diff --git a/codex-rs/core/src/environment_selection.rs b/codex-rs/core/src/environment_selection.rs
index d96d9425db..013db32cf2 100644
--- a/codex-rs/core/src/environment_selection.rs
+++ b/codex-rs/core/src/environment_selection.rs
@@ -41,14 +41,17 @@ impl ResolvedTurnEnvironments {
         self.turn_environments.first()
     }
 
-    pub(crate) fn get(&self, environment_id: &str) -> Option<&TurnEnvironment> {
+    pub(crate) fn get_by_id(&self, environment_id: &str) -> Option<&TurnEnvironment> {
         self.turn_environments
             .iter()
             .find(|environment| environment.environment_id == environment_id)
     }
 
-    pub(crate) fn select(&self, environment_id: Option<&str>) -> Option<&TurnEnvironment> {
-        environment_id.map_or_else(|| self.primary(), |environment_id| self.get(environment_id))
+    pub(crate) fn get_or_primary(&self, environment_id: Option<&str>) -> Option<&TurnEnvironment> {
+        environment_id.map_or_else(
+            || self.primary(),
+            |environment_id| self.get_by_id(environment_id),
+        )
     }
 
     pub(crate) fn primary_environment(&self) -> Option<Arc<codex_exec_server::Environment>> {
@@ -189,7 +192,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn resolved_environment_selections_selects_by_id_or_primary() {
+    async fn resolved_environment_selections_gets_by_id_or_primary() {
         let cwd = AbsolutePathBuf::current_dir().expect("cwd");
         let manager = EnvironmentManager::default_for_tests();
 
@@ -204,18 +207,18 @@ mod tests {
 
         assert_eq!(
             resolved
-                .select(/*environment_id*/ None)
+                .get_or_primary(/*environment_id*/ None)
                 .expect("primary environment")
                 .environment_id,
             "local"
         );
         assert_eq!(
             resolved
-                .select(Some("local"))
+                .get_or_primary(Some("local"))
                 .expect("selected environment")
                 .environment_id,
             "local"
         );
-        assert!(resolved.select(Some("unknown")).is_none());
+        assert!(resolved.get_or_primary(Some("unknown")).is_none());
     }
 }
diff --git a/codex-rs/core/src/tools/handlers/mod.rs b/codex-rs/core/src/tools/handlers/mod.rs
index ae915e33ef..27058d059b 100644
--- a/codex-rs/core/src/tools/handlers/mod.rs
+++ b/codex-rs/core/src/tools/handlers/mod.rs
@@ -94,7 +94,7 @@ fn resolve_workdir_base_path(
 }
 
 #[derive(Debug, Deserialize)]
-struct EnvironmentWorkdirArgs {
+struct EnvironmentTargetArgs {
     #[serde(default)]
     environment_id: Option<String>,
     // Keep this raw until after environment selection; relative paths must be
@@ -108,12 +108,13 @@ struct EnvironmentWorkdirArgs {
 /// Returns the selected turn environment plus the effective execution cwd. The
 /// returned cwd is `turn_environment.cwd.join(workdir)` when `workdir` is
 /// provided and non-empty, otherwise it is the selected `turn_environment.cwd`.
-fn resolve_environment_workdir_target(
+fn resolve_environment_target(
     arguments: &str,
     environments: &ResolvedTurnEnvironments,
 ) -> Result<Option<(TurnEnvironment, AbsolutePathBuf)>, FunctionCallError> {
-    let target_args: EnvironmentWorkdirArgs = parse_arguments(arguments)?;
-    let Some(turn_environment) = environments.select(target_args.environment_id.as_deref()) else {
+    let target_args: EnvironmentTargetArgs = parse_arguments(arguments)?;
+    let Some(turn_environment) = environments.get_or_primary(target_args.environment_id.as_deref())
+    else {
         return Ok(None);
     };
     let cwd = target_args
diff --git a/codex-rs/core/src/tools/handlers/shell.rs b/codex-rs/core/src/tools/handlers/shell.rs
index ea91e27ec4..3dd17c5e8a 100644
--- a/codex-rs/core/src/tools/handlers/shell.rs
+++ b/codex-rs/core/src/tools/handlers/shell.rs
@@ -26,8 +26,7 @@ use crate::tools::handlers::implicit_granted_permissions;
 use crate::tools::handlers::normalize_and_validate_additional_permissions;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::handlers::parse_arguments_with_base_path;
-use crate::tools::handlers::resolve_environment_workdir_target;
-use crate::tools::handlers::resolve_workdir_base_path;
+use crate::tools::handlers::resolve_environment_target;
 use crate::tools::hook_names::HookToolName;
 use crate::tools::orchestrator::ToolOrchestrator;
 use crate::tools::registry::PostToolUsePayload;
@@ -109,10 +108,11 @@ impl ShellHandler {
         params: &ShellToolCallParams,
         turn_context: &TurnContext,
         thread_id: ThreadId,
+        cwd: codex_utils_absolute_path::AbsolutePathBuf,
     ) -> ExecParams {
         ExecParams {
             command: params.command.clone(),
-            cwd: turn_context.resolve_path(params.workdir.clone()),
+            cwd,
             expiration: params.timeout_ms.into(),
             capture_policy: ExecCapturePolicy::ShellTool,
             env: create_env(&turn_context.shell_environment_policy, Some(thread_id)),
@@ -254,7 +254,7 @@ impl ToolHandler for ShellHandler {
         let params: ShellToolCallParams = parse_arguments_with_base_path(&arguments, &cwd)?;
         let prefix_rule = params.prefix_rule.clone();
         let exec_params =
-            ShellHandler::to_exec_params(&params, turn.as_ref(), session.conversation_id);
+            ShellHandler::to_exec_params(&params, turn.as_ref(), session.conversation_id, cwd);
         ShellHandler::run_exec_like(RunExecLikeArgs {
             tool_name: "shell".to_string(),
             exec_params,
@@ -341,7 +341,7 @@ impl ToolHandler for ContainerExecHandler {
         let params: ShellToolCallParams = parse_arguments_with_base_path(&arguments, &cwd)?;
         let prefix_rule = params.prefix_rule.clone();
         let exec_params =
-            ShellHandler::to_exec_params(&params, turn.as_ref(), session.conversation_id);
+            ShellHandler::to_exec_params(&params, turn.as_ref(), session.conversation_id, cwd);
         ShellHandler::run_exec_like(RunExecLikeArgs {
             tool_name: "container.exec".to_string(),
             exec_params,
@@ -430,8 +430,12 @@ impl ToolHandler for LocalShellHandler {
             ));
         };
 
-        let exec_params =
-            ShellHandler::to_exec_params(&params, turn.as_ref(), session.conversation_id);
+        let exec_params = ShellHandler::to_exec_params(
+            &params,
+            turn.as_ref(),
+            session.conversation_id,
+            turn.resolve_path(params.workdir.clone()),
+        );
         ShellHandler::run_exec_like(RunExecLikeArgs {
             tool_name: "local_shell".to_string(),
             exec_params,
@@ -556,7 +560,7 @@ impl ToolHandler for ShellCommandHandler {
         };
 
         let Some((turn_environment, cwd)) =
-            resolve_environment_workdir_target(&arguments, &turn.environments)?
+            resolve_environment_target(&arguments, &turn.environments)?
         else {
             return Err(FunctionCallError::RespondToModel(
                 "shell is unavailable in this session".to_string(),
diff --git a/codex-rs/core/src/tools/handlers/unified_exec.rs b/codex-rs/core/src/tools/handlers/unified_exec.rs
index 4cc7e52760..4612e8be24 100644
--- a/codex-rs/core/src/tools/handlers/unified_exec.rs
+++ b/codex-rs/core/src/tools/handlers/unified_exec.rs
@@ -13,7 +13,7 @@ use crate::tools::handlers::implicit_granted_permissions;
 use crate::tools::handlers::normalize_and_validate_additional_permissions;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::handlers::parse_arguments_with_base_path;
-use crate::tools::handlers::resolve_environment_workdir_target;
+use crate::tools::handlers::resolve_environment_target;
 use crate::tools::hook_names::HookToolName;
 use crate::tools::registry::PostToolUsePayload;
 use crate::tools::registry::PreToolUsePayload;
@@ -182,7 +182,7 @@ impl ToolHandler for ExecCommandHandler {
         let manager: &UnifiedExecProcessManager = &session.services.unified_exec_manager;
         let context = UnifiedExecContext::new(session.clone(), turn.clone(), call_id.clone());
         let Some((turn_environment, cwd)) =
-            resolve_environment_workdir_target(&arguments, &turn.environments)?
+            resolve_environment_target(&arguments, &turn.environments)?
         else {
             return Err(FunctionCallError::RespondToModel(
                 "unified exec is unavailable in this session".to_string(),