Use public plugin service credential routes

codex-rs/Cargo.lock

@@ -2432,6 +2432,7 @@ dependencies = [
  "dunce",
  "futures",
  "gethostname",
+ "indexmap 2.13.0",
  "libc",
  "multimap",
  "pretty_assertions",
@@ -2492,6 +2493,7 @@ dependencies = [
  "codex-app-server-protocol",
  "codex-apply-patch",
  "codex-async-utils",
+ "codex-backend-client",
  "codex-code-mode",
  "codex-config",
  "codex-connectors",
@@ -3303,6 +3305,7 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "async-trait",
+ "base64 0.22.1",
  "chrono",
  "clap",
  "codex-utils-absolute-path",
@@ -3318,6 +3321,7 @@ dependencies = [
  "rama-tcp",
  "rama-tls-rustls",
  "rama-unix",
+ "rustls-native-certs",
  "serde",
  "serde_json",
  "tempfile",

codex-rs/app-server/src/config/external_agent_config.rs

@@ -1491,10 +1491,12 @@ fn json_object_to_env_toml_table(
     object: &serde_json::Map<String, JsonValue>,
 ) -> toml::map::Map<String, TomlValue> {
     let mut table = toml::map::Map::new();
-    for (key, value) in object {
-        if let Some(value) = json_env_value_to_string(value) {
-            table.insert(key.clone(), TomlValue::String(value));
-        }
+    for (key, value) in object
+        .iter()
+        .filter_map(|(key, value)| json_env_value_to_string(value).map(|value| (key, value)))
+        .collect::<BTreeMap<_, _>>()
+    {
+        table.insert(key.clone(), TomlValue::String(value));
     }
     table
 }

codex-rs/backend-client/src/client.rs

@@ -1,5 +1,6 @@
 use crate::types::CodeTaskDetailsResponse;
 use crate::types::ConfigFileResponse;
+use crate::types::ListCredentialRoutesResponse;
 use crate::types::PaginatedListTaskListItem;
 use crate::types::RateLimitReachedKind as BackendRateLimitReachedKind;
 use crate::types::RateLimitStatusPayload;
@@ -408,6 +409,20 @@ impl Client {
             .map_err(RequestError::from)
     }
 
+    pub async fn list_credential_routes(&self) -> Result<ListCredentialRoutesResponse> {
+        let url = self.credential_routes_url();
+        let req = self.http.get(&url).headers(self.headers());
+        let (body, ct) = self.exec_request(req, "GET", &url).await?;
+        self.decode_json(&url, &ct, &body)
+    }
+
+    pub fn credential_routes_proxy_url(&self) -> String {
+        match self.path_style {
+            PathStyle::CodexApi => format!("{}/api/codex/credential_routes/proxy", self.base_url),
+            PathStyle::ChatGptApi => format!("{}/ps/credential_routes/proxy", self.base_url),
+        }
+    }
+
     /// Create a new task (user turn) by POSTing to the appropriate backend path
     /// based on `path_style`. Returns the created task id.
     pub async fn create_task(&self, request_body: serde_json::Value) -> Result<String> {
@@ -539,6 +554,13 @@ impl Client {
         }
     }
 
+    fn credential_routes_url(&self) -> String {
+        match self.path_style {
+            PathStyle::CodexApi => format!("{}/api/codex/credential_routes", self.base_url),
+            PathStyle::ChatGptApi => format!("{}/ps/credential_routes", self.base_url),
+        }
+    }
+
     fn map_rate_limit_window(
         window: Option<Option<Box<crate::types::RateLimitWindowSnapshot>>>,
     ) -> Option<RateLimitWindow> {
@@ -862,4 +884,43 @@ mod tests {
             serde_json::json!({ "credit_type": "usage_limit" })
         );
     }
+
+    #[test]
+    fn credential_routes_use_expected_paths() {
+        let codex_client = Client {
+            base_url: "https://example.test".to_string(),
+            http: reqwest::Client::new(),
+            auth_provider: codex_model_provider::unauthenticated_auth_provider(),
+            user_agent: None,
+            chatgpt_account_id: None,
+            chatgpt_account_is_fedramp: false,
+            path_style: PathStyle::CodexApi,
+        };
+        assert_eq!(
+            codex_client.credential_routes_url(),
+            "https://example.test/api/codex/credential_routes"
+        );
+        assert_eq!(
+            codex_client.credential_routes_proxy_url(),
+            "https://example.test/api/codex/credential_routes/proxy"
+        );
+
+        let chatgpt_client = Client {
+            base_url: "https://chatgpt.com/backend-api".to_string(),
+            http: reqwest::Client::new(),
+            auth_provider: codex_model_provider::unauthenticated_auth_provider(),
+            user_agent: None,
+            chatgpt_account_id: None,
+            chatgpt_account_is_fedramp: false,
+            path_style: PathStyle::ChatGptApi,
+        };
+        assert_eq!(
+            chatgpt_client.credential_routes_url(),
+            "https://chatgpt.com/backend-api/ps/credential_routes"
+        );
+        assert_eq!(
+            chatgpt_client.credential_routes_proxy_url(),
+            "https://chatgpt.com/backend-api/ps/credential_routes/proxy"
+        );
+    }
 }

codex-rs/backend-client/src/lib.rs

@@ -7,6 +7,9 @@ pub use client::RequestError;
 pub use types::CodeTaskDetailsResponse;
 pub use types::CodeTaskDetailsResponseExt;
 pub use types::ConfigFileResponse;
+pub use types::CredentialRouteAuthType;
+pub use types::ListCredentialRoutesResponse;
 pub use types::PaginatedListTaskListItem;
+pub use types::ResolvedCredentialRoute;
 pub use types::TaskListItem;
 pub use types::TurnAttemptsSiblingTurnsResponse;

codex-rs/backend-client/src/types.rs

@@ -13,6 +13,29 @@ use serde::de::Deserializer;
 use serde_json::Value;
 use std::collections::HashMap;
 
+#[derive(Clone, Debug, Deserialize, PartialEq, Eq)]
+pub struct ListCredentialRoutesResponse {
+    pub routes: Vec<ResolvedCredentialRoute>,
+}
+
+#[derive(Clone, Debug, Deserialize, PartialEq, Eq)]
+pub struct ResolvedCredentialRoute {
+    pub connector_id: String,
+    pub link_id: String,
+    pub auth_type: CredentialRouteAuthType,
+    pub base_url: String,
+}
+
+#[derive(Clone, Copy, Debug, Deserialize, PartialEq, Eq)]
+pub enum CredentialRouteAuthType {
+    #[serde(rename = "API_KEY")]
+    ApiKey,
+    #[serde(rename = "OAUTH")]
+    OAuth,
+    #[serde(rename = "NONE")]
+    None,
+}
+
 /// Hand-rolled models for the Cloud Tasks task-details response.
 /// The generated OpenAPI models are pretty bad. This is a half-step
 /// towards hand-rolling them.

codex-rs/config/Cargo.toml

@@ -28,6 +28,7 @@ codex-utils-path = { workspace = true }
 dunce = { workspace = true }
 futures = { workspace = true, features = ["alloc", "std"] }
 gethostname = { workspace = true }
+indexmap = { workspace = true, features = ["serde"] }
 multimap = { workspace = true }
 prost = "0.14.3"
 schemars = { workspace = true }
@@ -38,7 +39,7 @@ serde_path_to_error = { workspace = true }
 sha2 = { workspace = true }
 thiserror = { workspace = true }
 tokio = { workspace = true, features = ["fs"] }
-toml = { workspace = true }
+toml = { workspace = true, features = ["preserve_order"] }
 toml_edit = { workspace = true }
 tonic = { workspace = true }
 tonic-prost = { workspace = true }

codex-rs/config/src/permissions_toml.rs

@@ -1,11 +1,17 @@
 use std::collections::BTreeMap;
 
+use codex_network_proxy::InjectedHeaderConfig;
+use codex_network_proxy::MitmHookActionsConfig;
+use codex_network_proxy::MitmHookBodyConfig;
+use codex_network_proxy::MitmHookConfig;
+use codex_network_proxy::MitmHookMatchConfig;
 use codex_network_proxy::NetworkDomainPermission as ProxyNetworkDomainPermission;
 use codex_network_proxy::NetworkMode;
 use codex_network_proxy::NetworkProxyConfig;
 use codex_network_proxy::NetworkUnixSocketPermission as ProxyNetworkUnixSocketPermission;
 use codex_network_proxy::normalize_host;
 use codex_protocol::permissions::FileSystemAccessMode;
+use indexmap::IndexMap;
 use schemars::JsonSchema;
 use serde::Deserialize;
 use serde::Serialize;
@@ -173,6 +179,38 @@ pub struct NetworkToml {
     pub domains: Option<NetworkDomainPermissionsToml>,
     pub unix_sockets: Option<NetworkUnixSocketPermissionsToml>,
     pub allow_local_binding: Option<bool>,
+    pub mitm: Option<NetworkMitmToml>,
+}
+
+#[derive(Serialize, Debug, Clone, Default, PartialEq, Eq, JsonSchema)]
+#[schemars(deny_unknown_fields)]
+pub struct NetworkMitmToml {
+    #[schemars(with = "Option<BTreeMap<String, NetworkMitmHookToml>>")]
+    pub hooks: Option<IndexMap<String, NetworkMitmHookToml>>,
+    #[schemars(with = "Option<BTreeMap<String, NetworkMitmActionToml>>")]
+    pub actions: Option<IndexMap<String, NetworkMitmActionToml>>,
+}
+
+#[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
+struct NetworkMitmTomlUnchecked {
+    pub hooks: Option<IndexMap<String, NetworkMitmHookToml>>,
+    pub actions: Option<IndexMap<String, NetworkMitmActionToml>>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq, Eq, JsonSchema)]
+#[schemars(deny_unknown_fields)]
+pub struct NetworkMitmHookToml {
+    pub host: String,
+    pub methods: Vec<String>,
+    pub path_prefixes: Vec<String>,
+    #[serde(default)]
+    pub query: BTreeMap<String, Vec<String>>,
+    #[serde(default)]
+    pub headers: BTreeMap<String, Vec<String>>,
+    #[schemars(with = "Option<MitmHookBodyConfigSchema>")]
+    pub body: Option<MitmHookBodyConfig>,
+    pub action: Vec<String>,
 }
 
 #[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
@@ -182,6 +220,114 @@ enum NetworkModeSchema {
     Full,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq, Eq, JsonSchema)]
+#[serde(default)]
+pub struct NetworkMitmActionToml {
+    pub strip_request_headers: Vec<String>,
+    pub inject_request_headers: Vec<NetworkMitmInjectedHeaderToml>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq, Eq, JsonSchema)]
+#[serde(default)]
+pub struct NetworkMitmInjectedHeaderToml {
+    pub name: String,
+    pub secret_env_var: Option<String>,
+    pub secret_file: Option<String>,
+    pub prefix: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema)]
+#[serde(transparent)]
+struct MitmHookBodyConfigSchema(pub serde_json::Value);
+
+impl<'de> Deserialize<'de> for NetworkMitmToml {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let unchecked = NetworkMitmTomlUnchecked::deserialize(deserializer)?;
+        let mitm = Self {
+            hooks: unchecked.hooks,
+            actions: unchecked.actions,
+        };
+        mitm.validate_action_definitions()
+            .map_err(serde::de::Error::custom)?;
+        Ok(mitm)
+    }
+}
+
+impl NetworkMitmToml {
+    pub fn validate_action_definitions(&self) -> Result<(), String> {
+        if let Some(actions) = self.actions.as_ref() {
+            for (action_name, action) in actions {
+                if action.is_empty() {
+                    return Err(format!(
+                        "network.mitm.actions.{action_name} must define at least one operation"
+                    ));
+                }
+            }
+        }
+
+        let Some(hooks) = self.hooks.as_ref() else {
+            return Ok(());
+        };
+
+        for (hook_name, hook) in hooks {
+            if hook.action.is_empty() {
+                return Err(format!(
+                    "network.mitm.hooks.{hook_name}.action must not be empty"
+                ));
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn validate_action_references(
+        &self,
+        actions_by_name: &IndexMap<String, NetworkMitmActionToml>,
+    ) -> Result<(), String> {
+        self.validate_action_definitions()?;
+
+        let Some(hooks) = self.hooks.as_ref() else {
+            return Ok(());
+        };
+
+        for (hook_name, hook) in hooks {
+            for action_name in &hook.action {
+                if !actions_by_name.contains_key(action_name) {
+                    return Err(format!(
+                        "network.mitm.hooks.{hook_name}.action references undefined action `{action_name}`"
+                    ));
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn to_runtime_hooks(
+        &self,
+        actions_by_name: Option<&IndexMap<String, NetworkMitmActionToml>>,
+    ) -> Vec<MitmHookConfig> {
+        self.hooks
+            .as_ref()
+            .map(|hooks| {
+                hooks
+                    .values()
+                    .map(|hook| hook.to_runtime(actions_by_name))
+                    .collect()
+            })
+            .unwrap_or_default()
+    }
+}
+
+impl NetworkMitmActionToml {
+    pub fn is_empty(&self) -> bool {
+        self.strip_request_headers.is_empty() && self.inject_request_headers.is_empty()
+    }
+}
+
 impl NetworkToml {
     pub fn apply_to_network_proxy_config(&self, config: &mut NetworkProxyConfig) {
         if let Some(enabled) = self.enabled {
@@ -234,6 +380,11 @@ impl NetworkToml {
         if let Some(allow_local_binding) = self.allow_local_binding {
             config.network.allow_local_binding = allow_local_binding;
         }
+        if let Some(mitm) = self.mitm.as_ref() {
+            config.network.mitm_hooks = mitm.to_runtime_hooks(mitm.actions.as_ref());
+        }
+        config.network.mitm =
+            config.network.mode == NetworkMode::Limited || !config.network.mitm_hooks.is_empty();
     }
 
     pub fn to_network_proxy_config(&self) -> NetworkProxyConfig {
@@ -243,6 +394,61 @@ impl NetworkToml {
     }
 }
 
+impl NetworkMitmHookToml {
+    fn to_runtime(
+        &self,
+        actions_by_name: Option<&IndexMap<String, NetworkMitmActionToml>>,
+    ) -> MitmHookConfig {
+        MitmHookConfig {
+            host: self.host.clone(),
+            matcher: MitmHookMatchConfig {
+                methods: self.methods.clone(),
+                path_prefixes: self.path_prefixes.clone(),
+                query: self.query.clone(),
+                headers: self.headers.clone(),
+                body: self.body.clone(),
+            },
+            actions: self.selected_actions(actions_by_name),
+        }
+    }
+
+    fn selected_actions(
+        &self,
+        actions_by_name: Option<&IndexMap<String, NetworkMitmActionToml>>,
+    ) -> MitmHookActionsConfig {
+        let Some(actions_by_name) = actions_by_name else {
+            return MitmHookActionsConfig::default();
+        };
+
+        let mut selected = MitmHookActionsConfig::default();
+        for action_name in &self.action {
+            if let Some(action) = actions_by_name.get(action_name) {
+                selected
+                    .strip_request_headers
+                    .extend(action.strip_request_headers.clone());
+                selected.inject_request_headers.extend(
+                    action
+                        .inject_request_headers
+                        .iter()
+                        .map(NetworkMitmInjectedHeaderToml::to_runtime),
+                );
+            }
+        }
+        selected
+    }
+}
+
+impl NetworkMitmInjectedHeaderToml {
+    fn to_runtime(&self) -> InjectedHeaderConfig {
+        InjectedHeaderConfig {
+            name: self.name.clone(),
+            secret_env_var: self.secret_env_var.clone(),
+            secret_file: self.secret_file.clone(),
+            prefix: self.prefix.clone(),
+        }
+    }
+}
+
 pub fn overlay_network_domain_permissions(
     config: &mut NetworkProxyConfig,
     domains: &NetworkDomainPermissionsToml,

codex-rs/core/Cargo.toml

@@ -29,6 +29,7 @@ codex-api = { workspace = true }
 codex-app-server-protocol = { workspace = true }
 codex-apply-patch = { workspace = true }
 codex-async-utils = { workspace = true }
+codex-backend-client = { workspace = true }
 codex-code-mode = { workspace = true }
 codex-connectors = { workspace = true }
 codex-config = { workspace = true }

codex-rs/core/config.schema.json

@@ -1535,6 +1535,118 @@
     "NetworkDomainPermissionsToml": {
       "type": "object"
     },
+    "NetworkMitmActionToml": {
+      "properties": {
+        "inject_request_headers": {
+          "default": [],
+          "items": {
+            "$ref": "#/definitions/NetworkMitmInjectedHeaderToml"
+          },
+          "type": "array"
+        },
+        "strip_request_headers": {
+          "default": [],
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        }
+      },
+      "type": "object"
+    },
+    "NetworkMitmHookToml": {
+      "additionalProperties": false,
+      "properties": {
+        "action": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "body": true,
+        "headers": {
+          "additionalProperties": {
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
+          "default": {},
+          "type": "object"
+        },
+        "host": {
+          "type": "string"
+        },
+        "methods": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "path_prefixes": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "query": {
+          "additionalProperties": {
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
+          "default": {},
+          "type": "object"
+        }
+      },
+      "required": [
+        "action",
+        "host",
+        "methods",
+        "path_prefixes"
+      ],
+      "type": "object"
+    },
+    "NetworkMitmInjectedHeaderToml": {
+      "properties": {
+        "name": {
+          "default": "",
+          "type": "string"
+        },
+        "prefix": {
+          "default": null,
+          "type": "string"
+        },
+        "secret_env_var": {
+          "default": null,
+          "type": "string"
+        },
+        "secret_file": {
+          "default": null,
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "NetworkMitmToml": {
+      "additionalProperties": false,
+      "properties": {
+        "actions": {
+          "additionalProperties": {
+            "$ref": "#/definitions/NetworkMitmActionToml"
+          },
+          "type": "object"
+        },
+        "hooks": {
+          "additionalProperties": {
+            "$ref": "#/definitions/NetworkMitmHookToml"
+          },
+          "type": "object"
+        }
+      },
+      "type": "object"
+    },
     "NetworkModeSchema": {
       "enum": [
         "limited",
@@ -1638,6 +1750,9 @@
         "enabled": {
           "type": "boolean"
         },
+        "mitm": {
+          "$ref": "#/definitions/NetworkMitmToml"
+        },
         "mode": {
           "$ref": "#/definitions/NetworkModeSchema"
         },

codex-rs/core/src/config/config_tests.rs

@@ -26,6 +26,9 @@ use codex_config::permissions_toml::FilesystemPermissionToml;
 use codex_config::permissions_toml::FilesystemPermissionsToml;
 use codex_config::permissions_toml::NetworkDomainPermissionToml;
 use codex_config::permissions_toml::NetworkDomainPermissionsToml;
+use codex_config::permissions_toml::NetworkMitmActionToml;
+use codex_config::permissions_toml::NetworkMitmHookToml;
+use codex_config::permissions_toml::NetworkMitmToml;
 use codex_config::permissions_toml::NetworkToml;
 use codex_config::permissions_toml::PermissionProfileToml;
 use codex_config::permissions_toml::PermissionsToml;
@@ -69,6 +72,7 @@ use codex_model_provider_info::LMSTUDIO_OSS_PROVIDER_ID;
 use codex_model_provider_info::OLLAMA_OSS_PROVIDER_ID;
 use codex_model_provider_info::WireApi;
 use codex_models_manager::bundled_models_response;
+use codex_network_proxy::NetworkMode;
 use codex_protocol::config_types::ServiceTier;
 use codex_protocol::models::ActivePermissionProfile;
 use codex_protocol::models::BUILT_IN_PERMISSION_PROFILE_DANGER_FULL_ACCESS;
@@ -94,6 +98,7 @@ use core_test_support::PathBufExt;
 use core_test_support::PathExt;
 use core_test_support::TempDirExt;
 use core_test_support::test_absolute_path;
+use indexmap::IndexMap;
 use pretty_assertions::assert_eq;
 use rmcp::model::ElicitationCapability;
 use rmcp::model::FormElicitationCapability;
@@ -750,9 +755,19 @@ enabled = true
 proxy_url = "http://127.0.0.1:43128"
 enable_socks5 = false
 allow_upstream_proxy = false
+mode = "full"
 
 [permissions.workspace.network.domains]
 "openai.com" = "allow"
+
+[permissions.workspace.network.mitm.hooks.github_write]
+host = "api.github.com"
+methods = ["POST", "PUT"]
+path_prefixes = ["/repos/openai/"]
+action = ["strip_auth"]
+
+[permissions.workspace.network.mitm.actions.strip_auth]
+strip_request_headers = ["authorization"]
 "#;
     let cfg: ConfigToml =
         toml::from_str(toml).expect("TOML deserialization should succeed for permissions profiles");
@@ -795,7 +810,7 @@ allow_upstream_proxy = false
                         allow_upstream_proxy: Some(false),
                         dangerously_allow_non_loopback_proxy: None,
                         dangerously_allow_all_unix_sockets: None,
-                        mode: None,
+                        mode: Some(NetworkMode::Full),
                         domains: Some(NetworkDomainPermissionsToml {
                             entries: BTreeMap::from([(
                                 "openai.com".to_string(),
@@ -804,6 +819,27 @@ allow_upstream_proxy = false
                         }),
                         unix_sockets: None,
                         allow_local_binding: None,
+                        mitm: Some(NetworkMitmToml {
+                            hooks: Some(IndexMap::from([(
+                                "github_write".to_string(),
+                                NetworkMitmHookToml {
+                                    host: "api.github.com".to_string(),
+                                    methods: vec!["POST".to_string(), "PUT".to_string()],
+                                    path_prefixes: vec!["/repos/openai/".to_string()],
+                                    query: BTreeMap::new(),
+                                    headers: BTreeMap::new(),
+                                    body: None,
+                                    action: vec!["strip_auth".to_string()],
+                                },
+                            )])),
+                            actions: Some(IndexMap::from([(
+                                "strip_auth".to_string(),
+                                NetworkMitmActionToml {
+                                    strip_request_headers: vec!["authorization".to_string()],
+                                    inject_request_headers: Vec::new(),
+                                },
+                            )])),
+                        }),
                     }),
                 },
             )]),
@@ -811,6 +847,140 @@ allow_upstream_proxy = false
     );
 }
 
+#[test]
+fn config_toml_rejects_empty_mitm_action_reference_list() {
+    let toml = r#"
+default_permissions = "workspace"
+
+[permissions.workspace.network.mitm.hooks.github_write]
+host = "api.github.com"
+methods = ["POST"]
+path_prefixes = ["/repos/openai/"]
+action = []
+
+[permissions.workspace.network.mitm.actions.strip_auth]
+strip_request_headers = ["authorization"]
+"#;
+
+    let err =
+        toml::from_str::<ConfigToml>(toml).expect_err("empty MITM action refs should fail closed");
+
+    assert!(
+        err.to_string()
+            .contains("network.mitm.hooks.github_write.action must not be empty"),
+        "{err}"
+    );
+}
+
+#[test]
+fn config_toml_rejects_empty_mitm_action_definition() {
+    let toml = r#"
+default_permissions = "workspace"
+
+[permissions.workspace.network.mitm.hooks.github_write]
+host = "api.github.com"
+methods = ["POST"]
+path_prefixes = ["/repos/openai/"]
+action = ["strip_auth"]
+
+[permissions.workspace.network.mitm.actions.strip_auth]
+"#;
+
+    let err = toml::from_str::<ConfigToml>(toml)
+        .expect_err("empty MITM action definitions should fail closed");
+
+    assert!(
+        err.to_string()
+            .contains("network.mitm.actions.strip_auth must define at least one operation"),
+        "{err}"
+    );
+}
+
+#[test]
+fn permissions_profile_network_to_proxy_config_preserves_mitm_hooks() {
+    let network = NetworkToml {
+        mode: Some(NetworkMode::Full),
+        mitm: Some(NetworkMitmToml {
+            hooks: Some(IndexMap::from([(
+                "github_write".to_string(),
+                NetworkMitmHookToml {
+                    host: "api.github.com".to_string(),
+                    methods: vec!["POST".to_string()],
+                    path_prefixes: vec!["/repos/openai/".to_string()],
+                    action: vec!["strip_auth".to_string()],
+                    ..NetworkMitmHookToml::default()
+                },
+            )])),
+            actions: Some(IndexMap::from([(
+                "strip_auth".to_string(),
+                NetworkMitmActionToml {
+                    strip_request_headers: vec!["authorization".to_string()],
+                    inject_request_headers: Vec::new(),
+                },
+            )])),
+        }),
+        ..NetworkToml::default()
+    };
+
+    let config = network.to_network_proxy_config();
+
+    assert_eq!(config.network.mode, NetworkMode::Full);
+    assert!(config.network.mitm);
+    assert_eq!(config.network.mitm_hooks.len(), 1);
+    assert_eq!(config.network.mitm_hooks[0].host, "api.github.com");
+    assert_eq!(
+        config.network.mitm_hooks[0].matcher.methods,
+        vec!["POST".to_string()]
+    );
+    assert_eq!(
+        config.network.mitm_hooks[0].actions.strip_request_headers,
+        vec!["authorization".to_string()]
+    );
+}
+
+#[test]
+fn permissions_profile_network_to_proxy_config_preserves_mitm_hook_declaration_order() {
+    let toml = r#"
+default_permissions = "workspace"
+
+[permissions.workspace.network.mitm.actions.noop]
+strip_request_headers = ["authorization"]
+
+[permissions.workspace.network.mitm.hooks.z_first]
+host = "api.github.com"
+methods = ["POST"]
+path_prefixes = ["/repos/openai/"]
+action = ["noop"]
+
+[permissions.workspace.network.mitm.hooks.a_second]
+host = "api.github.com"
+methods = ["POST"]
+path_prefixes = ["/repos/"]
+action = ["noop"]
+"#;
+    let cfg: ConfigToml = toml::from_str(toml).expect("permissions profile should deserialize");
+    let permissions = cfg.permissions.expect("permissions should deserialize");
+    let network = permissions
+        .entries
+        .get("workspace")
+        .expect("workspace profile should exist")
+        .network
+        .as_ref()
+        .expect("network profile should exist");
+
+    let config = network.to_network_proxy_config();
+
+    assert_eq!(config.network.mitm_hooks.len(), 2);
+    assert_eq!(
+        config.network.mitm_hooks[0].matcher.path_prefixes,
+        vec!["/repos/openai/".to_string()]
+    );
+    assert_eq!(
+        config.network.mitm_hooks[1].matcher.path_prefixes,
+        vec!["/repos/".to_string()]
+    );
+}
+
 #[tokio::test]
 async fn permissions_profiles_proxy_policy_does_not_start_managed_network_proxy_without_feature()
 -> std::io::Result<()> {

codex-rs/core/src/config/permissions.rs

@@ -185,6 +185,7 @@ pub(crate) fn apply_network_proxy_feature_config(
             }
         }),
         allow_local_binding: feature_config.allow_local_binding,
+        mitm: None,
     }
     .apply_to_network_proxy_config(config);
 }

codex-rs/core/src/credentialed_routes.rs

@@ -0,0 +1,36 @@
+use codex_backend_client::Client as BackendClient;
+use codex_backend_client::ResolvedCredentialRoute;
+use codex_login::CodexAuth;
+use tracing::debug;
+use tracing::warn;
+
+pub(crate) async fn load_for_session(
+    chatgpt_base_url: &str,
+    auth: Option<&CodexAuth>,
+) -> Vec<ResolvedCredentialRoute> {
+    let Some(auth) = auth.filter(|auth| auth.uses_codex_backend()) else {
+        return Vec::new();
+    };
+
+    let client = match BackendClient::from_auth(chatgpt_base_url.to_string(), auth) {
+        Ok(client) => client,
+        Err(err) => {
+            warn!(error = %err, "failed to initialize credentialed routes client");
+            return Vec::new();
+        }
+    };
+
+    match client.list_credential_routes().await {
+        Ok(response) => {
+            debug!(
+                credentialed_routes = response.routes.len(),
+                "loaded credentialed routes for session"
+            );
+            response.routes
+        }
+        Err(err) => {
+            warn!(error = %err, "failed to load credentialed routes for session");
+            Vec::new()
+        }
+    }
+}

codex-rs/core/src/lib.rs

@@ -19,6 +19,7 @@ mod codex_thread;
 mod compact_remote;
 mod compact_remote_v2;
 mod config_lock;
+mod credentialed_routes;
 pub use codex_thread::CodexThread;
 pub use codex_thread::CodexThreadTurnContextOverrides;
 pub use codex_thread::ThreadConfigSnapshot;

codex-rs/core/src/network_proxy_loader.rs

@@ -13,12 +13,16 @@ use codex_config::ConfigLayerStack;
 use codex_config::ConfigLayerStackOrdering;
 use codex_config::LoaderOverrides;
 use codex_config::loader::load_config_layers_state;
+use codex_config::permissions_toml::NetworkMitmActionToml;
+use codex_config::permissions_toml::NetworkMitmHookToml;
+use codex_config::permissions_toml::NetworkMitmToml;
 use codex_config::permissions_toml::NetworkToml;
 use codex_config::permissions_toml::PermissionsToml;
 use codex_config::permissions_toml::overlay_network_domain_permissions;
 use codex_exec_server::LOCAL_FS;
 use codex_network_proxy::ConfigReloader;
 use codex_network_proxy::ConfigState;
+use codex_network_proxy::NetworkMode;
 use codex_network_proxy::NetworkProxyConfig;
 use codex_network_proxy::NetworkProxyConstraintError;
 use codex_network_proxy::NetworkProxyConstraints;
@@ -27,6 +31,7 @@ use codex_network_proxy::build_config_state;
 use codex_network_proxy::normalize_host;
 use codex_network_proxy::validate_policy_against_constraints;
 use codex_utils_absolute_path::AbsolutePathBuf;
+use indexmap::IndexMap;
 use serde::Deserialize;
 use std::sync::Arc;
 use tokio::sync::RwLock;
@@ -198,6 +203,7 @@ fn selected_network_from_tables(parsed: NetworkTablesToml) -> Result<Option<Netw
     Ok(profile.network.clone())
 }
 
+#[cfg(test)]
 fn apply_network_tables(config: &mut NetworkProxyConfig, parsed: NetworkTablesToml) -> Result<()> {
     if let Some(network) = selected_network_from_tables(parsed)? {
         network.apply_to_network_proxy_config(config);
@@ -205,18 +211,66 @@ fn apply_network_tables(config: &mut NetworkProxyConfig, parsed: NetworkTablesTo
     Ok(())
 }
 
+#[derive(Default)]
+struct NetworkConfigAccumulator {
+    config: NetworkProxyConfig,
+    mitm_hooks: IndexMap<String, NetworkMitmHookToml>,
+    mitm_actions: IndexMap<String, NetworkMitmActionToml>,
+}
+
+impl NetworkConfigAccumulator {
+    fn apply_network_tables(&mut self, parsed: NetworkTablesToml) -> Result<()> {
+        if let Some(network) = selected_network_from_tables(parsed)? {
+            self.apply_network(network);
+        }
+        Ok(())
+    }
+
+    fn apply_network(&mut self, mut network: NetworkToml) {
+        let mitm = network.mitm.take();
+        network.apply_to_network_proxy_config(&mut self.config);
+
+        if let Some(mitm) = mitm {
+            if let Some(actions) = mitm.actions {
+                self.mitm_actions.extend(actions);
+            }
+            if let Some(hooks) = mitm.hooks {
+                self.mitm_hooks.extend(hooks);
+            }
+        }
+    }
+
+    fn finish(mut self) -> Result<NetworkProxyConfig> {
+        if !self.mitm_hooks.is_empty() {
+            let actions = self.mitm_actions;
+            let mitm = NetworkMitmToml {
+                hooks: Some(self.mitm_hooks),
+                actions: Some(actions.clone()),
+            };
+            mitm.validate_action_references(&actions)
+                .map_err(anyhow::Error::msg)?;
+            self.config.network.mitm_hooks = mitm.to_runtime_hooks(Some(&actions));
+        }
+
+        self.config.network.mitm = self.config.network.mode == NetworkMode::Limited
+            || !self.config.network.mitm_hooks.is_empty();
+        Ok(self.config)
+    }
+}
+
 fn config_from_layers(
     layers: &ConfigLayerStack,
     exec_policy: &codex_execpolicy::Policy,
 ) -> Result<NetworkProxyConfig> {
-    let mut config = NetworkProxyConfig::default();
+    let mut accumulator = NetworkConfigAccumulator::default();
     for layer in layers.get_layers(
         ConfigLayerStackOrdering::LowestPrecedenceFirst,
         /*include_disabled*/ false,
     ) {
         let parsed = network_tables_from_toml(&layer.config)?;
-        apply_network_tables(&mut config, parsed)?;
+        accumulator.apply_network_tables(parsed)?;
     }
+    let mut config = accumulator.finish()?;
     apply_exec_policy_network_rules(&mut config, exec_policy);
     Ok(config)
 }

codex-rs/core/src/network_proxy_loader_tests.rs

@@ -104,6 +104,76 @@ default_permissions = "workspace"
     assert_eq!(config.network.denied_domains(), None);
 }
 
+#[test]
+fn higher_precedence_profile_network_overrides_named_mitm_actions() {
+    let lower_network: toml::Value = toml::from_str(
+        r#"
+default_permissions = "workspace"
+
+[permissions.workspace.network]
+mode = "full"
+
+[permissions.workspace.network.domains]
+"lower.example.com" = "allow"
+
+[permissions.workspace.network.mitm.hooks.github_write]
+host = "api.github.com"
+methods = ["POST"]
+path_prefixes = ["/repos/openai/"]
+action = ["strip_auth"]
+
+[permissions.workspace.network.mitm.actions.strip_auth]
+strip_request_headers = ["authorization"]
+"#,
+    )
+    .expect("lower layer should parse");
+    let higher_network: toml::Value = toml::from_str(
+        r#"
+default_permissions = "workspace"
+
+[permissions.workspace.network]
+mode = "full"
+
+[permissions.workspace.network.domains]
+"higher.example.com" = "allow"
+
+[permissions.workspace.network.mitm.actions.strip_auth]
+strip_request_headers = ["x-api-key"]
+"#,
+    )
+    .expect("higher layer should parse");
+
+    let mut accumulator = NetworkConfigAccumulator::default();
+    accumulator
+        .apply_network_tables(
+            network_tables_from_toml(&lower_network).expect("lower layer should deserialize"),
+        )
+        .expect("lower layer should apply");
+    accumulator
+        .apply_network_tables(
+            network_tables_from_toml(&higher_network).expect("higher layer should deserialize"),
+        )
+        .expect("higher layer should apply");
+    let config = accumulator.finish().expect("merged config should build");
+
+    assert_eq!(config.network.mode, codex_network_proxy::NetworkMode::Full);
+    assert!(config.network.mitm);
+    assert_eq!(
+        config.network.allowed_domains(),
+        Some(vec![
+            "lower.example.com".to_string(),
+            "higher.example.com".to_string()
+        ])
+    );
+    assert_eq!(config.network.mitm_hooks.len(), 1);
+    assert_eq!(config.network.mitm_hooks[0].host, "api.github.com");
+    assert_eq!(config.network.mitm_hooks[0].matcher.methods, vec!["POST"]);
+    assert_eq!(
+        config.network.mitm_hooks[0].actions.strip_request_headers,
+        vec!["x-api-key"]
+    );
+}
+
 #[test]
 fn execpolicy_network_rules_overlay_network_lists() {
     let mut config = NetworkProxyConfig::default();

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

@@ -875,6 +875,17 @@ async fn thread_title_from_thread_store(
     (!title.is_empty() && thread.preview.trim() != title).then(|| title.to_string())
 }
 
+struct ManagedNetworkProxyStartParams<'a> {
+    spec: &'a crate::config::NetworkProxySpec,
+    credentialed_routes: &'a [codex_backend_client::ResolvedCredentialRoute],
+    exec_policy: &'a codex_execpolicy::Policy,
+    permission_profile: &'a PermissionProfile,
+    network_policy_decider: Option<Arc<dyn codex_network_proxy::NetworkPolicyDecider>>,
+    blocked_request_observer: Option<Arc<dyn codex_network_proxy::BlockedRequestObserver>>,
+    managed_network_requirements_enabled: bool,
+    audit_metadata: NetworkProxyAuditMetadata,
+}
+
 impl Session {
     pub(crate) async fn app_server_client_metadata(&self) -> AppServerClientMetadata {
         let state = self.state.lock().await;
@@ -938,14 +949,21 @@ impl Session {
     }
 
     async fn start_managed_network_proxy(
-        spec: &crate::config::NetworkProxySpec,
-        exec_policy: &codex_execpolicy::Policy,
-        permission_profile: &PermissionProfile,
-        network_policy_decider: Option<Arc<dyn codex_network_proxy::NetworkPolicyDecider>>,
-        blocked_request_observer: Option<Arc<dyn codex_network_proxy::BlockedRequestObserver>>,
-        managed_network_requirements_enabled: bool,
-        audit_metadata: NetworkProxyAuditMetadata,
+        ManagedNetworkProxyStartParams {
+            spec,
+            credentialed_routes,
+            exec_policy,
+            permission_profile,
+            network_policy_decider,
+            blocked_request_observer,
+            managed_network_requirements_enabled,
+            audit_metadata,
+        }: ManagedNetworkProxyStartParams<'_>,
     ) -> anyhow::Result<(StartedNetworkProxy, SessionNetworkProxyRuntime)> {
+        debug!(
+            credentialed_routes = credentialed_routes.len(),
+            "starting managed network proxy"
+        );
         let spec = spec
             .with_exec_policy_network_rules(exec_policy)
             .map_err(|err| {

codex-rs/core/src/session/session.rs

@@ -813,15 +813,24 @@ impl Session {
                     });
             let (network_proxy, session_network_proxy) =
                 if let Some(spec) = config.permissions.network.as_ref() {
+                    let credentialed_routes =
+                        crate::credentialed_routes::load_for_session(&config.chatgpt_base_url, auth)
+                            .await;
                     let current_exec_policy = exec_policy.current();
                     let (network_proxy, session_network_proxy) = Self::start_managed_network_proxy(
-                        spec,
-                        current_exec_policy.as_ref(),
-                        config.permissions.permission_profile(),
-                        network_policy_decider.as_ref().map(Arc::clone),
-                        blocked_request_observer.as_ref().map(Arc::clone),
-                        managed_network_requirements_configured,
-                        network_proxy_audit_metadata,
+                        ManagedNetworkProxyStartParams {
+                            spec,
+                            credentialed_routes: &credentialed_routes,
+                            exec_policy: current_exec_policy.as_ref(),
+                            permission_profile: config.permissions.permission_profile(),
+                            network_policy_decider: network_policy_decider.as_ref().map(Arc::clone),
+                            blocked_request_observer: blocked_request_observer
+                                .as_ref()
+                                .map(Arc::clone),
+                            managed_network_requirements_enabled:
+                                managed_network_requirements_configured,
+                            audit_metadata: network_proxy_audit_metadata,
+                        },
                     )
                     .instrument(info_span!(
                         "session_init.network_proxy",

codex-rs/core/src/session/tests.rs

@@ -683,15 +683,18 @@ async fn start_managed_network_proxy_applies_execpolicy_network_rules() -> anyho
         /*justification*/ None,
     )?;
 
-    let (started_proxy, _) = Session::start_managed_network_proxy(
-        &spec,
-        &exec_policy,
-        &permission_profile_for_sandbox_policy(&SandboxPolicy::new_workspace_write_policy()),
-        /*network_policy_decider*/ None,
-        /*blocked_request_observer*/ None,
-        /*managed_network_requirements_enabled*/ false,
-        crate::config::NetworkProxyAuditMetadata::default(),
-    )
+    let (started_proxy, _) = Session::start_managed_network_proxy(ManagedNetworkProxyStartParams {
+        spec: &spec,
+        credentialed_routes: &[],
+        exec_policy: &exec_policy,
+        permission_profile: &permission_profile_for_sandbox_policy(
+            &SandboxPolicy::new_workspace_write_policy(),
+        ),
+        network_policy_decider: None,
+        blocked_request_observer: None,
+        managed_network_requirements_enabled: false,
+        audit_metadata: crate::config::NetworkProxyAuditMetadata::default(),
+    })
     .await?;
 
     let current_cfg = started_proxy.proxy().current_cfg().await?;
@@ -727,15 +730,18 @@ async fn start_managed_network_proxy_ignores_invalid_execpolicy_network_rules()
         /*justification*/ None,
     )?;
 
-    let (started_proxy, _) = Session::start_managed_network_proxy(
-        &spec,
-        &exec_policy,
-        &permission_profile_for_sandbox_policy(&SandboxPolicy::new_workspace_write_policy()),
-        /*network_policy_decider*/ None,
-        /*blocked_request_observer*/ None,
-        /*managed_network_requirements_enabled*/ false,
-        crate::config::NetworkProxyAuditMetadata::default(),
-    )
+    let (started_proxy, _) = Session::start_managed_network_proxy(ManagedNetworkProxyStartParams {
+        spec: &spec,
+        credentialed_routes: &[],
+        exec_policy: &exec_policy,
+        permission_profile: &permission_profile_for_sandbox_policy(
+            &SandboxPolicy::new_workspace_write_policy(),
+        ),
+        network_policy_decider: None,
+        blocked_request_observer: None,
+        managed_network_requirements_enabled: false,
+        audit_metadata: crate::config::NetworkProxyAuditMetadata::default(),
+    })
     .await?;
 
     let current_cfg = started_proxy.proxy().current_cfg().await?;
@@ -766,15 +772,18 @@ async fn managed_network_proxy_decider_survives_full_access_start() -> anyhow::R
         }
     });
 
-    let (started_proxy, _) = Session::start_managed_network_proxy(
-        &spec,
-        &exec_policy,
-        &permission_profile_for_sandbox_policy(&SandboxPolicy::DangerFullAccess),
-        Some(network_policy_decider),
-        /*blocked_request_observer*/ None,
-        /*managed_network_requirements_enabled*/ true,
-        crate::config::NetworkProxyAuditMetadata::default(),
-    )
+    let (started_proxy, _) = Session::start_managed_network_proxy(ManagedNetworkProxyStartParams {
+        spec: &spec,
+        credentialed_routes: &[],
+        exec_policy: &exec_policy,
+        permission_profile: &permission_profile_for_sandbox_policy(
+            &SandboxPolicy::DangerFullAccess,
+        ),
+        network_policy_decider: Some(network_policy_decider),
+        blocked_request_observer: None,
+        managed_network_requirements_enabled: true,
+        audit_metadata: crate::config::NetworkProxyAuditMetadata::default(),
+    })
     .await?;
 
     let spec = spec.recompute_for_permission_profile(&permission_profile_for_sandbox_policy(
@@ -838,15 +847,16 @@ async fn new_turn_refreshes_managed_network_proxy_for_sandbox_change() -> anyhow
         Some(requirements),
         &permission_profile_for_sandbox_policy(&initial_policy),
     )?;
-    let (started_proxy, _) = Session::start_managed_network_proxy(
-        &spec,
-        &Policy::empty(),
-        &permission_profile_for_sandbox_policy(&initial_policy),
-        /*network_policy_decider*/ None,
-        /*blocked_request_observer*/ None,
-        /*managed_network_requirements_enabled*/ false,
-        crate::config::NetworkProxyAuditMetadata::default(),
-    )
+    let (started_proxy, _) = Session::start_managed_network_proxy(ManagedNetworkProxyStartParams {
+        spec: &spec,
+        credentialed_routes: &[],
+        exec_policy: &Policy::empty(),
+        permission_profile: &permission_profile_for_sandbox_policy(&initial_policy),
+        network_policy_decider: None,
+        blocked_request_observer: None,
+        managed_network_requirements_enabled: false,
+        audit_metadata: crate::config::NetworkProxyAuditMetadata::default(),
+    })
     .await?;
     assert_eq!(
         started_proxy

codex-rs/network-proxy/Cargo.toml

@@ -15,6 +15,7 @@ workspace = true
 [dependencies]
 anyhow = { workspace = true }
 async-trait = { workspace = true }
+base64 = { workspace = true }
 clap = { workspace = true, features = ["derive"] }
 chrono = { workspace = true }
 codex-utils-absolute-path = { workspace = true }
@@ -35,6 +36,7 @@ rama-net = { version = "=0.3.0-alpha.4", features = ["http", "tls"] }
 rama-socks5 = { version = "=0.3.0-alpha.4" }
 rama-tcp = { version = "=0.3.0-alpha.4", features = ["http"] }
 rama-tls-rustls = { version = "=0.3.0-alpha.4", features = ["http"] }
+rustls-native-certs = { workspace = true }
 
 [dev-dependencies]
 pretty_assertions = { workspace = true }

codex-rs/network-proxy/README.md

@@ -33,9 +33,10 @@ allow_upstream_proxy = true
 # If you want to expose these listeners beyond localhost, you must opt in explicitly.
 dangerously_allow_non_loopback_proxy = false
 mode = "full" # default when unset; use "limited" for read-only mode
-# When true, HTTPS CONNECT can be terminated so limited-mode method policy still applies.
-mitm = false
+# HTTPS MITM is enabled automatically when `mode = "limited"` or when MITM hooks are configured.
 # CA cert/key are managed internally under $CODEX_HOME/proxy/ (ca.pem + ca.key).
+# When MITM is active, spawned commands receive CA bundle env vars pointing at
+# $CODEX_HOME/proxy/ca-bundle.pem so common HTTPS clients trust the managed CA.
 
 # If false, local/private networking is rejected. Explicit allowlisting of local IP literals
 # (or `localhost`) is required to permit them.
@@ -57,6 +58,17 @@ dangerously_allow_all_unix_sockets = false
 "::1" = "allow"
 "evil.example" = "deny"
 
+# MITM hooks match HTTPS requests after CONNECT is terminated.
+[permissions.workspace.network.mitm.hooks.github_write]
+host = "api.github.com"
+methods = ["POST", "PUT"]
+path_prefixes = ["/repos/openai/"]
+action = ["strip_auth"]
+
+# Named actions can be shared across hooks and overridden by higher-precedence config layers.
+[permissions.workspace.network.mitm.actions.strip_auth]
+strip_request_headers = ["authorization"]
+
 # macOS-only: allows proxying to a unix socket when request includes `x-unix-socket: /path`.
 [permissions.workspace.network.unix_sockets]
 "/tmp/example.sock" = "allow"

codex-rs/network-proxy/src/certs.rs

@@ -1,6 +1,7 @@
 use anyhow::Context as _;
 use anyhow::Result;
 use anyhow::anyhow;
+use base64::Engine as _;
 use codex_utils_home_dir::find_codex_home;
 use rama_net::tls::ApplicationProtocol;
 use rama_tls_rustls::dep::pki_types::CertificateDer;
@@ -19,6 +20,7 @@ use rama_tls_rustls::dep::rcgen::PKCS_ECDSA_P256_SHA256;
 use rama_tls_rustls::dep::rcgen::SanType;
 use rama_tls_rustls::dep::rustls;
 use rama_tls_rustls::server::TlsAcceptorData;
+use std::collections::HashMap;
 use std::fs;
 use std::fs::File;
 use std::fs::OpenOptions;
@@ -29,6 +31,7 @@ use std::path::PathBuf;
 use std::time::SystemTime;
 use std::time::UNIX_EPOCH;
 use tracing::info;
+use tracing::warn;
 
 pub(super) struct ManagedMitmCa {
     issuer: Issuer<'static, KeyPair>,
@@ -95,6 +98,20 @@ fn issue_host_certificate_pem(
 const MANAGED_MITM_CA_DIR: &str = "proxy";
 const MANAGED_MITM_CA_CERT: &str = "ca.pem";
 const MANAGED_MITM_CA_KEY: &str = "ca.key";
+const MANAGED_MITM_CA_TRUST_BUNDLE: &str = "ca-bundle.pem";
+
+const CUSTOM_CA_ENV_KEYS: &[&str] = &[
+    "CODEX_CA_CERTIFICATE",
+    "SSL_CERT_FILE",
+    "REQUESTS_CA_BUNDLE",
+    "CURL_CA_BUNDLE",
+    "NODE_EXTRA_CA_CERTS",
+    "GIT_SSL_CAINFO",
+    "PIP_CERT",
+    "BUNDLE_SSL_CA_CERT",
+    "npm_config_cafile",
+    "NPM_CONFIG_CAFILE",
+];
 
 fn managed_ca_paths() -> Result<(PathBuf, PathBuf)> {
     let codex_home =
@@ -106,6 +123,85 @@ fn managed_ca_paths() -> Result<(PathBuf, PathBuf)> {
     ))
 }
 
+pub(crate) fn managed_ca_trust_bundle_path(env: &HashMap<String, String>) -> Result<PathBuf> {
+    let (cert_path, _) = managed_ca_paths()?;
+    let trust_bundle_path = cert_path
+        .parent()
+        .ok_or_else(|| anyhow!("managed MITM CA cert path is missing a parent"))?
+        .join(MANAGED_MITM_CA_TRUST_BUNDLE);
+    let trust_bundle = build_managed_ca_trust_bundle(&cert_path, env)?;
+    write_atomic_replace(
+        &trust_bundle_path,
+        trust_bundle.as_bytes(),
+        /*mode*/ 0o644,
+    )
+    .with_context(|| {
+        format!(
+            "failed to persist managed MITM CA trust bundle {}",
+            trust_bundle_path.display()
+        )
+    })?;
+    Ok(trust_bundle_path)
+}
+
+fn build_managed_ca_trust_bundle(
+    managed_ca_cert_path: &Path,
+    env: &HashMap<String, String>,
+) -> Result<String> {
+    let mut trust_bundle = String::new();
+    let rustls_native_certs::CertificateResult { certs, errors, .. } =
+        rustls_native_certs::load_native_certs();
+    if !errors.is_empty() {
+        warn!(
+            native_root_error_count = errors.len(),
+            "encountered errors while loading native root certificates for MITM trust bundle"
+        );
+    }
+    for cert in certs {
+        push_certificate_pem(&mut trust_bundle, cert.as_ref());
+    }
+
+    let mut custom_ca_paths = Vec::new();
+    for key in CUSTOM_CA_ENV_KEYS {
+        let Some(path) = env.get(*key).filter(|path| !path.is_empty()) else {
+            continue;
+        };
+        let path = PathBuf::from(path);
+        if path == managed_ca_cert_path || custom_ca_paths.contains(&path) {
+            continue;
+        }
+        custom_ca_paths.push(path);
+    }
+    for path in custom_ca_paths {
+        append_pem_file(&mut trust_bundle, &path)?;
+    }
+    append_pem_file(&mut trust_bundle, managed_ca_cert_path)?;
+    Ok(trust_bundle)
+}
+
+fn append_pem_file(bundle: &mut String, path: &Path) -> Result<()> {
+    if !bundle.ends_with('\n') {
+        bundle.push('\n');
+    }
+    let pem = fs::read_to_string(path)
+        .with_context(|| format!("failed to read CA bundle {}", path.display()))?;
+    bundle.push_str(&pem);
+    if !bundle.ends_with('\n') {
+        bundle.push('\n');
+    }
+    Ok(())
+}
+
+fn push_certificate_pem(bundle: &mut String, der: &[u8]) {
+    bundle.push_str("-----BEGIN CERTIFICATE-----\n");
+    let encoded = base64::engine::general_purpose::STANDARD.encode(der);
+    for chunk in encoded.as_bytes().chunks(64) {
+        bundle.push_str(&String::from_utf8_lossy(chunk));
+        bundle.push('\n');
+    }
+    bundle.push_str("-----END CERTIFICATE-----\n");
+}
+
 fn load_or_create_ca() -> Result<(String, String)> {
     let (cert_path, key_path) = managed_ca_paths()?;
 
@@ -238,6 +334,55 @@ fn write_atomic_create_new(path: &Path, contents: &[u8], mode: u32) -> Result<()
     Ok(())
 }
 
+fn write_atomic_replace(path: &Path, contents: &[u8], mode: u32) -> Result<()> {
+    if fs::read(path).ok().as_deref() == Some(contents) {
+        return Ok(());
+    }
+
+    let parent = path
+        .parent()
+        .ok_or_else(|| anyhow!("missing parent directory"))?;
+    fs::create_dir_all(parent).with_context(|| format!("failed to create {}", parent.display()))?;
+    if fs::symlink_metadata(path)
+        .ok()
+        .is_some_and(|metadata| metadata.file_type().is_symlink())
+    {
+        return Err(anyhow!("refusing to overwrite symlink {}", path.display()));
+    }
+
+    let nanos = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_nanos();
+    let pid = std::process::id();
+    let file_name = path.file_name().unwrap_or_default().to_string_lossy();
+    let tmp_path = parent.join(format!(".{file_name}.tmp.{pid}.{nanos}"));
+
+    let mut file = open_create_new_with_mode(&tmp_path, mode)?;
+    file.write_all(contents)
+        .with_context(|| format!("failed to write {}", tmp_path.display()))?;
+    file.sync_all()
+        .with_context(|| format!("failed to fsync {}", tmp_path.display()))?;
+    drop(file);
+
+    #[cfg(windows)]
+    if path.exists() {
+        fs::remove_file(path).with_context(|| format!("failed to remove {}", path.display()))?;
+    }
+    fs::rename(&tmp_path, path).with_context(|| {
+        format!(
+            "failed to rename {} -> {}",
+            tmp_path.display(),
+            path.display()
+        )
+    })?;
+
+    let dir = File::open(parent).with_context(|| format!("failed to open {}", parent.display()))?;
+    dir.sync_all()
+        .with_context(|| format!("failed to fsync {}", parent.display()))?;
+    Ok(())
+}
+
 #[cfg(unix)]
 fn validate_existing_ca_key_file(path: &Path) -> Result<()> {
     use std::os::unix::fs::PermissionsExt;

codex-rs/network-proxy/src/config.rs

@@ -13,6 +13,8 @@ use std::path::Path;
 use tracing::warn;
 use url::Url;
 
+use crate::mitm_hook::MitmHookConfig;
+
 #[derive(Debug, Clone, Serialize, Deserialize, Default, PartialEq, Eq)]
 pub struct NetworkProxyConfig {
     #[serde(default)]
@@ -139,6 +141,8 @@ pub struct NetworkProxySettings {
     pub allow_local_binding: bool,
     #[serde(default)]
     pub mitm: bool,
+    #[serde(default)]
+    pub mitm_hooks: Vec<MitmHookConfig>,
 }
 
 impl Default for NetworkProxySettings {
@@ -157,6 +161,7 @@ impl Default for NetworkProxySettings {
             unix_sockets: None,
             allow_local_binding: false,
             mitm: false,
+            mitm_hooks: Vec::new(),
         }
     }
 }
@@ -273,8 +278,8 @@ pub enum NetworkMode {
     /// blocked unless MITM is enabled so the proxy can enforce method policy on inner requests.
     /// SOCKS5 remains blocked in limited mode.
     Limited,
-    /// Full network access: all HTTP methods are allowed, and HTTPS CONNECTs are tunneled without
-    /// MITM interception.
+    /// Full network access: all HTTP methods are allowed. HTTPS CONNECTs are tunneled directly.
+    /// MITM hooks do not currently make full mode enter MITM.
     #[default]
     Full,
 }
@@ -588,6 +593,7 @@ mod tests {
                 unix_sockets: None,
                 allow_local_binding: false,
                 mitm: false,
+                mitm_hooks: Vec::new(),
             }
         );
     }
@@ -652,6 +658,7 @@ mod tests {
                     "unix_sockets": null,
                     "allow_local_binding": false,
                     "mitm": false,
+                    "mitm_hooks": [],
                 }
             })
         );

codex-rs/network-proxy/src/http_proxy.rs

@@ -80,6 +80,9 @@ use tracing::error;
 use tracing::info;
 use tracing::warn;
 
+#[derive(Clone, Copy, Debug)]
+struct ConnectMitmEnabled(bool);
+
 pub async fn run_http_proxy(
     state: Arc<NetworkProxyState>,
     addr: SocketAddr,
@@ -256,10 +259,18 @@ async fn http_connect_accept(
             return Err(text_response(StatusCode::INTERNAL_SERVER_ERROR, "error"));
         }
     };
+    let host_has_mitm_hooks = match app_state.host_has_mitm_hooks(&host).await {
+        Ok(has_hooks) => has_hooks,
+        Err(err) => {
+            error!("failed to inspect MITM hooks for {host}: {err}");
+            return Err(text_response(StatusCode::INTERNAL_SERVER_ERROR, "error"));
+        }
+    };
+    let connect_needs_mitm = mode == NetworkMode::Limited || host_has_mitm_hooks;
 
-    if mode == NetworkMode::Limited && mitm_state.is_none() {
-        // Limited mode is designed to be read-only. Without MITM, a CONNECT tunnel would hide the
-        // inner HTTP method/headers from the proxy, effectively bypassing method policy.
+    if connect_needs_mitm && mitm_state.is_none() {
+        // CONNECT needs MITM whenever HTTPS policy depends on inner-request inspection, either for
+        // limited-mode method enforcement or for host-specific MITM hooks.
         emit_http_block_decision_audit_event(
             &app_state,
             BlockDecisionAuditEventArgs {
@@ -286,7 +297,7 @@ async fn http_connect_accept(
                 reason: REASON_MITM_REQUIRED.to_string(),
                 client: client.clone(),
                 method: Some("CONNECT".to_string()),
-                mode: Some(NetworkMode::Limited),
+                mode: Some(mode),
                 protocol: "http-connect".to_string(),
                 decision: Some(details.decision.as_str().to_string()),
                 source: Some(details.source.as_str().to_string()),
@@ -295,14 +306,16 @@ async fn http_connect_accept(
             .await;
         let client = client.as_deref().unwrap_or_default();
         warn!(
-            "CONNECT blocked; MITM required for read-only HTTPS in limited mode (client={client}, host={host}, mode=limited, allowed_methods=GET, HEAD, OPTIONS)"
+            "CONNECT blocked; MITM required to enforce HTTPS policy (client={client}, host={host}, mode={mode:?}, hooked_host={host_has_mitm_hooks})"
         );
         return Err(blocked_text_with_details(REASON_MITM_REQUIRED, &details));
     }
 
     req.extensions_mut().insert(ProxyTarget(authority));
+    req.extensions_mut()
+        .insert(ConnectMitmEnabled(connect_needs_mitm));
     req.extensions_mut().insert(mode);
-    if let Some(mitm_state) = mitm_state {
+    if connect_needs_mitm && let Some(mitm_state) = mitm_state {
         req.extensions_mut().insert(mitm_state);
     }
 
@@ -331,7 +344,10 @@ async fn http_connect_proxy(upgraded: Upgraded) -> Result<(), Infallible> {
         return Ok(());
     };
 
-    if mode == NetworkMode::Limited
+    if upgraded
+        .extensions()
+        .get::<ConnectMitmEnabled>()
+        .is_some_and(|enabled| enabled.0)
         && upgraded
             .extensions()
             .get::<Arc<mitm::MitmState>>()
@@ -1094,6 +1110,42 @@ mod tests {
         assert_eq!(response.status(), StatusCode::OK);
     }
 
+    #[tokio::test]
+    async fn http_connect_accept_blocks_hooked_host_in_full_mode_without_mitm_state() {
+        let mut policy = NetworkProxySettings {
+            mitm: true,
+            mitm_hooks: vec![crate::mitm_hook::MitmHookConfig {
+                host: "api.github.com".to_string(),
+                matcher: crate::mitm_hook::MitmHookMatchConfig {
+                    methods: vec!["POST".to_string()],
+                    path_prefixes: vec!["/repos/openai/".to_string()],
+                    ..crate::mitm_hook::MitmHookMatchConfig::default()
+                },
+                actions: crate::mitm_hook::MitmHookActionsConfig::default(),
+            }],
+            ..Default::default()
+        };
+        policy.set_allowed_domains(vec!["api.github.com".to_string()]);
+        let state = Arc::new(network_proxy_state_for_policy(policy));
+
+        let mut req = Request::builder()
+            .method(Method::CONNECT)
+            .uri("https://api.github.com:443")
+            .header("host", "api.github.com:443")
+            .body(Body::empty())
+            .unwrap();
+        req.extensions_mut().insert(state);
+
+        let response = http_connect_accept(/*policy_decider*/ None, req)
+            .await
+            .unwrap_err();
+        assert_eq!(response.status(), StatusCode::FORBIDDEN);
+        assert_eq!(
+            response.headers().get("x-proxy-error").unwrap(),
+            "blocked-by-mitm-required"
+        );
+    }
+
     #[tokio::test]
     async fn http_proxy_listener_accepts_plain_http1_connect_requests() {
         let target_listener = TokioTcpListener::bind((Ipv4Addr::LOCALHOST, 0))

codex-rs/network-proxy/src/lib.rs

@@ -5,6 +5,7 @@ mod config;
 mod connect_policy;
 mod http_proxy;
 mod mitm;
+mod mitm_hook;
 mod network_policy;
 mod policy;
 mod proxy;
@@ -23,6 +24,11 @@ pub use config::NetworkProxyConfig;
 pub use config::NetworkUnixSocketPermission;
 pub use config::NetworkUnixSocketPermissions;
 pub use config::host_and_port_from_network_addr;
+pub use mitm_hook::InjectedHeaderConfig;
+pub use mitm_hook::MitmHookActionsConfig;
+pub use mitm_hook::MitmHookBodyConfig;
+pub use mitm_hook::MitmHookConfig;
+pub use mitm_hook::MitmHookMatchConfig;
 pub use network_policy::NetworkDecision;
 pub use network_policy::NetworkDecisionSource;
 pub use network_policy::NetworkPolicyDecider;

codex-rs/network-proxy/src/mitm.rs

@@ -1,7 +1,10 @@
 use crate::certs::ManagedMitmCa;
 use crate::config::NetworkMode;
+use crate::mitm_hook::HookEvaluation;
+use crate::mitm_hook::MitmHookActions;
 use crate::policy::normalize_host;
 use crate::reasons::REASON_METHOD_NOT_ALLOWED;
+use crate::reasons::REASON_MITM_HOOK_DENIED;
 use crate::responses::blocked_text_response;
 use crate::responses::text_response;
 use crate::runtime::HostBlockDecision;
@@ -23,6 +26,7 @@ use rama_core::rt::Executor;
 use rama_core::service::service_fn;
 use rama_http::Body;
 use rama_http::BodyDataStream;
+use rama_http::HeaderMap;
 use rama_http::HeaderValue;
 use rama_http::Request;
 use rama_http::Response;
@@ -71,6 +75,13 @@ struct MitmRequestContext {
     mitm: Arc<MitmState>,
 }
 
+enum MitmPolicyDecision {
+    Allow {
+        hook_actions: Option<MitmHookActions>,
+    },
+    Block(Response),
+}
+
 const MITM_INSPECT_BODIES: bool = false;
 const MITM_MAX_BODY_BYTES: usize = 4096;
 
@@ -86,9 +97,10 @@ impl std::fmt::Debug for MitmState {
 
 impl MitmState {
     pub(crate) fn new(config: MitmUpstreamConfig) -> Result<Self> {
-        // MITM exists to make limited-mode HTTPS enforceable: once CONNECT is established, plain
-        // proxying would lose visibility into the inner HTTP request. We generate/load a local CA
-        // and issue per-host leaf certs so we can terminate TLS and apply policy.
+        // MITM exists when HTTPS policy depends on the inner request: limited-mode method clamps
+        // and host-specific hooks both need visibility after CONNECT is established. We
+        // generate/load a local CA and issue per-host leaf certs so we can terminate TLS and
+        // apply policy.
         let ca = ManagedMitmCa::load_or_create()?;
 
         let upstream = if config.allow_upstream_proxy {
@@ -200,9 +212,10 @@ async fn handle_mitm_request(
 }
 
 async fn forward_request(req: Request, request_ctx: &MitmRequestContext) -> Result<Response> {
-    if let Some(response) = mitm_blocking_response(&req, &request_ctx.policy).await? {
-        return Ok(response);
-    }
+    let hook_actions = match evaluate_mitm_policy(&req, &request_ctx.policy).await? {
+        MitmPolicyDecision::Allow { hook_actions } => hook_actions,
+        MitmPolicyDecision::Block(response) => return Ok(response),
+    };
 
     let target_host = request_ctx.policy.target_host.clone();
     let target_port = request_ctx.policy.target_port;
@@ -213,6 +226,7 @@ async fn forward_request(req: Request, request_ctx: &MitmRequestContext) -> Resu
     let log_path = path_for_log(req.uri());
 
     let (mut parts, body) = req.into_parts();
+    apply_mitm_hook_actions(&mut parts.headers, hook_actions.as_ref());
     let authority = authority_header_value(&target_host, target_port);
     parts.uri = build_https_uri(&authority, &path)?;
     parts
@@ -247,12 +261,23 @@ async fn forward_request(req: Request, request_ctx: &MitmRequestContext) -> Resu
     )
 }
 
+#[cfg_attr(not(test), allow(dead_code))]
 async fn mitm_blocking_response(
     req: &Request,
     policy: &MitmPolicyContext,
 ) -> Result<Option<Response>> {
+    match evaluate_mitm_policy(req, policy).await? {
+        MitmPolicyDecision::Allow { .. } => Ok(None),
+        MitmPolicyDecision::Block(response) => Ok(Some(response)),
+    }
+}
+
+async fn evaluate_mitm_policy(
+    req: &Request,
+    policy: &MitmPolicyContext,
+) -> Result<MitmPolicyDecision> {
     if req.method().as_str() == "CONNECT" {
-        return Ok(Some(text_response(
+        return Ok(MitmPolicyDecision::Block(text_response(
             StatusCode::METHOD_NOT_ALLOWED,
             "CONNECT not supported inside MITM",
         )));
@@ -272,7 +297,7 @@ async fn mitm_blocking_response(
                 "MITM host mismatch (target={}, request_host={normalized})",
                 policy.target_host
             );
-            return Ok(Some(text_response(
+            return Ok(MitmPolicyDecision::Block(text_response(
                 StatusCode::BAD_REQUEST,
                 "host mismatch",
             )));
@@ -307,7 +332,43 @@ async fn mitm_blocking_response(
             "MITM blocked local/private target after CONNECT (host={}, port={}, method={method}, path={log_path})",
             policy.target_host, policy.target_port
         );
-        return Ok(Some(blocked_text_response(reason)));
+        return Ok(MitmPolicyDecision::Block(blocked_text_response(reason)));
+    }
+
+    match policy
+        .app_state
+        .evaluate_mitm_hook_request(&policy.target_host, req)
+        .await?
+    {
+        HookEvaluation::Matched { actions } => {
+            return Ok(MitmPolicyDecision::Allow {
+                hook_actions: Some(actions),
+            });
+        }
+        HookEvaluation::HookedHostNoMatch => {
+            let _ = policy
+                .app_state
+                .record_blocked(BlockedRequest::new(BlockedRequestArgs {
+                    host: policy.target_host.clone(),
+                    reason: REASON_MITM_HOOK_DENIED.to_string(),
+                    client: client.clone(),
+                    method: Some(method.clone()),
+                    mode: Some(policy.mode),
+                    protocol: "https".to_string(),
+                    decision: None,
+                    source: None,
+                    port: Some(policy.target_port),
+                }))
+                .await;
+            warn!(
+                "MITM blocked by hook policy (host={}, method={method}, mode={:?})",
+                policy.target_host, policy.mode
+            );
+            return Ok(MitmPolicyDecision::Block(blocked_text_response(
+                REASON_MITM_HOOK_DENIED,
+            )));
+        }
+        HookEvaluation::NoHooksForHost => {}
     }
 
     if !policy.mode.allows_method(&method) {
@@ -329,10 +390,25 @@ async fn mitm_blocking_response(
             "MITM blocked by method policy (host={}, method={method}, path={log_path}, mode={:?}, allowed_methods=GET, HEAD, OPTIONS)",
             policy.target_host, policy.mode
         );
-        return Ok(Some(blocked_text_response(REASON_METHOD_NOT_ALLOWED)));
+        return Ok(MitmPolicyDecision::Block(blocked_text_response(
+            REASON_METHOD_NOT_ALLOWED,
+        )));
     }
 
-    Ok(None)
+    Ok(MitmPolicyDecision::Allow { hook_actions: None })
+}
+
+fn apply_mitm_hook_actions(headers: &mut HeaderMap, actions: Option<&MitmHookActions>) {
+    let Some(actions) = actions else {
+        return;
+    };
+
+    for header_name in &actions.strip_request_headers {
+        headers.remove(header_name);
+    }
+    for injected_header in &actions.inject_request_headers {
+        headers.insert(injected_header.name.clone(), injected_header.value.clone());
+    }
 }
 
 fn respond_with_inspection(

codex-rs/network-proxy/src/mitm_tests.rs

@@ -2,13 +2,39 @@ use super::*;
 
 use crate::config::NetworkProxySettings;
 use crate::reasons::REASON_METHOD_NOT_ALLOWED;
+use crate::reasons::REASON_MITM_HOOK_DENIED;
 use crate::reasons::REASON_NOT_ALLOWED_LOCAL;
 use crate::runtime::network_proxy_state_for_policy;
+use codex_utils_absolute_path::AbsolutePathBuf;
 use pretty_assertions::assert_eq;
 use rama_http::Body;
+use rama_http::HeaderMap;
+use rama_http::HeaderValue;
 use rama_http::Method;
 use rama_http::Request;
 use rama_http::StatusCode;
+use rama_http::header::HeaderName;
+use tempfile::NamedTempFile;
+
+fn github_write_hook() -> crate::mitm_hook::MitmHookConfig {
+    crate::mitm_hook::MitmHookConfig {
+        host: "api.github.com".to_string(),
+        matcher: crate::mitm_hook::MitmHookMatchConfig {
+            methods: vec!["POST".to_string(), "PUT".to_string()],
+            path_prefixes: vec!["/repos/openai/".to_string()],
+            ..crate::mitm_hook::MitmHookMatchConfig::default()
+        },
+        actions: crate::mitm_hook::MitmHookActionsConfig {
+            strip_request_headers: vec!["authorization".to_string()],
+            inject_request_headers: vec![crate::mitm_hook::InjectedHeaderConfig {
+                name: "authorization".to_string(),
+                secret_env_var: Some("CODEX_GITHUB_TOKEN".to_string()),
+                secret_file: None,
+                prefix: Some("Bearer ".to_string()),
+            }],
+        },
+    }
+}
 
 fn policy_ctx(
     app_state: Arc<NetworkProxyState>,
@@ -126,3 +152,125 @@ async fn mitm_policy_rechecks_local_private_target_after_connect() {
     assert_eq!(blocked[0].host, "10.0.0.1");
     assert_eq!(blocked[0].port, Some(443));
 }
+
+#[tokio::test]
+async fn mitm_policy_allows_matching_hooked_write_in_full_mode() {
+    let secret_file = NamedTempFile::new().unwrap();
+    std::fs::write(secret_file.path(), "ghp-secret\n").unwrap();
+    let mut hook = github_write_hook();
+    hook.actions.inject_request_headers[0].secret_env_var = None;
+    hook.actions.inject_request_headers[0].secret_file =
+        Some(secret_file.path().display().to_string());
+    let mut network = NetworkProxySettings {
+        mitm: true,
+        mitm_hooks: vec![hook],
+        mode: NetworkMode::Full,
+        ..NetworkProxySettings::default()
+    };
+    network.set_allowed_domains(vec!["api.github.com".to_string()]);
+    let app_state = Arc::new(network_proxy_state_for_policy(network));
+    let ctx = policy_ctx(
+        app_state.clone(),
+        NetworkMode::Full,
+        "api.github.com",
+        /*target_port*/ 443,
+    );
+    let req = Request::builder()
+        .method(Method::POST)
+        .uri("/repos/openai/codex/issues")
+        .header(HOST, "api.github.com")
+        .body(Body::empty())
+        .unwrap();
+
+    let response = mitm_blocking_response(&req, &ctx).await.unwrap();
+
+    assert!(
+        response.is_none(),
+        "matching hook should bypass method clamp"
+    );
+    assert_eq!(app_state.blocked_snapshot().await.unwrap().len(), 0);
+}
+
+#[tokio::test]
+async fn mitm_policy_blocks_hook_miss_for_hooked_host_and_records_telemetry_in_full_mode() {
+    let secret_file = NamedTempFile::new().unwrap();
+    std::fs::write(secret_file.path(), "ghp-secret\n").unwrap();
+    let mut hook = github_write_hook();
+    hook.actions.inject_request_headers[0].secret_env_var = None;
+    hook.actions.inject_request_headers[0].secret_file =
+        Some(secret_file.path().display().to_string());
+    let mut network = NetworkProxySettings {
+        mitm: true,
+        mitm_hooks: vec![hook],
+        mode: NetworkMode::Full,
+        ..NetworkProxySettings::default()
+    };
+    network.set_allowed_domains(vec!["api.github.com".to_string()]);
+    let app_state = Arc::new(network_proxy_state_for_policy(network));
+    let ctx = policy_ctx(
+        app_state.clone(),
+        NetworkMode::Full,
+        "api.github.com",
+        /*target_port*/ 443,
+    );
+    let req = Request::builder()
+        .method(Method::GET)
+        .uri("/repos/openai/codex/issues?token=secret")
+        .header(HOST, "api.github.com")
+        .header("authorization", "Bearer user-supplied")
+        .body(Body::empty())
+        .unwrap();
+
+    let response = mitm_blocking_response(&req, &ctx)
+        .await
+        .unwrap()
+        .expect("hook miss should be blocked");
+
+    assert_eq!(response.status(), StatusCode::FORBIDDEN);
+    assert_eq!(
+        response.headers().get("x-proxy-error").unwrap(),
+        "blocked-by-mitm-hook"
+    );
+
+    let blocked = app_state.drain_blocked().await.unwrap();
+    assert_eq!(blocked.len(), 1);
+    assert_eq!(blocked[0].reason, REASON_MITM_HOOK_DENIED);
+    assert_eq!(blocked[0].method.as_deref(), Some("GET"));
+    assert_eq!(blocked[0].host, "api.github.com");
+    assert_eq!(blocked[0].port, Some(443));
+}
+
+#[test]
+fn apply_mitm_hook_actions_replaces_authorization_header() {
+    let mut headers = HeaderMap::new();
+    headers.append(
+        HeaderName::from_static("authorization"),
+        HeaderValue::from_static("Bearer user-supplied"),
+    );
+    headers.append(
+        HeaderName::from_static("x-request-id"),
+        HeaderValue::from_static("req_123"),
+    );
+
+    let actions = crate::mitm_hook::MitmHookActions {
+        strip_request_headers: vec![HeaderName::from_static("authorization")],
+        inject_request_headers: vec![crate::mitm_hook::ResolvedInjectedHeader {
+            name: HeaderName::from_static("authorization"),
+            value: HeaderValue::from_static("Bearer secret-token"),
+            source: crate::mitm_hook::SecretSource::File(
+                AbsolutePathBuf::try_from("/tmp/github-token").unwrap(),
+            ),
+        }],
+    };
+
+    apply_mitm_hook_actions(&mut headers, Some(&actions));
+
+    assert_eq!(
+        headers.get("authorization"),
+        Some(&HeaderValue::from_static("Bearer secret-token"))
+    );
+    assert_eq!(
+        headers.get("x-request-id"),
+        Some(&HeaderValue::from_static("req_123"))
+    );
+}

codex-rs/network-proxy/src/proxy.rs

@@ -12,6 +12,8 @@ use clap::Parser;
 use std::collections::HashMap;
 use std::net::SocketAddr;
 use std::net::TcpListener as StdTcpListener;
+use std::path::Path;
+use std::path::PathBuf;
 use std::sync::Arc;
 use std::sync::Mutex;
 use std::sync::RwLock;
@@ -223,7 +225,7 @@ impl NetworkProxyBuilder {
             socks_enabled: current_cfg.network.enable_socks5,
             runtime_settings: Arc::new(RwLock::new(NetworkProxyRuntimeSettings::from_config(
                 &current_cfg,
-            ))),
+            )?)),
             reserved_listeners,
             policy_decider: self.policy_decider,
         })
@@ -299,15 +301,22 @@ struct NetworkProxyRuntimeSettings {
     allow_local_binding: bool,
     allow_unix_sockets: Arc<[String]>,
     dangerously_allow_all_unix_sockets: bool,
+    mitm_ca_trust_bundle_path: Option<PathBuf>,
 }
 
 impl NetworkProxyRuntimeSettings {
-    fn from_config(config: &config::NetworkProxyConfig) -> Self {
-        Self {
+    fn from_config(config: &config::NetworkProxyConfig) -> Result<Self> {
+        let mitm_ca_trust_bundle_path = config
+            .network
+            .mitm
+            .then(|| crate::certs::managed_ca_trust_bundle_path(&std::env::vars().collect()))
+            .transpose()?;
+        Ok(Self {
             allow_local_binding: config.network.allow_local_binding,
             allow_unix_sockets: config.network.allow_unix_sockets().into(),
             dangerously_allow_all_unix_sockets: config.network.dangerously_allow_all_unix_sockets,
-        }
+            mitm_ca_trust_bundle_path,
+        })
     }
 }
 
@@ -403,6 +412,16 @@ pub const PROXY_ENV_KEYS: &[&str] = &[
     "all_proxy",
     "FTP_PROXY",
     "ftp_proxy",
+    "CODEX_CA_CERTIFICATE",
+    "SSL_CERT_FILE",
+    "REQUESTS_CA_BUNDLE",
+    "CURL_CA_BUNDLE",
+    "NODE_EXTRA_CA_CERTS",
+    "GIT_SSL_CAINFO",
+    "PIP_CERT",
+    "BUNDLE_SSL_CA_CERT",
+    "npm_config_cafile",
+    "NPM_CONFIG_CAFILE",
 ];
 
 #[cfg(target_os = "macos")]
@@ -475,6 +494,7 @@ fn apply_proxy_env_overrides(
     socks_addr: SocketAddr,
     socks_enabled: bool,
     allow_local_binding: bool,
+    mitm_ca_trust_bundle_path: Option<&Path>,
 ) {
     let http_proxy_url = format!("http://{http_addr}");
     let socks_proxy_url = format!("socks5h://{socks_addr}");
@@ -552,6 +572,26 @@ fn apply_proxy_env_overrides(
             }
         }
     }
+
+    if let Some(mitm_ca_trust_bundle_path) = mitm_ca_trust_bundle_path {
+        let mitm_ca_trust_bundle_path = mitm_ca_trust_bundle_path.to_string_lossy();
+        set_env_keys(
+            env,
+            &[
+                "CODEX_CA_CERTIFICATE",
+                "SSL_CERT_FILE",
+                "REQUESTS_CA_BUNDLE",
+                "CURL_CA_BUNDLE",
+                "NODE_EXTRA_CA_CERTS",
+                "GIT_SSL_CAINFO",
+                "PIP_CERT",
+                "BUNDLE_SSL_CA_CERT",
+                "npm_config_cafile",
+                "NPM_CONFIG_CAFILE",
+            ],
+            &mitm_ca_trust_bundle_path,
+        );
+    }
 }
 
 impl NetworkProxy {
@@ -592,7 +632,7 @@ impl NetworkProxy {
     }
 
     pub fn apply_to_env(&self, env: &mut HashMap<String, String>) {
-        let allow_local_binding = self.allow_local_binding();
+        let runtime_settings = self.runtime_settings();
         // Enforce proxying for child processes. We intentionally override existing values so
         // command-level environment cannot bypass the managed proxy endpoint.
         apply_proxy_env_overrides(
@@ -600,7 +640,8 @@ impl NetworkProxy {
             self.http_addr,
             self.socks_addr,
             self.socks_enabled,
-            allow_local_binding,
+            runtime_settings.allow_local_binding,
+            runtime_settings.mitm_ca_trust_bundle_path.as_deref(),
         );
     }
 
@@ -627,7 +668,7 @@ impl NetworkProxy {
             "cannot update network.enable_socks5_udp on a running proxy"
         );
 
-        let settings = NetworkProxyRuntimeSettings::from_config(&new_state.config);
+        let settings = NetworkProxyRuntimeSettings::from_config(&new_state.config)?;
         self.state.replace_config_state(new_state).await?;
         let mut guard = self
             .runtime_settings
@@ -975,6 +1016,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8081),
             /*socks_enabled*/ true,
             /*allow_local_binding*/ false,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         assert_eq!(
@@ -1037,6 +1079,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8081),
             /*socks_enabled*/ true,
             /*allow_local_binding*/ false,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         for key in env.keys() {
@@ -1049,6 +1092,38 @@ mod tests {
         }
     }
 
+    #[test]
+    fn apply_proxy_env_overrides_sets_mitm_ca_trust_bundle_vars() {
+        let mut env = HashMap::new();
+        let mitm_ca_trust_bundle_path = Path::new("/tmp/codex-proxy/ca-bundle.pem");
+        apply_proxy_env_overrides(
+            &mut env,
+            SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 3128),
+            SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8081),
+            /*socks_enabled*/ true,
+            /*allow_local_binding*/ false,
+            Some(mitm_ca_trust_bundle_path),
+        );
+
+        for key in [
+            "CODEX_CA_CERTIFICATE",
+            "SSL_CERT_FILE",
+            "REQUESTS_CA_BUNDLE",
+            "CURL_CA_BUNDLE",
+            "NODE_EXTRA_CA_CERTS",
+            "GIT_SSL_CAINFO",
+            "PIP_CERT",
+            "BUNDLE_SSL_CA_CERT",
+            "npm_config_cafile",
+            "NPM_CONFIG_CAFILE",
+        ] {
+            assert_eq!(
+                env.get(key),
+                Some(&mitm_ca_trust_bundle_path.display().to_string())
+            );
+        }
+    }
+
     #[test]
     fn apply_proxy_env_overrides_uses_http_for_all_proxy_without_socks() {
         let mut env = HashMap::new();
@@ -1058,6 +1133,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8081),
             /*socks_enabled*/ false,
             /*allow_local_binding*/ true,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         assert_eq!(
@@ -1076,6 +1152,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8081),
             /*socks_enabled*/ true,
             /*allow_local_binding*/ false,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         assert_eq!(
@@ -1124,6 +1201,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 8081),
             /*socks_enabled*/ true,
             /*allow_local_binding*/ false,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         assert_eq!(
@@ -1146,6 +1224,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 48081),
             /*socks_enabled*/ true,
             /*allow_local_binding*/ false,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         assert_eq!(
@@ -1169,6 +1248,7 @@ mod tests {
             SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 48081),
             /*socks_enabled*/ true,
             /*allow_local_binding*/ false,
+            /*mitm_ca_trust_bundle_path*/ None,
         );
 
         assert_eq!(

codex-rs/network-proxy/src/reasons.rs

@@ -1,5 +1,6 @@
 pub(crate) const REASON_DENIED: &str = "denied";
 pub(crate) const REASON_METHOD_NOT_ALLOWED: &str = "method_not_allowed";
+pub(crate) const REASON_MITM_HOOK_DENIED: &str = "mitm_hook_denied";
 pub(crate) const REASON_MITM_REQUIRED: &str = "mitm_required";
 pub(crate) const REASON_NOT_ALLOWED: &str = "not_allowed";
 pub(crate) const REASON_NOT_ALLOWED_LOCAL: &str = "not_allowed_local";

codex-rs/network-proxy/src/responses.rs

@@ -3,6 +3,7 @@ use crate::network_policy::NetworkPolicyDecision;
 use crate::network_policy::NetworkProtocol;
 use crate::reasons::REASON_DENIED;
 use crate::reasons::REASON_METHOD_NOT_ALLOWED;
+use crate::reasons::REASON_MITM_HOOK_DENIED;
 use crate::reasons::REASON_MITM_REQUIRED;
 use crate::reasons::REASON_NOT_ALLOWED;
 use crate::reasons::REASON_NOT_ALLOWED_LOCAL;
@@ -53,6 +54,7 @@ pub fn blocked_header_value(reason: &str) -> &'static str {
         REASON_NOT_ALLOWED | REASON_NOT_ALLOWED_LOCAL => "blocked-by-allowlist",
         REASON_DENIED => "blocked-by-denylist",
         REASON_METHOD_NOT_ALLOWED => "blocked-by-method-policy",
+        REASON_MITM_HOOK_DENIED => "blocked-by-mitm-hook",
         REASON_MITM_REQUIRED => "blocked-by-mitm-required",
         _ => "blocked-by-policy",
     }
@@ -64,6 +66,7 @@ pub fn blocked_message(reason: &str) -> &'static str {
         REASON_NOT_ALLOWED_LOCAL => "Sandbox policy blocks local/private network addresses.",
         REASON_DENIED => "Domain denied by the sandbox policy.",
         REASON_METHOD_NOT_ALLOWED => "Method not allowed in limited mode.",
+        REASON_MITM_HOOK_DENIED => "HTTPS request denied by MITM hook policy.",
         REASON_MITM_REQUIRED => "MITM required for limited HTTPS.",
         REASON_PROXY_DISABLED => "network proxy is disabled",
         _ => "Request blocked by network policy.",

codex-rs/network-proxy/src/runtime.rs

@@ -3,6 +3,9 @@ use crate::config::NetworkMode;
 use crate::config::NetworkProxyConfig;
 use crate::config::ValidatedUnixSocketPath;
 use crate::mitm::MitmState;
+use crate::mitm_hook::HookEvaluation;
+use crate::mitm_hook::MitmHooksByHost;
+use crate::mitm_hook::evaluate_mitm_hooks;
 use crate::policy::Host;
 use crate::policy::is_loopback_host;
 use crate::policy::is_non_public_ip;
@@ -159,6 +162,7 @@ pub struct ConfigState {
     pub allow_set: GlobSet,
     pub deny_set: GlobSet,
     pub mitm: Option<Arc<MitmState>>,
+    pub mitm_hooks: MitmHooksByHost,
     pub constraints: NetworkProxyConstraints,
     pub blocked: VecDeque<BlockedRequest>,
     pub blocked_total: u64,
@@ -585,6 +589,22 @@ impl NetworkProxyState {
         Ok(guard.mitm.clone())
     }
 
+    pub(crate) async fn evaluate_mitm_hook_request(
+        &self,
+        host: &str,
+        req: &rama_http::Request,
+    ) -> Result<HookEvaluation> {
+        self.reload_if_needed().await?;
+        let guard = self.state.read().await;
+        Ok(evaluate_mitm_hooks(&guard.mitm_hooks, host, req))
+    }
+
+    pub async fn host_has_mitm_hooks(&self, host: &str) -> Result<bool> {
+        self.reload_if_needed().await?;
+        let guard = self.state.read().await;
+        Ok(guard.mitm_hooks.contains_key(&normalize_host(host)))
+    }
+
     pub async fn add_allowed_domain(&self, host: &str) -> Result<()> {
         self.update_domain_list(host, DomainListKind::Allow).await
     }
@@ -846,9 +866,23 @@ pub(crate) fn network_proxy_state_for_policy(
     mut network: crate::config::NetworkProxySettings,
 ) -> NetworkProxyState {
     network.enabled = true;
-    network.mode = NetworkMode::Full;
     let config = NetworkProxyConfig { network };
-    let state = build_config_state(config, NetworkProxyConstraints::default()).unwrap();
+    let state = ConfigState {
+        allow_set: crate::policy::compile_allowlist_globset(
+            &config.network.allowed_domains().unwrap_or_default(),
+        )
+        .unwrap(),
+        blocked: VecDeque::new(),
+        blocked_total: 0,
+        config: config.clone(),
+        constraints: NetworkProxyConstraints::default(),
+        deny_set: crate::policy::compile_denylist_globset(
+            &config.network.denied_domains().unwrap_or_default(),
+        )
+        .unwrap(),
+        mitm: None,
+        mitm_hooks: crate::mitm_hook::compile_mitm_hooks(&config).unwrap(),
+    };
 
     NetworkProxyState::with_reloader(state, Arc::new(NoopReloader))
 }

codex-rs/network-proxy/src/state.rs

@@ -4,6 +4,9 @@ use crate::config::NetworkProxyConfig;
 use crate::config::NetworkUnixSocketPermissions;
 use crate::mitm::MitmState;
 use crate::mitm::MitmUpstreamConfig;
+use crate::mitm_hook::MitmHookConfig;
+use crate::mitm_hook::compile_mitm_hooks;
+use crate::mitm_hook::validate_mitm_hook_config;
 use crate::policy::DomainPattern;
 use crate::policy::compile_allowlist_globset;
 use crate::policy::compile_denylist_globset;
@@ -53,6 +56,9 @@ pub struct PartialNetworkConfig {
     #[serde(default)]
     pub unix_sockets: Option<NetworkUnixSocketPermissions>,
     pub allow_local_binding: Option<bool>,
+    pub mitm: Option<bool>,
+    #[serde(default)]
+    pub mitm_hooks: Option<Vec<MitmHookConfig>>,
 }
 
 pub fn build_config_state(
@@ -66,6 +72,7 @@ pub fn build_config_state(
         .map_err(NetworkProxyConstraintError::into_anyhow)?;
     let deny_set = compile_denylist_globset(&denied_domains)?;
     let allow_set = compile_allowlist_globset(&allowed_domains)?;
+    let mitm_hooks = compile_mitm_hooks(&config)?;
     let mitm = if config.network.mitm {
         Some(Arc::new(MitmState::new(MitmUpstreamConfig {
             allow_upstream_proxy: config.network.allow_upstream_proxy,
@@ -79,6 +86,7 @@ pub fn build_config_state(
         allow_set,
         deny_set,
         mitm,
+        mitm_hooks,
         constraints,
         blocked: std::collections::VecDeque::new(),
         blocked_total: 0,
@@ -116,6 +124,7 @@ pub fn validate_policy_against_constraints(
         .map(|entry| entry.to_ascii_lowercase())
         .collect();
     let config_allow_unix_sockets = config.network.allow_unix_sockets();
+    validate_mitm_hook_config(config).map_err(invalid_mitm_hook_configuration)?;
     validate_non_global_wildcard_domain_patterns("network.denied_domains", &config_denied_domains)?;
     if let Some(max_enabled) = constraints.enabled {
         validate(enabled, move |candidate| {
@@ -376,6 +385,14 @@ pub fn validate_policy_against_constraints(
     Ok(())
 }
 
+fn invalid_mitm_hook_configuration(err: anyhow::Error) -> NetworkProxyConstraintError {
+    NetworkProxyConstraintError::InvalidValue {
+        field_name: "network.mitm_hooks",
+        candidate: err.to_string(),
+        allowed: "valid MITM hook configuration".to_string(),
+    }
+}
+
 fn validate_non_global_wildcard_domain_patterns(
     field_name: &'static str,
     patterns: &[String],

codex-rs/network-proxy/src/upstream.rs

@@ -1,5 +1,6 @@
 use crate::connect_policy::TargetCheckedTcpConnector;
 use crate::state::NetworkProxyState;
+use codex_utils_rustls_provider::ensure_rustls_crypto_provider;
 use rama_core::Layer;
 use rama_core::Service;
 use rama_core::error::BoxError;
@@ -225,6 +226,7 @@ fn build_http_connector(
     EstablishedClientConnection<HttpClientService<Body>, Request<Body>>,
     BoxError,
 > {
+    ensure_rustls_crypto_provider();
     let proxy = HttpProxyConnectorLayer::optional().into_layer(transport);
     let tls_config = TlsConnectorDataBuilder::new()
         .with_alpn_protocols_http_auto()