fix(codex): bundle codex-code-mode-host next to the codex binary

The codex 0.140.0 -> 0.144.0 bump (#3567) introduced a new runtime
dependency: codex resolves codex-code-mode-host as a sibling of its own
executable and routes all command execution through it for code-mode
models (gpt-5.6 family advertises tool_mode: code_mode_only). We only
shipped codex and rg into .vite/build/codex-acp, so Codex sessions could
chat but every command/edit failed with the host binary missing.

Download the host from the same codex release, stage it next to codex,
and make the packaged-app verification fail the release when any codex
sibling binary is missing.

Generated-By: PostHog Code
Task-Id: 541351db-2923-49df-8b67-45e277f5dce8

Author: adboio

.github/workflows/code-release.yml

@@ -199,9 +199,10 @@ jobs:
             echo "OK: $bin"
           done
 
-          # The native codex CLI must ship as a sibling of codex-acp, or the
-          # app-server harness silently falls back to codex-acp in production.
-          for f in codex rg; do
+          # codex resolves codex-code-mode-host and rg as siblings of its own
+          # executable; shipping codex without them breaks command execution
+          # at runtime (code-mode models route all commands through the host).
+          for f in codex codex-code-mode-host rg; do
             if [[ ! -f "$RESOURCES/app.asar.unpacked/.vite/build/codex-acp/$f" ]]; then
               echo "FAIL: codex-acp/$f missing in bundled binaries"
               exit 1

apps/code/scripts/download-binaries.mjs

@@ -19,40 +19,56 @@ import { extract } from "tar";
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const DEST_DIR = join(__dirname, "..", "resources", "codex-acp");
 
+const CODEX_VERSION = "0.144.0";
+
+function nativeTarget() {
+  const { platform, arch } = process;
+  const targets = {
+    darwin: { arm64: "aarch64-apple-darwin", x64: "x86_64-apple-darwin" },
+    linux: {
+      arm64: "aarch64-unknown-linux-musl",
+      x64: "x86_64-unknown-linux-musl",
+    },
+    win32: {
+      arm64: "aarch64-pc-windows-msvc",
+      x64: "x86_64-pc-windows-msvc",
+    },
+  };
+  const target = targets[platform]?.[arch];
+  if (!target) throw new Error(`Unsupported platform: ${platform}/${arch}`);
+  return target;
+}
+
+function codexReleaseUrl(binary, version, target) {
+  const suffix = target.includes("windows") ? ".exe.zip" : ".tar.gz";
+  return `https://github.com/openai/codex/releases/download/rust-v${version}/${binary}-${target}${suffix}`;
+}
+
+// Codex release archives contain a target-suffixed binary
+// (e.g. `codex-aarch64-apple-darwin`); rename it after extract.
+const codexArchiveBinaryName = (binary) => (target) =>
+  process.platform === "win32"
+    ? `${binary}-${target}.exe`
+    : `${binary}-${target}`;
+
 const BINARIES = [
   {
     name: "codex",
-    version: "0.144.0",
-    getUrl: (version, target) => {
-      if (target.includes("windows")) {
-        return `https://github.com/openai/codex/releases/download/rust-v${version}/codex-${target}.exe.zip`;
-      }
-      return `https://github.com/openai/codex/releases/download/rust-v${version}/codex-${target}.tar.gz`;
-    },
-    getTarget: () => {
-      const { platform, arch } = process;
-      const targets = {
-        darwin: { arm64: "aarch64-apple-darwin", x64: "x86_64-apple-darwin" },
-        linux: {
-          arm64: "aarch64-unknown-linux-musl",
-          x64: "x86_64-unknown-linux-musl",
-        },
-        win32: {
-          arm64: "aarch64-pc-windows-msvc",
-          x64: "x86_64-pc-windows-msvc",
-        },
-      };
-      const platformTargets = targets[platform];
-      if (!platformTargets)
-        throw new Error(`Unsupported platform: ${platform}`);
-      const target = platformTargets[arch];
-      if (!target) throw new Error(`Unsupported arch: ${arch}`);
-      return target;
-    },
-    // The codex release archive contains a target-suffixed binary
-    // (e.g. `codex-aarch64-apple-darwin`); rename it to `codex` after extract.
-    archiveBinaryName: (target) =>
-      process.platform === "win32" ? `codex-${target}.exe` : `codex-${target}`,
+    version: CODEX_VERSION,
+    getUrl: (version, target) => codexReleaseUrl("codex", version, target),
+    getTarget: nativeTarget,
+    archiveBinaryName: codexArchiveBinaryName("codex"),
+  },
+  {
+    // codex resolves this host as a sibling of its own executable and routes
+    // all command execution through it for code-mode models (gpt-5.6+). It is
+    // released per codex version, so it must stay in lockstep with `codex`.
+    name: "codex-code-mode-host",
+    version: CODEX_VERSION,
+    getUrl: (version, target) =>
+      codexReleaseUrl("codex-code-mode-host", version, target),
+    getTarget: nativeTarget,
+    archiveBinaryName: codexArchiveBinaryName("codex-code-mode-host"),
   },
   {
     name: "rg",
@@ -61,26 +77,7 @@ const BINARIES = [
       const ext = target.includes("windows") ? "zip" : "tar.gz";
       return `https://github.com/microsoft/ripgrep-prebuilt/releases/download/v${version}/ripgrep-v${version}-${target}.${ext}`;
     },
-    getTarget: () => {
-      const { platform, arch } = process;
-      const targets = {
-        darwin: { arm64: "aarch64-apple-darwin", x64: "x86_64-apple-darwin" },
-        linux: {
-          arm64: "aarch64-unknown-linux-musl",
-          x64: "x86_64-unknown-linux-musl",
-        },
-        win32: {
-          arm64: "aarch64-pc-windows-msvc",
-          x64: "x86_64-pc-windows-msvc",
-        },
-      };
-      const platformTargets = targets[platform];
-      if (!platformTargets)
-        throw new Error(`Unsupported platform: ${platform}`);
-      const target = platformTargets[arch];
-      if (!target) throw new Error(`Unsupported arch: ${arch}`);
-      return target;
-    },
+    getTarget: nativeTarget,
   },
 ];
 

apps/code/vite-main-plugins.mts

@@ -592,10 +592,12 @@ export function copyCodexAcpBinaries(): Plugin {
       const sourceDir = join(__dirname, "resources/codex-acp");
       const binaries = [
         { name: "codex", winName: "codex.exe" },
-        // The native codex CLI must ship next to codex-acp: the app-server
-        // sub-adapter resolves it as a sibling and silently falls back to
-        // codex-acp when it's missing.
-        { name: "codex", winName: "codex.exe" },
+        // codex resolves the code-mode host as a sibling of its own executable;
+        // code-mode models (gpt-5.6+) cannot run commands without it.
+        {
+          name: "codex-code-mode-host",
+          winName: "codex-code-mode-host.exe",
+        },
         { name: "rg", winName: "rg.exe" },
       ];