feat: introduce ExternalSandbox policy (#8290)

## Description

Introduced `ExternalSandbox` policy to cover use case when sandbox
defined by outside environment, effectively it translates to
`SandboxMode#DangerFullAccess` for file system (since sandbox configured
on container level) and configurable `network_access` (either Restricted
or Enabled by outside environment).

as example you can configure `ExternalSandbox` policy as part of
`sendUserTurn` v1 app_server API:

```
 {
            "conversationId": <id>,
            "cwd": <cwd>,
            "approvalPolicy": "never",
            "sandboxPolicy": {
                  "type": ""external-sandbox",
                  "network_access": "enabled"/"restricted"
            },
            "model": <model>,
            "effort": <effort>,
            ....
        }
```

codex-rs/Cargo.lock

@@ -1244,6 +1244,8 @@ dependencies = [
  "codex-lmstudio",
  "codex-ollama",
  "codex-protocol",
+ "codex-utils-absolute-path",
+ "pretty_assertions",
  "serde",
  "toml 0.9.5",
 ]
@@ -1316,7 +1318,6 @@ dependencies = [
  "sha2",
  "shlex",
  "similar",
- "strum_macros 0.27.2",
  "tempfile",
  "test-case",
  "test-log",
@@ -1913,6 +1914,7 @@ dependencies = [
  "codex-utils-absolute-path",
  "dirs-next",
  "dunce",
+ "pretty_assertions",
  "rand 0.8.5",
  "serde",
  "serde_json",

codex-rs/app-server-protocol/src/protocol/v2.rs

@@ -18,6 +18,7 @@ use codex_protocol::plan_tool::StepStatus as CorePlanStepStatus;
 use codex_protocol::protocol::AskForApproval as CoreAskForApproval;
 use codex_protocol::protocol::CodexErrorInfo as CoreCodexErrorInfo;
 use codex_protocol::protocol::CreditsSnapshot as CoreCreditsSnapshot;
+use codex_protocol::protocol::NetworkAccess as CoreNetworkAccess;
 use codex_protocol::protocol::RateLimitSnapshot as CoreRateLimitSnapshot;
 use codex_protocol::protocol::RateLimitWindow as CoreRateLimitWindow;
 use codex_protocol::protocol::SessionSource as CoreSessionSource;
@@ -470,6 +471,15 @@ pub enum ApprovalDecision {
     Cancel,
 }
 
+#[derive(Serialize, Deserialize, Debug, Default, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum NetworkAccess {
+    #[default]
+    Restricted,
+    Enabled,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
 #[serde(tag = "type", rename_all = "camelCase")]
 #[ts(tag = "type")]
@@ -479,6 +489,12 @@ pub enum SandboxPolicy {
     ReadOnly,
     #[serde(rename_all = "camelCase")]
     #[ts(rename_all = "camelCase")]
+    ExternalSandbox {
+        #[serde(default)]
+        network_access: NetworkAccess,
+    },
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
     WorkspaceWrite {
         #[serde(default)]
         writable_roots: Vec<AbsolutePathBuf>,
@@ -498,6 +514,14 @@ impl SandboxPolicy {
                 codex_protocol::protocol::SandboxPolicy::DangerFullAccess
             }
             SandboxPolicy::ReadOnly => codex_protocol::protocol::SandboxPolicy::ReadOnly,
+            SandboxPolicy::ExternalSandbox { network_access } => {
+                codex_protocol::protocol::SandboxPolicy::ExternalSandbox {
+                    network_access: match network_access {
+                        NetworkAccess::Restricted => CoreNetworkAccess::Restricted,
+                        NetworkAccess::Enabled => CoreNetworkAccess::Enabled,
+                    },
+                }
+            }
             SandboxPolicy::WorkspaceWrite {
                 writable_roots,
                 network_access,
@@ -520,6 +544,14 @@ impl From<codex_protocol::protocol::SandboxPolicy> for SandboxPolicy {
                 SandboxPolicy::DangerFullAccess
             }
             codex_protocol::protocol::SandboxPolicy::ReadOnly => SandboxPolicy::ReadOnly,
+            codex_protocol::protocol::SandboxPolicy::ExternalSandbox { network_access } => {
+                SandboxPolicy::ExternalSandbox {
+                    network_access: match network_access {
+                        CoreNetworkAccess::Restricted => NetworkAccess::Restricted,
+                        CoreNetworkAccess::Enabled => NetworkAccess::Enabled,
+                    },
+                }
+            }
             codex_protocol::protocol::SandboxPolicy::WorkspaceWrite {
                 writable_roots,
                 network_access,
@@ -1916,11 +1948,30 @@ mod tests {
     use codex_protocol::items::TurnItem;
     use codex_protocol::items::UserMessageItem;
     use codex_protocol::items::WebSearchItem;
+    use codex_protocol::protocol::NetworkAccess as CoreNetworkAccess;
     use codex_protocol::user_input::UserInput as CoreUserInput;
     use pretty_assertions::assert_eq;
     use serde_json::json;
     use std::path::PathBuf;
 
+    #[test]
+    fn sandbox_policy_round_trips_external_sandbox_network_access() {
+        let v2_policy = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        };
+
+        let core_policy = v2_policy.to_core();
+        assert_eq!(
+            core_policy,
+            codex_protocol::protocol::SandboxPolicy::ExternalSandbox {
+                network_access: CoreNetworkAccess::Enabled,
+            }
+        );
+
+        let back_to_v2 = SandboxPolicy::from(core_policy);
+        assert_eq!(back_to_v2, v2_policy);
+    }
+
     #[test]
     fn core_turn_item_into_thread_item_converts_supported_variants() {
         let user_item = TurnItem::UserMessage(UserMessageItem {

codex-rs/app-server/README.md

@@ -172,7 +172,7 @@ You can optionally specify config overrides on the new turn. If specified, these
     "cwd": "/Users/me/project",
     "approvalPolicy": "unlessTrusted",
     "sandboxPolicy": {
-        "mode": "workspaceWrite",
+        "type": "workspaceWrite",
         "writableRoots": ["/Users/me/project"],
         "networkAccess": true
     },
@@ -285,10 +285,12 @@ Run a standalone command (argv vector) in the server’s sandbox without creatin
 { "id": 32, "result": { "exitCode": 0, "stdout": "...", "stderr": "" } }
 ```
 
+- For clients that are already sandboxed externally, set `sandboxPolicy` to `{"type":"externalSandbox","networkAccess":"enabled"}` (or omit `networkAccess` to keep it restricted). Codex will not enforce its own sandbox in this mode; it tells the model it has full file-system access and passes the `networkAccess` state through `environment_context`.
+
 Notes:
 
 - Empty `command` arrays are rejected.
-- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags).
+- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags, `externalSandbox` with `networkAccess` `restricted|enabled`).
 - When omitted, `timeoutMs` falls back to the server default.
 
 ## Events

codex-rs/common/Cargo.toml

@@ -21,3 +21,10 @@ toml = { workspace = true, optional = true }
 cli = ["clap", "serde", "toml"]
 elapsed = []
 sandbox_summary = []
+
+[dev-dependencies]
+clap = { workspace = true, features = ["derive", "wrap_help"] }
+codex-utils-absolute-path = { workspace = true }
+pretty_assertions = { workspace = true }
+serde = { workspace = true }
+toml = { workspace = true }

codex-rs/common/src/sandbox_mode_cli_arg.rs

@@ -26,3 +26,22 @@ impl From<SandboxModeCliArg> for SandboxMode {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn maps_cli_args_to_protocol_modes() {
+        assert_eq!(SandboxMode::ReadOnly, SandboxModeCliArg::ReadOnly.into());
+        assert_eq!(
+            SandboxMode::WorkspaceWrite,
+            SandboxModeCliArg::WorkspaceWrite.into()
+        );
+        assert_eq!(
+            SandboxMode::DangerFullAccess,
+            SandboxModeCliArg::DangerFullAccess.into()
+        );
+    }
+}

codex-rs/common/src/sandbox_summary.rs

@@ -1,9 +1,17 @@
+use codex_core::protocol::NetworkAccess;
 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::ExternalSandbox { network_access } => {
+            let mut summary = "external-sandbox".to_string();
+            if matches!(network_access, NetworkAccess::Enabled) {
+                summary.push_str(" (network access enabled)");
+            }
+            summary
+        }
         SandboxPolicy::WorkspaceWrite {
             writable_roots,
             network_access,
@@ -34,3 +42,45 @@ pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use codex_utils_absolute_path::AbsolutePathBuf;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn summarizes_external_sandbox_without_network_access_suffix() {
+        let summary = summarize_sandbox_policy(&SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Restricted,
+        });
+        assert_eq!(summary, "external-sandbox");
+    }
+
+    #[test]
+    fn summarizes_external_sandbox_with_enabled_network() {
+        let summary = summarize_sandbox_policy(&SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        });
+        assert_eq!(summary, "external-sandbox (network access enabled)");
+    }
+
+    #[test]
+    fn workspace_write_summary_still_includes_network_access() {
+        let root = if cfg!(windows) { "C:\\repo" } else { "/repo" };
+        let writable_root = AbsolutePathBuf::try_from(root).unwrap();
+        let summary = summarize_sandbox_policy(&SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![writable_root.clone()],
+            network_access: true,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+        });
+        assert_eq!(
+            summary,
+            format!(
+                "workspace-write [workdir, {}] (network access enabled)",
+                writable_root.to_string_lossy()
+            )
+        );
+    }
+}

codex-rs/core/Cargo.toml

@@ -61,7 +61,6 @@ sha1 = { workspace = true }
 sha2 = { workspace = true }
 shlex = { workspace = true }
 similar = { workspace = true }
-strum_macros = { workspace = true }
 tempfile = { workspace = true }
 test-case = "3.3.1"
 test-log = { workspace = true }

codex-rs/core/src/command_safety/is_dangerous_command.rs

@@ -21,8 +21,11 @@ pub fn requires_initial_appoval(
     match policy {
         AskForApproval::Never | AskForApproval::OnFailure => false,
         AskForApproval::OnRequest => {
-            // In DangerFullAccess, only prompt if the command looks dangerous.
-            if matches!(sandbox_policy, SandboxPolicy::DangerFullAccess) {
+            // In DangerFullAccess or ExternalSandbox, only prompt if the command looks dangerous.
+            if matches!(
+                sandbox_policy,
+                SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+            ) {
                 return command_might_be_dangerous(command);
             }
 
@@ -83,6 +86,7 @@ fn is_dangerous_to_call_with_exec(command: &[String]) -> bool {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use codex_protocol::protocol::NetworkAccess;
 
     fn vec_str(items: &[&str]) -> Vec<String> {
         items.iter().map(std::string::ToString::to_string).collect()
@@ -150,4 +154,23 @@ mod tests {
     fn rm_f_is_dangerous() {
         assert!(command_might_be_dangerous(&vec_str(&["rm", "-f", "/"])));
     }
+
+    #[test]
+    fn external_sandbox_only_prompts_for_dangerous_commands() {
+        let external_policy = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Restricted,
+        };
+        assert!(!requires_initial_appoval(
+            AskForApproval::OnRequest,
+            &external_policy,
+            &vec_str(&["ls"]),
+            SandboxPermissions::UseDefault,
+        ));
+        assert!(requires_initial_appoval(
+            AskForApproval::OnRequest,
+            &external_policy,
+            &vec_str(&["rm", "-rf", "/"]),
+            SandboxPermissions::UseDefault,
+        ));
+    }
 }

codex-rs/core/src/environment_context.rs

@@ -1,10 +1,6 @@
-use codex_utils_absolute_path::AbsolutePathBuf;
-use serde::Deserialize;
-use serde::Serialize;
-use strum_macros::Display as DeriveDisplay;
-
 use crate::codex::TurnContext;
 use crate::protocol::AskForApproval;
+use crate::protocol::NetworkAccess;
 use crate::protocol::SandboxPolicy;
 use crate::shell::Shell;
 use codex_protocol::config_types::SandboxMode;
@@ -12,15 +8,11 @@ use codex_protocol::models::ContentItem;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::protocol::ENVIRONMENT_CONTEXT_CLOSE_TAG;
 use codex_protocol::protocol::ENVIRONMENT_CONTEXT_OPEN_TAG;
+use codex_utils_absolute_path::AbsolutePathBuf;
+use serde::Deserialize;
+use serde::Serialize;
 use std::path::PathBuf;
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, DeriveDisplay)]
-#[serde(rename_all = "kebab-case")]
-#[strum(serialize_all = "kebab-case")]
-pub enum NetworkAccess {
-    Restricted,
-    Enabled,
-}
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 #[serde(rename = "environment_context", rename_all = "snake_case")]
 pub(crate) struct EnvironmentContext {
@@ -45,12 +37,14 @@ impl EnvironmentContext {
             sandbox_mode: match sandbox_policy {
                 Some(SandboxPolicy::DangerFullAccess) => Some(SandboxMode::DangerFullAccess),
                 Some(SandboxPolicy::ReadOnly) => Some(SandboxMode::ReadOnly),
+                Some(SandboxPolicy::ExternalSandbox { .. }) => Some(SandboxMode::DangerFullAccess),
                 Some(SandboxPolicy::WorkspaceWrite { .. }) => Some(SandboxMode::WorkspaceWrite),
                 None => None,
             },
             network_access: match sandbox_policy {
                 Some(SandboxPolicy::DangerFullAccess) => Some(NetworkAccess::Enabled),
                 Some(SandboxPolicy::ReadOnly) => Some(NetworkAccess::Restricted),
+                Some(SandboxPolicy::ExternalSandbox { network_access }) => Some(network_access),
                 Some(SandboxPolicy::WorkspaceWrite { network_access, .. }) => {
                     if network_access {
                         Some(NetworkAccess::Enabled)
@@ -272,6 +266,48 @@ mod tests {
         assert_eq!(context.serialize_to_xml(), expected);
     }
 
+    #[test]
+    fn serialize_external_sandbox_environment_context() {
+        let context = EnvironmentContext::new(
+            None,
+            Some(AskForApproval::OnRequest),
+            Some(SandboxPolicy::ExternalSandbox {
+                network_access: NetworkAccess::Enabled,
+            }),
+            fake_shell(),
+        );
+
+        let expected = r#"<environment_context>
+  <approval_policy>on-request</approval_policy>
+  <sandbox_mode>danger-full-access</sandbox_mode>
+  <network_access>enabled</network_access>
+  <shell>bash</shell>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+
+    #[test]
+    fn serialize_external_sandbox_with_restricted_network_environment_context() {
+        let context = EnvironmentContext::new(
+            None,
+            Some(AskForApproval::OnRequest),
+            Some(SandboxPolicy::ExternalSandbox {
+                network_access: NetworkAccess::Restricted,
+            }),
+            fake_shell(),
+        );
+
+        let expected = r#"<environment_context>
+  <approval_policy>on-request</approval_policy>
+  <sandbox_mode>danger-full-access</sandbox_mode>
+  <network_access>restricted</network_access>
+  <shell>bash</shell>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+
     #[test]
     fn serialize_full_access_environment_context() {
         let context = EnvironmentContext::new(

codex-rs/core/src/exec.rs

@@ -135,7 +135,9 @@ pub async fn process_exec_tool_call(
     stdout_stream: Option<StdoutStream>,
 ) -> Result<ExecToolCallOutput> {
     let sandbox_type = match &sandbox_policy {
-        SandboxPolicy::DangerFullAccess => SandboxType::None,
+        SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+            SandboxType::None
+        }
         _ => get_platform_sandbox().unwrap_or(SandboxType::None),
     };
     tracing::debug!("Sandbox type: {sandbox_type:?}");
@@ -523,7 +525,10 @@ async fn exec(
 ) -> Result<RawExecToolCallOutput> {
     #[cfg(target_os = "windows")]
     if sandbox == SandboxType::WindowsRestrictedToken
-        && !matches!(sandbox_policy, SandboxPolicy::DangerFullAccess)
+        && !matches!(
+            sandbox_policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        )
     {
         return exec_windows_sandbox(params, sandbox_policy).await;
     }

codex-rs/core/src/safety.rs

@@ -91,7 +91,10 @@ pub fn assess_patch_safety(
     if is_write_patch_constrained_to_writable_paths(action, sandbox_policy, cwd)
         || policy == AskForApproval::OnFailure
     {
-        if matches!(sandbox_policy, SandboxPolicy::DangerFullAccess) {
+        if matches!(
+            sandbox_policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        ) {
             // DangerFullAccess is intended to bypass sandboxing entirely.
             SafetyCheck::AutoApprove {
                 sandbox_type: SandboxType::None,
@@ -147,7 +150,7 @@ fn is_write_patch_constrained_to_writable_paths(
         SandboxPolicy::ReadOnly => {
             return false;
         }
-        SandboxPolicy::DangerFullAccess => {
+        SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
             return true;
         }
         SandboxPolicy::WorkspaceWrite { .. } => sandbox_policy.get_writable_roots_with_cwd(cwd),
@@ -262,4 +265,23 @@ mod tests {
             &cwd,
         ));
     }
+
+    #[test]
+    fn external_sandbox_auto_approves_in_on_request() {
+        let tmp = TempDir::new().unwrap();
+        let cwd = tmp.path().to_path_buf();
+        let add_inside = ApplyPatchAction::new_add_for_test(&cwd.join("inner.txt"), "".to_string());
+
+        let policy = SandboxPolicy::ExternalSandbox {
+            network_access: codex_protocol::protocol::NetworkAccess::Enabled,
+        };
+
+        assert_eq!(
+            assess_patch_safety(&add_inside, AskForApproval::OnRequest, &policy, &cwd,),
+            SafetyCheck::AutoApprove {
+                sandbox_type: SandboxType::None,
+                user_explicitly_approved: false,
+            }
+        );
+    }
 }

codex-rs/core/src/sandboxing/mod.rs

@@ -85,7 +85,9 @@ impl SandboxManager {
                 crate::safety::get_platform_sandbox().unwrap_or(SandboxType::None)
             }
             SandboxablePreference::Auto => match policy {
-                SandboxPolicy::DangerFullAccess => SandboxType::None,
+                SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+                    SandboxType::None
+                }
                 _ => crate::safety::get_platform_sandbox().unwrap_or(SandboxType::None),
             },
         }

codex-rs/core/src/tools/sandboxing.rs

@@ -132,7 +132,10 @@ pub(crate) fn default_exec_approval_requirement(
 ) -> ExecApprovalRequirement {
     let needs_approval = match policy {
         AskForApproval::Never | AskForApproval::OnFailure => false,
-        AskForApproval::OnRequest => !matches!(sandbox_policy, SandboxPolicy::DangerFullAccess),
+        AskForApproval::OnRequest => !matches!(
+            sandbox_policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        ),
         AskForApproval::UnlessTrusted => true,
     };
 
@@ -253,3 +256,37 @@ impl<'a> SandboxAttempt<'a> {
         )
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use codex_protocol::protocol::NetworkAccess;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn external_sandbox_skips_exec_approval_on_request() {
+        assert_eq!(
+            default_exec_approval_requirement(
+                AskForApproval::OnRequest,
+                &SandboxPolicy::ExternalSandbox {
+                    network_access: NetworkAccess::Restricted,
+                },
+            ),
+            ExecApprovalRequirement::Skip {
+                bypass_sandbox: false,
+                proposed_execpolicy_amendment: None,
+            }
+        );
+    }
+
+    #[test]
+    fn restricted_sandbox_requires_exec_approval_on_request() {
+        assert_eq!(
+            default_exec_approval_requirement(AskForApproval::OnRequest, &SandboxPolicy::ReadOnly),
+            ExecApprovalRequirement::NeedsApproval {
+                reason: None,
+                proposed_execpolicy_amendment: None,
+            }
+        );
+    }
+}

codex-rs/docs/codex_mcp_interface.md

@@ -59,7 +59,7 @@ Request `newConversation` params (subset):
 - `profile`: optional named profile
 - `cwd`: optional working directory
 - `approvalPolicy`: `untrusted` | `on-request` | `on-failure` | `never`
-- `sandbox`: `read-only` | `workspace-write` | `danger-full-access`
+- `sandbox`: `read-only` | `workspace-write` | `external-sandbox` (honors `networkAccess` restricted/enabled) | `danger-full-access`
 - `config`: map of additional config overrides
 - `baseInstructions`: optional instruction override
 - `compactPrompt`: optional replacement for the default compaction prompt

codex-rs/protocol/src/protocol.rs

@@ -268,6 +268,24 @@ pub enum AskForApproval {
     Never,
 }
 
+/// Represents whether outbound network access is available to the agent.
+#[derive(
+    Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Display, Default, JsonSchema, TS,
+)]
+#[serde(rename_all = "kebab-case")]
+#[strum(serialize_all = "kebab-case")]
+pub enum NetworkAccess {
+    #[default]
+    Restricted,
+    Enabled,
+}
+
+impl NetworkAccess {
+    pub fn is_enabled(self) -> bool {
+        matches!(self, NetworkAccess::Enabled)
+    }
+}
+
 /// Determines execution restrictions for model shell commands.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Display, JsonSchema, TS)]
 #[strum(serialize_all = "kebab-case")]
@@ -281,6 +299,15 @@ pub enum SandboxPolicy {
     #[serde(rename = "read-only")]
     ReadOnly,
 
+    /// Indicates the process is already in an external sandbox. Allows full
+    /// disk access while honoring the provided network setting.
+    #[serde(rename = "external-sandbox")]
+    ExternalSandbox {
+        /// Whether the external sandbox permits outbound network traffic.
+        #[serde(default)]
+        network_access: NetworkAccess,
+    },
+
     /// Same as `ReadOnly` but additionally grants write access to the current
     /// working directory ("workspace").
     #[serde(rename = "workspace-write")]
@@ -373,6 +400,7 @@ impl SandboxPolicy {
     pub fn has_full_disk_write_access(&self) -> bool {
         match self {
             SandboxPolicy::DangerFullAccess => true,
+            SandboxPolicy::ExternalSandbox { .. } => true,
             SandboxPolicy::ReadOnly => false,
             SandboxPolicy::WorkspaceWrite { .. } => false,
         }
@@ -381,6 +409,7 @@ impl SandboxPolicy {
     pub fn has_full_network_access(&self) -> bool {
         match self {
             SandboxPolicy::DangerFullAccess => true,
+            SandboxPolicy::ExternalSandbox { network_access } => network_access.is_enabled(),
             SandboxPolicy::ReadOnly => false,
             SandboxPolicy::WorkspaceWrite { network_access, .. } => *network_access,
         }
@@ -392,6 +421,7 @@ impl SandboxPolicy {
     pub fn get_writable_roots_with_cwd(&self, cwd: &Path) -> Vec<WritableRoot> {
         match self {
             SandboxPolicy::DangerFullAccess => Vec::new(),
+            SandboxPolicy::ExternalSandbox { .. } => Vec::new(),
             SandboxPolicy::ReadOnly => Vec::new(),
             SandboxPolicy::WorkspaceWrite {
                 writable_roots,
@@ -1830,6 +1860,21 @@ mod tests {
     use serde_json::json;
     use tempfile::NamedTempFile;
 
+    #[test]
+    fn external_sandbox_reports_full_access_flags() {
+        let restricted = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Restricted,
+        };
+        assert!(restricted.has_full_disk_write_access());
+        assert!(!restricted.has_full_network_access());
+
+        let enabled = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        };
+        assert!(enabled.has_full_disk_write_access());
+        assert!(enabled.has_full_network_access());
+    }
+
     #[test]
     fn item_started_event_from_web_search_emits_begin_event() {
         let event = ItemStartedEvent {

codex-rs/tui/src/additional_dirs.rs

@@ -13,7 +13,9 @@ pub fn add_dir_warning_message(
     }
 
     match sandbox_policy {
-        SandboxPolicy::WorkspaceWrite { .. } | SandboxPolicy::DangerFullAccess => None,
+        SandboxPolicy::WorkspaceWrite { .. }
+        | SandboxPolicy::DangerFullAccess
+        | SandboxPolicy::ExternalSandbox { .. } => None,
         SandboxPolicy::ReadOnly => Some(format_warning(additional_dirs)),
     }
 }
@@ -32,6 +34,7 @@ fn format_warning(additional_dirs: &[PathBuf]) -> String {
 #[cfg(test)]
 mod tests {
     use super::add_dir_warning_message;
+    use codex_core::protocol::NetworkAccess;
     use codex_core::protocol::SandboxPolicy;
     use pretty_assertions::assert_eq;
     use std::path::PathBuf;
@@ -50,6 +53,15 @@ mod tests {
         assert_eq!(add_dir_warning_message(&dirs, &sandbox), None);
     }
 
+    #[test]
+    fn returns_none_for_external_sandbox() {
+        let sandbox = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        };
+        let dirs = vec![PathBuf::from("/tmp/example")];
+        assert_eq!(add_dir_warning_message(&dirs, &sandbox), None);
+    }
+
     #[test]
     fn warns_for_read_only() {
         let sandbox = SandboxPolicy::ReadOnly;

codex-rs/tui/src/status/card.rs

@@ -8,6 +8,7 @@ use chrono::Local;
 use codex_common::create_config_summary_entries;
 use codex_core::config::Config;
 use codex_core::openai_models::model_family::ModelFamily;
+use codex_core::protocol::NetworkAccess;
 use codex_core::protocol::SandboxPolicy;
 use codex_core::protocol::TokenUsage;
 use codex_protocol::ConversationId;
@@ -122,6 +123,13 @@ impl StatusHistoryCell {
             SandboxPolicy::DangerFullAccess => "danger-full-access".to_string(),
             SandboxPolicy::ReadOnly => "read-only".to_string(),
             SandboxPolicy::WorkspaceWrite { .. } => "workspace-write".to_string(),
+            SandboxPolicy::ExternalSandbox { network_access } => {
+                if matches!(network_access, NetworkAccess::Enabled) {
+                    "external-sandbox (network access enabled)".to_string()
+                } else {
+                    "external-sandbox".to_string()
+                }
+            }
         };
         let agents_summary = compose_agents_summary(config);
         let account = compose_account_display(auth_manager, plan_type);

codex-rs/tui2/src/additional_dirs.rs

@@ -13,7 +13,9 @@ pub fn add_dir_warning_message(
     }
 
     match sandbox_policy {
-        SandboxPolicy::WorkspaceWrite { .. } | SandboxPolicy::DangerFullAccess => None,
+        SandboxPolicy::WorkspaceWrite { .. }
+        | SandboxPolicy::DangerFullAccess
+        | SandboxPolicy::ExternalSandbox { .. } => None,
         SandboxPolicy::ReadOnly => Some(format_warning(additional_dirs)),
     }
 }
@@ -32,6 +34,7 @@ fn format_warning(additional_dirs: &[PathBuf]) -> String {
 #[cfg(test)]
 mod tests {
     use super::add_dir_warning_message;
+    use codex_core::protocol::NetworkAccess;
     use codex_core::protocol::SandboxPolicy;
     use pretty_assertions::assert_eq;
     use std::path::PathBuf;
@@ -50,6 +53,15 @@ mod tests {
         assert_eq!(add_dir_warning_message(&dirs, &sandbox), None);
     }
 
+    #[test]
+    fn returns_none_for_external_sandbox() {
+        let sandbox = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        };
+        let dirs = vec![PathBuf::from("/tmp/example")];
+        assert_eq!(add_dir_warning_message(&dirs, &sandbox), None);
+    }
+
     #[test]
     fn warns_for_read_only() {
         let sandbox = SandboxPolicy::ReadOnly;

codex-rs/tui2/src/status/card.rs

@@ -8,6 +8,7 @@ use chrono::Local;
 use codex_common::create_config_summary_entries;
 use codex_core::config::Config;
 use codex_core::openai_models::model_family::ModelFamily;
+use codex_core::protocol::NetworkAccess;
 use codex_core::protocol::SandboxPolicy;
 use codex_core::protocol::TokenUsage;
 use codex_protocol::ConversationId;
@@ -122,6 +123,13 @@ impl StatusHistoryCell {
             SandboxPolicy::DangerFullAccess => "danger-full-access".to_string(),
             SandboxPolicy::ReadOnly => "read-only".to_string(),
             SandboxPolicy::WorkspaceWrite { .. } => "workspace-write".to_string(),
+            SandboxPolicy::ExternalSandbox { network_access } => {
+                if matches!(network_access, NetworkAccess::Enabled) {
+                    "external-sandbox (network access enabled)".to_string()
+                } else {
+                    "external-sandbox".to_string()
+                }
+            }
         };
         let agents_summary = compose_agents_summary(config);
         let account = compose_account_display(auth_manager, plan_type);

codex-rs/windows-sandbox-rs/Cargo.toml

@@ -77,6 +77,7 @@ features = [
 version = "0.52"
 
 [dev-dependencies]
+pretty_assertions = { workspace = true }
 tempfile = "3"
 
 [build-dependencies]

codex-rs/windows-sandbox-rs/src/audit.rs

@@ -271,7 +271,7 @@ pub fn apply_capability_denies_for_world_writable(
             })?,
             Vec::new(),
         ),
-        SandboxPolicy::DangerFullAccess => {
+        SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
             return Ok(());
         }
     };

codex-rs/windows-sandbox-rs/src/command_runner_win.rs

@@ -106,7 +106,9 @@ pub fn main() -> Result<()> {
             SandboxPolicy::WorkspaceWrite { .. } => {
                 create_workspace_write_token_with_cap_from(base, psid_cap)
             }
-            SandboxPolicy::DangerFullAccess => unreachable!(),
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+                unreachable!()
+            }
         }
     };
     let (h_token, psid_to_use) = token_res?;

codex-rs/windows-sandbox-rs/src/elevated_impl.rs

@@ -239,8 +239,11 @@ mod windows_impl {
             require_logon_sandbox_creds(&policy, sandbox_policy_cwd, cwd, &env_map, codex_home)?;
         log_note("cli creds ready", logs_base_dir);
         // Build capability SID for ACL grants.
-        if matches!(&policy, SandboxPolicy::DangerFullAccess) {
-            anyhow::bail!("DangerFullAccess is not supported for sandboxing")
+        if matches!(
+            &policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        ) {
+            anyhow::bail!("DangerFullAccess and ExternalSandbox are not supported for sandboxing")
         }
         let caps = load_or_create_cap_sids(codex_home)?;
         let (psid_to_use, cap_sid_str) = match &policy {
@@ -252,7 +255,9 @@ mod windows_impl {
                 unsafe { convert_string_sid_to_sid(&caps.workspace).unwrap() },
                 caps.workspace.clone(),
             ),
-            SandboxPolicy::DangerFullAccess => unreachable!("DangerFullAccess handled above"),
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+                unreachable!("DangerFullAccess handled above")
+            }
         };
 
         let AllowDenyPaths { allow: _, deny: _ } =

codex-rs/windows-sandbox-rs/src/lib.rs

@@ -194,8 +194,11 @@ mod windows_impl {
         log_start(&command, logs_base_dir);
         let is_workspace_write = matches!(&policy, SandboxPolicy::WorkspaceWrite { .. });
 
-        if matches!(&policy, SandboxPolicy::DangerFullAccess) {
-            anyhow::bail!("DangerFullAccess is not supported for sandboxing")
+        if matches!(
+            &policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        ) {
+            anyhow::bail!("DangerFullAccess and ExternalSandbox are not supported for sandboxing")
         }
         let caps = load_or_create_cap_sids(codex_home)?;
         let (h_token, psid_to_use): (HANDLE, *mut c_void) = unsafe {
@@ -208,7 +211,9 @@ mod windows_impl {
                     let psid = convert_string_sid_to_sid(&caps.workspace).unwrap();
                     super::token::create_workspace_write_token_with_cap(psid)?
                 }
-                SandboxPolicy::DangerFullAccess => unreachable!("DangerFullAccess handled above"),
+                SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+                    unreachable!("DangerFullAccess handled above")
+                }
             }
         };
 

codex-rs/windows-sandbox-rs/src/policy.rs

@@ -5,13 +5,53 @@ pub fn parse_policy(value: &str) -> Result<SandboxPolicy> {
     match value {
         "read-only" => Ok(SandboxPolicy::ReadOnly),
         "workspace-write" => Ok(SandboxPolicy::new_workspace_write_policy()),
-        "danger-full-access" => anyhow::bail!("DangerFullAccess is not supported for sandboxing"),
+        "danger-full-access" | "external-sandbox" => anyhow::bail!(
+            "DangerFullAccess and ExternalSandbox are not supported for sandboxing"
+        ),
         other => {
             let parsed: SandboxPolicy = serde_json::from_str(other)?;
-            if matches!(parsed, SandboxPolicy::DangerFullAccess) {
-                anyhow::bail!("DangerFullAccess is not supported for sandboxing");
+            if matches!(
+                parsed,
+                SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+            ) {
+                anyhow::bail!(
+                    "DangerFullAccess and ExternalSandbox are not supported for sandboxing"
+                );
             }
             Ok(parsed)
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn rejects_external_sandbox_preset() {
+        let err = parse_policy("external-sandbox").unwrap_err();
+        assert!(err
+            .to_string()
+            .contains("DangerFullAccess and ExternalSandbox are not supported"));
+    }
+
+    #[test]
+    fn rejects_external_sandbox_json() {
+        let payload = serde_json::to_string(
+            &codex_protocol::protocol::SandboxPolicy::ExternalSandbox {
+                network_access: codex_protocol::protocol::NetworkAccess::Enabled,
+            },
+        )
+        .unwrap();
+        let err = parse_policy(&payload).unwrap_err();
+        assert!(err
+            .to_string()
+            .contains("DangerFullAccess and ExternalSandbox are not supported"));
+    }
+
+    #[test]
+    fn parses_read_only_policy() {
+        assert_eq!(parse_policy("read-only").unwrap(), SandboxPolicy::ReadOnly);
+    }
+}

codex-rs/windows-sandbox-rs/src/setup_orchestrator.rs

@@ -52,7 +52,10 @@ pub fn run_setup_refresh(
     codex_home: &Path,
 ) -> Result<()> {
     // Skip in danger-full-access.
-    if matches!(policy, SandboxPolicy::DangerFullAccess) {
+    if matches!(
+        policy,
+        SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+    ) {
         return Ok(());
     }
     let (read_roots, write_roots) = build_payload_roots(