function requireEnv(name) {
+  const value = process.env[name]?.trim();
+  if (!value) {
+    throw new Error(`missing ${name}`);
+  }
+  return value;
+}
+
+const root = requireEnv("OPENCLAW_E2E_ROOT");
+const sandboxImage = requireEnv("OPENCLAW_E2E_SANDBOX_IMAGE");
+const browserImage = requireEnv("OPENCLAW_E2E_BROWSER_IMAGE");
+const sandboxPrefix = requireEnv("OPENCLAW_E2E_SANDBOX_PREFIX");
+const browserPrefix = requireEnv("OPENCLAW_E2E_BROWSER_PREFIX");
+const browserNetwork = requireEnv("OPENCLAW_E2E_BROWSER_NETWORK");
+const stateDir = path.join(root, "state");
+const workspaceDir = path.join(root, "workspace");
+const sandboxRoot = path.join(root, "sandboxes");
+const configPath = path.join(stateDir, "openclaw.json");
+const sessionKey = "agent:main:sandbox-browser-sidecar";
+const browserToken = `sandbox-browser-sidecar-${process.pid}`;
+const marker = `OPENCLAW_SANDBOX_BROWSER_SIDECAR_${process.pid}`;
+const ownedContainerNames = new Set();
+
+process.env.HOME = path.join(root, "home");
+process.env.OPENCLAW_STATE_DIR = stateDir;
+process.env.OPENCLAW_CONFIG_PATH = configPath;
+
+const config = {
+  gateway: {
+    auth: {
+      mode: "token",
+      token: browserToken,
+    },
+  },
+  browser: {
+    enabled: true,
+    ssrfPolicy: {
+      dangerouslyAllowPrivateNetwork: true,
+    },
+  },
+  tools: {
+    sandbox: {
+      tools: {
+        allow: ["browser"],
+      },
+    },
+  },
+  agents: {
+    defaults: {
+      workspace: workspaceDir,
+      sandbox: {
+        mode: "all",
+        backend: "docker",
+        scope: "session",
+        workspaceAccess: "rw",
+        workspaceRoot: sandboxRoot,
+        docker: {
+          image: sandboxImage,
+          containerPrefix: sandboxPrefix,
+          network: "none",
+          extraHosts: ["host.docker.internal:host-gateway"],
+        },
+        browser: {
+          enabled: true,
+          image: browserImage,
+          containerPrefix: browserPrefix,
+          network: browserNetwork,
+          headless: true,
+          noVncEnabled: false,
+          autoStart: true,
+          autoStartTimeoutMs: 120_000,
+        },
+      },
+    },
+  },
+};
+
+async function run(command, args, options = {}) {
+  return await execFileAsync(command, args, {
+    cwd: "/app",
+    env: process.env,
+    maxBuffer: 8 * 1024 * 1024,
+    ...options,
+  });
+}
+
+async function docker(args, options) {
+  return await run("docker", args, options);
+}
+
+async function listTaskContainers() {
+  const { stdout } = await docker(["ps", "-a", "--format", "{{.Names}}"]);
+  return stdout
+    .split(/\r?\n/u)
+    .map((value) => value.trim())
+    .filter((name) => name.startsWith(sandboxPrefix) || name.startsWith(browserPrefix));
+}
+
+async function cleanupTaskResources() {
+  const names = new Set([...ownedContainerNames, ...(await listTaskContainers().catch(() => []))]);
+  for (const name of names) {
+    await docker(["rm", "-f", name]).catch(() => undefined);
+  }
+  await docker(["network", "rm", browserNetwork]).catch(() => undefined);
+}
+
+function requestJson(baseUrl, requestPath, init = {}) {
+  return fetch(`${baseUrl}${requestPath}`, {
+    ...init,
+    headers: {
+      Authorization: `Bearer ${browserToken}`,
+      ...(init.body ? { "Content-Type": "application/json" } : {}),
+      ...init.headers,
+    },
+  }).then(async (response) => {
+    const text = await response.text();
+    assert.equal(response.ok, true, `${requestPath} failed (${response.status}): ${text}`);
+    return text ? JSON.parse(text) : {};
+  });
+}
+
+async function startFixtureServer() {
+  const server = http.createServer((_request, response) => {
+    response.writeHead(200, { "content-type": "text/html; charset=utf-8" });
+    response.end(`<!doctype html><html><body><main><h1>${marker}</h1></main></body></html>`);
+  });
+  await new Promise((resolve, reject) => {
+    server.once("error", reject);
+    server.listen(0, "0.0.0.0", resolve);
+  });
+  const address = server.address();
+  assert(address && typeof address === "object", "fixture server did not bind a TCP port");
+  return {
+    server,
+    port: address.port,
+  };
+}
+
+await fs.mkdir(process.env.HOME, { recursive: true });
+await fs.mkdir(stateDir, { recursive: true });
+await fs.mkdir(workspaceDir, { recursive: true });
+await fs.writeFile(configPath, `${JSON.stringify(config, null, 2)}\n`, "utf8");
+
+const fixture = await startFixtureServer();
+
+try {
+  const params = {
+    config,
+    agentId: "main",
+    sessionKey,
+    workspaceDir,
+  };
+  const [first, second] = await Promise.all([
+    resolveSandboxContext(params),
+    resolveSandboxContext(params),
+  ]);
+
+  assert(first, "first sandbox context was not provisioned");
+  assert(second, "second sandbox context was not provisioned");
+  assert(first.browser, "first sandbox browser context was not provisioned");
+  assert(second.browser, "second sandbox browser context was not provisioned");
+  assert.equal(first.containerName, second.containerName, "concurrent calls split sandbox runtime");
+  assert.equal(
+    first.browser.containerName,
+    second.browser.containerName,
+    "concurrent calls split browser runtime",
+  );
+  assert.equal(
+    first.browser.bridgeUrl,
+    second.browser.bridgeUrl,
+    "concurrent calls split browser bridge",
+  );
+  const { stdout: gatewayStdout } = await docker([
+    "network",
+    "inspect",
+    "-f",
+    "{{(index .IPAM.Config 0).Gateway}}",
+    browserNetwork,
+  ]);
+  const gateway = gatewayStdout.trim();
+  assert(gateway, "browser Docker network did not report a gateway");
+  const fixtureUrl = `http://${gateway}:${fixture.port}/`;
+  ownedContainerNames.add(first.containerName);
+  ownedContainerNames.add(first.browser.containerName);
+
+  const unauthenticated = await fetch(`${first.browser.bridgeUrl}/`);
+  assert.equal(unauthenticated.status, 401, "browser bridge accepted an unauthenticated request");
+  await unauthenticated.body?.cancel();
+
+  const opened = await requestJson(first.browser.bridgeUrl, "/tabs/open", {
+    method: "POST",
+    body: JSON.stringify({ url: fixtureUrl }),
+  });
+  assert.equal(typeof opened.targetId, "string", "bridge did not return an opened tab");
+
+  const snapshot = await requestJson(
+    first.browser.bridgeUrl,
+    `/snapshot?format=ai&targetId=${encodeURIComponent(opened.targetId)}`,
+  );
+  assert.equal(snapshot.format, "ai", "bridge returned the wrong snapshot format");
+  assert.match(snapshot.snapshot, new RegExp(marker), "snapshot did not contain the HTML marker");
+
+  const { stdout: listStdout } = await run("openclaw", ["sandbox", "list", "--browser", "--json"]);
+  const listed = JSON.parse(listStdout);
+  const browserEntry = listed.browsers?.find(
+    (entry) => entry.containerName === first.browser.containerName,
+  );
+  assert(browserEntry, "packaged sandbox list did not report the browser container");
+  assert.equal(browserEntry.sessionKey, sessionKey);
+  assert.equal(browserEntry.running, true);
+
+  await run("openclaw", ["sandbox", "recreate", "--browser", "--session", sessionKey, "--force"]);
+  const remaining = await listTaskContainers();
+  assert(
+    !remaining.includes(first.browser.containerName),
+    "packaged recreate kept browser container",
+  );
+  assert(remaining.includes(first.containerName), "packaged recreate removed normal sandbox");
+
+  process.stdout.write(
+    `${JSON.stringify({
+      ok: true,
+      sandboxContainer: first.containerName,
+      browserContainer: first.browser.containerName,
+      marker,
+    })}\n`,
+  );
+} finally {
+  await new Promise((resolve) => {
+    fixture.server.close(resolve);
+  });
+  await cleanupTaskResources();
+}
+
+// resolveSandboxContext owns an in-process bridge server that intentionally
+// stays live for agent reuse. This standalone scenario has finished its cleanup.
+process.exit(0);
diff --git a/scripts/e2e/parallels/npm-update-smoke.ts b/scripts/e2e/parallels/npm-update-smoke.ts
index 18afbf9ba00f..f0137125d000 100755
--- a/scripts/e2e/parallels/npm-update-smoke.ts
+++ b/scripts/e2e/parallels/npm-update-smoke.ts
@@ -11,7 +11,7 @@ import {
   clampTimerTimeoutMs,
   finiteSecondsToTimerSafeMilliseconds,
 } from "@openclaw/normalization-core/number-coercion";
-import { formatDurationCompact } from "../../../src/infra/format-time/format-duration.ts";
+import prettyMilliseconds from "pretty-ms";
 import {
   die,
   ensureValue,
@@ -532,7 +532,17 @@ function platformRecord<T>(value: T): Record<Platform, T> {
 }
 
 function formatDuration(durationMs: number): string {
-  return formatDurationCompact(durationMs, { spaced: true }) ?? "0ms";
+  if (!Number.isFinite(durationMs) || durationMs <= 0) {
+    return "0ms";
+  }
+  const roundedMs = Math.round(durationMs);
+  if (roundedMs < 1000) {
+    return prettyMilliseconds(roundedMs);
+  }
+  return prettyMilliseconds(Math.round(durationMs / 1000) * 1000, {
+    hideYear: true,
+    unitCount: 2,
+  });
 }
 
 function readHarnessCheckoutVersion(): string {
diff --git a/scripts/e2e/sandbox-browser-sidecar-docker.sh b/scripts/e2e/sandbox-browser-sidecar-docker.sh
new file mode 100755
index 000000000000..50ba769b4624
--- /dev/null
+++ b/scripts/e2e/sandbox-browser-sidecar-docker.sh
@@ -0,0 +1,116 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+source "$ROOT_DIR/scripts/lib/docker-e2e-image.sh"
+
+FUNCTIONAL_IMAGE="$(docker_e2e_resolve_image \
+  "openclaw-sandbox-browser-sidecar-functional:local" \
+  OPENCLAW_SANDBOX_BROWSER_SIDECAR_FUNCTIONAL_IMAGE)"
+RUNNER_IMAGE="${OPENCLAW_SANDBOX_BROWSER_SIDECAR_RUNNER_IMAGE:-openclaw-sandbox-browser-sidecar-e2e:${OPENCLAW_DOCKER_ALL_LANE_NAME:-local}}"
+SANDBOX_IMAGE="${OPENCLAW_SANDBOX_IMAGE:-openclaw-sandbox:bookworm-slim}"
+BROWSER_IMAGE="${OPENCLAW_SANDBOX_BROWSER_IMAGE:-openclaw-sandbox-browser:bookworm-slim}"
+RUN_ID="$$-$(date +%s)"
+SANDBOX_PREFIX="openclaw-e2e-sbx-${RUN_ID}-"
+BROWSER_PREFIX="openclaw-e2e-browser-${RUN_ID}-"
+NETWORK_NAME="openclaw-e2e-browser-${RUN_ID}"
+SCENARIO_ROOT="$(mktemp -d /tmp/openclaw-sandbox-browser-sidecar.XXXXXX)"
+BUILD_DIR="$(mktemp -d /tmp/openclaw-sandbox-browser-sidecar-build.XXXXXX)"
+DOCKER_SOCKET="${OPENCLAW_DOCKER_SOCKET:-/var/run/docker.sock}"
+SCENARIO_SOURCE="$ROOT_DIR/scripts/e2e/lib/sandbox-browser-sidecar/scenario.mjs"
+DOCKER_COMMAND_TIMEOUT="${OPENCLAW_SANDBOX_BROWSER_SIDECAR_DOCKER_TIMEOUT:-1200s}"
+
+docker_socket_gid() {
+  if stat -c "%g" "$DOCKER_SOCKET" >/dev/null 2>&1; then
+    stat -c "%g" "$DOCKER_SOCKET"
+    return
+  fi
+  stat -f "%g" "$DOCKER_SOCKET"
+}
+
+remove_prefixed_containers() {
+  local prefix="$1"
+  local name
+  while IFS= read -r name; do
+    case "$name" in
+      "$prefix"*) docker_e2e_docker_cmd rm -f "$name" >/dev/null 2>&1 || true ;;
+    esac
+  done < <(docker_e2e_docker_cmd ps -a --format '{{.Names}}' 2>/dev/null || true)
+}
+
+cleanup() {
+  remove_prefixed_containers "$SANDBOX_PREFIX"
+  remove_prefixed_containers "$BROWSER_PREFIX"
+  docker_e2e_docker_cmd network rm "$NETWORK_NAME" >/dev/null 2>&1 || true
+  docker_e2e_docker_cmd run --rm --user 0:0 \
+    -v "$SCENARIO_ROOT:/target" \
+    "$SANDBOX_IMAGE" \
+    sh -c 'rm -rf /target/* /target/.[!.]* /target/..?*' >/dev/null 2>&1 || true
+  rm -rf "$SCENARIO_ROOT" "$BUILD_DIR"
+}
+trap cleanup EXIT
+
+if [ ! -S "$DOCKER_SOCKET" ]; then
+  echo "Docker socket not found: $DOCKER_SOCKET" >&2
+  exit 1
+fi
+
+# The inner sandbox containers bind host paths. Keep this path identical in the
+# package runner so the Docker daemon resolves the same task-owned directory.
+chmod 0777 "$SCENARIO_ROOT"
+
+docker_e2e_build_or_reuse \
+  "$FUNCTIONAL_IMAGE" \
+  sandbox-browser-sidecar-functional \
+  "$ROOT_DIR/scripts/e2e/Dockerfile" \
+  "$ROOT_DIR" \
+  functional
+
+docker_build_run sandbox-browser-sidecar-sandbox-build \
+  -t "$SANDBOX_IMAGE" \
+  -f "$ROOT_DIR/scripts/docker/sandbox/Dockerfile" \
+  "$ROOT_DIR"
+
+docker_build_run sandbox-browser-sidecar-browser-build \
+  -t "$BROWSER_IMAGE" \
+  -f "$ROOT_DIR/scripts/docker/sandbox/Dockerfile.browser" \
+  "$ROOT_DIR"
+
+cat >"$BUILD_DIR/Dockerfile" <<'EOF'
+ARG BASE_IMAGE
+FROM ${BASE_IMAGE}
+USER root
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends docker.io \
+ && rm -rf /var/lib/apt/lists/*
+USER appuser
+EOF
+
+docker_build_run sandbox-browser-sidecar-runner-build \
+  --build-arg "BASE_IMAGE=$FUNCTIONAL_IMAGE" \
+  -t "$RUNNER_IMAGE" \
+  -f "$BUILD_DIR/Dockerfile" \
+  "$BUILD_DIR"
+
+SOCKET_GID="$(docker_socket_gid)"
+
+echo "Running package-backed sandbox browser sidecar Docker E2E..."
+docker_e2e_run_logged_print_with_harness sandbox-browser-sidecar \
+  --network host \
+  --group-add "$SOCKET_GID" \
+  -e COREPACK_ENABLE_DOWNLOAD_PROMPT=0 \
+  -e "OPENCLAW_E2E_ROOT=$SCENARIO_ROOT" \
+  -e "OPENCLAW_E2E_SANDBOX_IMAGE=$SANDBOX_IMAGE" \
+  -e "OPENCLAW_E2E_BROWSER_IMAGE=$BROWSER_IMAGE" \
+  -e "OPENCLAW_E2E_SANDBOX_PREFIX=$SANDBOX_PREFIX" \
+  -e "OPENCLAW_E2E_BROWSER_PREFIX=$BROWSER_PREFIX" \
+  -e "OPENCLAW_E2E_BROWSER_NETWORK=$NETWORK_NAME" \
+  -v "$DOCKER_SOCKET:/var/run/docker.sock" \
+  -v "$SCENARIO_ROOT:$SCENARIO_ROOT" \
+  -v "$SCENARIO_SOURCE:/tmp/openclaw-sandbox-browser-sidecar-scenario.mjs:ro" \
+  "$RUNNER_IMAGE" \
+  bash -lc \
+  'cp /tmp/openclaw-sandbox-browser-sidecar-scenario.mjs /app/sandbox-browser-sidecar-scenario.mjs
+   exec node /app/sandbox-browser-sidecar-scenario.mjs'
+
+echo "Sandbox browser sidecar Docker E2E passed."
diff --git a/scripts/lib/docker-e2e-scenarios.mjs b/scripts/lib/docker-e2e-scenarios.mjs
index 3daba16f856f..1ae0f4c782c1 100644
--- a/scripts/lib/docker-e2e-scenarios.mjs
+++ b/scripts/lib/docker-e2e-scenarios.mjs
@@ -472,6 +472,15 @@ export const mainLanes = [
     timeoutMs: 20 * 60 * 1000,
     weight: 3,
   }),
+  serviceLane(
+    "sandbox-browser-sidecar",
+    "OPENCLAW_SKIP_DOCKER_BUILD=1 pnpm test:docker:sandbox-browser-sidecar",
+    {
+      stateScenario: "empty",
+      timeoutMs: 20 * 60 * 1000,
+      weight: 4,
+    },
+  ),
   serviceLane(
     "agents-delete-shared-workspace",
     "OPENCLAW_SKIP_DOCKER_BUILD=1 pnpm test:docker:agents-delete-shared-workspace",
diff --git a/src/agents/sandbox/browser.create.test.ts b/src/agents/sandbox/browser.create.test.ts
index 865d5187381b..578e8c81a6a2 100644
--- a/src/agents/sandbox/browser.create.test.ts
+++ b/src/agents/sandbox/browser.create.test.ts
@@ -363,6 +363,55 @@ describe("ensureSandboxBrowser create args", () => {
     expect(createArgs).toContain(`openclaw.createArgsEpoch=${SANDBOX_DOCKER_CREATE_ARGS_EPOCH}`);
   });
 
+  it("serializes concurrent provisioning for the same browser container", async () => {
+    let created = false;
+    let cdpAuthToken: string | undefined;
+    let configHash: string | undefined;
+    dockerMocks.dockerContainerState.mockImplementation(async () => ({
+      exists: created,
+      running: created,
+    }));
+    dockerMocks.readDockerContainerEnvVar.mockImplementation(async (_containerName, key) =>
+      key === "OPENCLAW_BROWSER_CDP_AUTH_TOKEN" ? (cdpAuthToken ?? null) : null,
+    );
+    dockerMocks.readDockerContainerLabel.mockImplementation(async () => configHash ?? null);
+    dockerMocks.execDocker.mockImplementation(async (args: string[]) => {
+      if (args[0] === "image" && args[1] === "inspect") {
+        return { stdout: `${SANDBOX_BROWSER_IMAGE_CONTRACT_EPOCH}\n`, stderr: "", code: 0 };
+      }
+      if (args[0] === "create") {
+        if (created) {
+          throw new Error("docker name conflict");
+        }
+        created = true;
+        cdpAuthToken = collectDockerFlagValues(args, "-e")
+          .find((entry) => entry.startsWith("OPENCLAW_BROWSER_CDP_AUTH_TOKEN="))
+          ?.slice("OPENCLAW_BROWSER_CDP_AUTH_TOKEN=".length);
+        configHash = collectDockerFlagValues(args, "--label")
+          .find((entry) => entry.startsWith("openclaw.configHash="))
+          ?.slice("openclaw.configHash=".length);
+      }
+      return { stdout: "", stderr: "", code: 0 };
+    });
+
+    const params = {
+      scopeKey: "session:test",
+      workspaceDir: "/tmp/workspace",
+      agentWorkspaceDir: "/tmp/workspace",
+      cfg: buildConfig(false),
+    };
+    await expect(
+      Promise.all([ensureTestSandboxBrowser(params), ensureTestSandboxBrowser(params)]),
+    ).resolves.toHaveLength(2);
+
+    expect(dockerMocks.execDocker.mock.calls.filter(([args]) => args[0] === "create")).toHaveLength(
+      1,
+    );
+    expect(dockerMocks.execDocker.mock.calls.filter(([args]) => args[0] === "start")).toHaveLength(
+      1,
+    );
+  });
+
   it("recreates a cold browser container when the shared args epoch changes", async () => {
     const cfg = buildConfig(false);
     const oldHash = computeTestBrowserHash({
diff --git a/src/agents/sandbox/browser.ts b/src/agents/sandbox/browser.ts
index ac1d2c51b009..f5b9c4412f30 100644
--- a/src/agents/sandbox/browser.ts
+++ b/src/agents/sandbox/browser.ts
@@ -19,6 +19,7 @@ import {
   resolveProfile,
   type ResolvedBrowserConfig,
 } from "../../plugin-sdk/browser-profiles.js";
+import { KeyedAsyncQueue } from "../../plugin-sdk/keyed-async-queue.js";
 import { defaultRuntime } from "../../runtime.js";
 import {
   BROWSER_BRIDGES,
@@ -69,6 +70,8 @@ const HOT_BROWSER_WINDOW_MS = 5 * 60 * 1000;
 const CDP_SOURCE_RANGE_ENV_KEY = "OPENCLAW_BROWSER_CDP_SOURCE_RANGE";
 const CDP_AUTH_TOKEN_ENV_KEY = "OPENCLAW_BROWSER_CDP_AUTH_TOKEN";
 const SANDBOX_BROWSER_IMAGE_CONTRACT_LABEL = "org.openclaw.sandbox-browser.contract";
+const browserContainerLifecycleQueue = new KeyedAsyncQueue();
+const browserNetworkLifecycleQueue = new KeyedAsyncQueue();
 
 function buildSandboxCdpAuthHeader(token: string): string {
   return `Basic ${Buffer.from(`openclaw:${token}`).toString("base64")}`;
@@ -212,14 +215,16 @@ async function ensureDockerNetwork(
   if (!normalized || normalized === "bridge" || normalized === "none") {
     return;
   }
-  const inspect = await execDocker(["network", "inspect", network], { allowFailure: true });
-  if (inspect.code === 0) {
-    return;
-  }
-  await execDocker(["network", "create", "--driver", "bridge", network]);
+  await browserNetworkLifecycleQueue.enqueue(normalized, async () => {
+    const inspect = await execDocker(["network", "inspect", network], { allowFailure: true });
+    if (inspect.code === 0) {
+      return;
+    }
+    await execDocker(["network", "create", "--driver", "bridge", network]);
+  });
 }
 
-export async function ensureSandboxBrowser(params: {
+type EnsureSandboxBrowserParams = {
   scopeKey: string;
   workspaceDir: string;
   agentWorkspaceDir: string;
@@ -228,7 +233,11 @@ export async function ensureSandboxBrowser(params: {
   evaluateEnabled?: boolean;
   bridgeAuth?: { token?: string; password?: string };
   ssrfPolicy?: SsrFPolicy;
-}): Promise<SandboxBrowserContext | null> {
+};
+
+export async function ensureSandboxBrowser(
+  params: EnsureSandboxBrowserParams,
+): Promise<SandboxBrowserContext | null> {
   if (!params.cfg.browser.enabled) {
     return null;
   }
@@ -243,6 +252,19 @@ export async function ensureSandboxBrowser(params: {
 
   const slug = params.cfg.scope === "shared" ? "shared" : slugifySessionKey(params.scopeKey);
   const containerName = buildSandboxContainerName(params.cfg.browser.containerPrefix, slug);
+
+  // Independent agent runs can converge on one Docker resource. Serialize the
+  // full lifecycle so followers re-read container and bridge state after the
+  // preceding create, start, or replacement has settled.
+  return await browserContainerLifecycleQueue.enqueue(containerName, async () => {
+    return await ensureSandboxBrowserContainer(params, containerName);
+  });
+}
+
+async function ensureSandboxBrowserContainer(
+  params: EnsureSandboxBrowserParams,
+  containerName: string,
+): Promise<SandboxBrowserContext> {
   let existing = BROWSER_BRIDGES.get(params.scopeKey);
   const stopExistingForContainer = async () => {
     await stopCachedBrowserBridgesForContainer(containerName);
diff --git a/src/agents/sandbox/docker.config-hash-recreate.test.ts b/src/agents/sandbox/docker.config-hash-recreate.test.ts
index c7e93e10d5ab..4e3877a482d4 100644
--- a/src/agents/sandbox/docker.config-hash-recreate.test.ts
+++ b/src/agents/sandbox/docker.config-hash-recreate.test.ts
@@ -20,6 +20,7 @@ type SpawnCall = {
 
 const spawnState = vi.hoisted(() => ({
   calls: [] as SpawnCall[],
+  containerExists: true,
   inspectRunning: true,
   labelHash: "",
 }));
@@ -63,19 +64,43 @@ async function spawnDockerProcess(commandAndArgs: string[]) {
     code = 1;
     stderr = `unexpected command: ${command}`;
   } else if (args[0] === "inspect" && args[1] === "-f" && args[2] === "{{.State.Running}}") {
-    stdout = spawnState.inspectRunning ? "true\n" : "false\n";
+    if (!spawnState.containerExists) {
+      code = 1;
+      stderr = "No such object";
+    } else {
+      stdout = spawnState.inspectRunning ? "true\n" : "false\n";
+    }
   } else if (
     args[0] === "inspect" &&
     args[1] === "-f" &&
     args[2]?.includes('index .Config.Labels "openclaw.configHash"')
   ) {
-    stdout = `${spawnState.labelHash}\n`;
-  } else if (
-    (args[0] === "rm" && args[1] === "-f") ||
-    (args[0] === "image" && args[1] === "inspect") ||
-    args[0] === "create" ||
-    args[0] === "start"
-  ) {
+    if (!spawnState.containerExists) {
+      code = 1;
+      stderr = "No such object";
+    } else {
+      stdout = `${spawnState.labelHash}\n`;
+    }
+  } else if (args[0] === "rm" && args[1] === "-f") {
+    spawnState.containerExists = false;
+    spawnState.inspectRunning = false;
+  } else if (args[0] === "image" && args[1] === "inspect") {
+    code = 0;
+  } else if (args[0] === "create") {
+    if (spawnState.containerExists) {
+      code = 1;
+      stderr = "container name is already in use";
+    } else {
+      spawnState.containerExists = true;
+      spawnState.inspectRunning = false;
+      spawnState.labelHash =
+        args
+          .find((arg) => arg.startsWith("openclaw.configHash="))
+          ?.slice("openclaw.configHash=".length) ?? "";
+    }
+  } else if (args[0] === "start") {
+    spawnState.inspectRunning = true;
+  } else if (args[0] === "exec") {
     code = 0;
   } else {
     code = 1;
@@ -193,6 +218,7 @@ describe("ensureSandboxContainer config-hash recreation", () => {
 
   beforeEach(async () => {
     spawnState.calls.length = 0;
+    spawnState.containerExists = true;
     spawnState.inspectRunning = true;
     spawnState.labelHash = "";
     registryMocks.readRegistryEntry.mockClear();
@@ -202,6 +228,31 @@ describe("ensureSandboxContainer config-hash recreation", () => {
     await loadFreshDockerModuleForTest();
   });
 
+  it("serializes concurrent provisioning for one container", async () => {
+    const workspaceDir = makeTempDir();
+    const cfg = createSandboxConfig([], [`${workspaceDir}:/workspace:rw`]);
+    spawnState.containerExists = false;
+    spawnState.inspectRunning = false;
+    registryMocks.readRegistryEntry.mockResolvedValue(null);
+
+    const params = {
+      sessionKey: "agent:main:session-1",
+      workspaceDir,
+      agentWorkspaceDir: workspaceDir,
+      cfg,
+    };
+    const [first, second] = await Promise.all([
+      ensureSandboxContainer(params),
+      ensureSandboxContainer(params),
+    ]);
+
+    expect(first).toBe("oc-test-shared");
+    expect(second).toBe(first);
+    expect(spawnState.calls.filter((call) => call.args[0] === "create")).toHaveLength(1);
+    expect(spawnState.calls.filter((call) => call.args[0] === "start")).toHaveLength(1);
+    expect(registryMocks.updateRegistry).toHaveBeenCalledTimes(2);
+  });
+
   it("recreates shared container when array-order change alters hash", async () => {
     // Docker flag order is part of the runtime contract, so order-sensitive
     // config changes must invalidate a shared container.
diff --git a/src/agents/sandbox/docker.ts b/src/agents/sandbox/docker.ts
index a7a9f9d58c22..fb3dce94d036 100644
--- a/src/agents/sandbox/docker.ts
+++ b/src/agents/sandbox/docker.ts
@@ -84,6 +84,7 @@ export async function execDockerRaw(
 }
 
 import { markOpenClawExecEnv } from "../../infra/openclaw-exec-env.js";
+import { KeyedAsyncQueue } from "../../plugin-sdk/keyed-async-queue.js";
 import {
   computeSandboxConfigHash,
   SANDBOX_DOCKER_EXPLICIT_ENV_POLICY_EPOCH,
@@ -110,6 +111,7 @@ import {
 const log = createSubsystemLogger("docker");
 
 const HOT_CONTAINER_WINDOW_MS = 5 * 60 * 1000;
+const sandboxContainerLifecycleQueue = new KeyedAsyncQueue();
 
 type ExecDockerOptions = ExecDockerRawOptions;
 
@@ -493,17 +495,32 @@ async function readContainerConfigHash(containerName: string): Promise<string |
   return await readDockerContainerLabel(containerName, "openclaw.configHash");
 }
 
-export async function ensureSandboxContainer(params: {
+type EnsureSandboxContainerParams = {
   sessionKey: string;
   workspaceDir: string;
   agentWorkspaceDir: string;
   skillsWorkspaceDir?: string;
   cfg: SandboxConfig;
   requireCurrentConfig?: boolean;
-}) {
+};
+
+export async function ensureSandboxContainer(params: EnsureSandboxContainerParams) {
   const scopeKey = resolveSandboxScopeKey(params.cfg.scope, params.sessionKey);
   const slug = params.cfg.scope === "shared" ? "shared" : slugifySessionKey(scopeKey);
   const containerName = buildSandboxContainerName(params.cfg.docker.containerPrefix, slug);
+
+  // Independent agent runs can converge on one Docker resource. Serialize the
+  // full lifecycle so followers re-read state after create, start, or replace.
+  return await sandboxContainerLifecycleQueue.enqueue(containerName, async () => {
+    return await ensureSandboxContainerLifecycle(params, scopeKey, containerName);
+  });
+}
+
+async function ensureSandboxContainerLifecycle(
+  params: EnsureSandboxContainerParams,
+  scopeKey: string,
+  containerName: string,
+) {
   const readOnlyWorkspaceSkillMounts = resolveReadOnlyWorkspaceSkillMounts({
     workspaceDir: params.workspaceDir,
     agentWorkspaceDir: params.agentWorkspaceDir,
diff --git a/test/scripts/code-mode-model-matrix.test.ts b/test/scripts/code-mode-model-matrix.test.ts
index f4825d8b9119..90c76d50270d 100644
--- a/test/scripts/code-mode-model-matrix.test.ts
+++ b/test/scripts/code-mode-model-matrix.test.ts
@@ -3,7 +3,7 @@ import fs from "node:fs/promises";
 import os from "node:os";
 import path from "node:path";
 import { describe, expect, it } from "vitest";
-import { validateQaEvidenceSummaryJson } from "../../extensions/qa-lab/api.ts";
+import { validateQaEvidenceSummaryJson } from "../../extensions/qa-lab/api.js";
 import {
   buildCodeModeMatrixAgentEnv,
   classifyCodeModeMatrixCell,
diff --git a/test/scripts/docker-build-helper.test.ts b/test/scripts/docker-build-helper.test.ts
index 254e014e8d39..c3e9b78ff104 100644
--- a/test/scripts/docker-build-helper.test.ts
+++ b/test/scripts/docker-build-helper.test.ts
@@ -107,9 +107,13 @@ const UPGRADE_SURVIVOR_UPDATE_RESTART_AUTH_PATH =
   "scripts/e2e/lib/upgrade-survivor/update-restart-auth.sh";
 const GATEWAY_NETWORK_DOCKER_E2E_PATH = "scripts/e2e/gateway-network-docker.sh";
 const BROWSER_CDP_SNAPSHOT_DOCKER_E2E_PATH = "scripts/e2e/browser-cdp-snapshot-docker.sh";
+const SANDBOX_BROWSER_SIDECAR_DOCKER_E2E_PATH = "scripts/e2e/sandbox-browser-sidecar-docker.sh";
+const SANDBOX_BROWSER_SIDECAR_SCENARIO_PATH =
+  "scripts/e2e/lib/sandbox-browser-sidecar/scenario.mjs";
 const CENTRALIZED_BUILD_SCRIPTS = [
   "scripts/docker/setup.sh",
   BROWSER_CDP_SNAPSHOT_DOCKER_E2E_PATH,
+  SANDBOX_BROWSER_SIDECAR_DOCKER_E2E_PATH,
   "scripts/e2e/qr-import-docker.sh",
   "scripts/lib/docker-e2e-image.sh",
   "scripts/sandbox-browser-setup.sh",
@@ -325,6 +329,25 @@ fi
     expect(installE2eSmoke).not.toContain("docker run --rm \\");
   });
 
+  it("runs the sandbox browser sidecar proof from the package-installed image", () => {
+    const runner = readFileSync(SANDBOX_BROWSER_SIDECAR_DOCKER_E2E_PATH, "utf8");
+    const scenario = readFileSync(SANDBOX_BROWSER_SIDECAR_SCENARIO_PATH, "utf8");
+
+    expect(runner).toContain('source "$ROOT_DIR/scripts/lib/docker-e2e-image.sh"');
+    expect(runner).toContain("docker_e2e_build_or_reuse");
+    expect(runner).toContain("--network host");
+    expect(runner).toContain('--group-add "$SOCKET_GID"');
+    expect(runner).toContain('-v "$DOCKER_SOCKET:/var/run/docker.sock"');
+    expect(runner).toContain('-v "$SCENARIO_ROOT:$SCENARIO_ROOT"');
+    expect(runner).toContain("scripts/docker/sandbox/Dockerfile.browser");
+    expect(runner).toContain("remove_prefixed_containers");
+    expect(scenario).toContain('from "openclaw/plugin-sdk/agent-harness-runtime"');
+    expect(scenario).toContain("Promise.all([");
+    expect(scenario).toContain('"sandbox", "list", "--browser", "--json"');
+    expect(scenario).toContain('"sandbox", "recreate", "--browser", "--session"');
+    expect(scenario).not.toMatch(/from\s+["'][.]{1,2}\/.*src\//u);
+  });
+
   it("gives cleanup-smoke builds enough Node heap while preserving explicit callers", () => {
     const cleanupRun = readFileSync(CLEANUP_SMOKE_RUN_PATH, "utf8");
 
diff --git a/test/scripts/docker-e2e-plan.test.ts b/test/scripts/docker-e2e-plan.test.ts
index a7f3566ff295..89e58cbe13ec 100644
--- a/test/scripts/docker-e2e-plan.test.ts
+++ b/test/scripts/docker-e2e-plan.test.ts
@@ -126,6 +126,26 @@ describe("scripts/lib/docker-e2e-plan", () => {
     );
   });
 
+  it("plans the package-backed sandbox browser sidecar lane", () => {
+    const plan = planFor({
+      selectedLaneNames: ["sandbox-browser-sidecar"],
+    });
+
+    expect(plan.lanes.map(summarizeLane)).toEqual([
+      {
+        command: "OPENCLAW_SKIP_DOCKER_BUILD=1 pnpm test:docker:sandbox-browser-sidecar",
+        imageKind: "functional",
+        live: false,
+        name: "sandbox-browser-sidecar",
+        resources: ["docker", "service"],
+        stateScenario: "empty",
+        timeoutMs: 1_200_000,
+        weight: 4,
+      },
+    ]);
+    expect(plan.needs.functionalImage).toBe(true);
+  });
+
   it("routes live Docker scripts through the nested trusted release harness", () => {
     const sourceLane = allReleasePathLanes({ releaseProfile: "beta" }).find(
       (candidate) => candidate.name === "live-codex-npm-plugin",