diff --git a/scripts/check-changed.mjs b/scripts/check-changed.mjs
index 5bf1b3b0033..ecbf6470149 100644
--- a/scripts/check-changed.mjs
+++ b/scripts/check-changed.mjs
@@ -8,6 +8,7 @@ import {
 import { booleanFlag, parseFlagArgs, stringFlag } from "./lib/arg-utils.mjs";
 import { printTimingSummary } from "./lib/check-timing-summary.mjs";
 import { runManagedCommand } from "./lib/managed-child-process.mjs";
+import { isCiLikeEnv } from "./lib/vitest-local-scheduling.mjs";
 import { resolveChangedTestTargetPlan } from "./test-projects.test-support.mjs";
 
 export const CHANGED_CHECK_VITEST_NO_OUTPUT_TIMEOUT_MS = "600000";
@@ -15,13 +16,30 @@ const VITEST_NO_OUTPUT_TIMEOUT_ENV_KEY = "OPENCLAW_VITEST_NO_OUTPUT_TIMEOUT_MS";
 const VITEST_NO_OUTPUT_RETRY_ENV_KEY = "OPENCLAW_VITEST_NO_OUTPUT_RETRY";
 
 export function createChangedCheckVitestEnv(baseEnv = process.env) {
-  return {
+  const env = {
     ...baseEnv,
     [VITEST_NO_OUTPUT_TIMEOUT_ENV_KEY]:
       baseEnv[VITEST_NO_OUTPUT_TIMEOUT_ENV_KEY]?.trim() ||
       CHANGED_CHECK_VITEST_NO_OUTPUT_TIMEOUT_MS,
     [VITEST_NO_OUTPUT_RETRY_ENV_KEY]: baseEnv[VITEST_NO_OUTPUT_RETRY_ENV_KEY]?.trim() || "0",
   };
+
+  const hasWorkerOverride = Boolean(
+    (baseEnv.OPENCLAW_VITEST_MAX_WORKERS ?? baseEnv.OPENCLAW_TEST_WORKERS)?.trim(),
+  );
+  const hasParallelOverride = Boolean(baseEnv.OPENCLAW_TEST_PROJECTS_PARALLEL?.trim());
+  const serialOverride = baseEnv.OPENCLAW_TEST_PROJECTS_SERIAL?.trim();
+  if (
+    !isCiLikeEnv(baseEnv) &&
+    !hasWorkerOverride &&
+    !hasParallelOverride &&
+    serialOverride !== "0"
+  ) {
+    env.OPENCLAW_TEST_PROJECTS_SERIAL = serialOverride || "1";
+    env.OPENCLAW_VITEST_MAX_WORKERS = "1";
+  }
+
+  return env;
 }
 
 export function createChangedCheckPlan(result, options = {}) {
diff --git a/scripts/run-oxlint.mjs b/scripts/run-oxlint.mjs
index cfbdf9cdc02..fb400bea29e 100644
--- a/scripts/run-oxlint.mjs
+++ b/scripts/run-oxlint.mjs
@@ -1,3 +1,5 @@
+import { spawnSync } from "node:child_process";
+import fs from "node:fs";
 import path from "node:path";
 import {
   acquireLocalHeavyCheckLockSync,
@@ -20,10 +22,105 @@ const OXLINT_PREPARE_SKIP_FLAGS = new Set([
   "--init",
   "--lsp",
 ]);
+const OXLINT_VALUE_FLAGS = new Set([
+  "--config",
+  "--deny",
+  "--env",
+  "--format",
+  "--globals",
+  "--ignore-path",
+  "--max-warnings",
+  "--output-file",
+  "--plugin",
+  "--rules",
+  "--tsconfig",
+  "--warn",
+]);
+
 export function shouldPrepareExtensionPackageBoundaryArtifacts(args) {
   return !args.some((arg) => OXLINT_PREPARE_SKIP_FLAGS.has(arg));
 }
 
+export function filterSparseMissingOxlintTargets(
+  args,
+  {
+    cwd = process.cwd(),
+    fileExists = fs.existsSync,
+    isSparseCheckoutEnabled = getSparseCheckoutEnabled,
+    isTrackedPath = hasTrackedPath,
+  } = {},
+) {
+  if (!isSparseCheckoutEnabled({ cwd })) {
+    return { args, hadExplicitTargets: false, remainingExplicitTargets: 0, skippedTargets: [] };
+  }
+
+  const filteredArgs = [];
+  const skippedTargets = [];
+  let hadExplicitTargets = false;
+  let remainingExplicitTargets = 0;
+  let consumeNextValue = false;
+
+  for (const arg of args) {
+    if (consumeNextValue) {
+      filteredArgs.push(arg);
+      consumeNextValue = false;
+      continue;
+    }
+
+    if (arg === "--") {
+      filteredArgs.push(arg);
+      continue;
+    }
+
+    if (arg.startsWith("--")) {
+      filteredArgs.push(arg);
+      if (!arg.includes("=") && OXLINT_VALUE_FLAGS.has(arg)) {
+        consumeNextValue = true;
+      }
+      continue;
+    }
+
+    if (arg.startsWith("-")) {
+      filteredArgs.push(arg);
+      continue;
+    }
+
+    hadExplicitTargets = true;
+    const absoluteTarget = path.resolve(cwd, arg);
+    if (!fileExists(absoluteTarget) && isTrackedPath({ cwd, target: arg })) {
+      skippedTargets.push(arg);
+      continue;
+    }
+
+    remainingExplicitTargets += 1;
+    filteredArgs.push(arg);
+  }
+
+  return { args: filteredArgs, hadExplicitTargets, remainingExplicitTargets, skippedTargets };
+}
+
+function getSparseCheckoutEnabled({ cwd }) {
+  const result = spawnSync("git", ["config", "--get", "--bool", "core.sparseCheckout"], {
+    cwd,
+    encoding: "utf8",
+    stdio: ["ignore", "pipe", "pipe"],
+    shell: process.platform === "win32",
+  });
+
+  return result.status === 0 && result.stdout.trim() === "true";
+}
+
+function hasTrackedPath({ cwd, target }) {
+  const result = spawnSync("git", ["ls-files", "--", target], {
+    cwd,
+    encoding: "utf8",
+    stdio: ["ignore", "pipe", "pipe"],
+    shell: process.platform === "win32",
+  });
+
+  return result.status === 0 && result.stdout.trim().length > 0;
+}
+
 async function prepareExtensionPackageBoundaryArtifacts(env) {
   const releaseArtifactsLock = acquireLocalHeavyCheckLockSync({
     cwd: process.cwd(),
@@ -50,7 +147,19 @@ async function prepareExtensionPackageBoundaryArtifacts(env) {
 }
 
 export async function main(argv = process.argv.slice(2), runtimeEnv = process.env) {
-  const { args: finalArgs, env } = applyLocalOxlintPolicy(argv, runtimeEnv);
+  const { args: policyArgs, env } = applyLocalOxlintPolicy(argv, runtimeEnv);
+  const sparseTargets = filterSparseMissingOxlintTargets(policyArgs);
+  const finalArgs = sparseTargets.args;
+  if (sparseTargets.skippedTargets.length > 0) {
+    console.error(
+      `[oxlint] sparse checkout is missing tracked target(s); skipping ${sparseTargets.skippedTargets.join(", ")}`,
+    );
+  }
+  if (sparseTargets.hadExplicitTargets && sparseTargets.remainingExplicitTargets === 0) {
+    console.error("[oxlint] no present sparse-checkout targets remain; skipping oxlint.");
+    return;
+  }
+
   const releaseLock =
     env.OPENCLAW_OXLINT_SKIP_LOCK === "1"
       ? () => {}
diff --git a/scripts/test-projects.test-support.mjs b/scripts/test-projects.test-support.mjs
index bf1289a6945..e8baedd4d3a 100644
--- a/scripts/test-projects.test-support.mjs
+++ b/scripts/test-projects.test-support.mjs
@@ -232,6 +232,7 @@ const TOOLING_SOURCE_TEST_TARGETS = new Map([
     "scripts/run-vitest.mjs",
     ["test/scripts/test-projects.test.ts", "test/scripts/vitest-local-scheduling.test.ts"],
   ],
+  ["scripts/run-oxlint.mjs", ["test/scripts/run-oxlint.test.ts"]],
   ["scripts/test-extension-batch.mjs", ["test/scripts/test-extension.test.ts"]],
   ["scripts/lib/extension-test-plan.mjs", ["test/scripts/test-extension.test.ts"]],
   ["scripts/lib/vitest-batch-runner.mjs", ["test/scripts/test-extension.test.ts"]],
diff --git a/test/scripts/changed-lanes.test.ts b/test/scripts/changed-lanes.test.ts
index 0eb0e2acf8d..618ab07a932 100644
--- a/test/scripts/changed-lanes.test.ts
+++ b/test/scripts/changed-lanes.test.ts
@@ -370,6 +370,8 @@ describe("scripts/changed-lanes", () => {
       PATH: "/usr/bin",
       OPENCLAW_VITEST_NO_OUTPUT_TIMEOUT_MS: CHANGED_CHECK_VITEST_NO_OUTPUT_TIMEOUT_MS,
       OPENCLAW_VITEST_NO_OUTPUT_RETRY: "0",
+      OPENCLAW_TEST_PROJECTS_SERIAL: "1",
+      OPENCLAW_VITEST_MAX_WORKERS: "1",
     });
 
     expect(
@@ -382,4 +384,16 @@ describe("scripts/changed-lanes", () => {
       OPENCLAW_VITEST_NO_OUTPUT_RETRY: "1",
     });
   });
+
+  it("does not force serial changed-check tests in CI or when workers are explicit", () => {
+    expect(createChangedCheckVitestEnv({ CI: "true" })).not.toHaveProperty(
+      "OPENCLAW_VITEST_MAX_WORKERS",
+    );
+    expect(createChangedCheckVitestEnv({ OPENCLAW_VITEST_MAX_WORKERS: "4" })).toMatchObject({
+      OPENCLAW_VITEST_MAX_WORKERS: "4",
+    });
+    expect(
+      createChangedCheckVitestEnv({ OPENCLAW_TEST_PROJECTS_PARALLEL: "4" }),
+    ).not.toHaveProperty("OPENCLAW_TEST_PROJECTS_SERIAL");
+  });
 });
diff --git a/test/scripts/run-oxlint.test.ts b/test/scripts/run-oxlint.test.ts
index 354d4d40056..e8292f200ee 100644
--- a/test/scripts/run-oxlint.test.ts
+++ b/test/scripts/run-oxlint.test.ts
@@ -1,6 +1,9 @@
 import { readFileSync } from "node:fs";
 import { describe, expect, it } from "vitest";
-import { shouldPrepareExtensionPackageBoundaryArtifacts } from "../../scripts/run-oxlint.mjs";
+import {
+  filterSparseMissingOxlintTargets,
+  shouldPrepareExtensionPackageBoundaryArtifacts,
+} from "../../scripts/run-oxlint.mjs";
 
 describe("run-oxlint", () => {
   it("prepares extension package boundary artifacts for normal lint runs", () => {
@@ -30,4 +33,36 @@ describe("run-oxlint", () => {
     expect(shardedLintRunner).toContain("prepare-extension-package-boundary-artifacts.mjs");
     expect(shardedLintRunner).toContain('OPENCLAW_OXLINT_SKIP_PREPARE: "1"');
   });
+
+  it("filters tracked targets missing from sparse checkouts", () => {
+    const result = filterSparseMissingOxlintTargets(
+      ["--tsconfig", "tsconfig.oxlint.core.json", "src", "ui", "packages", "--threads=1"],
+      {
+        fileExists: (target: string) => target.endsWith("/src"),
+        isSparseCheckoutEnabled: () => true,
+        isTrackedPath: ({ target }: { target: string }) => target === "ui" || target === "packages",
+      },
+    );
+
+    expect(result).toEqual({
+      args: ["--tsconfig", "tsconfig.oxlint.core.json", "src", "--threads=1"],
+      hadExplicitTargets: true,
+      remainingExplicitTargets: 1,
+      skippedTargets: ["ui", "packages"],
+    });
+  });
+
+  it("keeps missing untracked oxlint targets so typos still fail", () => {
+    const result = filterSparseMissingOxlintTargets(["src", "typo"], {
+      fileExists: (target: string) => target.endsWith("/src"),
+      isSparseCheckoutEnabled: () => true,
+      isTrackedPath: () => false,
+    });
+
+    expect(result).toMatchObject({
+      args: ["src", "typo"],
+      remainingExplicitTargets: 2,
+      skippedTargets: [],
+    });
+  });
 });