diff --git a/codex-rs/common/Cargo.toml b/codex-rs/common/Cargo.toml
index b4b658da..eff7a6c0 100644
--- a/codex-rs/common/Cargo.toml
+++ b/codex-rs/common/Cargo.toml
@@ -16,3 +16,4 @@ serde = { version = "1", optional = true }
 # Separate feature so that `clap` is not a mandatory dependency.
 cli = ["clap", "toml", "serde"]
 elapsed = []
+sandbox_summary = []
diff --git a/codex-rs/common/src/lib.rs b/codex-rs/common/src/lib.rs
index 074f648f..18ed49e5 100644
--- a/codex-rs/common/src/lib.rs
+++ b/codex-rs/common/src/lib.rs
@@ -12,3 +12,8 @@ mod config_override;
 
 #[cfg(feature = "cli")]
 pub use config_override::CliConfigOverrides;
+
+mod sandbox_summary;
+
+#[cfg(feature = "sandbox_summary")]
+pub use sandbox_summary::summarize_sandbox_policy;
diff --git a/codex-rs/common/src/sandbox_summary.rs b/codex-rs/common/src/sandbox_summary.rs
new file mode 100644
index 00000000..3d33d928
--- /dev/null
+++ b/codex-rs/common/src/sandbox_summary.rs
@@ -0,0 +1,28 @@
+use codex_core::protocol::SandboxPolicy;
+
+pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
+    match sandbox_policy {
+        SandboxPolicy::DangerFullAccess => "danger-full-access".to_string(),
+        SandboxPolicy::ReadOnly => "read-only".to_string(),
+        SandboxPolicy::WorkspaceWrite {
+            writable_roots,
+            network_access,
+        } => {
+            let mut summary = "workspace-write".to_string();
+            if !writable_roots.is_empty() {
+                summary.push_str(&format!(
+                    " [{}]",
+                    writable_roots
+                        .iter()
+                        .map(|p| p.to_string_lossy())
+                        .collect::<Vec<_>>()
+                        .join(", ")
+                ));
+            }
+            if *network_access {
+                summary.push_str(" (network access enabled)");
+            }
+            summary
+        }
+    }
+}
diff --git a/codex-rs/core/src/protocol.rs b/codex-rs/core/src/protocol.rs
index f3250de4..42cf9299 100644
--- a/codex-rs/core/src/protocol.rs
+++ b/codex-rs/core/src/protocol.rs
@@ -183,17 +183,8 @@ impl SandboxPolicy {
     /// the current working directory and the per-user tmp dir on macOS. It does
     /// not allow network access.
     pub fn new_workspace_write_policy() -> Self {
-        let mut writable_roots = vec![];
-
-        // Also include the per-user tmp dir on macOS.
-        if cfg!(target_os = "macos") {
-            if let Some(tmpdir) = std::env::var_os("TMPDIR") {
-                writable_roots.push(PathBuf::from(tmpdir));
-            }
-        }
-
         SandboxPolicy::WorkspaceWrite {
-            writable_roots,
+            writable_roots: vec![],
             network_access: false,
         }
     }
@@ -229,6 +220,17 @@ impl SandboxPolicy {
             SandboxPolicy::WorkspaceWrite { writable_roots, .. } => {
                 let mut roots = writable_roots.clone();
                 roots.push(cwd.to_path_buf());
+
+                // Also include the per-user tmp dir on macOS.
+                // Note this is added dynamically rather than storing it in
+                // writable_roots because writable_roots contains only static
+                // values deserialized from the config file.
+                if cfg!(target_os = "macos") {
+                    if let Some(tmpdir) = std::env::var_os("TMPDIR") {
+                        roots.push(PathBuf::from(tmpdir));
+                    }
+                }
+
                 roots
             }
         }
diff --git a/codex-rs/exec/Cargo.toml b/codex-rs/exec/Cargo.toml
index c3bde697..8c0c3737 100644
--- a/codex-rs/exec/Cargo.toml
+++ b/codex-rs/exec/Cargo.toml
@@ -19,7 +19,11 @@ anyhow = "1"
 chrono = "0.4.40"
 clap = { version = "4", features = ["derive"] }
 codex-core = { path = "../core" }
-codex-common = { path = "../common", features = ["cli", "elapsed"] }
+codex-common = { path = "../common", features = [
+    "cli",
+    "elapsed",
+    "sandbox_summary",
+] }
 codex-linux-sandbox = { path = "../linux-sandbox" }
 mcp-types = { path = "../mcp-types" }
 owo-colors = "4.2.0"
diff --git a/codex-rs/exec/src/event_processor.rs b/codex-rs/exec/src/event_processor.rs
index 4cbbd25f..e2a8bbb2 100644
--- a/codex-rs/exec/src/event_processor.rs
+++ b/codex-rs/exec/src/event_processor.rs
@@ -1,4 +1,5 @@
 use codex_common::elapsed::format_elapsed;
+use codex_common::summarize_sandbox_policy;
 use codex_core::WireApi;
 use codex_core::config::Config;
 use codex_core::model_supports_reasoning_summaries;
@@ -134,7 +135,7 @@ impl EventProcessor {
             ("model", config.model.clone()),
             ("provider", config.model_provider_id.clone()),
             ("approval", format!("{:?}", config.approval_policy)),
-            ("sandbox", format!("{:?}", config.sandbox_policy)),
+            ("sandbox", summarize_sandbox_policy(&config.sandbox_policy)),
         ];
         if config.model_provider.wire_api == WireApi::Responses
             && model_supports_reasoning_summaries(&config.model)
diff --git a/codex-rs/tui/Cargo.toml b/codex-rs/tui/Cargo.toml
index 2d7840e6..0891517d 100644
--- a/codex-rs/tui/Cargo.toml
+++ b/codex-rs/tui/Cargo.toml
@@ -20,7 +20,11 @@ base64 = "0.22.1"
 clap = { version = "4", features = ["derive"] }
 codex-ansi-escape = { path = "../ansi-escape" }
 codex-core = { path = "../core" }
-codex-common = { path = "../common", features = ["cli", "elapsed"] }
+codex-common = { path = "../common", features = [
+    "cli",
+    "elapsed",
+    "sandbox_summary",
+] }
 codex-linux-sandbox = { path = "../linux-sandbox" }
 codex-login = { path = "../login" }
 color-eyre = "0.6.3"
diff --git a/codex-rs/tui/src/history_cell.rs b/codex-rs/tui/src/history_cell.rs
index 481576b5..e2a54283 100644
--- a/codex-rs/tui/src/history_cell.rs
+++ b/codex-rs/tui/src/history_cell.rs
@@ -6,6 +6,7 @@ use crate::text_formatting::format_and_truncate_tool_result;
 use base64::Engine;
 use codex_ansi_escape::ansi_escape_line;
 use codex_common::elapsed::format_duration;
+use codex_common::summarize_sandbox_policy;
 use codex_core::WireApi;
 use codex_core::config::Config;
 use codex_core::model_supports_reasoning_summaries;
@@ -152,7 +153,7 @@ impl HistoryCell {
                 ("model", config.model.clone()),
                 ("provider", config.model_provider_id.clone()),
                 ("approval", format!("{:?}", config.approval_policy)),
-                ("sandbox", format!("{:?}", config.sandbox_policy)),
+                ("sandbox", summarize_sandbox_policy(&config.sandbox_policy)),
             ];
             if config.model_provider.wire_api == WireApi::Responses
                 && model_supports_reasoning_summaries(&config.model)