diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index 4d97a2c316..34898774be 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -41,6 +41,7 @@ use crate::models::ContentItem;
 use crate::models::FunctionCallOutputPayload;
 use crate::models::ResponseInputItem;
 use crate::models::ResponseItem;
+use crate::models::ShellToolCallParams;
 use crate::protocol::AskForApproval;
 use crate::protocol::Event;
 use crate::protocol::EventMsg;
diff --git a/codex-rs/core/src/linux.rs b/codex-rs/core/src/linux.rs
index 8fa07d549d..4f3ca34da5 100644
--- a/codex-rs/core/src/linux.rs
+++ b/codex-rs/core/src/linux.rs
@@ -195,7 +195,7 @@ mod tests_linux {
     async fn run_cmd(cmd: &[&str], writable_roots: &[PathBuf], timeout_ms: u64) {
         let params = ExecParams {
             command: cmd.iter().map(|elm| elm.to_string()).collect(),
-            workdir: None,
+            cwd: None,
             timeout_ms: Some(timeout_ms),
         };
 
@@ -268,7 +268,7 @@ mod tests_linux {
     async fn assert_network_blocked(cmd: &[&str]) {
         let params = ExecParams {
             command: cmd.iter().map(|s| s.to_string()).collect(),
-            workdir: None,
+            cwd: None,
             // Give the tool a generous 2‑second timeout so even slow DNS timeouts
             // do not stall the suite.
             timeout_ms: Some(2_000),
diff --git a/codex-rs/core/src/models.rs b/codex-rs/core/src/models.rs
index 2665e8c17b..b1a131da8c 100644
--- a/codex-rs/core/src/models.rs
+++ b/codex-rs/core/src/models.rs
@@ -102,6 +102,20 @@ impl From<Vec<InputItem>> for ResponseInputItem {
     }
 }
 
+/// If the `name` of a `ResponseItem::FunctionCall` is either `container.exec`
+/// or shell`, the `arguments` field should deserialize to this struct.
+#[derive(Deserialize, Debug, Clone, PartialEq)]
+pub struct ShellToolCallParams {
+    pub command: Vec<String>,
+    pub workdir: Option<String>,
+
+    /// This is the maximum time in seconds that the command is allowed to run.
+    #[serde(rename = "timeout")]
+    // The wire format uses `timeout`, which has ambiguous units, so we use
+    // `timeout_ms` as the field name so it is clear in code.
+    pub timeout_ms: Option<u64>,
+}
+
 #[expect(dead_code)]
 #[derive(Deserialize, Debug, Clone)]
 pub struct FunctionCallOutputPayload {
@@ -183,4 +197,23 @@ mod tests {
 
         assert_eq!(v.get("output").unwrap().as_str().unwrap(), "bad");
     }
+
+    #[test]
+    fn deserialize_shell_tool_call_params() {
+        let json = r#"{
+            "command": ["ls", "-l"],
+            "workdir": "/tmp",
+            "timeout": 1000
+        }"#;
+
+        let params: ShellToolCallParams = serde_json::from_str(json).unwrap();
+        assert_eq!(
+            ShellToolCallParams {
+                command: vec!["ls".to_string(), "-l".to_string()],
+                workdir: Some("/tmp".to_string()),
+                timeout_ms: Some(1000),
+            },
+            params
+        );
+    }
 }