Author: Danny Milosavljevic <dannym@friendly-machines.com>
Date: 2026-04-13
License: ASL2.0

Make V8 an optional dependency in codex-code-mode.

The V8 engine is only needed for actually executing JavaScript in the
code-mode sandbox.  The description helpers, tool name constants, and
data types do not require V8.  Gate the runtime and service modules
behind a "v8-runtime" feature so that consumers like codex-acp that
never use code-mode can avoid the V8 build dependency.

--- a/codex-rs/code-mode/Cargo.toml	2026-04-13 16:14:49.459504037 +0000
+++ codex-rs/code-mode/Cargo.toml	2026-04-13 16:14:49.466438318 +0000
@@ -12,6 +12,10 @@
 [lints]
 workspace = true

+[features]
+default = ["v8-runtime"]
+v8-runtime = ["dep:v8"]
+
 [dependencies]
 async-trait = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
@@ -19,7 +23,7 @@
 tokio = { workspace = true, features = ["macros", "rt", "sync", "time"] }
 tokio-util = { workspace = true, features = ["rt"] }
 tracing = { workspace = true }
-v8 = { workspace = true }
+v8 = { workspace = true, optional = true }

 [dev-dependencies]
 pretty_assertions = { workspace = true }
--- a/codex-rs/code-mode/src/lib.rs	2026-04-13 16:14:49.461337956 +0000
+++ codex-rs/code-mode/src/lib.rs	2026-04-13 16:14:49.470869556 +0000
@@ -1,6 +1,8 @@
 mod description;
 mod response;
+#[cfg(feature = "v8-runtime")]
 mod runtime;
+#[cfg(feature = "v8-runtime")]
 mod service;

 pub use description::CODE_MODE_PRAGMA_PREFIX;
@@ -16,15 +18,82 @@
 pub use description::render_json_schema_to_typescript;
 pub use response::FunctionCallOutputContentItem;
 pub use response::ImageDetail;
+
+#[cfg(feature = "v8-runtime")]
 pub use runtime::DEFAULT_EXEC_YIELD_TIME_MS;
+#[cfg(feature = "v8-runtime")]
 pub use runtime::DEFAULT_MAX_OUTPUT_TOKENS_PER_EXEC_CALL;
+#[cfg(feature = "v8-runtime")]
 pub use runtime::DEFAULT_WAIT_YIELD_TIME_MS;
+#[cfg(feature = "v8-runtime")]
 pub use runtime::ExecuteRequest;
+#[cfg(feature = "v8-runtime")]
 pub use runtime::RuntimeResponse;
+#[cfg(feature = "v8-runtime")]
 pub use runtime::WaitRequest;
+#[cfg(feature = "v8-runtime")]
 pub use service::CodeModeService;
+#[cfg(feature = "v8-runtime")]
 pub use service::CodeModeTurnHost;
+#[cfg(feature = "v8-runtime")]
 pub use service::CodeModeTurnWorker;

+// Stub types when V8 is not available.
+#[cfg(not(feature = "v8-runtime"))]
+pub const DEFAULT_EXEC_YIELD_TIME_MS: u64 = 10_000;
+#[cfg(not(feature = "v8-runtime"))]
+pub const DEFAULT_MAX_OUTPUT_TOKENS_PER_EXEC_CALL: usize = 10_000;
+#[cfg(not(feature = "v8-runtime"))]
+pub const DEFAULT_WAIT_YIELD_TIME_MS: u64 = 10_000;
+
+#[cfg(not(feature = "v8-runtime"))]
+pub struct ExecuteRequest {
+    pub tool_call_id: String,
+    pub enabled_tools: Vec<ToolDefinition>,
+    pub source: String,
+    pub stored_values: std::collections::HashMap<String, serde_json::Value>,
+    pub yield_time_ms: Option<u64>,
+    pub max_output_tokens: Option<usize>,
+}
+
+#[cfg(not(feature = "v8-runtime"))]
+#[derive(Clone, Debug)]
+pub struct WaitRequest {
+    pub cell_id: String,
+    pub yield_time_ms: u64,
+    pub terminate: bool,
+}
+
+#[cfg(not(feature = "v8-runtime"))]
+#[derive(Debug, PartialEq)]
+pub enum RuntimeResponse {
+    Yielded { cell_id: String, content_items: Vec<FunctionCallOutputContentItem> },
+    Terminated { cell_id: String, content_items: Vec<FunctionCallOutputContentItem> },
+    Result { cell_id: String, content_items: Vec<FunctionCallOutputContentItem>, stored_values: std::collections::HashMap<String, serde_json::Value>, error_text: Option<String> },
+}
+
+#[cfg(not(feature = "v8-runtime"))]
+#[async_trait::async_trait]
+pub trait CodeModeTurnHost: Send + Sync {
+    async fn invoke_tool(&self, tool_name: String, input: Option<serde_json::Value>, cancellation_token: tokio_util::sync::CancellationToken) -> Result<serde_json::Value, String>;
+    async fn notify(&self, call_id: String, cell_id: String, text: String) -> Result<(), String>;
+}
+
+#[cfg(not(feature = "v8-runtime"))]
+pub struct CodeModeService;
+
+#[cfg(not(feature = "v8-runtime"))]
+impl CodeModeService {
+    pub fn new() -> Self { Self }
+    pub async fn stored_values(&self) -> std::collections::HashMap<String, serde_json::Value> { Default::default() }
+    pub async fn replace_stored_values(&self, _values: std::collections::HashMap<String, serde_json::Value>) {}
+    pub async fn execute(&self, _request: ExecuteRequest) -> Result<RuntimeResponse, String> { Err("code-mode requires v8-runtime feature".into()) }
+    pub async fn wait(&self, _request: WaitRequest) -> Result<RuntimeResponse, String> { Err("code-mode requires v8-runtime feature".into()) }
+    pub fn start_turn_worker(&self, _host: std::sync::Arc<dyn CodeModeTurnHost>) -> CodeModeTurnWorker { CodeModeTurnWorker }
+}
+
+#[cfg(not(feature = "v8-runtime"))]
+pub struct CodeModeTurnWorker;
+
 pub const PUBLIC_TOOL_NAME: &str = "exec";
 pub const WAIT_TOOL_NAME: &str = "wait";