diff --git a/codex-rs/app-server/src/request_processors/user_instructions.rs b/codex-rs/app-server/src/request_processors/user_instructions.rs
index 0696b4ad51..ae9a4dce3c 100644
--- a/codex-rs/app-server/src/request_processors/user_instructions.rs
+++ b/codex-rs/app-server/src/request_processors/user_instructions.rs
@@ -1,6 +1,7 @@
+use codex_core::AgentsMdManager;
 use codex_core::ThreadManager;
 use codex_core::config::Config;
-use codex_core::load_thread_user_instructions as preload_thread_user_instructions;
+use codex_protocol::error::CodexErr;
 use codex_protocol::error::Result as CodexResult;
 use codex_protocol::protocol::TurnEnvironmentSelection;
 
@@ -11,10 +12,24 @@ pub(super) async fn load_thread_user_instructions(
     config: &mut Config,
     environments: &[TurnEnvironmentSelection],
 ) -> CodexResult<()> {
-    preload_thread_user_instructions(
-        config,
-        thread_manager.environment_manager().as_ref(),
-        environments,
-    )
-    .await
+    let Some(primary_selection) = environments.first() else {
+        config.user_instructions = None;
+        return Ok(());
+    };
+    let environment = thread_manager
+        .environment_manager()
+        .get_environment(&primary_selection.environment_id)
+        .ok_or_else(|| {
+            CodexErr::InvalidRequest(format!(
+                "unknown turn environment id `{}`",
+                primary_selection.environment_id
+            ))
+        })?;
+    let mut warnings = Vec::new();
+    let user_instructions = AgentsMdManager::new(config)
+        .load_user_instructions(environment.as_ref(), &mut warnings)
+        .await;
+    config.startup_warnings.extend(warnings);
+    config.user_instructions = user_instructions;
+    Ok(())
 }
diff --git a/codex-rs/core-api/src/lib.rs b/codex-rs/core-api/src/lib.rs
index cd7cf2a1c3..4951f1286e 100644
--- a/codex-rs/core-api/src/lib.rs
+++ b/codex-rs/core-api/src/lib.rs
@@ -42,7 +42,6 @@ pub use codex_core::config::TerminalResizeReflowConfig;
 pub use codex_core::config::ThreadStoreConfig;
 pub use codex_core::config::find_codex_home;
 pub use codex_core::init_state_db;
-pub use codex_core::load_thread_user_instructions;
 pub use codex_core::resolve_installation_id;
 pub use codex_core::skills::SkillsManager;
 pub use codex_core::thread_store_from_config;
@@ -78,4 +77,36 @@ pub use codex_protocol::protocol::SessionSource;
 pub use codex_protocol::protocol::TurnEnvironmentSelection;
 pub use codex_protocol::protocol::W3cTraceContext;
 pub use codex_protocol::user_input::UserInput;
+
+/// Preloads AGENTS.md instructions for thread construction from the primary
+/// selected environment.
+///
+/// Call this after the selected environments have been materialized and before
+/// passing `config` to a thread start, resume, or fork operation. When no
+/// environment is selected, this clears [`Config::user_instructions`].
+pub async fn load_thread_user_instructions(
+    config: &mut Config,
+    environment_manager: &EnvironmentManager,
+    environments: &[TurnEnvironmentSelection],
+) -> CodexResult<()> {
+    let Some(primary_selection) = environments.first() else {
+        config.user_instructions = None;
+        return Ok(());
+    };
+    let environment = environment_manager
+        .get_environment(&primary_selection.environment_id)
+        .ok_or_else(|| {
+            codex_protocol::error::CodexErr::InvalidRequest(format!(
+                "unknown turn environment id `{}`",
+                primary_selection.environment_id
+            ))
+        })?;
+    let mut warnings = Vec::new();
+    let user_instructions = codex_core::AgentsMdManager::new(config)
+        .load_user_instructions(environment.as_ref(), &mut warnings)
+        .await;
+    config.startup_warnings.extend(warnings);
+    config.user_instructions = user_instructions;
+    Ok(())
+}
 pub use codex_utils_absolute_path::AbsolutePathBuf;
diff --git a/codex-rs/core/src/agents_md.rs b/codex-rs/core/src/agents_md.rs
index ba7b59c328..0cba5b4f17 100644
--- a/codex-rs/core/src/agents_md.rs
+++ b/codex-rs/core/src/agents_md.rs
@@ -22,13 +22,9 @@ use codex_config::default_project_root_markers;
 use codex_config::merge_toml_values;
 use codex_config::project_root_markers_from_config;
 use codex_exec_server::Environment;
-use codex_exec_server::EnvironmentManager;
 use codex_exec_server::ExecutorFileSystem;
 use codex_features::Feature;
 use codex_prompts::HIERARCHICAL_AGENTS_MESSAGE;
-use codex_protocol::error::CodexErr;
-use codex_protocol::error::Result as CodexResult;
-use codex_protocol::protocol::TurnEnvironmentSelection;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use std::io;
 use toml::Value as TomlValue;
@@ -43,38 +39,6 @@ pub const LOCAL_AGENTS_MD_FILENAME: &str = "AGENTS.override.md";
 /// concatenated with the following separator.
 const AGENTS_MD_SEPARATOR: &str = "\n\n--- project-doc ---\n\n";
 
-/// Preloads AGENTS.md instructions for thread construction from the primary
-/// selected environment.
-///
-/// Call this after the selected environments have been materialized and before
-/// passing `config` to a thread start, resume, or fork operation. When no
-/// environment is selected, this clears [`Config::user_instructions`].
-pub async fn load_thread_user_instructions(
-    config: &mut Config,
-    environment_manager: &EnvironmentManager,
-    environments: &[TurnEnvironmentSelection],
-) -> CodexResult<()> {
-    let Some(primary_selection) = environments.first() else {
-        config.user_instructions = None;
-        return Ok(());
-    };
-    let environment = environment_manager
-        .get_environment(&primary_selection.environment_id)
-        .ok_or_else(|| {
-            CodexErr::InvalidRequest(format!(
-                "unknown turn environment id `{}`",
-                primary_selection.environment_id
-            ))
-        })?;
-    let mut warnings = Vec::new();
-    let user_instructions = AgentsMdManager::new(config)
-        .load_user_instructions(environment.as_ref(), &mut warnings)
-        .await;
-    config.startup_warnings.extend(warnings);
-    config.user_instructions = user_instructions;
-    Ok(())
-}
-
 /// Resolves AGENTS.md files into model-visible user instructions and source
 /// paths.
 pub struct AgentsMdManager<'a> {
diff --git a/codex-rs/core/src/agents_md_tests.rs b/codex-rs/core/src/agents_md_tests.rs
index 477302e8ee..f7b313c4a1 100644
--- a/codex-rs/core/src/agents_md_tests.rs
+++ b/codex-rs/core/src/agents_md_tests.rs
@@ -1,9 +1,7 @@
 use super::*;
 use crate::config::ConfigBuilder;
-use codex_exec_server::EnvironmentManager;
 use codex_exec_server::LOCAL_FS;
 use codex_features::Feature;
-use codex_protocol::protocol::TurnEnvironmentSelection;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use core_test_support::PathBufExt;
 use core_test_support::TempDirExt;
@@ -400,34 +398,6 @@ async fn resolving_again_replaces_project_instructions() {
     );
 }
 
-#[tokio::test]
-async fn load_thread_user_instructions_uses_primary_environment() {
-    let tmp = tempfile::tempdir().expect("tempdir");
-    fs::write(tmp.path().join("AGENTS.md"), "project instructions").unwrap();
-    let mut config = make_config(&tmp, /*limit*/ 4096, Some("user instructions")).await;
-    let environment_manager = EnvironmentManager::default_for_tests();
-    let environment_id = environment_manager
-        .default_environment_id()
-        .expect("default environment")
-        .to_string();
-    let environments = vec![TurnEnvironmentSelection {
-        environment_id,
-        cwd: config.cwd.clone(),
-    }];
-
-    load_thread_user_instructions(&mut config, &environment_manager, &environments)
-        .await
-        .expect("load thread instructions");
-
-    assert_eq!(
-        config
-            .user_instructions
-            .expect("instructions expected")
-            .text(),
-        format!("user instructions{AGENTS_MD_SEPARATOR}project instructions")
-    );
-}
-
 /// When both the repository root and the working directory contain
 /// AGENTS.md files, their contents are concatenated from root to cwd.
 #[tokio::test]
diff --git a/codex-rs/core/src/lib.rs b/codex-rs/core/src/lib.rs
index 28ae2b62b0..4dc19de7e6 100644
--- a/codex-rs/core/src/lib.rs
+++ b/codex-rs/core/src/lib.rs
@@ -131,7 +131,6 @@ pub use agents_md::AgentsMdManager;
 pub use agents_md::DEFAULT_AGENTS_MD_FILENAME;
 pub use agents_md::LOCAL_AGENTS_MD_FILENAME;
 pub use agents_md::LoadedAgentsMd;
-pub use agents_md::load_thread_user_instructions;
 mod rollout;
 pub(crate) mod safety;
 mod session_rollout_init_error;
diff --git a/codex-rs/memories/write/src/runtime.rs b/codex-rs/memories/write/src/runtime.rs
index 3b72a3454e..0c5534c1a2 100644
--- a/codex-rs/memories/write/src/runtime.rs
+++ b/codex-rs/memories/write/src/runtime.rs
@@ -1,3 +1,4 @@
+use codex_core::AgentsMdManager;
 use codex_core::CodexThread;
 use codex_core::ModelClient;
 use codex_core::NewThread;
@@ -7,7 +8,6 @@ use codex_core::StartThreadOptions;
 use codex_core::ThreadManager;
 use codex_core::config::Config;
 use codex_core::content_items_to_text;
-use codex_core::load_thread_user_instructions;
 use codex_core::resolve_installation_id;
 use codex_features::Feature;
 use codex_login::AuthManager;
@@ -237,12 +237,20 @@ impl MemoryStartupContext {
         let environments = self
             .thread_manager
             .default_environment_selections(&config.cwd);
-        load_thread_user_instructions(
-            &mut config,
-            self.thread_manager.environment_manager().as_ref(),
-            &environments,
-        )
-        .await?;
+        let mut warnings = Vec::new();
+        config.user_instructions = match environments.first().and_then(|selection| {
+            self.thread_manager
+                .environment_manager()
+                .get_environment(&selection.environment_id)
+        }) {
+            Some(environment) => {
+                AgentsMdManager::new(&config)
+                    .load_user_instructions(environment.as_ref(), &mut warnings)
+                    .await
+            }
+            None => None,
+        };
+        config.startup_warnings.extend(warnings);
         let NewThread {
             thread_id, thread, ..
         } = self