feat: bind package manager (#13571)

codex-rs/Cargo.lock

@@ -1548,6 +1548,7 @@ dependencies = [
  "thiserror 2.0.18",
  "tokio",
  "url",
+ "which",
  "wiremock",
  "zip",
 ]
@@ -2212,6 +2213,7 @@ dependencies = [
 name = "codex-package-manager"
 version = "0.0.0"
 dependencies = [
+ "fd-lock",
  "flate2",
  "pretty_assertions",
  "reqwest",

codex-rs/Cargo.toml

@@ -178,6 +178,7 @@ dirs = "6"
 dotenvy = "0.15.7"
 dunce = "1.0.4"
 encoding_rs = "0.8.35"
+fd-lock = "4.0.4"
 env-flags = "0.1.1"
 env_logger = "0.11.9"
 eventsource-stream = "0.2.3"

codex-rs/artifacts/Cargo.toml

@@ -13,6 +13,7 @@ tempfile = { workspace = true }
 thiserror = { workspace = true }
 tokio = { workspace = true, features = ["fs", "io-util", "process", "time"] }
 url = { workspace = true }
+which = { workspace = true }
 
 [lints]
 workspace = true

codex-rs/artifacts/src/client.rs

@@ -43,6 +43,7 @@ impl ArtifactsClient {
         request: ArtifactBuildRequest,
     ) -> Result<ArtifactCommandOutput, ArtifactsError> {
         let runtime = self.resolve_runtime().await?;
+        let js_runtime = runtime.resolve_js_runtime()?;
         let staging_dir = TempDir::new().map_err(|source| ArtifactsError::Io {
             context: "failed to create build staging directory".to_string(),
             source,
@@ -56,7 +57,7 @@ impl ArtifactsClient {
                 source,
             })?;
 
-        let mut command = Command::new(runtime.node_path());
+        let mut command = Command::new(js_runtime.executable_path());
         command
             .arg(&script_path)
             .current_dir(&request.cwd)
@@ -67,6 +68,9 @@ impl ArtifactsClient {
             )
             .stdout(Stdio::piped())
             .stderr(Stdio::piped());
+        if js_runtime.requires_electron_run_as_node() {
+            command.env("ELECTRON_RUN_AS_NODE", "1");
+        }
         for (key, value) in &request.env {
             command.env(key, value);
         }
@@ -83,13 +87,17 @@ impl ArtifactsClient {
         request: ArtifactRenderCommandRequest,
     ) -> Result<ArtifactCommandOutput, ArtifactsError> {
         let runtime = self.resolve_runtime().await?;
-        let mut command = Command::new(runtime.node_path());
+        let js_runtime = runtime.resolve_js_runtime()?;
+        let mut command = Command::new(js_runtime.executable_path());
         command
             .arg(runtime.render_cli_path())
             .args(request.target.to_args())
             .current_dir(&request.cwd)
             .stdout(Stdio::piped())
             .stderr(Stdio::piped());
+        if js_runtime.requires_electron_run_as_node() {
+            command.env("ELECTRON_RUN_AS_NODE", "1");
+        }
         for (key, value) in &request.env {
             command.env(key, value);
         }

codex-rs/artifacts/src/lib.rs

@@ -15,9 +15,14 @@ pub use runtime::ArtifactRuntimeManagerConfig;
 pub use runtime::ArtifactRuntimePlatform;
 pub use runtime::ArtifactRuntimeReleaseLocator;
 pub use runtime::DEFAULT_CACHE_ROOT_RELATIVE;
+pub use runtime::DEFAULT_RELEASE_BASE_URL;
 pub use runtime::DEFAULT_RELEASE_TAG_PREFIX;
 pub use runtime::ExtractedRuntimeManifest;
 pub use runtime::InstalledArtifactRuntime;
+pub use runtime::JsRuntime;
+pub use runtime::JsRuntimeKind;
 pub use runtime::ReleaseManifest;
 pub use runtime::RuntimeEntrypoints;
 pub use runtime::RuntimePathEntry;
+pub use runtime::is_js_runtime_available;
+pub use runtime::load_cached_runtime;

codex-rs/artifacts/src/runtime.rs

@@ -13,9 +13,82 @@ use std::path::Path;
 use std::path::PathBuf;
 use thiserror::Error;
 use url::Url;
+use which::which;
 
 pub const DEFAULT_RELEASE_TAG_PREFIX: &str = "artifact-runtime-v";
 pub const DEFAULT_CACHE_ROOT_RELATIVE: &str = "packages/artifacts";
+pub const DEFAULT_RELEASE_BASE_URL: &str = "https://github.com/openai/codex/releases/download/";
+const CODEX_APP_PRODUCT_NAMES: [&str; 6] = [
+    "Codex",
+    "Codex (Dev)",
+    "Codex (Agent)",
+    "Codex (Nightly)",
+    "Codex (Alpha)",
+    "Codex (Beta)",
+];
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum JsRuntimeKind {
+    Node,
+    Electron,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct JsRuntime {
+    executable_path: PathBuf,
+    kind: JsRuntimeKind,
+}
+
+impl JsRuntime {
+    fn node(executable_path: PathBuf) -> Self {
+        Self {
+            executable_path,
+            kind: JsRuntimeKind::Node,
+        }
+    }
+
+    fn electron(executable_path: PathBuf) -> Self {
+        Self {
+            executable_path,
+            kind: JsRuntimeKind::Electron,
+        }
+    }
+
+    pub fn executable_path(&self) -> &Path {
+        &self.executable_path
+    }
+
+    pub fn requires_electron_run_as_node(&self) -> bool {
+        self.kind == JsRuntimeKind::Electron
+    }
+}
+
+pub fn is_js_runtime_available(codex_home: &Path, runtime_version: &str) -> bool {
+    load_cached_runtime(codex_home, runtime_version)
+        .ok()
+        .and_then(|runtime| runtime.resolve_js_runtime().ok())
+        .or_else(resolve_machine_js_runtime)
+        .is_some()
+}
+
+pub fn load_cached_runtime(
+    codex_home: &Path,
+    runtime_version: &str,
+) -> Result<InstalledArtifactRuntime, ArtifactRuntimeError> {
+    let platform = ArtifactRuntimePlatform::detect_current()?;
+    let install_dir = cached_runtime_install_dir(codex_home, runtime_version, platform);
+    if !install_dir.exists() {
+        return Err(ArtifactRuntimeError::Io {
+            context: format!(
+                "artifact runtime {runtime_version} is not installed at {}",
+                install_dir.display()
+            ),
+            source: std::io::Error::new(std::io::ErrorKind::NotFound, "missing artifact runtime"),
+        });
+    }
+
+    InstalledArtifactRuntime::load(install_dir, platform)
+}
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct ArtifactRuntimeReleaseLocator {
@@ -56,9 +129,25 @@ impl ArtifactRuntimeReleaseLocator {
 
     pub fn manifest_url(&self) -> Result<Url, PackageManagerError> {
         self.base_url
-            .join(&self.manifest_file_name())
+            .join(&format!(
+                "{}/{}",
+                self.release_tag(),
+                self.manifest_file_name()
+            ))
             .map_err(PackageManagerError::InvalidBaseUrl)
     }
+
+    pub fn default(runtime_version: impl Into<String>) -> Self {
+        Self::new(
+            match Url::parse(DEFAULT_RELEASE_BASE_URL) {
+                Ok(url) => url,
+                Err(error) => {
+                    panic!("hard-coded artifact runtime release base URL must be valid: {error}")
+                }
+            },
+            runtime_version,
+        )
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -76,6 +165,13 @@ impl ArtifactRuntimeManagerConfig {
         }
     }
 
+    pub fn with_default_release(codex_home: PathBuf, runtime_version: impl Into<String>) -> Self {
+        Self::new(
+            codex_home,
+            ArtifactRuntimeReleaseLocator::default(runtime_version),
+        )
+    }
+
     pub fn with_cache_root(mut self, cache_root: PathBuf) -> Self {
         self.package_manager = self.package_manager.with_cache_root(cache_root);
         self
@@ -163,7 +259,11 @@ impl ManagedPackage for ArtifactRuntimePackage {
     fn archive_url(&self, archive: &PackageReleaseArchive) -> Result<Url, PackageManagerError> {
         self.release
             .base_url()
-            .join(&archive.archive)
+            .join(&format!(
+                "{}/{}",
+                self.release.release_tag(),
+                archive.archive
+            ))
             .map_err(PackageManagerError::InvalidBaseUrl)
     }
 
@@ -285,6 +385,8 @@ impl InstalledArtifactRuntime {
             &root_dir,
             &manifest.entrypoints.render_cli.relative_path,
         )?;
+        verify_required_runtime_path(&build_js_path)?;
+        verify_required_runtime_path(&render_cli_path)?;
 
         Ok(Self::new(
             root_dir,
@@ -324,6 +426,18 @@ impl InstalledArtifactRuntime {
     pub fn render_cli_path(&self) -> &Path {
         &self.render_cli_path
     }
+
+    pub fn resolve_js_runtime(&self) -> Result<JsRuntime, ArtifactRuntimeError> {
+        resolve_js_runtime_from_candidates(
+            Some(self.node_path()),
+            system_node_runtime(),
+            system_electron_runtime(),
+            codex_app_runtime_candidates(),
+        )
+        .ok_or_else(|| ArtifactRuntimeError::MissingJsRuntime {
+            root_dir: self.root_dir.clone(),
+        })
+    }
 }
 
 #[derive(Debug, Error)]
@@ -344,6 +458,125 @@ pub enum ArtifactRuntimeError {
     },
     #[error("runtime path `{0}` is invalid")]
     InvalidRuntimePath(String),
+    #[error(
+        "no compatible JavaScript runtime found for artifact runtime at {root_dir}; install Node or the Codex desktop app"
+    )]
+    MissingJsRuntime { root_dir: PathBuf },
+}
+
+fn cached_runtime_install_dir(
+    codex_home: &Path,
+    runtime_version: &str,
+    platform: ArtifactRuntimePlatform,
+) -> PathBuf {
+    codex_home
+        .join(DEFAULT_CACHE_ROOT_RELATIVE)
+        .join(runtime_version)
+        .join(platform.as_str())
+}
+
+fn resolve_machine_js_runtime() -> Option<JsRuntime> {
+    resolve_js_runtime_from_candidates(
+        None,
+        system_node_runtime(),
+        system_electron_runtime(),
+        codex_app_runtime_candidates(),
+    )
+}
+
+fn resolve_js_runtime_from_candidates(
+    preferred_node_path: Option<&Path>,
+    node_runtime: Option<JsRuntime>,
+    electron_runtime: Option<JsRuntime>,
+    codex_app_candidates: Vec<PathBuf>,
+) -> Option<JsRuntime> {
+    preferred_node_path
+        .and_then(node_runtime_from_path)
+        .or(node_runtime)
+        .or(electron_runtime)
+        .or_else(|| {
+            codex_app_candidates
+                .into_iter()
+                .find_map(|candidate| electron_runtime_from_path(&candidate))
+        })
+}
+
+fn system_node_runtime() -> Option<JsRuntime> {
+    which("node")
+        .ok()
+        .and_then(|path| node_runtime_from_path(&path))
+}
+
+fn system_electron_runtime() -> Option<JsRuntime> {
+    which("electron")
+        .ok()
+        .and_then(|path| electron_runtime_from_path(&path))
+}
+
+fn node_runtime_from_path(path: &Path) -> Option<JsRuntime> {
+    path.is_file().then(|| JsRuntime::node(path.to_path_buf()))
+}
+
+fn electron_runtime_from_path(path: &Path) -> Option<JsRuntime> {
+    path.is_file()
+        .then(|| JsRuntime::electron(path.to_path_buf()))
+}
+
+fn codex_app_runtime_candidates() -> Vec<PathBuf> {
+    match std::env::consts::OS {
+        "macos" => {
+            let mut roots = vec![PathBuf::from("/Applications")];
+            if let Some(home) = std::env::var_os("HOME") {
+                roots.push(PathBuf::from(home).join("Applications"));
+            }
+
+            roots
+                .into_iter()
+                .flat_map(|root| {
+                    CODEX_APP_PRODUCT_NAMES
+                        .into_iter()
+                        .map(move |product_name| {
+                            root.join(format!("{product_name}.app"))
+                                .join("Contents")
+                                .join("MacOS")
+                                .join(product_name)
+                        })
+                })
+                .collect()
+        }
+        "windows" => {
+            let mut roots = Vec::new();
+            if let Some(local_app_data) = std::env::var_os("LOCALAPPDATA") {
+                roots.push(PathBuf::from(local_app_data).join("Programs"));
+            }
+            if let Some(program_files) = std::env::var_os("ProgramFiles") {
+                roots.push(PathBuf::from(program_files));
+            }
+            if let Some(program_files_x86) = std::env::var_os("ProgramFiles(x86)") {
+                roots.push(PathBuf::from(program_files_x86));
+            }
+
+            roots
+                .into_iter()
+                .flat_map(|root| {
+                    CODEX_APP_PRODUCT_NAMES
+                        .into_iter()
+                        .map(move |product_name| {
+                            root.join(product_name).join(format!("{product_name}.exe"))
+                        })
+                })
+                .collect()
+        }
+        "linux" => [PathBuf::from("/opt"), PathBuf::from("/usr/lib")]
+            .into_iter()
+            .flat_map(|root| {
+                CODEX_APP_PRODUCT_NAMES
+                    .into_iter()
+                    .map(move |product_name| root.join(product_name).join(product_name))
+            })
+            .collect(),
+        _ => Vec::new(),
+    }
 }
 
 fn resolve_relative_runtime_path(
@@ -369,6 +602,17 @@ fn resolve_relative_runtime_path(
     Ok(root_dir.join(relative))
 }
 
+fn verify_required_runtime_path(path: &Path) -> Result<(), ArtifactRuntimeError> {
+    if path.is_file() {
+        return Ok(());
+    }
+
+    Err(ArtifactRuntimeError::Io {
+        context: format!("required runtime file is missing: {}", path.display()),
+        source: std::io::Error::new(std::io::ErrorKind::NotFound, "missing runtime file"),
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -397,7 +641,20 @@ mod tests {
             .unwrap_or_else(|error| panic!("{error}"));
         assert_eq!(
             url.as_str(),
-            "https://example.test/releases/artifact-runtime-v0.1.0-manifest.json"
+            "https://example.test/releases/artifact-runtime-v0.1.0/artifact-runtime-v0.1.0-manifest.json"
+        );
+    }
+
+    #[test]
+    fn default_release_locator_uses_openai_codex_github_releases() {
+        let locator = ArtifactRuntimeReleaseLocator::default("0.1.0");
+        let url = locator
+            .manifest_url()
+            .unwrap_or_else(|error| panic!("{error}"));
+
+        assert_eq!(
+            url.as_str(),
+            "https://github.com/openai/codex/releases/download/artifact-runtime-v0.1.0/artifact-runtime-v0.1.0-manifest.json"
         );
     }
 
@@ -430,13 +687,15 @@ mod tests {
         };
         Mock::given(method("GET"))
             .and(path(format!(
-                "/artifact-runtime-v{runtime_version}-manifest.json"
+                "/artifact-runtime-v{runtime_version}/artifact-runtime-v{runtime_version}-manifest.json"
             )))
             .respond_with(ResponseTemplate::new(200).set_body_json(&manifest))
             .mount(&server)
             .await;
         Mock::given(method("GET"))
-            .and(path(format!("/{archive_name}")))
+            .and(path(format!(
+                "/artifact-runtime-v{runtime_version}/{archive_name}"
+            )))
             .respond_with(ResponseTemplate::new(200).set_body_bytes(archive_bytes))
             .mount(&server)
             .await;
@@ -467,8 +726,31 @@ mod tests {
         assert!(
             runtime
                 .render_cli_path()
-                .ends_with(Path::new("granola-render/dist/cli.mjs"))
+                .ends_with(Path::new("granola-render/dist/render_cli.mjs"))
         );
+        assert_eq!(
+            runtime.resolve_js_runtime().expect("resolve js runtime"),
+            JsRuntime::node(runtime.node_path().to_path_buf())
+        );
+    }
+
+    #[test]
+    fn resolve_js_runtime_uses_codex_app_electron_candidate() {
+        let temp_dir = TempDir::new().unwrap_or_else(|error| panic!("{error}"));
+        let electron_path = temp_dir.path().join("Codex");
+        let missing_node = temp_dir.path().join("missing-node");
+        std::fs::write(&electron_path, "#!/bin/sh\n").unwrap_or_else(|error| panic!("{error}"));
+
+        let runtime = resolve_js_runtime_from_candidates(
+            Some(missing_node.as_path()),
+            None,
+            None,
+            vec![electron_path.clone()],
+        )
+        .expect("resolve js runtime");
+
+        assert_eq!(runtime, JsRuntime::electron(electron_path));
+        assert!(runtime.requires_electron_run_as_node());
     }
 
     fn build_zip_archive(runtime_version: &str) -> Vec<u8> {
@@ -482,8 +764,11 @@ mod tests {
                 .unwrap_or_else(|error| panic!("{error}"));
             zip.write_all(&manifest)
                 .unwrap_or_else(|error| panic!("{error}"));
-            zip.start_file("artifact-runtime/node/bin/node", options)
-                .unwrap_or_else(|error| panic!("{error}"));
+            zip.start_file(
+                "artifact-runtime/node/bin/node",
+                options.unix_permissions(0o755),
+            )
+            .unwrap_or_else(|error| panic!("{error}"));
             zip.write_all(b"#!/bin/sh\n")
                 .unwrap_or_else(|error| panic!("{error}"));
             zip.start_file(
@@ -493,8 +778,11 @@ mod tests {
             .unwrap_or_else(|error| panic!("{error}"));
             zip.write_all(b"export const ok = true;\n")
                 .unwrap_or_else(|error| panic!("{error}"));
-            zip.start_file("artifact-runtime/granola-render/dist/cli.mjs", options)
-                .unwrap_or_else(|error| panic!("{error}"));
+            zip.start_file(
+                "artifact-runtime/granola-render/dist/render_cli.mjs",
+                options,
+            )
+            .unwrap_or_else(|error| panic!("{error}"));
             zip.write_all(b"export const ok = true;\n")
                 .unwrap_or_else(|error| panic!("{error}"));
             zip.finish().unwrap_or_else(|error| panic!("{error}"));
@@ -514,7 +802,7 @@ mod tests {
                     relative_path: "artifact-tool/dist/artifact_tool.mjs".to_string(),
                 },
                 render_cli: RuntimePathEntry {
-                    relative_path: "granola-render/dist/cli.mjs".to_string(),
+                    relative_path: "granola-render/dist/render_cli.mjs".to_string(),
                 },
             },
         }

codex-rs/core/src/codex.rs

@@ -730,6 +730,7 @@ impl TurnContext {
                 .with_updates(Some(model.clone()), Some(reasoning_effort), None);
         let features = self.features.clone();
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: self.tools_config.web_search_mode,
@@ -1103,6 +1104,7 @@ impl Session {
         let per_turn_config = Arc::new(per_turn_config);
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &per_turn_config.codex_home,
             model_info: &model_info,
             features: &per_turn_config.features,
             web_search_mode: Some(per_turn_config.web_search_mode.value()),
@@ -4710,6 +4712,7 @@ async fn spawn_review_thread(
     let _ = review_features.disable(crate::features::Feature::WebSearchCached);
     let review_web_search_mode = WebSearchMode::Disabled;
     let tools_config = ToolsConfig::new(&ToolsConfigParams {
+        codex_home: &config.codex_home,
         model_info: &review_model_info,
         features: &review_features,
         web_search_mode: Some(review_web_search_mode),

codex-rs/core/src/tools/handlers/artifacts.rs

@@ -1,13 +1,11 @@
 use async_trait::async_trait;
 use codex_artifacts::ArtifactBuildRequest;
 use codex_artifacts::ArtifactCommandOutput;
-use codex_artifacts::ArtifactRuntimeError;
-use codex_artifacts::ArtifactRuntimePlatform;
+use codex_artifacts::ArtifactRuntimeManager;
+use codex_artifacts::ArtifactRuntimeManagerConfig;
 use codex_artifacts::ArtifactsClient;
 use codex_artifacts::ArtifactsError;
-use codex_artifacts::InstalledArtifactRuntime;
 use serde_json::Value as JsonValue;
-use std::path::Path;
 use std::time::Duration;
 use std::time::Instant;
 
@@ -31,7 +29,7 @@ use codex_protocol::models::FunctionCallOutputBody;
 
 const ARTIFACTS_TOOL_NAME: &str = "artifacts";
 const ARTIFACTS_PRAGMA_PREFIXES: [&str; 2] = ["// codex-artifacts:", "// codex-artifact-tool:"];
-const PINNED_ARTIFACT_RUNTIME_VERSION: &str = "2.4.0";
+pub(crate) const PINNED_ARTIFACT_RUNTIME_VERSION: &str = "2.4.0";
 const DEFAULT_EXECUTION_TIMEOUT: Duration = Duration::from_secs(30);
 
 pub struct ArtifactsHandler;
@@ -80,10 +78,9 @@ impl ToolHandler for ArtifactsHandler {
             }
         };
 
-        let runtime = resolve_preinstalled_runtime(&turn.config.codex_home)
-            .await
-            .map_err(artifacts_error)?;
-        let client = ArtifactsClient::from_installed_runtime(runtime);
+        let client = ArtifactsClient::from_runtime_manager(default_runtime_manager(
+            turn.config.codex_home.clone(),
+        ));
 
         let started_at = Instant::now();
         emit_exec_begin(session.as_ref(), turn.as_ref(), &call_id).await;
@@ -122,31 +119,6 @@ impl ToolHandler for ArtifactsHandler {
     }
 }
 
-async fn resolve_preinstalled_runtime(
-    codex_home: &Path,
-) -> Result<InstalledArtifactRuntime, ArtifactsError> {
-    let platform = ArtifactRuntimePlatform::detect_current()
-        .map_err(ArtifactRuntimeError::from)
-        .map_err(ArtifactsError::Runtime)?;
-    let install_dir = codex_home
-        .join("packages")
-        .join("artifacts")
-        .join(PINNED_ARTIFACT_RUNTIME_VERSION)
-        .join(platform.as_str());
-    if !install_dir.exists() {
-        return Err(ArtifactsError::Io {
-            context: format!(
-                "artifact runtime {} is not installed at {}",
-                PINNED_ARTIFACT_RUNTIME_VERSION,
-                install_dir.display()
-            ),
-            source: std::io::Error::new(std::io::ErrorKind::NotFound, "missing artifact runtime"),
-        });
-    }
-
-    InstalledArtifactRuntime::load(install_dir, platform).map_err(ArtifactsError::Runtime)
-}
-
 fn parse_freeform_args(input: &str) -> Result<ArtifactsToolArgs, FunctionCallError> {
     if input.trim().is_empty() {
         return Err(FunctionCallError::RespondToModel(
@@ -240,8 +212,11 @@ fn parse_pragma_prefix(line: &str) -> Option<&str> {
         .find_map(|prefix| line.strip_prefix(prefix))
 }
 
-fn artifacts_error(error: ArtifactsError) -> FunctionCallError {
-    FunctionCallError::RespondToModel(error.to_string())
+fn default_runtime_manager(codex_home: std::path::PathBuf) -> ArtifactRuntimeManager {
+    ArtifactRuntimeManager::new(ArtifactRuntimeManagerConfig::with_default_release(
+        codex_home,
+        PINNED_ARTIFACT_RUNTIME_VERSION,
+    ))
 }
 
 async fn emit_exec_begin(session: &Session, turn: &TurnContext, call_id: &str) {
@@ -357,10 +332,26 @@ mod tests {
         );
     }
 
-    #[tokio::test]
-    async fn resolve_preinstalled_runtime_reads_pinned_cache_path() {
+    #[test]
+    fn default_runtime_manager_uses_openai_codex_release_base() {
         let codex_home = TempDir::new().expect("create temp codex home");
-        let platform = ArtifactRuntimePlatform::detect_current().expect("detect platform");
+        let manager = default_runtime_manager(codex_home.path().to_path_buf());
+
+        assert_eq!(
+            manager.config().release().base_url().as_str(),
+            "https://github.com/openai/codex/releases/download/"
+        );
+        assert_eq!(
+            manager.config().release().runtime_version(),
+            PINNED_ARTIFACT_RUNTIME_VERSION
+        );
+    }
+
+    #[test]
+    fn load_cached_runtime_reads_pinned_cache_path() {
+        let codex_home = TempDir::new().expect("create temp codex home");
+        let platform =
+            codex_artifacts::ArtifactRuntimePlatform::detect_current().expect("detect platform");
         let install_dir = codex_home
             .path()
             .join("packages")
@@ -382,10 +373,26 @@ mod tests {
             .to_string(),
         )
         .expect("write manifest");
+        std::fs::create_dir_all(install_dir.join("artifact-tool/dist"))
+            .expect("create build entrypoint dir");
+        std::fs::create_dir_all(install_dir.join("granola-render/dist"))
+            .expect("create render entrypoint dir");
+        std::fs::write(
+            install_dir.join("artifact-tool/dist/artifact_tool.mjs"),
+            "export const ok = true;\n",
+        )
+        .expect("write build entrypoint");
+        std::fs::write(
+            install_dir.join("granola-render/dist/render_cli.mjs"),
+            "export const ok = true;\n",
+        )
+        .expect("write render entrypoint");
 
-        let runtime = resolve_preinstalled_runtime(codex_home.path())
-            .await
-            .expect("resolve runtime");
+        let runtime = codex_artifacts::load_cached_runtime(
+            codex_home.path(),
+            PINNED_ARTIFACT_RUNTIME_VERSION,
+        )
+        .expect("resolve runtime");
         assert_eq!(runtime.runtime_version(), PINNED_ARTIFACT_RUNTIME_VERSION);
         assert_eq!(
             runtime.manifest().entrypoints,

codex-rs/core/src/tools/handlers/mod.rs

@@ -29,6 +29,7 @@ use crate::sandboxing::SandboxPermissions;
 use crate::sandboxing::normalize_additional_permissions;
 pub use apply_patch::ApplyPatchHandler;
 pub use artifacts::ArtifactsHandler;
+pub(crate) use artifacts::PINNED_ARTIFACT_RUNTIME_VERSION;
 use codex_protocol::models::PermissionProfile;
 use codex_protocol::protocol::AskForApproval;
 pub use dynamic::DynamicToolHandler;

codex-rs/core/src/tools/spec.rs

@@ -7,6 +7,7 @@ use crate::features::Feature;
 use crate::features::Features;
 use crate::mcp_connection_manager::ToolInfo;
 use crate::models_manager::collaboration_mode_presets::CollaborationModesConfig;
+use crate::tools::handlers::PINNED_ARTIFACT_RUNTIME_VERSION;
 use crate::tools::handlers::PLAN_TOOL;
 use crate::tools::handlers::SEARCH_TOOL_BM25_DEFAULT_LIMIT;
 use crate::tools::handlers::SEARCH_TOOL_BM25_TOOL_NAME;
@@ -34,6 +35,7 @@ use serde_json::Value as JsonValue;
 use serde_json::json;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
+use std::path::Path;
 
 const SEARCH_TOOL_BM25_DESCRIPTION_TEMPLATE: &str =
     include_str!("../../templates/search_tool/tool_description.md");
@@ -75,6 +77,7 @@ pub(crate) struct ToolsConfig {
 }
 
 pub(crate) struct ToolsConfigParams<'a> {
+    pub(crate) codex_home: &'a Path,
     pub(crate) model_info: &'a ModelInfo,
     pub(crate) features: &'a Features,
     pub(crate) web_search_mode: Option<WebSearchMode>,
@@ -84,6 +87,7 @@ pub(crate) struct ToolsConfigParams<'a> {
 impl ToolsConfig {
     pub fn new(params: &ToolsConfigParams) -> Self {
         let ToolsConfigParams {
+            codex_home,
             model_info,
             features,
             web_search_mode,
@@ -98,7 +102,11 @@ impl ToolsConfig {
         let include_default_mode_request_user_input =
             include_request_user_input && features.enabled(Feature::DefaultModeRequestUserInput);
         let include_search_tool = features.enabled(Feature::Apps);
-        let include_artifact_tools = features.enabled(Feature::Artifact);
+        let include_artifact_tools = features.enabled(Feature::Artifact)
+            && codex_artifacts::is_js_runtime_available(
+                codex_home,
+                PINNED_ARTIFACT_RUNTIME_VERSION,
+            );
         let include_image_gen_tool =
             features.enabled(Feature::ImageGeneration) && supports_image_generation(model_info);
         let include_agent_jobs = include_collab_tools && features.enabled(Feature::Sqlite);
@@ -1405,7 +1413,7 @@ JS_SOURCE: /(?:\s*)(?:[^\s{\"`]|`[^`]|``[^`])[\s\S]*/
 
     ToolSpec::Freeform(FreeformTool {
         name: "artifacts".to_string(),
-        description: "Runs raw JavaScript against the preinstalled Codex @oai/artifact-tool runtime for creating presentations or spreadsheets. This is plain JavaScript executed by Node with top-level await, not TypeScript: do not use type annotations, `interface`, `type`, or `import type`. Author code the same way you would for `import { Presentation, Workbook, PresentationFile, SpreadsheetFile, FileBlob, ... } from \"@oai/artifact-tool\"`, but omit that import line because the package surface is already preloaded. Named exports are available directly on `globalThis`, and the full module is available as `globalThis.artifactTool` (also aliased as `globalThis.artifacts` and `globalThis.codexArtifacts`). Node built-ins such as `node:fs/promises` may still be imported when needed for saving preview bytes. This is a freeform tool: send raw JavaScript source text, optionally with a first-line pragma like `// codex-artifacts: timeout_ms=15000` or `// codex-artifact-tool: timeout_ms=15000`; do not send JSON/quotes/markdown fences."
+        description: "Runs raw JavaScript against the preinstalled Codex @oai/artifact-tool runtime for creating presentations or spreadsheets. This is plain JavaScript executed by a local Node-compatible runtime with top-level await, not TypeScript: do not use type annotations, `interface`, `type`, or `import type`. Author code the same way you would for `import { Presentation, Workbook, PresentationFile, SpreadsheetFile, FileBlob, ... } from \"@oai/artifact-tool\"`, but omit that import line because the package surface is already preloaded. Named exports are available directly on `globalThis`, and the full module is available as `globalThis.artifactTool` (also aliased as `globalThis.artifacts` and `globalThis.codexArtifacts`). Node built-ins such as `node:fs/promises` may still be imported when needed for saving preview bytes. This is a freeform tool: send raw JavaScript source text, optionally with a first-line pragma like `// codex-artifacts: timeout_ms=15000` or `// codex-artifact-tool: timeout_ms=15000`; do not send JSON/quotes/markdown fences."
             .to_string(),
         format: FreeformToolFormat {
             r#type: "grammar".to_string(),
@@ -2166,6 +2174,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: Path::new("."),
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Live),
@@ -2229,6 +2238,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::Collab);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2249,12 +2259,53 @@ mod tests {
 
     #[test]
     fn test_build_specs_artifact_tool_enabled() {
-        let config = test_config();
+        let mut config = test_config();
+        let runtime_root = tempfile::TempDir::new().expect("create temp codex home");
+        let platform = codex_artifacts::ArtifactRuntimePlatform::detect_current()
+            .expect("detect artifact platform");
+        let install_dir = runtime_root
+            .path()
+            .join("packages")
+            .join("artifacts")
+            .join(PINNED_ARTIFACT_RUNTIME_VERSION)
+            .join(platform.as_str());
+        std::fs::create_dir_all(install_dir.join("node/bin")).expect("create runtime dir");
+        std::fs::create_dir_all(install_dir.join("artifact-tool/dist"))
+            .expect("create build entrypoint dir");
+        std::fs::create_dir_all(install_dir.join("granola-render/dist"))
+            .expect("create render entrypoint dir");
+        std::fs::write(
+            install_dir.join("manifest.json"),
+            serde_json::json!({
+                "schema_version": 1,
+                "runtime_version": PINNED_ARTIFACT_RUNTIME_VERSION,
+                "node": { "relative_path": "node/bin/node" },
+                "entrypoints": {
+                    "build_js": { "relative_path": "artifact-tool/dist/artifact_tool.mjs" },
+                    "render_cli": { "relative_path": "granola-render/dist/render_cli.mjs" }
+                }
+            })
+            .to_string(),
+        )
+        .expect("write manifest");
+        std::fs::write(install_dir.join("node/bin/node"), "#!/bin/sh\n").expect("write node");
+        std::fs::write(
+            install_dir.join("artifact-tool/dist/artifact_tool.mjs"),
+            "export const ok = true;\n",
+        )
+        .expect("write build entrypoint");
+        std::fs::write(
+            install_dir.join("granola-render/dist/render_cli.mjs"),
+            "export const ok = true;\n",
+        )
+        .expect("write render entrypoint");
+        config.codex_home = runtime_root.path().to_path_buf();
         let model_info =
             ModelsManager::construct_model_info_offline_for_tests("gpt-5-codex", &config);
         let mut features = Features::with_defaults();
         features.enable(Feature::Artifact);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2273,6 +2324,7 @@ mod tests {
         features.enable(Feature::Collab);
         features.enable(Feature::Sqlite);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2303,6 +2355,7 @@ mod tests {
             ModelsManager::construct_model_info_offline_for_tests("gpt-5-codex", &config);
         let mut features = Features::with_defaults();
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2317,6 +2370,7 @@ mod tests {
 
         features.enable(Feature::DefaultModeRequestUserInput);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2340,6 +2394,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.disable(Feature::MemoryTool);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2360,6 +2415,7 @@ mod tests {
         let features = Features::with_defaults();
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2386,6 +2442,7 @@ mod tests {
         features.enable(Feature::JsRepl);
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2408,6 +2465,7 @@ mod tests {
         image_generation_features.enable(Feature::ImageGeneration);
 
         let default_tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &supported_model_info,
             features: &default_features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2422,6 +2480,7 @@ mod tests {
         );
 
         let supported_tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &supported_model_info,
             features: &image_generation_features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2431,6 +2490,7 @@ mod tests {
         assert_contains_tool_names(&supported_tools, &["image_generation"]);
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &unsupported_model_info,
             features: &image_generation_features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2466,8 +2526,10 @@ mod tests {
         web_search_mode: Option<WebSearchMode>,
         expected_tools: &[&str],
     ) {
+        let config = test_config();
         let model_info = model_info_from_models_json(model_slug);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features,
             web_search_mode,
@@ -2502,6 +2564,7 @@ mod tests {
         let features = Features::with_defaults();
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2527,6 +2590,7 @@ mod tests {
         let features = Features::with_defaults();
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Live),
@@ -2553,6 +2617,7 @@ mod tests {
         let features = Features::with_defaults();
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Live),
@@ -2582,6 +2647,7 @@ mod tests {
             ModelsManager::construct_model_info_offline_for_tests("gpt-5-codex", &config);
         let features = Features::with_defaults();
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2605,6 +2671,7 @@ mod tests {
             ModelsManager::construct_model_info_offline_for_tests("gpt-5-codex", &config);
         let features = Features::with_defaults();
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2796,6 +2863,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Live),
@@ -2820,6 +2888,7 @@ mod tests {
         features.enable(Feature::ShellZshFork);
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Live),
@@ -2846,6 +2915,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2862,6 +2932,7 @@ mod tests {
 
     #[test]
     fn test_test_model_info_includes_sync_tool() {
+        let config = test_config();
         let mut model_info = model_info_from_models_json("gpt-5-codex");
         model_info.experimental_supported_tools = vec![
             "test_sync_tool".to_string(),
@@ -2871,6 +2942,7 @@ mod tests {
         ];
         let features = Features::with_defaults();
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -2903,6 +2975,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Live),
@@ -2990,6 +3063,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -3036,6 +3110,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::Apps);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -3104,6 +3179,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -3159,6 +3235,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -3211,6 +3288,7 @@ mod tests {
         features.enable(Feature::UnifiedExec);
         features.enable(Feature::ApplyPatchFreeform);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -3265,6 +3343,7 @@ mod tests {
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),
@@ -3398,6 +3477,7 @@ Examples of valid command strings:
         let mut features = Features::with_defaults();
         features.enable(Feature::UnifiedExec);
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            codex_home: &config.codex_home,
             model_info: &model_info,
             features: &features,
             web_search_mode: Some(WebSearchMode::Cached),

codex-rs/package-manager/Cargo.toml

@@ -5,6 +5,7 @@ edition.workspace = true
 license.workspace = true
 
 [dependencies]
+fd-lock = { workspace = true }
 flate2 = { workspace = true }
 reqwest = { workspace = true, features = ["json", "stream"] }
 serde = { workspace = true, features = ["derive"] }
@@ -12,7 +13,7 @@ sha2 = { workspace = true }
 tar = { workspace = true }
 tempfile = { workspace = true }
 thiserror = { workspace = true }
-tokio = { workspace = true, features = ["fs", "rt", "sync"] }
+tokio = { workspace = true, features = ["fs", "rt", "sync", "time"] }
 url = { workspace = true }
 zip = { workspace = true }
 

codex-rs/package-manager/src/lib.rs

@@ -1,19 +1,27 @@
+use fd_lock::RwLock as FileRwLock;
 use flate2::read::GzDecoder;
 use reqwest::Client;
 use serde::de::DeserializeOwned;
 use sha2::Digest;
 use sha2::Sha256;
 use std::fs::File;
+use std::fs::OpenOptions;
+#[cfg(unix)]
+use std::os::unix::fs::PermissionsExt;
 use std::path::Component;
 use std::path::Path;
 use std::path::PathBuf;
+use std::time::Duration;
 use tar::Archive;
 use tempfile::tempdir_in;
 use thiserror::Error;
 use tokio::fs;
+use tokio::time::sleep;
 use url::Url;
 use zip::ZipArchive;
 
+const INSTALL_LOCK_POLL_INTERVAL: Duration = Duration::from_millis(50);
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct PackageManagerConfig<P> {
     codex_home: PathBuf,
@@ -86,6 +94,14 @@ impl<P: ManagedPackage> PackageManager<P> {
             .config
             .package()
             .install_dir(&self.config.cache_root(), platform);
+        self.resolve_cached_at(platform, install_dir).await
+    }
+
+    async fn resolve_cached_at(
+        &self,
+        platform: PackagePlatform,
+        install_dir: PathBuf,
+    ) -> Result<Option<P::Installed>, P::Error> {
         if !fs::try_exists(&install_dir)
             .await
             .map_err(|source| PackageManagerError::Io {
@@ -97,10 +113,10 @@ impl<P: ManagedPackage> PackageManager<P> {
             return Ok(None);
         }
 
-        let package = self
-            .config
-            .package()
-            .load_installed(install_dir, platform)?;
+        let package = match self.config.package().load_installed(install_dir, platform) {
+            Ok(package) => package,
+            Err(_) => return Ok(None),
+        };
         if self.config.package().installed_version(&package) != self.config.package().version() {
             return Ok(None);
         }
@@ -113,6 +129,61 @@ impl<P: ManagedPackage> PackageManager<P> {
         }
 
         let platform = PackagePlatform::detect_current().map_err(P::Error::from)?;
+        let cache_root = self.config.cache_root();
+        let install_dir = self.config.package().install_dir(&cache_root, platform);
+        if let Some(package) = self
+            .resolve_cached_at(platform, install_dir.clone())
+            .await?
+        {
+            return Ok(package);
+        }
+
+        if let Some(parent) = install_dir.parent() {
+            fs::create_dir_all(parent)
+                .await
+                .map_err(|source| PackageManagerError::Io {
+                    context: format!("failed to create {}", parent.display()),
+                    source,
+                })
+                .map_err(P::Error::from)?;
+        }
+
+        let lock_path = install_dir.with_extension("lock");
+        let lock_file = OpenOptions::new()
+            .create(true)
+            .read(true)
+            .write(true)
+            .truncate(false)
+            .open(&lock_path)
+            .map_err(|source| PackageManagerError::Io {
+                context: format!("failed to open {}", lock_path.display()),
+                source,
+            })
+            .map_err(P::Error::from)?;
+        let mut install_lock = FileRwLock::new(lock_file);
+        let _install_guard = loop {
+            match install_lock.try_write() {
+                Ok(guard) => break guard,
+                Err(source) if source.kind() == std::io::ErrorKind::WouldBlock => {
+                    sleep(INSTALL_LOCK_POLL_INTERVAL).await;
+                }
+                Err(source) => {
+                    return Err(PackageManagerError::Io {
+                        context: format!("failed to lock {}", lock_path.display()),
+                        source,
+                    }
+                    .into());
+                }
+            }
+        };
+
+        if let Some(package) = self
+            .resolve_cached_at(platform, install_dir.clone())
+            .await?
+        {
+            return Ok(package);
+        }
+
         let manifest = self.fetch_release_manifest().await?;
         if self.config.package().release_version(&manifest) != self.config.package().version() {
             return Err(PackageManagerError::UnexpectedPackageVersion {
@@ -122,6 +193,22 @@ impl<P: ManagedPackage> PackageManager<P> {
             .into());
         }
 
+        fs::create_dir_all(&cache_root)
+            .await
+            .map_err(|source| PackageManagerError::Io {
+                context: format!("failed to create {}", cache_root.display()),
+                source,
+            })
+            .map_err(P::Error::from)?;
+        let staging_root = cache_root.join(".staging");
+        fs::create_dir_all(&staging_root)
+            .await
+            .map_err(|source| PackageManagerError::Io {
+                context: format!("failed to create {}", staging_root.display()),
+                source,
+            })
+            .map_err(P::Error::from)?;
+
         let platform_archive = self
             .config
             .package()
@@ -134,41 +221,11 @@ impl<P: ManagedPackage> PackageManager<P> {
         let archive_bytes = self.download_bytes(&archive_url).await?;
         verify_sha256(&archive_bytes, &platform_archive.sha256).map_err(P::Error::from)?;
 
-        let install_dir = self
-            .config
-            .package()
-            .install_dir(&self.config.cache_root(), platform);
-        if fs::try_exists(&install_dir)
-            .await
-            .map_err(|source| PackageManagerError::Io {
-                context: format!("failed to read {}", install_dir.display()),
-                source,
-            })
-            .map_err(P::Error::from)?
-        {
-            fs::remove_dir_all(&install_dir)
-                .await
-                .map_err(|source| PackageManagerError::Io {
-                    context: format!("failed to remove {}", install_dir.display()),
-                    source,
-                })
-                .map_err(P::Error::from)?;
-        }
-
-        let cache_root = self.config.cache_root();
-        fs::create_dir_all(&cache_root)
-            .await
-            .map_err(|source| PackageManagerError::Io {
-                context: format!("failed to create {}", cache_root.display()),
-                source,
-            })
-            .map_err(P::Error::from)?;
-
-        let staging_dir = tempdir_in(&cache_root)
+        let staging_dir = tempdir_in(&staging_root)
             .map_err(|source| PackageManagerError::Io {
                 context: format!(
                     "failed to create staging directory in {}",
-                    cache_root.display()
+                    staging_root.display()
                 ),
                 source,
             })
@@ -222,17 +279,91 @@ impl<P: ManagedPackage> PackageManager<P> {
                 .map_err(P::Error::from)?;
         }
 
-        fs::rename(&extracted_root, &install_dir)
+        let mut replaced_install_dir = None;
+        if fs::try_exists(&install_dir)
             .await
             .map_err(|source| PackageManagerError::Io {
-                context: format!(
-                    "failed to move {} to {}",
-                    extracted_root.display(),
-                    install_dir.display()
-                ),
+                context: format!("failed to read {}", install_dir.display()),
                 source,
             })
-            .map_err(P::Error::from)?;
+            .map_err(P::Error::from)?
+        {
+            let install_name = install_dir.file_name().ok_or_else(|| {
+                PackageManagerError::ArchiveExtraction(format!(
+                    "install path `{}` has no terminal component",
+                    install_dir.display()
+                ))
+            })?;
+            let install_name = install_name.to_string_lossy();
+            let mut suffix = 0u32;
+            loop {
+                let quarantined_path = install_dir.with_file_name(format!(
+                    ".{install_name}.replaced-{}-{suffix}",
+                    std::process::id()
+                ));
+                match fs::rename(&install_dir, &quarantined_path).await {
+                    Ok(()) => {
+                        replaced_install_dir = Some(quarantined_path);
+                        break;
+                    }
+                    Err(source) if source.kind() == std::io::ErrorKind::AlreadyExists => {
+                        suffix += 1;
+                    }
+                    Err(source) => {
+                        return Err(PackageManagerError::Io {
+                            context: format!(
+                                "failed to quarantine {} to {}",
+                                install_dir.display(),
+                                quarantined_path.display()
+                            ),
+                            source,
+                        }
+                        .into());
+                    }
+                }
+            }
+        }
+
+        match fs::rename(&extracted_root, &install_dir).await {
+            Ok(()) => {}
+            Err(source)
+                if matches!(
+                    source.kind(),
+                    std::io::ErrorKind::AlreadyExists | std::io::ErrorKind::DirectoryNotEmpty
+                ) =>
+            {
+                if let Some(package) = self
+                    .resolve_cached_at(platform, install_dir.clone())
+                    .await?
+                {
+                    return Ok(package);
+                }
+                return Err(PackageManagerError::Io {
+                    context: format!(
+                        "failed to move {} to {}",
+                        extracted_root.display(),
+                        install_dir.display()
+                    ),
+                    source,
+                }
+                .into());
+            }
+            Err(source) => {
+                return Err(PackageManagerError::Io {
+                    context: format!(
+                        "failed to move {} to {}",
+                        extracted_root.display(),
+                        install_dir.display()
+                    ),
+                    source,
+                }
+                .into());
+            }
+        }
+
+        if let Some(replaced_install_dir) = replaced_install_dir {
+            let _ = fs::remove_dir_all(replaced_install_dir).await;
+        }
 
         self.config.package().load_installed(install_dir, platform)
     }
@@ -505,10 +636,35 @@ fn extract_zip_archive(archive_path: &Path, destination: &Path) -> Result<(), Pa
             context: format!("failed to write {}", output_path.display()),
             source,
         })?;
+        apply_zip_permissions(&entry, &output_path)?;
     }
     Ok(())
 }
 
+#[cfg(unix)]
+fn apply_zip_permissions(
+    entry: &zip::read::ZipFile<'_>,
+    output_path: &Path,
+) -> Result<(), PackageManagerError> {
+    let Some(mode) = entry.unix_mode() else {
+        return Ok(());
+    };
+    std::fs::set_permissions(output_path, std::fs::Permissions::from_mode(mode)).map_err(|source| {
+        PackageManagerError::Io {
+            context: format!("failed to set permissions on {}", output_path.display()),
+            source,
+        }
+    })
+}
+
+#[cfg(not(unix))]
+fn apply_zip_permissions(
+    _entry: &zip::read::ZipFile<'_>,
+    _output_path: &Path,
+) -> Result<(), PackageManagerError> {
+    Ok(())
+}
+
 fn extract_tar_gz_archive(
     archive_path: &Path,
     destination: &Path,
@@ -573,7 +729,9 @@ mod tests {
     use std::collections::BTreeMap;
     use std::io::Cursor;
     use std::io::Write;
+    use std::sync::Arc;
     use tempfile::TempDir;
+    use tokio::sync::Barrier;
     use wiremock::Mock;
     use wiremock::MockServer;
     use wiremock::ResponseTemplate;
@@ -732,6 +890,138 @@ mod tests {
                     .join(platform.as_str()),
             }
         );
+
+        #[cfg(unix)]
+        {
+            let executable_mode = std::fs::metadata(installed.root_dir.join("bin/tool"))
+                .unwrap_or_else(|error| panic!("{error}"))
+                .permissions()
+                .mode();
+            assert_eq!(executable_mode & 0o111, 0o111);
+        }
+    }
+
+    #[tokio::test]
+    async fn ensure_installed_replaces_invalid_cached_install() {
+        let server = MockServer::start().await;
+        let version = "0.1.0";
+        let platform = PackagePlatform::detect_current().unwrap_or_else(|error| panic!("{error}"));
+        let archive_name = format!("test-package-v{version}-{}.zip", platform.as_str());
+        let archive_bytes = build_zip_archive(version);
+        let archive_sha = format!("{:x}", Sha256::digest(&archive_bytes));
+        let manifest = serde_json::json!({
+            "package_version": version,
+            "platforms": {
+                platform.as_str(): {
+                    "archive": archive_name,
+                    "sha256": archive_sha,
+                    "format": "zip",
+                    "size_bytes": archive_bytes.len(),
+                }
+            }
+        });
+        Mock::given(method("GET"))
+            .and(path(format!("/test-package-v{version}-manifest.json")))
+            .respond_with(ResponseTemplate::new(200).set_body_json(&manifest))
+            .mount(&server)
+            .await;
+        Mock::given(method("GET"))
+            .and(path(format!("/{archive_name}")))
+            .respond_with(ResponseTemplate::new(200).set_body_bytes(archive_bytes))
+            .mount(&server)
+            .await;
+
+        let codex_home = TempDir::new().unwrap_or_else(|error| panic!("{error}"));
+        let install_dir = codex_home
+            .path()
+            .join("packages")
+            .join("test-package")
+            .join(version)
+            .join(platform.as_str());
+        std::fs::create_dir_all(&install_dir).unwrap_or_else(|error| panic!("{error}"));
+        std::fs::write(install_dir.join("broken.txt"), "stale")
+            .unwrap_or_else(|error| panic!("{error}"));
+
+        let manager = PackageManager::new(PackageManagerConfig::new(
+            codex_home.path().to_path_buf(),
+            TestPackage {
+                base_url: Url::parse(&format!("{}/", server.uri()))
+                    .unwrap_or_else(|error| panic!("{error}")),
+                version: version.to_string(),
+            },
+        ));
+
+        let installed = manager
+            .ensure_installed()
+            .await
+            .unwrap_or_else(|error| panic!("{error}"));
+
+        assert_eq!(installed.version, version);
+        assert!(installed.root_dir.join("manifest.json").exists());
+        assert!(!installed.root_dir.join("broken.txt").exists());
+    }
+
+    #[tokio::test]
+    async fn ensure_installed_serializes_concurrent_installs() {
+        let server = MockServer::start().await;
+        let version = "0.1.0";
+        let platform = PackagePlatform::detect_current().unwrap_or_else(|error| panic!("{error}"));
+        let archive_name = format!("test-package-v{version}-{}.zip", platform.as_str());
+        let archive_bytes = build_zip_archive(version);
+        let archive_sha = format!("{:x}", Sha256::digest(&archive_bytes));
+        let manifest = serde_json::json!({
+            "package_version": version,
+            "platforms": {
+                platform.as_str(): {
+                    "archive": archive_name,
+                    "sha256": archive_sha,
+                    "format": "zip",
+                    "size_bytes": archive_bytes.len(),
+                }
+            }
+        });
+        Mock::given(method("GET"))
+            .and(path(format!("/test-package-v{version}-manifest.json")))
+            .respond_with(ResponseTemplate::new(200).set_body_json(&manifest))
+            .expect(1)
+            .mount(&server)
+            .await;
+        Mock::given(method("GET"))
+            .and(path(format!("/{archive_name}")))
+            .respond_with(ResponseTemplate::new(200).set_body_bytes(archive_bytes))
+            .expect(1)
+            .mount(&server)
+            .await;
+
+        let codex_home = TempDir::new().unwrap_or_else(|error| panic!("{error}"));
+        let config = PackageManagerConfig::new(
+            codex_home.path().to_path_buf(),
+            TestPackage {
+                base_url: Url::parse(&format!("{}/", server.uri()))
+                    .unwrap_or_else(|error| panic!("{error}")),
+                version: version.to_string(),
+            },
+        );
+        let manager_one = PackageManager::new(config.clone());
+        let manager_two = PackageManager::new(config);
+        let barrier = Arc::new(Barrier::new(2));
+        let barrier_one = Arc::clone(&barrier);
+        let barrier_two = Arc::clone(&barrier);
+
+        let (first, second) = tokio::join!(
+            async {
+                barrier_one.wait().await;
+                manager_one.ensure_installed().await
+            },
+            async {
+                barrier_two.wait().await;
+                manager_two.ensure_installed().await
+            }
+        );
+
+        let first = first.unwrap_or_else(|error| panic!("{error}"));
+        let second = second.unwrap_or_else(|error| panic!("{error}"));
+        assert_eq!(first, second);
     }
 
     #[test]
@@ -759,6 +1049,10 @@ mod tests {
                 .unwrap_or_else(|error| panic!("{error}"));
             zip.write_all(version.as_bytes())
                 .unwrap_or_else(|error| panic!("{error}"));
+            zip.start_file("test-package/bin/tool", options.unix_permissions(0o755))
+                .unwrap_or_else(|error| panic!("{error}"));
+            zip.write_all(b"#!/bin/sh\n")
+                .unwrap_or_else(|error| panic!("{error}"));
             zip.finish().unwrap_or_else(|error| panic!("{error}"));
         }
         bytes.into_inner()