feat: wire ephemeral in codex exec (#10758)

codex-rs/exec/src/cli.rs

@@ -71,6 +71,10 @@ pub struct Cli {
     #[arg(long = "add-dir", value_name = "DIR", value_hint = clap::ValueHint::DirPath)]
     pub add_dir: Vec<PathBuf>,
 
+    /// Run without persisting session files to disk.
+    #[arg(long = "ephemeral", global = true, default_value_t = false)]
+    pub ephemeral: bool,
+
     /// Path to a JSON Schema file describing the model's final response shape.
     #[arg(long = "output-schema", value_name = "FILE")]
     pub output_schema: Option<PathBuf>,
@@ -262,9 +266,11 @@ mod tests {
             "gpt-5.2-codex",
             "--dangerously-bypass-approvals-and-sandbox",
             "--skip-git-repo-check",
+            "--ephemeral",
             PROMPT,
         ]);
 
+        assert!(cli.ephemeral);
         let Some(Command::Resume(args)) = cli.command else {
             panic!("expected resume command");
         };

codex-rs/exec/src/lib.rs

@@ -103,6 +103,7 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         cwd,
         skip_git_repo_check,
         add_dir,
+        ephemeral,
         color,
         last_message_file,
         json: json_mode,
@@ -254,7 +255,7 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         include_apply_patch_tool: None,
         show_raw_agent_reasoning: oss.then_some(true),
         tools_web_search_request: None,
-        ephemeral: None,
+        ephemeral: ephemeral.then_some(true),
         additional_writable_roots: add_dir,
     };