feat: add support for -c/--config to override individual config items

codex-rs/exec/src/cli.rs

@@ -1,5 +1,6 @@
 use clap::Parser;
 use clap::ValueEnum;
+use codex_common::CliConfigOverrides;
 use codex_common::SandboxPermissionOption;
 use std::path::PathBuf;
 
@@ -37,6 +38,9 @@ pub struct Cli {
     #[arg(long = "disable-response-storage", default_value_t = false)]
     pub disable_response_storage: bool,
 
+    #[clap(flatten)]
+    pub config_overrides: CliConfigOverrides,
+
     /// Specifies color settings for use in the output.
     #[arg(long = "color", value_enum, default_value_t = Color::Auto)]
     pub color: Color,

codex-rs/exec/src/lib.rs

@@ -38,6 +38,7 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         color,
         last_message_file,
         prompt,
+        config_overrides,
     } = cli;
 
     let (stdout_with_ansi, stderr_with_ansi) = match color {
@@ -72,7 +73,16 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         model_provider: None,
         codex_linux_sandbox_exe,
     };
-    let config = Config::load_with_overrides(overrides)?;
+    // Parse `-c` overrides.
+    let cli_kv_overrides = match config_overrides.parse_overrides() {
+        Ok(v) => v,
+        Err(e) => {
+            eprintln!("Error parsing -c overrides: {e}");
+            std::process::exit(1);
+        }
+    };
+
+    let config = Config::load_with_cli_overrides(cli_kv_overrides, overrides)?;
     // Print the effective configuration so users can see what Codex is using.
     print_config_summary(&config, stdout_with_ansi);