fix(cli): protect existing Windows Codex shims

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

packages/omo-codex/scripts/install-local.mjs

@@ -18,6 +18,7 @@ export async function installMarketplaceLocally(options = {}) {
 	const repoRoot = resolve(options.repoRoot ?? process.cwd());
 	const codexHome = resolve(options.codexHome ?? process.env.CODEX_HOME ?? join(homedir(), ".codex"));
 	const binDir = resolve(options.binDir ?? process.env.CODEX_LOCAL_BIN_DIR ?? join(homedir(), ".local", "bin"));
+	const platform = options.platform ?? process.platform;
 	const runCommand = options.runCommand ?? defaultRunCommand;
 	const log = options.log ?? console.log;
 	const marketplace = await readMarketplace(repoRoot);
@@ -43,7 +44,7 @@ export async function installMarketplaceLocally(options = {}) {
 			sourcePath,
 			version,
 		});
-		const binLinks = await linkCachedPluginBins({ binDir, pluginRoot: plugin.path });
+		const binLinks = await linkCachedPluginBins({ binDir, pluginRoot: plugin.path, platform });
 		for (const link of binLinks) {
 			log(`Linked ${link.name} -> ${link.target}`);
 		}

packages/omo-codex/scripts/install-local.test.mjs

@@ -100,6 +100,7 @@ test("#given local marketplace #when installing #then copies versioned plugins a
 		repoRoot,
 		codexHome,
 		binDir,
+		platform: "linux",
 		runCommand: async (command, args, options) => {
 			commands.push([command, args, options.cwd]);
 		},
@@ -232,3 +233,27 @@ test("#given Windows platform #when linking cached plugin bins #then writes comm
 	assert.match(shim, /@echo off/);
 	assert.match(shim, new RegExp(`node "${join(pluginRoot, "dist", "cli.js").replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}" %\\*`));
 });
+
+test("#given existing custom Windows command shim #when linking bins #then rejects without overwriting", async () => {
+	const root = await makeTempDir();
+	const pluginRoot = join(root, "plugin");
+	const binDir = join(root, "bin");
+
+	await mkdir(pluginRoot, { recursive: true });
+	await mkdir(binDir, { recursive: true });
+	await writeJson(join(pluginRoot, "package.json"), {
+		name: "@example/alpha",
+		bin: {
+			alpha: "./dist/cli.js",
+		},
+	});
+	await mkdir(join(pluginRoot, "dist"), { recursive: true });
+	await writeFile(join(pluginRoot, "dist", "cli.js"), "#!/usr/bin/env node\n");
+	await writeFile(join(binDir, "alpha.cmd"), "@echo off\r\necho custom\r\n");
+
+	await assert.rejects(
+		linkCachedPluginBins({ binDir, pluginRoot, platform: "win32" }),
+		/already exists and is not a generated command shim/,
+	);
+	assert.match(await readFile(join(binDir, "alpha.cmd"), "utf8"), /echo custom/);
+});

packages/omo-codex/scripts/install/cache.mjs

@@ -3,6 +3,8 @@ import { cp, lstat, mkdir, readFile, readdir, readlink, rename, rm, symlink, wri
 
 import { exists, isRecord } from "./utils.mjs";
 
+const COMMAND_SHIM_MARKER = ":: generated by oh-my-openagent Codex installer";
+
 export async function installCachedPlugin({ codexHome, marketplaceName, name, runCommand, sourcePath, version }) {
 	await maybeRunNpmInstall(sourcePath, runCommand);
 	await maybeRunNpmBuild(sourcePath, runCommand);
@@ -120,13 +122,16 @@ async function replaceCommandShim(linkPath, targetPath) {
 	if (await existingNonShim(linkPath)) {
 		throw new Error(`${linkPath} already exists and is not a command shim`);
 	}
-	await writeFile(linkPath, `@echo off\r\nnode "${targetPath}" %*\r\n`);
+	await writeFile(linkPath, `@echo off\r\n${COMMAND_SHIM_MARKER}\r\nnode "${targetPath}" %*\r\n`);
 }
 
 async function existingNonShim(path) {
 	try {
 		const stat = await lstat(path);
-		return !stat.isFile();
+		if (!stat.isFile()) return true;
+		const content = await readFile(path, "utf8");
+		if (content.includes(COMMAND_SHIM_MARKER)) return false;
+		throw new Error(`${path} already exists and is not a generated command shim`);
 	} catch (error) {
 		if (error instanceof Error && "code" in error && error.code === "ENOENT") return false;
 		throw error;

src/cli/install-codex/codex-cache.test.ts

@@ -1,3 +1,6 @@
+/// <reference path="../../../bun-test.d.ts" />
+/// <reference types="bun-types" />
+
 import { describe, expect, test } from "bun:test"
 import { mkdir, mkdtemp, readFile, readlink, writeFile } from "node:fs/promises"
 import { tmpdir } from "node:os"
@@ -35,8 +38,8 @@ describe("codex-cache", () => {
     await writeFile(join(pluginRoot, "dist", "cli.js"), "#!/usr/bin/env node\n")
 
     // when
-    const first = await linkCachedPluginBins({ binDir, pluginRoot })
+    const first = await linkCachedPluginBins({ binDir, pluginRoot, platform: "linux" })
-    const second = await linkCachedPluginBins({ binDir, pluginRoot })
+    const second = await linkCachedPluginBins({ binDir, pluginRoot, platform: "linux" })
 
     // then
     expect(first).toHaveLength(1)
@@ -64,4 +67,29 @@ describe("codex-cache", () => {
     expect(commandShim).toContain("@echo off")
     expect(commandShim).toContain(`node "${join(pluginRoot, "dist", "cli.js")}" %*`)
   })
+
+  test("rejects existing non-generated Windows command shims", async () => {
+    // given
+    const root = await mkdtemp(join(tmpdir(), "omo-codex-cache-"))
+    const pluginRoot = join(root, "plugin")
+    const binDir = join(root, "bin")
+    await mkdir(pluginRoot, { recursive: true })
+    await mkdir(binDir, { recursive: true })
+    await writeFile(join(pluginRoot, "package.json"), JSON.stringify({ name: "@scope/omo", bin: { "omo-hook": "dist/cli.js" } }))
+    await mkdir(join(pluginRoot, "dist"), { recursive: true })
+    await writeFile(join(pluginRoot, "dist", "cli.js"), "#!/usr/bin/env node\n")
+    await writeFile(join(binDir, "omo-hook.cmd"), "@echo off\r\necho custom\r\n")
+
+    // when
+    let rejected = false
+    try {
+      await linkCachedPluginBins({ binDir, pluginRoot, platform: "win32" })
+    } catch (error) {
+      rejected = error instanceof Error && error.message.includes("already exists and is not a generated command shim")
+    }
+
+    // then
+    expect(rejected).toBe(true)
+    expect(await readFile(join(binDir, "omo-hook.cmd"), "utf8")).toContain("echo custom")
+  })
 })

src/cli/install-codex/codex-cache.ts

@@ -4,6 +4,8 @@ import type { InstalledPlugin, RunCommand } from "./types"
 
 type LinkPlatform = NodeJS.Platform
 
+const COMMAND_SHIM_MARKER = ":: generated by oh-my-openagent Codex installer"
+
 export async function installCachedPlugin(input: {
   readonly codexHome: string
   readonly marketplaceName: string
@@ -163,13 +165,16 @@ async function replaceSymlink(linkPath: string, targetPath: string): Promise<voi
 
 async function replaceCommandShim(linkPath: string, targetPath: string): Promise<void> {
   if (await existingNonShim(linkPath)) throw new Error(`${linkPath} already exists and is not a command shim`)
-  await writeFile(linkPath, `@echo off\r\nnode "${targetPath}" %*\r\n`)
+  await writeFile(linkPath, `@echo off\r\n${COMMAND_SHIM_MARKER}\r\nnode "${targetPath}" %*\r\n`)
 }
 
 async function existingNonShim(path: string): Promise<boolean> {
   try {
     const stat = await lstat(path)
-    return !stat.isFile()
+    if (!stat.isFile()) return true
+    const content = await readFile(path, "utf8")
+    if (content.includes(COMMAND_SHIM_MARKER)) return false
+    throw new Error(`${path} already exists and is not a generated command shim`)
   } catch (error) {
     if (isNodeErrorWithCode(error) && error.code === "ENOENT") return false
     throw error