codex/codex-rs/core/src/agent/control_tests.rs

use super::*;
use crate::CodexThread;
use crate::StateDbHandle;
use crate::ThreadManager;
use crate::agent::agent_status_from_event;
use crate::agent::next_thread_spawn_depth;
use crate::agent_communication::AgentCommunicationContext;
use crate::agent_communication::AgentCommunicationKind;
use crate::config::AgentRoleConfig;
use crate::config::Config;
use crate::config::ConfigBuilder;
use crate::context::ContextualUserFragment;
use crate::context::ManagedDeveloperInstructions;
use crate::context::MultiAgentRoleInstructions;
use crate::context::SubagentNotification;
use crate::init_state_db;
use crate::session::SessionSettingsUpdate;
use crate::thread_manager::StartThreadOptions;
use crate::tools::handlers::multi_agents_common::thread_spawn_source;
use assert_matches::assert_matches;
use codex_extension_api::ExtensionDataInit;
use codex_extension_api::Instructions;
use codex_extension_api::LoadInstructionsFuture;
use codex_extension_api::LoadedUserInstructions;
use codex_extension_api::ThreadInstructionsProvider;
use codex_extension_api::empty_extension_registry;
use codex_features::Feature;
use codex_history::CompactedItem;
use codex_history::InitialHistory;
use codex_history::ResumedHistory;
use codex_history::RolloutItem;
use codex_login::AuthManager;
use codex_login::CodexAuth;
use codex_protocol::AgentPath;
use codex_protocol::ResponseItemId;
use codex_protocol::capabilities::CapabilityRootLocation;
use codex_protocol::capabilities::SelectedCapabilityRoot;
use codex_protocol::config_types::ApprovalsReviewer;
use codex_protocol::config_types::CollaborationMode;
use codex_protocol::config_types::ModeKind;
use codex_protocol::config_types::Settings;
use codex_protocol::error::CodexErrorDetails;
use codex_protocol::items::TurnItem;
use codex_protocol::items::UserMessageItem;
use codex_protocol::mcp::ClientMcpExtensions;
use codex_protocol::mcp::OPENAI_FORM_EXTENSION_ID;
use codex_protocol::models::ContentItem;
use codex_protocol::models::ContentItemKind;
use codex_protocol::models::FunctionCallOutputPayload;
use codex_protocol::models::InternalChatMessageMetadataPassthrough;
use codex_protocol::models::MessagePhase;
use codex_protocol::models::PermissionProfile;
use codex_protocol::models::ResponseItem;
use codex_protocol::protocol::AskForApproval;
use codex_protocol::protocol::EnvironmentConfigState;
use codex_protocol::protocol::ErrorEvent;
use codex_protocol::protocol::EventMsg;
use codex_protocol::protocol::InterAgentCommunication;
use codex_protocol::protocol::ItemCompletedEvent;
use codex_protocol::protocol::SessionSource;
use codex_protocol::protocol::SubAgentSource;
use codex_protocol::protocol::ThreadHistoryMode;
use codex_protocol::protocol::ThreadSettingsAppliedEvent;
use codex_protocol::protocol::ThreadSettingsSnapshot;
use codex_protocol::protocol::TokenUsage;
use codex_protocol::protocol::TokenUsageRecord;
use codex_protocol::protocol::TurnAbortReason;
use codex_protocol::protocol::TurnAbortedEvent;
use codex_protocol::protocol::TurnCompleteEvent;
use codex_protocol::protocol::TurnEnvironmentSelections;
use codex_protocol::protocol::TurnStartedEvent;
use codex_thread_store::ArchiveThreadParams;
use codex_thread_store::InMemoryThreadStore;
use codex_thread_store::LocalThreadStore;
use codex_thread_store::LocalThreadStoreConfig;
use codex_thread_store::PersistContext;
use codex_thread_store::ThreadStore;
use codex_utils_path_uri::PathUri;
use core_test_support::responses::strip_response_item_ids;
use pretty_assertions::assert_eq;
use tempfile::TempDir;
use tokio::time::Duration;
use tokio::time::sleep;
use tokio::time::timeout;
use toml::Value as TomlValue;

async fn test_config_with_cli_overrides(
    mut cli_overrides: Vec<(String, TomlValue)>,
) -> (TempDir, Config) {
    let home = TempDir::new().expect("create temp dir");
    cli_overrides.push((
        "model".to_string(),
        TomlValue::String("gpt-5.5".to_string()),
    ));
    let config = ConfigBuilder::without_managed_config_for_tests()
        .codex_home(home.path().to_path_buf())
        .cli_overrides(cli_overrides)
        .build()
        .await
        .expect("load default test config");
    (home, config)
}

async fn test_config() -> (TempDir, Config) {
    test_config_with_cli_overrides(Vec::new()).await
}

fn text_input(text: &str) -> Vec<UserInput> {
    vec![UserInput::Text {
        text: text.to_string(),
        text_elements: Vec::new(),
    }]
}

fn captured_op_matches(actual: &(ThreadId, Op), expected: &(ThreadId, Op)) -> bool {
    if actual.0 != expected.0 {
        return false;
    }
    match (&actual.1, &expected.1) {
        (
            Op::InterAgentCommunication {
                communication: actual,
                ..
            },
            Op::InterAgentCommunication {
                communication: expected,
                ..
            },
        ) => actual == expected,
        _ => false,
    }
}

fn rollout_response_item(item: ResponseItem) -> RolloutItem {
    RolloutItem::ResponseItem(item.into())
}

fn user_message(text: &str) -> ResponseItem {
    ResponseItem::Message {
        id: None,
        role: "user".to_string(),
        content: vec![ContentItem::InputText {
            text: text.to_string(),
        }],
        phase: None,
        internal_chat_message_metadata_passthrough: None,
    }
}

fn assistant_message(text: &str, phase: Option<MessagePhase>) -> ResponseItem {
    ResponseItem::Message {
        id: None,
        role: "assistant".to_string(),
        content: vec![ContentItem::OutputText {
            text: text.to_string(),
        }],
        phase,
        internal_chat_message_metadata_passthrough: None,
    }
}

#[test]
fn register_session_root_skips_threads_with_explicit_parent() {
    let control = AgentControl::default();

    control.register_session_root(ThreadId::new(), Some(ThreadId::new()));

    assert_eq!(control.state.agent_id_for_path(&AgentPath::root()), None);
}

fn spawn_agent_call(call_id: &str) -> ResponseItem {
    ResponseItem::FunctionCall {
        id: None,
        name: "spawn_agent".to_string(),
        namespace: None,
        arguments: "{}".to_string(),
        call_id: call_id.to_string(),
        encrypted_function_args: None,
        internal_chat_message_metadata_passthrough: None,
    }
}

struct AgentControlHarness {
    _home: TempDir,
    config: Config,
    state_db: Option<StateDbHandle>,
    manager: ThreadManager,
    control: AgentControl,
}

impl AgentControlHarness {
    async fn new() -> Self {
        let (home, config) = test_config().await;
        Self::new_with_config(home, config).await
    }

    async fn new_with_config(home: TempDir, config: Config) -> Self {
        let state_db = init_state_db(&config).await;
        let manager = ThreadManager::with_models_provider_home_and_state_for_tests(
            CodexAuth::from_api_key("dummy"),
            config.model_provider.clone(),
            config.codex_home.to_path_buf(),
            std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
            state_db.clone(),
        );
        let control = manager.agent_control();
        Self {
            _home: home,
            config,
            state_db,
            manager,
            control,
        }
    }

    async fn start_thread(&self) -> (ThreadId, Arc<CodexThread>) {
        let new_thread = self
            .manager
            .start_thread(StartThreadOptions::new(self.config.clone()))
            .await
            .expect("start thread");
        (new_thread.thread_id, new_thread.thread)
    }

    async fn start_paginated_thread(&self) -> (ThreadId, Arc<CodexThread>) {
        let new_thread = self
            .manager
            .start_thread(StartThreadOptions {
                history_mode: Some(ThreadHistoryMode::Paginated),
                environments: Some(Vec::new()),
                ..StartThreadOptions::new(self.config.clone())
            })
            .await
            .expect("start paginated thread");
        (new_thread.thread_id, new_thread.thread)
    }

    async fn spawn_anonymous_child(
        &self,
        parent_thread_id: ThreadId,
        options: SpawnAgentOptions,
    ) -> ThreadId {
        self.control
            .spawn_agent_with_metadata(
                self.config.clone(),
                text_input("child task"),
                Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                    parent_thread_id,
                    depth: 1,
                    agent_path: None,
                    agent_nickname: None,
                    agent_role: None,
                })),
                options,
            )
            .await
            .expect("child spawn should succeed")
            .thread_id
    }
}

async fn persisted_originator(thread: &CodexThread) -> String {
    thread.ensure_rollout_materialized().await;
    thread
        .flush_rollout()
        .await
        .expect("thread rollout should flush");
    let stored_thread = thread
        .read_thread(
            /*include_archived*/ true, /*include_history*/ true,
        )
        .await
        .expect("thread should be readable");
    let history = stored_thread.history.expect("history should be loaded");
    history
        .items
        .iter()
        .find_map(|item| match item {
            RolloutItem::SessionMeta(meta_line) => Some(meta_line.meta.originator.clone()),
            RolloutItem::ResponseItem(_)
            | RolloutItem::InterAgentCommunication(_)
            | RolloutItem::InterAgentCommunicationMetadata { .. }
            | RolloutItem::EventMsg(_)
            | RolloutItem::Compacted(_)
            | RolloutItem::WorldState(_)
            | RolloutItem::RealtimeItem(_)
            | RolloutItem::RetainedContext(_)
            | RolloutItem::SecurityRiskScore(_)
            | RolloutItem::TokenUsageRecord(_)
            | RolloutItem::TurnContext(_) => None,
        })
        .expect("session metadata should be persisted")
}

fn has_subagent_notification<'a>(
    history_items: impl IntoIterator<Item = &'a ResponseItem>,
) -> bool {
    history_items.into_iter().any(|item| {
        let ResponseItem::Message { role, content, .. } = item else {
            return false;
        };
        if role != "user" {
            return false;
        }
        content.iter().any(|content_item| match content_item {
            ContentItem::InputText { text } | ContentItem::OutputText { text } => {
                SubagentNotification::matches_text(text)
            }
            ContentItem::InputImage { .. } | ContentItem::InputAudio { .. } => false,
        })
    })
}

/// Returns true when any message item contains `needle` in a text span.
fn history_contains_text<'a>(
    history_items: impl IntoIterator<Item = &'a ResponseItem>,
    needle: &str,
) -> bool {
    history_items.into_iter().any(|item| {
        let ResponseItem::Message { content, .. } = item else {
            return false;
        };
        content.iter().any(|content_item| match content_item {
            ContentItem::InputText { text } | ContentItem::OutputText { text } => {
                text.contains(needle)
            }
            ContentItem::InputImage { .. } | ContentItem::InputAudio { .. } => false,
        })
    })
}

async fn wait_for_recorded_user_message(thread: &CodexThread, needle: &str) {
    timeout(Duration::from_secs(5), async {
        loop {
            let event = thread
                .next_event()
                .await
                .expect("event stream should stay open");
            if let EventMsg::ItemCompleted(ItemCompletedEvent {
                item: TurnItem::UserMessage(item),
                ..
            }) = event.msg
                && item.content.iter().any(
                    |input| matches!(input, UserInput::Text { text, .. } if text.contains(needle)),
                )
            {
                return;
            }
        }
    })
    .await
    .expect("timed out waiting for user message recording");
}

fn history_contains_assistant_inter_agent_communication<'a>(
    history_items: impl IntoIterator<Item = &'a ResponseItem>,
    expected: &InterAgentCommunication,
) -> bool {
    history_items.into_iter().any(|item| {
        let ResponseItem::Message { role, content, .. } = item else {
            return false;
        };
        if role != "assistant" {
            return false;
        }
        content.iter().any(|content_item| match content_item {
            ContentItem::OutputText { text } => {
                serde_json::from_str::<InterAgentCommunication>(text)
                    .ok()
                    .as_ref()
                    == Some(expected)
            }
            ContentItem::InputText { .. }
            | ContentItem::InputImage { .. }
            | ContentItem::InputAudio { .. } => false,
        })
    })
}

async fn wait_for_subagent_notification(parent_thread: &Arc<CodexThread>) -> bool {
    let wait = async {
        loop {
            let history = parent_thread.session.clone_history().await;
            if has_subagent_notification(history.raw_items()) {
                return true;
            }
            sleep(Duration::from_millis(25)).await;
        }
    };
    // CI can take several seconds to schedule the detached completion watcher,
    // especially on slower Windows runners.
    timeout(Duration::from_secs(10), wait).await.is_ok()
}

async fn persist_thread_for_tree_resume(thread: &Arc<CodexThread>, message: &str) {
    // These tests only need a durable resume fixture. Stop the child prompt
    // first so this marker records directly instead of waiting behind an
    // unrelated active turn.
    thread
        .session
        .abort_all_tasks(TurnAbortReason::Interrupted)
        .await;
    thread
        .inject_response_items(vec![user_message(message)])
        .await
        .expect("inject thread resume context");
    thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    thread
        .session
        .flush_rollout()
        .await
        .expect("test thread rollout should flush");
}

async fn wait_for_live_thread_spawn_children(
    control: &AgentControl,
    parent_thread_id: ThreadId,
    expected_children: &[ThreadId],
) {
    let mut expected_children = expected_children.to_vec();
    expected_children.sort_by_key(std::string::ToString::to_string);

    timeout(Duration::from_secs(5), async {
        loop {
            let mut child_ids = control
                .open_thread_spawn_children(parent_thread_id)
                .await
                .expect("live child list should load")
                .into_iter()
                .map(|(thread_id, _)| thread_id)
                .collect::<Vec<_>>();
            child_ids.sort_by_key(std::string::ToString::to_string);
            if child_ids == expected_children {
                break;
            }
            sleep(Duration::from_millis(25)).await;
        }
    })
    .await
    .expect("expected persisted child tree");
}

async fn assert_thread_not_loaded(manager: &ThreadManager, thread_id: ThreadId) {
    match manager.get_thread(thread_id).await {
        Err(err) => match err.details() {
            CodexErrorDetails::ThreadNotFound(id) => assert_eq!(*id, thread_id),
            _ => panic!("expected ThreadNotFound, got {err:?}"),
        },
        Ok(_) => panic!("expected thread not to be loaded"),
    }
}

#[tokio::test]
async fn send_input_errors_when_manager_dropped() {
    let control = AgentControl::default();
    let err = control
        .send_input(
            ThreadId::new(),
            vec![UserInput::Text {
                text: "hello".to_string(),
                text_elements: Vec::new(),
            }],
            Default::default(),
        )
        .await
        .expect_err("send_input should fail without a manager");
    assert_eq!(
        err.to_string(),
        "unsupported operation: thread manager dropped"
    );
}

#[tokio::test]
async fn get_status_returns_not_found_without_manager() {
    let control = AgentControl::default();
    let got = control.get_status(ThreadId::new()).await;
    assert_eq!(got, AgentStatus::NotFound);
}

#[tokio::test]
async fn on_event_updates_status_from_task_started() {
    let status = agent_status_from_event(&EventMsg::TurnStarted(TurnStartedEvent {
        turn_id: "turn-1".to_string(),
        root_turn_id: None,
        trace_id: None,
        started_at: None,
        model_context_window: None,
        collaboration_mode_kind: ModeKind::Default,
    }));
    assert_eq!(status, Some(AgentStatus::Running));
}

#[tokio::test]
async fn on_event_updates_status_from_task_complete() {
    for (error, expected) in [
        (None, AgentStatus::Completed(Some("done".to_string()))),
        (
            Some(ErrorEvent {
                misalignment: None,
                message: "denied".to_string(),
                codex_error_info: None,
            }),
            AgentStatus::Errored("denied".to_string()),
        ),
    ] {
        let status = agent_status_from_event(&EventMsg::TurnComplete(TurnCompleteEvent {
            turn_id: "turn-1".to_string(),
            started_at: None,
            last_agent_message: Some("done".to_string()),
            error,
            completed_at: None,
            duration_ms: None,
            time_to_first_token_ms: None,
        }));
        assert_eq!(status, Some(expected));
    }
}

#[tokio::test]
async fn on_event_updates_status_from_error() {
    let status = agent_status_from_event(&EventMsg::Error(ErrorEvent {
        misalignment: None,
        message: "boom".to_string(),
        codex_error_info: None,
    }));

    let expected = AgentStatus::Errored("boom".to_string());
    assert_eq!(status, Some(expected));
}

#[tokio::test]
async fn on_event_updates_status_from_turn_aborted() {
    let status = agent_status_from_event(&EventMsg::TurnAborted(TurnAbortedEvent {
        turn_id: Some("turn-1".to_string()),
        started_at: None,
        reason: TurnAbortReason::Interrupted,
        completed_at: None,
        duration_ms: None,
    }));

    let expected = AgentStatus::Interrupted;
    assert_eq!(status, Some(expected));
}

#[tokio::test]
async fn on_event_updates_status_from_shutdown_complete() {
    let status = agent_status_from_event(&EventMsg::ShutdownComplete);
    assert_eq!(status, Some(AgentStatus::Shutdown));
}

#[tokio::test]
async fn spawn_agent_errors_when_manager_dropped() {
    let control = AgentControl::default();
    let (_home, config) = test_config().await;
    let err = control
        .spawn_agent(config, text_input("hello"), /*session_source*/ None)
        .await
        .expect_err("spawn_agent should fail without a manager");
    assert_eq!(
        err.to_string(),
        "unsupported operation: thread manager dropped"
    );
}

#[tokio::test]
async fn resume_agent_errors_when_manager_dropped() {
    let control = AgentControl::default();
    let (_home, config) = test_config().await;
    let err = control
        .resume_agent_from_rollout(config, ThreadId::new(), SessionSource::Exec)
        .await
        .expect_err("resume_agent should fail without a manager");
    assert_eq!(
        err.to_string(),
        "unsupported operation: thread manager dropped"
    );
}

#[tokio::test]
async fn send_input_errors_when_thread_missing() {
    let harness = AgentControlHarness::new().await;
    let thread_id = ThreadId::new();
    let err = harness
        .control
        .send_input(
            thread_id,
            vec![UserInput::Text {
                text: "hello".to_string(),
                text_elements: Vec::new(),
            }],
            Default::default(),
        )
        .await
        .expect_err("send_input should fail for missing thread");
    assert_matches!(
        err.details(),
        CodexErrorDetails::ThreadNotFound(id) if *id == thread_id
    );
}

#[tokio::test]
async fn get_status_returns_not_found_for_missing_thread() {
    let harness = AgentControlHarness::new().await;
    let status = harness.control.get_status(ThreadId::new()).await;
    assert_eq!(status, AgentStatus::NotFound);
}

#[tokio::test]
async fn get_status_returns_pending_init_for_new_thread() {
    let harness = AgentControlHarness::new().await;
    let (thread_id, _) = harness.start_thread().await;
    let status = harness.control.get_status(thread_id).await;
    assert_eq!(status, AgentStatus::PendingInit);
}

#[tokio::test]
async fn subscribe_status_errors_for_missing_thread() {
    let harness = AgentControlHarness::new().await;
    let thread_id = ThreadId::new();
    let err = harness
        .control
        .subscribe_status(thread_id)
        .await
        .expect_err("subscribe_status should fail for missing thread");
    assert_matches!(
        err.details(),
        CodexErrorDetails::ThreadNotFound(id) if *id == thread_id
    );
}

#[tokio::test]
async fn subscribe_status_updates_on_shutdown() {
    let harness = AgentControlHarness::new().await;
    let (thread_id, thread) = harness.start_thread().await;
    let mut status_rx = harness
        .control
        .subscribe_status(thread_id)
        .await
        .expect("subscribe_status should succeed");
    assert_eq!(status_rx.borrow().clone(), AgentStatus::PendingInit);

    let _ = thread
        .submit(Op::Shutdown {})
        .await
        .expect("shutdown should submit");

    let _ = status_rx.changed().await;
    assert_eq!(status_rx.borrow().clone(), AgentStatus::Shutdown);
}

#[tokio::test]
async fn send_input_submits_user_message() {
    let harness = AgentControlHarness::new().await;
    let (thread_id, thread) = harness.start_thread().await;

    let submission_id = harness
        .control
        .send_input(
            thread_id,
            vec![UserInput::Text {
                text: "hello from tests".to_string(),
                text_elements: Vec::new(),
            }],
            Default::default(),
        )
        .await
        .expect("send_input should succeed");
    assert!(!submission_id.is_empty());
    wait_for_recorded_user_message(thread.as_ref(), "hello from tests").await;
}

#[tokio::test]
async fn send_inter_agent_communication_without_turn_queues_message_without_triggering_turn() {
    let harness = AgentControlHarness::new().await;
    let (thread_id, thread) = harness.start_thread().await;
    let communication = InterAgentCommunication::new(
        AgentPath::root(),
        AgentPath::try_from("/root/worker").expect("agent path"),
        Vec::new(),
        "hello from tests".to_string(),
        /*trigger_turn*/ false,
    );

    let submission_id = harness
        .control
        .send_inter_agent_communication(
            thread_id,
            communication.clone(),
            AgentCommunicationContext::new(AgentCommunicationKind::Message, ThreadId::new()),
            Default::default(),
        )
        .await
        .expect("send_inter_agent_communication should succeed");
    assert!(!submission_id.is_empty());

    let expected = (
        thread_id,
        Op::InterAgentCommunication {
            communication: communication.clone(),
            start_options: Default::default(),
        },
    );
    let captured = harness
        .manager
        .captured_ops()
        .into_iter()
        .find(|entry| captured_op_matches(entry, &expected));
    assert!(captured.is_some());

    timeout(Duration::from_secs(5), async {
        loop {
            if thread
                .session
                .input_queue
                .has_pending_input(&thread.session.active_turn)
                .await
            {
                break;
            }
            sleep(Duration::from_millis(10)).await;
        }
    })
    .await
    .expect("inter-agent communication should stay pending");

    let history = thread.session.clone_history().await;
    assert!(!history_contains_assistant_inter_agent_communication(
        history.raw_items(),
        &communication
    ));
}

#[tokio::test]
async fn ensure_v2_agent_loaded_reloads_registered_unloaded_agent() {
    check_v2_agent_reload(V2ReloadRoute::Sender).await;
}

#[tokio::test]
async fn ensure_v2_child_loaded_preserves_evicted_parent_authority() {
    check_v2_agent_reload(V2ReloadRoute::NestedParent).await;
}

#[derive(Clone, Copy)]
enum V2ReloadRoute {
    Sender,
    NestedParent,
}

async fn spawn_v2_reload_test_child(
    control: &AgentControl,
    config: Config,
    parent: &CodexThread,
    task_name: &str,
) -> LiveAgent {
    let source = thread_spawn_source(
        parent.session.thread_id,
        &parent.session_source,
        next_thread_spawn_depth(&parent.session_source),
        /*agent_role*/ None,
        Some(task_name.to_string()),
    )
    .expect("child source");
    control
        .spawn_agent_with_metadata(
            config,
            text_input("hello child"),
            Some(source),
            SpawnAgentOptions {
                parent_thread_id: Some(parent.session.thread_id),
                ..Default::default()
            },
        )
        .await
        .expect("spawn_agent should succeed")
}

async fn check_v2_agent_reload(route: V2ReloadRoute) {
    let (home, mut config) = test_config().await;
    let _ = config.features.enable(Feature::MultiAgentV2);
    let _ = config.features.enable(Feature::Sqlite);
    config.model = Some("gpt-5.6-sol".to_string());
    config.multi_agent_v2.max_concurrent_threads_per_session = 3;
    config.permissions.allow_login_shell = true;
    config
        .permissions
        .set_permission_profile(PermissionProfile::read_only())
        .expect("read-only parent profile");
    let harness = AgentControlHarness::new_with_config(home, config).await;
    let client_mcp_extensions =
        ClientMcpExtensions::new([(OPENAI_FORM_EXTENSION_ID.to_string(), serde_json::json!({}))]);
    let root = harness
        .manager
        .start_thread(StartThreadOptions {
            history_mode: Some(ThreadHistoryMode::Paginated),
            client_mcp_extensions: client_mcp_extensions.clone(),
            user_instructions: Some(LoadedUserInstructions {
                instructions: Some(Instructions {
                    text: "global instructions survive parent eviction".to_string(),
                    source: None,
                }),
                warnings: Vec::new(),
            }),
            thread_instructions_provider: Some(Arc::new(StaticThreadInstructionsProvider(
                "thread instructions survive parent eviction",
            ))),
            ..StartThreadOptions::new(harness.config.clone())
        })
        .await
        .expect("start root thread");
    let control = root.thread.session.services.agent_control.clone();
    let parent_thread = match route {
        V2ReloadRoute::Sender => root.thread,
        V2ReloadRoute::NestedParent => {
            let parent = spawn_v2_reload_test_child(
                &control,
                harness.config.clone(),
                &root.thread,
                "parent",
            )
            .await;
            harness
                .manager
                .get_thread(parent.thread_id)
                .await
                .expect("nested parent should exist")
        }
    };
    let parent_thread_id = parent_thread.session.thread_id;
    let inherited_instructions = parent_thread.session.inherited_instructions().await;
    assert!(inherited_instructions.user.is_some());
    assert!(inherited_instructions.thread.is_some());
    let mut child_config = harness.config.clone();
    child_config.model = Some("gpt-5.6-luna".to_string());
    let spawned_agent =
        spawn_v2_reload_test_child(&control, child_config, &parent_thread, "worker").await;
    let agent_path = spawned_agent
        .metadata
        .agent_path
        .clone()
        .expect("agent path");
    let child_thread = harness
        .manager
        .get_thread(spawned_agent.thread_id)
        .await
        .expect("child thread should exist");
    child_thread
        .inject_response_items(vec![assistant_message(
            "child persisted",
            Some(MessagePhase::FinalAnswer),
        )])
        .await
        .expect("child rollout should persist with v2 metadata");
    child_thread
        .shutdown_and_wait()
        .await
        .expect("child thread should shut down");
    let stored_child = child_thread
        .read_thread(
            /*include_archived*/ true, /*include_history*/ false,
        )
        .await
        .expect("child metadata should be readable");
    assert_eq!(stored_child.history_mode, ThreadHistoryMode::Paginated);

    assert!(
        harness
            .manager
            .remove_thread(&spawned_agent.thread_id)
            .await
            .is_some()
    );
    match harness.manager.get_thread(spawned_agent.thread_id).await {
        Err(err) => match err.details() {
            CodexErrorDetails::ThreadNotFound(id) => assert_eq!(*id, spawned_agent.thread_id),
            _ => panic!("expected ThreadNotFound, got {err:?}"),
        },
        Ok(_) => panic!("expected thread to be removed"),
    }

    let mut sender_config = harness.config.clone();
    sender_config.model_provider_id = "ollama".to_string();
    sender_config.model_provider = sender_config
        .model_providers
        .get("ollama")
        .cloned()
        .expect("ollama provider should be configured");

    let mut parent_turn = parent_thread.session.new_default_turn().await;
    match route {
        V2ReloadRoute::Sender => control
            .ensure_v2_agent_loaded(sender_config, spawned_agent.thread_id, /*parent*/ None)
            .await
            .expect("known v2 agent should reload"),
        V2ReloadRoute::NestedParent => {
            let environment = parent_turn
                .environments
                .primary()
                .expect("parent environment");
            let mut owner_config = environment.config().clone();
            owner_config.allow_login_shell = false;
            let mut selection = environment.selection();
            selection.config = EnvironmentConfigState::Ready(owner_config);
            parent_thread
                .session
                .update_settings(SessionSettingsUpdate {
                    environments: Some(TurnEnvironmentSelections::new(
                        parent_turn.config.cwd.clone(),
                        vec![selection],
                    )),
                    ..Default::default()
                })
                .await
                .expect("save parent environments");
            parent_thread.session.mark_interrupted();
            // The fixture has no task runner to finish the turn or consume child results.
            *parent_thread.session.active_turn.lock().await = None;
            let _ = parent_thread
                .session
                .input_queue
                .drain_mailbox_input_items()
                .await;
            harness
                .manager
                .ensure_multi_agent_v2_child_loaded(spawned_agent.thread_id)
                .await
                .expect("known child should reload through its parent");
            parent_turn = parent_thread.session.new_default_turn().await;
            assert!(harness.manager.get_thread(parent_thread_id).await.is_err());
        }
    }
    let reloaded_child = harness
        .manager
        .get_thread(spawned_agent.thread_id)
        .await
        .expect("reloaded child thread should exist");
    let reloaded_instructions = reloaded_child.session.inherited_instructions().await;
    assert_eq!(
        (reloaded_instructions.user, reloaded_instructions.thread),
        (inherited_instructions.user, inherited_instructions.thread),
        "reloading a child must retain both parent snapshots, even if residency evicts the parent",
    );
    if matches!(route, V2ReloadRoute::NestedParent) {
        let reloaded_turn = reloaded_child.session.new_default_turn().await;
        assert_eq!(
            (
                reloaded_turn.environments.to_selections(),
                reloaded_turn.permission_profile(),
                reloaded_child.client_mcp_extensions(),
            ),
            (
                parent_turn.environments.to_selections(),
                parent_turn.permission_profile(),
                client_mcp_extensions,
            ),
        );
        assert!(Arc::ptr_eq(
            &reloaded_child.session.services.exec_policy,
            &parent_thread.session.services.exec_policy,
        ));
    }
    assert_eq!(
        reloaded_child.config_snapshot().await.model,
        "gpt-5.6-luna",
        "residency reload must preserve the worker model instead of inheriting its parent model",
    );
    assert_eq!(
        (
            reloaded_child.config_snapshot().await.model_provider_id,
            reloaded_child
                .session
                .new_default_turn()
                .await
                .provider
                .info()
                .clone(),
        ),
        (
            stored_child.model_provider,
            harness.config.model_provider.clone()
        ),
        "residency reload must preserve the worker provider instead of inheriting its sender's provider",
    );

    let communication = InterAgentCommunication::new(
        AgentPath::root(),
        agent_path,
        Vec::new(),
        "hello after reload".to_string(),
        /*trigger_turn*/ false,
    );
    control
        .send_inter_agent_communication(
            spawned_agent.thread_id,
            communication.clone(),
            AgentCommunicationContext::new(AgentCommunicationKind::Message, ThreadId::new()),
            Default::default(),
        )
        .await
        .expect("send_inter_agent_communication should succeed after reload");
    let expected = (
        spawned_agent.thread_id,
        Op::InterAgentCommunication {
            communication,
            start_options: Default::default(),
        },
    );
    let captured = harness
        .manager
        .captured_ops()
        .into_iter()
        .find(|entry| captured_op_matches(entry, &expected));
    assert!(captured.is_some());
}

#[tokio::test]
async fn resume_agent_from_rollout_does_not_reopen_v2_descendants() {
    let (home, mut config) = test_config().await;
    let _ = config.features.enable(Feature::MultiAgentV2);
    let _ = config.features.enable(Feature::Sqlite);
    let harness = AgentControlHarness::new_with_config(home, config).await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;
    let worker_path = AgentPath::root().join("worker").expect("worker path");
    let worker_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello worker"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: Some(worker_path.clone()),
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("worker spawn should succeed");
    let reviewer_path = worker_path.join("reviewer").expect("reviewer path");
    let reviewer_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello reviewer"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: worker_thread_id,
                depth: 2,
                agent_path: Some(reviewer_path.clone()),
                agent_nickname: None,
                agent_role: Some("reviewer".to_string()),
            })),
        )
        .await
        .expect("reviewer spawn should succeed");
    let sibling_thread_id = harness
        .spawn_anonymous_child(parent_thread_id, SpawnAgentOptions::default())
        .await;

    let worker_thread = harness
        .manager
        .get_thread(worker_thread_id)
        .await
        .expect("worker thread should exist");
    let reviewer_thread = harness
        .manager
        .get_thread(reviewer_thread_id)
        .await
        .expect("reviewer thread should exist");
    let sibling_thread = harness
        .manager
        .get_thread(sibling_thread_id)
        .await
        .expect("sibling thread should exist");
    persist_thread_for_tree_resume(&parent_thread, "parent persisted").await;
    persist_thread_for_tree_resume(&worker_thread, "worker persisted").await;
    persist_thread_for_tree_resume(&reviewer_thread, "reviewer persisted").await;
    persist_thread_for_tree_resume(&sibling_thread, "sibling persisted").await;
    wait_for_live_thread_spawn_children(
        &harness.control,
        parent_thread_id,
        &[worker_thread_id, sibling_thread_id],
    )
    .await;
    wait_for_live_thread_spawn_children(&harness.control, worker_thread_id, &[reviewer_thread_id])
        .await;

    let report = harness
        .manager
        .shutdown_all_threads_bounded(Duration::from_secs(5))
        .await;
    assert_eq!(report.submit_failed, Vec::<ThreadId>::new());
    assert_eq!(report.timed_out, Vec::<ThreadId>::new());

    let resumed_manager = ThreadManager::with_models_provider_home_and_state_for_tests(
        CodexAuth::from_api_key("dummy"),
        harness.config.model_provider.clone(),
        harness.config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
        harness.state_db.clone(),
    );
    let resumed_control = resumed_manager.agent_control();
    let resumed_parent_thread_id = resumed_control
        .resume_agent_from_rollout(
            harness.config.clone(),
            parent_thread_id,
            SessionSource::Exec,
        )
        .await
        .expect("v2 root resume should succeed");
    assert_eq!(resumed_parent_thread_id, parent_thread_id);
    assert_ne!(
        resumed_control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );
    assert_thread_not_loaded(&resumed_manager, worker_thread_id).await;
    assert_thread_not_loaded(&resumed_manager, reviewer_thread_id).await;
    assert_thread_not_loaded(&resumed_manager, sibling_thread_id).await;
    resumed_control
        .restore_v2_agent_metadata(&harness.config, parent_thread_id)
        .await;
    for thread_id in [worker_thread_id, sibling_thread_id] {
        assert!(resumed_control.ensure_agent_known(thread_id).is_ok());
    }

    resumed_control
        .close_agent(worker_thread_id)
        .await
        .expect("closing a restored sibling should succeed");

    let closed_worker = resumed_control.ensure_agent_known(worker_thread_id);
    let surviving_sibling = resumed_control.ensure_agent_known(sibling_thread_id);
    assert!(closed_worker.is_err());
    assert!(surviving_sibling.is_ok());
    assert_thread_not_loaded(&resumed_manager, sibling_thread_id).await;
}

struct StaticThreadInstructionsProvider(&'static str);

impl ThreadInstructionsProvider for StaticThreadInstructionsProvider {
    fn load_thread_instructions(&self) -> LoadInstructionsFuture<'_> {
        let instructions = Instructions {
            text: self.0.to_string(),
            source: None,
        };
        Box::pin(async move {
            LoadedUserInstructions {
                instructions: Some(instructions),
                warnings: Vec::new(),
            }
        })
    }
}

#[tokio::test]
async fn cold_resume_with_thread_instructions_preserves_lazy_v2_child_inheritance() {
    let (home, mut config) = test_config().await;
    let _ = config.features.enable(Feature::MultiAgentV2);
    let _ = config.features.enable(Feature::Sqlite);
    let harness = AgentControlHarness::new_with_config(home, config).await;
    let parent = harness
        .manager
        .start_thread(StartThreadOptions {
            thread_instructions_provider: Some(Arc::new(StaticThreadInstructionsProvider(
                "initial thread instructions",
            ))),
            ..StartThreadOptions::new(harness.config.clone())
        })
        .await
        .expect("start parent with thread instructions");
    let parent_thread_id = parent.thread_id;
    let control = &parent.thread.session.services.agent_control;
    let worker_thread_id =
        spawn_v2_reload_test_child(control, harness.config.clone(), &parent.thread, "worker")
            .await
            .thread_id;
    let worker = harness
        .manager
        .get_thread(worker_thread_id)
        .await
        .expect("worker should be loaded");
    persist_thread_for_tree_resume(&parent.thread, "parent persisted").await;
    persist_thread_for_tree_resume(&worker, "worker persisted").await;
    wait_for_live_thread_spawn_children(control, parent_thread_id, &[worker_thread_id]).await;

    let stored_parent = parent
        .thread
        .read_thread(
            /*include_archived*/ true, /*include_history*/ true,
        )
        .await
        .expect("read parent history");
    let initial_history = InitialHistory::Resumed(ResumedHistory {
        conversation_id: parent_thread_id,
        history: Arc::new(stored_parent.history.expect("parent history").items),
        rollout_path: stored_parent.rollout_path,
    });
    let report = harness
        .manager
        .shutdown_all_threads_bounded(Duration::from_secs(5))
        .await;
    assert_eq!(report.submit_failed, Vec::<ThreadId>::new());
    assert_eq!(report.timed_out, Vec::<ThreadId>::new());

    let resumed_manager = ThreadManager::with_models_provider_home_and_state_for_tests(
        CodexAuth::from_api_key("dummy"),
        harness.config.model_provider.clone(),
        harness.config.codex_home.to_path_buf(),
        Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
        harness.state_db.clone(),
    );
    let resumed_parent = resumed_manager
        .start_thread(StartThreadOptions {
            initial_history,
            session_source: Some(SessionSource::Exec),
            thread_instructions_provider: Some(Arc::new(StaticThreadInstructionsProvider(
                "resumed thread instructions",
            ))),
            ..StartThreadOptions::new(harness.config.clone())
        })
        .await
        .expect("cold resume parent with updated thread instructions");
    let thread_instructions = Instructions {
        text: "resumed thread instructions".to_string(),
        source: None,
    };
    assert_eq!(
        resumed_parent
            .thread
            .session
            .inherited_instructions()
            .await
            .thread,
        Some(thread_instructions.clone()),
    );
    assert_thread_not_loaded(&resumed_manager, worker_thread_id).await;

    resumed_manager
        .ensure_multi_agent_v2_child_loaded(worker_thread_id)
        .await
        .expect("resume v2 worker on demand");
    let resumed_worker = resumed_manager
        .get_thread(worker_thread_id)
        .await
        .expect("resumed worker should be loaded");
    assert_eq!(
        resumed_worker.session.inherited_instructions().await.thread,
        Some(thread_instructions),
    );
}

#[tokio::test]
async fn spawn_agent_creates_thread_and_sends_prompt() {
    let harness = AgentControlHarness::new().await;
    let thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("spawned"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed");
    let thread = harness
        .manager
        .get_thread(thread_id)
        .await
        .expect("thread should be registered");
    wait_for_recorded_user_message(thread.as_ref(), "spawned").await;
}

#[tokio::test]
async fn ephemeral_spawn_does_not_persist_agent_graph_edge() {
    let (home, mut config) = test_config().await;
    config.ephemeral = true;
    let harness = AgentControlHarness::new_with_config(home, config).await;
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;
    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("spawned"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
        )
        .await
        .expect("ephemeral agent spawn should succeed");

    let persisted_children = harness
        .state_db
        .as_ref()
        .expect("manager should retain state db")
        .list_thread_spawn_children(parent_thread_id)
        .await
        .expect("persisted child list should load");
    assert_eq!(persisted_children, Vec::<ThreadId>::new());
    assert!(
        harness.manager.get_thread(child_thread_id).await.is_ok(),
        "ephemeral child should remain live"
    );
}

#[tokio::test]
async fn spawn_agent_fork_from_paginated_parent_uses_model_context_prefix() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_paginated_thread().await;
    parent_thread
        .inject_response_items(vec![user_message("paginated parent context")])
        .await
        .expect("inject paginated parent context");
    let turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-paginated".to_string();
    parent_thread
        .session
        .record_conversation_items(
            turn_context.as_ref(),
            turn_context.model_info(),
            &[spawn_agent_call(&parent_spawn_call_id)],
        )
        .await;
    parent_thread
        .session
        .persist_rollout_items(&[
            rollout_response_item(ResponseItem::Message {
                id: None,
                role: "developer".to_string(),
                content: vec![ContentItem::InputText {
                    text: "id-less inherited context".to_string(),
                }],
                phase: None,
                internal_chat_message_metadata_passthrough: None,
            }),
            RolloutItem::EventMsg(EventMsg::ItemCompleted(ItemCompletedEvent {
                thread_id: parent_thread_id,
                turn_id: "parent-turn".to_string(),
                item: TurnItem::UserMessage(UserMessageItem {
                    id: "parent-user".to_string(),
                    client_id: None,
                    content: Vec::new(),
                }),
                started_at_ms: Some(0),
                completed_at_ms: 1,
            })),
            RolloutItem::EventMsg(EventMsg::ThreadSettingsApplied(
                ThreadSettingsAppliedEvent {
                    thread_id: Some(parent_thread_id),
                    thread_settings: ThreadSettingsSnapshot {
                        disabled_plugin_ids: Vec::new(),
                        model: "parent-only-model".to_string(),
                        model_provider_id: "parent-only-provider".to_string(),
                        service_tier: None,
                        approval_policy: AskForApproval::Never,
                        approvals_reviewer: ApprovalsReviewer::User,
                        permission_profile: PermissionProfile::workspace_write(),
                        active_permission_profile: None,
                        cwd: harness.config.cwd.clone(),
                        runtime_workspace_roots: None,
                        reasoning_effort: None,
                        reasoning_summary: None,
                        personality: None,
                        collaboration_mode: CollaborationMode {
                            mode: ModeKind::Default,
                            settings: Settings {
                                model: "parent-only-model".to_string(),
                                reasoning_effort: None,
                                developer_instructions: None,
                            },
                        },
                    },
                },
            )),
        ])
        .await;

    let child_thread_id = harness
        .spawn_anonymous_child(
            parent_thread_id,
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                ..Default::default()
            },
        )
        .await;
    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    assert!(
        history_contains_text(
            child_thread.session.clone_history().await.raw_items(),
            "paginated parent context",
        ),
        "bounded parent context should remain model-visible to the child"
    );
    child_thread.ensure_rollout_materialized().await;
    child_thread
        .flush_rollout()
        .await
        .expect("child rollout should flush");
    let rollout_path = child_thread
        .rollout_path()
        .expect("child rollout should exist");
    let lines = std::fs::read_to_string(&rollout_path)
        .expect("read child rollout")
        .lines()
        .map(|line| codex_rollout::parse_rollout_line(line).expect("parse rollout line"))
        .collect::<Vec<_>>();
    let RolloutItem::SessionMeta(meta_line) = &lines[0].item else {
        panic!("child rollout should start with session metadata");
    };
    assert_eq!(meta_line.meta.history_mode, ThreadHistoryMode::Paginated);
    assert_eq!(meta_line.meta.parent_thread_id, Some(parent_thread_id));
    assert_eq!(meta_line.meta.forked_from_id, Some(parent_thread_id));
    let prefix_end = usize::try_from(
        meta_line
            .meta
            .subagent_history_start_ordinal
            .expect("paginated child should mark its local history boundary"),
    )
    .expect("history boundary should fit in usize");
    let copied_prefix = &lines[1..prefix_end];
    let copied_idless_context = copied_prefix
        .iter()
        .find_map(|line| match &line.item {
            RolloutItem::ResponseItem(response_item)
                if serde_json::to_string(&response_item.item)
                    .expect("serialize response item")
                    .contains("id-less inherited context") =>
            {
                Some(response_item)
            }
            _ => None,
        })
        .expect("copied prefix should contain inherited response item");
    assert!(
        copied_idless_context.id().is_some_and(|id| !id.is_empty()),
        "copied model context should receive response item ids before persistence"
    );
    let copied_parent_context_count = lines
        .iter()
        .filter(|line| {
            serde_json::to_string(&line.item)
                .expect("serialize rollout item")
                .contains("paginated parent context")
        })
        .count();
    assert_eq!(
        copied_parent_context_count, 1,
        "copied model context should be persisted once"
    );
    assert!(
        !copied_prefix.iter().any(|line| {
            matches!(
                &line.item,
                RolloutItem::EventMsg(
                    EventMsg::ItemCompleted(_) | EventMsg::ThreadSettingsApplied(_)
                )
            )
        }),
        "copied non-structural presentation and metadata records should not enter the child rollout"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn spawn_agent_without_fork_from_paginated_parent_stays_fresh_and_paginated() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_paginated_thread().await;
    parent_thread
        .inject_response_items(vec![user_message("parent-only context")])
        .await
        .expect("inject parent-only context");

    let child_thread_id = harness
        .spawn_anonymous_child(
            parent_thread_id,
            SpawnAgentOptions {
                parent_thread_id: Some(parent_thread_id),
                ..Default::default()
            },
        )
        .await;
    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    assert!(
        !history_contains_text(
            child_thread.session.clone_history().await.raw_items(),
            "parent-only context",
        ),
        "fork_turns=none should not copy parent context"
    );
    child_thread.ensure_rollout_materialized().await;
    child_thread
        .flush_rollout()
        .await
        .expect("child rollout should flush");
    let meta = codex_rollout::read_session_meta_line(
        &child_thread
            .rollout_path()
            .expect("child rollout should exist"),
    )
    .await
    .expect("read child session metadata");
    assert_eq!(meta.meta.history_mode, ThreadHistoryMode::Paginated);
    assert_eq!(meta.meta.subagent_history_start_ordinal, None);

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[test_case::test_case(true; "thread context enabled")]
#[test_case::test_case(false; "thread context disabled")]
#[tokio::test]
async fn spawn_agent_fork_drops_inherited_token_usage_state(thread_context_enabled: bool) {
    let mut harness = AgentControlHarness::new().await;
    let _ = harness.config.features.disable(Feature::MultiAgentV2);
    harness
        .config
        .features
        .set_enabled(Feature::GuardianThreadContext, thread_context_enabled)
        .expect("test context mode");
    let (parent_thread_id, parent_thread) = harness.start_paginated_thread().await;
    let parent_usage = TokenUsage {
        total_tokens: 120,
        ..TokenUsage::default()
    };
    let parent_record = TokenUsageRecord {
        thread_id: parent_thread_id,
        turn_id: "parent-turn".to_string(),
        session_id: parent_thread.session.session_id(),
        root_turn_id: "parent-turn".to_string(),
        response_id: "parent-response".to_string(),
        usage: parent_usage.clone(),
        turn_token_usage: parent_usage.clone(),
        thread_token_usage: parent_usage,
    };
    let parent_spawn_call_id = "spawn-call-token-usage".to_string();
    parent_thread
        .session
        .persist_rollout_items(&[
            RolloutItem::Compacted(CompactedItem {
                message: String::new(),
                replacement_history: Some(vec![user_message("compacted parent context").into()]),
                retained_context: None,
                guardian_history: None,
                mcp_resource_origins: None,
                window_number: None,
                first_window_id: None,
                previous_window_id: None,
                window_id: None,
                compaction_response_id: None,
                latest_token_usage_record: Some(parent_record.clone()),
            }),
            RolloutItem::TokenUsageRecord(parent_record),
            rollout_response_item(spawn_agent_call(&parent_spawn_call_id)),
        ])
        .await;

    let child_thread_id = harness
        .spawn_anonymous_child(
            parent_thread_id,
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                ..Default::default()
            },
        )
        .await;
    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");

    let child_usage = TokenUsage {
        total_tokens: 80,
        ..TokenUsage::default()
    };
    assert!(
        !child_thread
            .session
            .clone_history()
            .await
            .retained_context()
            .user_messages_complete(),
        "V1 forks lack complete retained authorization in both context modes"
    );
    let turn_context = child_thread.session.new_default_turn().await;
    child_thread
        .session
        .record_observed_response_completed(
            turn_context.as_ref(),
            "child-response",
            Some(&child_usage),
            /*usage_metadata*/ None,
        )
        .await;
    child_thread
        .flush_rollout()
        .await
        .expect("child rollout should flush");
    let rollout_path = child_thread
        .rollout_path()
        .expect("child rollout should exist");
    let lines = std::fs::read_to_string(&rollout_path)
        .expect("read child rollout")
        .lines()
        .map(|line| codex_rollout::parse_rollout_line(line).expect("parse rollout line"))
        .collect::<Vec<_>>();
    assert!(
        !lines.iter().any(|line| {
            matches!(
                &line.item,
                RolloutItem::TokenUsageRecord(record) if record.thread_id == parent_thread_id
            )
        }),
        "child rollout should not inherit parent token usage records"
    );
    assert!(
        lines.iter().all(|line| {
            !matches!(
                &line.item,
                RolloutItem::Compacted(compacted)
                    if compacted.latest_token_usage_record.is_some()
            )
        }),
        "child rollout should not inherit parent token usage checkpoints"
    );
    let child_record = lines.iter().rev().find_map(|line| match &line.item {
        RolloutItem::TokenUsageRecord(record) => Some(record),
        _ => None,
    });
    assert_eq!(
        child_record,
        Some(&TokenUsageRecord {
            thread_id: child_thread_id,
            turn_id: turn_context.sub_id.clone(),
            session_id: child_thread.session.session_id(),
            root_turn_id: turn_context.sub_id.clone(),
            response_id: "child-response".to_string(),
            usage: child_usage.clone(),
            turn_token_usage: child_usage.clone(),
            thread_token_usage: child_usage,
        })
    );
}

#[tokio::test]
async fn spawn_agent_numeric_fork_from_compacted_paginated_parent_clamps_to_provable_turns() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_paginated_thread().await;
    let parent_spawn_call_id = "spawn-call-paginated-numeric".to_string();
    parent_thread
        .session
        .persist_rollout_items(&[
            RolloutItem::Compacted(CompactedItem {
                message: String::new(),
                replacement_history: Some(vec![
                    ResponseItem::Message {
                        id: None,
                        role: "user".to_string(),
                        content: vec![ContentItem::InputText {
                            text: "compacted summary".to_string(),
                        }],
                        phase: None,
                        internal_chat_message_metadata_passthrough: None,
                    }
                    .into(),
                ]),
                retained_context: None,
                guardian_history: None,
                mcp_resource_origins: None,
                window_number: None,
                first_window_id: None,
                previous_window_id: None,
                window_id: None,
                compaction_response_id: None,
                latest_token_usage_record: None,
            }),
            rollout_response_item(ResponseItem::Message {
                id: None,
                role: "user".to_string(),
                content: vec![ContentItem::InputText {
                    text: "recent parent turn".to_string(),
                }],
                phase: None,
                internal_chat_message_metadata_passthrough: None,
            }),
            rollout_response_item(spawn_agent_call(&parent_spawn_call_id)),
        ])
        .await;

    let clamped_child_thread_id = harness
        .spawn_anonymous_child(
            parent_thread_id,
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::LastNTurns(2)),
                ..Default::default()
            },
        )
        .await;
    let clamped_child_thread = harness
        .manager
        .get_thread(clamped_child_thread_id)
        .await
        .expect("clamped child thread should be registered");
    let clamped_history = clamped_child_thread.session.clone_history().await;
    assert!(
        history_contains_text(clamped_history.raw_items(), "recent parent turn"),
        "clamped numeric fork should keep the provable recent turn"
    );
    assert!(
        !history_contains_text(clamped_history.raw_items(), "compacted summary"),
        "clamped numeric fork should not expand into compacted parent context"
    );

    let _ = harness
        .control
        .shutdown_live_agent(clamped_child_thread_id)
        .await
        .expect("clamped child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn spawn_agent_can_fork_parent_thread_history_with_sanitized_items() {
    let managed_fragment = "<managed_developer_instructions>\nParent developer instructions.\n</managed_developer_instructions>";
    let persistent_fragment =
        "<persistent_mode>\nParent developer instructions.\n</persistent_mode>";
    let harness = AgentControlHarness::new().await;
    let mut parent_config = harness.config.clone();
    let _ = parent_config.features.enable(Feature::MultiAgentV2);
    parent_config.developer_instructions = Some("Parent developer instructions.".to_string());
    parent_config.multi_agent_v2.root_agent_usage_hint_text =
        Some("Parent root guidance.".to_string());
    parent_config.multi_agent_v2.subagent_usage_hint_text =
        Some("Parent subagent guidance.".to_string());
    let mut child_config = harness.config.clone();
    let _ = child_config.features.enable(Feature::MultiAgentV2);
    child_config.developer_instructions = Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.subagent_developer_instructions =
        Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.root_agent_usage_hint_text =
        Some("Child root guidance.".to_string());
    child_config.multi_agent_v2.subagent_usage_hint_text =
        Some("Child subagent guidance.".to_string());
    let new_thread = harness
        .manager
        .start_thread(StartThreadOptions::new(parent_config.clone()))
        .await
        .expect("start parent thread");
    let parent_thread_id = new_thread.thread_id;
    let parent_thread = new_thread.thread;
    parent_thread
        .session
        .inject_no_new_turn(
            vec![user_message("parent seed context")],
            /*current_turn_context*/ None,
        )
        .await;
    let expected_parent_seed = parent_thread
        .session
        .clone_history()
        .await
        .raw_items()
        .next()
        .cloned()
        .expect("parent seed should be recorded");
    let turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-history".to_string();
    let trigger_message = InterAgentCommunication::new(
        AgentPath::root(),
        AgentPath::try_from("/root/worker").expect("agent path"),
        Vec::new(),
        "parent trigger message".to_string(),
        /*trigger_turn*/ true,
    );
    let standalone_output = ResponseItem::FunctionCallOutput {
        id: None,
        call_id: None,
        name: Some("notifications".to_string()),
        namespace: Some("slack".to_string()),
        output: FunctionCallOutputPayload::from_text("parent notification".to_string()),
        internal_chat_message_metadata_passthrough: None,
    };
    parent_thread
        .session
        .record_conversation_items(
            turn_context.as_ref(), turn_context.model_info(),
            &[
                ResponseItem::Message {
                    id: None,
                    role: "developer".to_string(),
                    content: vec![ContentItem::InputText {
                        text: "Parent root guidance.".to_string(),
                    }],
                    phase: None,
                    internal_chat_message_metadata_passthrough: None,
                },
                ResponseItem::Message {
                    id: None,
                    role: "developer".to_string(),
                    content: vec![ContentItem::InputText {
                        text: "Parent subagent guidance.".to_string(),
                    }],
                    phase: None,
                    internal_chat_message_metadata_passthrough: None,
                },
                ResponseItem::Message {
                    id: None,
                    role: "developer".to_string(),
                    content: vec![
                        ContentItem::InputText {
                            text: "Developer context before.\nParent developer instructions.\nDeveloper context after."
                                .to_string(),
                        },
                        ContentItem::InputText {
                            text: "<multi_agent_mode>Proactive multi-agent delegation is active.</multi_agent_mode>"
                                .to_string(),
                        },
                        ContentItem::InputText {
                            text: "Preserved developer context.".to_string(),
                        },
                        ContentItem::InputText {
                            text: managed_fragment.to_string(),
                        },
                        ContentItem::InputText {
                            text: persistent_fragment.to_string(),
                        },
                    ],
                    phase: None,
                    internal_chat_message_metadata_passthrough: Some(
                        InternalChatMessageMetadataPassthrough {
                            content_item_kinds: Some(vec![
                                ContentItemKind("generic.developer_instructions".to_string()),
                                ContentItemKind("multi_agent.mode_instructions".to_string()),
                                ContentItemKind("generic.developer_policy".to_string()),
                                ContentItemKind("managed_config.developer_instructions".to_string()),
                                ContentItemKind("persistent_mode.instructions".to_string()),
                            ]),
                            ..Default::default()
                        },
                    ),
                },
                assistant_message("parent commentary", Some(MessagePhase::Commentary)),
                assistant_message("parent final answer", Some(MessagePhase::FinalAnswer)),
                standalone_output,
                assistant_message("parent unknown phase", /*phase*/ None),
                ResponseItem::Reasoning {
                    id: Some(ResponseItemId::with_suffix("rs", "parent-reasoning")),
                    summary: Vec::new(),
                    content: None,
                    encrypted_content: None,
                    internal_chat_message_metadata_passthrough: None,
                },
                trigger_message.to_response_input_item().into(),
                spawn_agent_call(&parent_spawn_call_id),
            ],
        )
        .await;
    let expected_standalone_output = parent_thread
        .session
        .clone_history()
        .await
        .raw_items()
        .find(|item| matches!(item, ResponseItem::FunctionCallOutput { call_id: None, .. }))
        .cloned()
        .expect("standalone output should be recorded");
    let parent_reference_context_item = turn_context.to_turn_context_item();
    parent_thread
        .session
        .persist_rollout_items(&[RolloutItem::TurnContext(
            parent_reference_context_item.clone(),
        )])
        .await;
    parent_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    parent_thread
        .session
        .flush_rollout()
        .await
        .expect("parent rollout should flush");
    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            child_config,
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id.clone()),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                ..Default::default()
            },
        )
        .await
        .expect("forked spawn should succeed")
        .thread_id;

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    assert_ne!(child_thread_id, parent_thread_id);
    assert_eq!(
        child_thread.config_snapshot().await.history_mode,
        ThreadHistoryMode::Legacy
    );
    let history = child_thread.session.clone_history().await;
    let history_items = history.raw_items().cloned().collect::<Vec<_>>();
    let expected_final_answer = parent_thread
        .session
        .clone_history()
        .await
        .raw_items()
        .find(|item| {
            matches!(
                item,
                ResponseItem::Message {
                    role,
                    phase: Some(MessagePhase::FinalAnswer),
                    ..
                } if role == "assistant"
            )
        })
        .cloned()
        .expect("parent final answer should be recorded");
    let mut expected_developer_message = ResponseItem::Message {
        id: None,
        role: "developer".to_string(),
        content: vec![
            ContentItem::InputText {
                text: "Developer context before.\nChild developer instructions.\nDeveloper context after."
                    .to_string(),
            },
            ContentItem::InputText {
                text: "Preserved developer context.".to_string(),
            },
            ContentItem::InputText {
                text: managed_fragment.to_string(),
            },
            ContentItem::InputText {
                text: persistent_fragment.to_string(),
            },
        ],
        phase: None,
        internal_chat_message_metadata_passthrough: Some(
            InternalChatMessageMetadataPassthrough {
                content_item_kinds: Some(vec![
                    ContentItemKind("generic.developer_instructions".to_string()),
                    ContentItemKind("generic.developer_policy".to_string()),
                    ContentItemKind("managed_config.developer_instructions".to_string()),
                    ContentItemKind("persistent_mode.instructions".to_string()),
                ]),
                ..Default::default()
            },
        ),
    };
    expected_developer_message.set_turn_id_if_missing(&turn_context.sub_id);
    expected_developer_message.set_create_time_if_missing(
        history_items[1]
            .executed_tool_call_metadata()
            .and_then(|metadata| metadata.create_time.clone())
            .expect("recorded developer message should have a creation timestamp"),
    );
    let expected_history = [
        expected_parent_seed,
        expected_developer_message,
        expected_final_answer,
        expected_standalone_output,
        ContextualUserFragment::into(MultiAgentRoleInstructions::Configured(
            "Child subagent guidance.".to_string(),
        )),
    ];
    assert_eq!(
        strip_response_item_ids(&history_items),
        strip_response_item_ids(&expected_history),
        "full-history forked child history should replace parent usage hints with the child subagent hint while filtering non-final assistant/tool chatter"
    );
    assert_eq!(
        serde_json::to_value(child_thread.session.reference_context_item().await)
            .expect("serialize child reference context item"),
        serde_json::to_value(Some(parent_reference_context_item))
            .expect("serialize expected reference context item"),
        "full-history forked child should preserve the parent diff baseline"
    );

    let mut no_hint_child_config = harness.config.clone();
    let _ = no_hint_child_config.features.enable(Feature::MultiAgentV2);
    no_hint_child_config.developer_instructions = Some(String::new());
    no_hint_child_config
        .multi_agent_v2
        .subagent_developer_instructions = Some(String::new());
    no_hint_child_config.multi_agent_v2.subagent_usage_hint_text = Some(String::new());
    let no_hint_child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            no_hint_child_config,
            text_input("child task without hints"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id.clone()),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                ..Default::default()
            },
        )
        .await
        .expect("forked spawn should honor an empty subagent usage hint")
        .thread_id;
    let no_hint_child_thread = harness
        .manager
        .get_thread(no_hint_child_thread_id)
        .await
        .expect("no-hint child thread should be registered");
    let no_hint_history = no_hint_child_thread.session.clone_history().await;
    assert!(
        !history_contains_text(no_hint_history.raw_items(), "Child subagent guidance.")
            && !history_contains_text(
                no_hint_history.raw_items(),
                "You are an agent in a team of agents"
            ),
        "full-history forked child should not add configured or bundled subagent guidance"
    );
    assert!(
        !history_contains_text(
            no_hint_history.raw_items(),
            "Developer context before.\nParent developer instructions."
        ),
        "empty child developer instructions should remove parent developer instructions"
    );
    assert!(
        history_contains_text(no_hint_history.raw_items(), managed_fragment)
            && history_contains_text(no_hint_history.raw_items(), persistent_fragment),
        "clearing child instructions must preserve overlapping managed and persistent instructions"
    );
    assert!(
        history_contains_text(
            no_hint_history.raw_items(),
            "Developer context before.\n\nDeveloper context after."
        ),
        "empty child developer instructions should preserve surrounding developer context"
    );
    assert!(
        history_contains_text(no_hint_history.raw_items(), "Preserved developer context."),
        "empty child developer instructions should preserve unrelated developer fragments"
    );

    wait_for_recorded_user_message(child_thread.as_ref(), "child task").await;

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = harness
        .control
        .shutdown_live_agent(no_hint_child_thread_id)
        .await
        .expect("no-hint child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[test_case::test_case(true; "thread context enabled")]
#[test_case::test_case(false; "thread context disabled")]
#[tokio::test]
async fn spawn_agent_fork_strips_parent_usage_hints_from_compacted_history(
    thread_context_enabled: bool,
) {
    let harness = AgentControlHarness::new().await;
    let mut parent_config = harness.config.clone();
    parent_config
        .features
        .set_enabled(Feature::GuardianThreadContext, thread_context_enabled)
        .expect("test context mode");
    let _ = parent_config.features.enable(Feature::MultiAgentV2);
    parent_config.developer_instructions = Some("Parent developer instructions.".to_string());
    parent_config.multi_agent_v2.root_agent_usage_hint_text =
        Some("Parent root guidance.".to_string());
    parent_config.multi_agent_v2.subagent_usage_hint_text =
        Some("Parent subagent guidance.".to_string());
    let mut child_config = harness.config.clone();
    child_config
        .features
        .set_enabled(Feature::GuardianThreadContext, thread_context_enabled)
        .expect("test context mode");
    let _ = child_config.features.enable(Feature::MultiAgentV2);
    child_config.developer_instructions = Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.subagent_developer_instructions =
        Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.root_agent_usage_hint_text =
        Some("Child root guidance.".to_string());
    child_config.multi_agent_v2.subagent_usage_hint_text =
        Some("Child subagent guidance.".to_string());
    let new_thread = harness
        .manager
        .start_thread(StartThreadOptions::new(parent_config))
        .await
        .expect("start parent thread");
    let parent_thread_id = new_thread.thread_id;
    let parent_thread = new_thread.thread;
    let turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-compacted-usage-hints".to_string();
    let catalog_role = |base: &str| MultiAgentRoleInstructions::Composed {
        base: base.to_string(),
        marked: true,
        omit_update_plan_instructions: false,
        max_concurrency: 2,
        wait_agent_enabled: false,
        expose_model_overrides: false,
    };
    let parent_task = InterAgentCommunication::new(
        AgentPath::root(),
        AgentPath::root().join("worker").expect("valid worker path"),
        Vec::new(),
        "compacted parent delegated task".to_string(),
        /*trigger_turn*/ true,
    );
    let replacement_history = vec![
        ContextualUserFragment::into(crate::context::GuardianApprovedAction::new("parent-private-release".to_owned())),
        ResponseItem::Message {
            id: None,
            role: "user".to_string(),
            content: vec![ContentItem::InputText {
                text: "compacted parent summary".to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        },
        ContextualUserFragment::into(catalog_role("Catalog parent root guidance.")),
        parent_task.to_model_input_item(),
        ResponseItem::Message {
            id: None,
            role: "developer".to_string(),
            content: vec![ContentItem::InputText {
                text: "Parent root guidance.".to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        },
        ResponseItem::Message {
            id: None,
            role: "developer".to_string(),
            content: vec![
                ContentItem::InputText {
                    text: "Compacted context before.\nParent developer instructions.\nCompacted context after."
                        .to_string(),
                },
                ContentItem::InputText {
                    text: "<multi_agent_mode>Proactive multi-agent delegation is active.</multi_agent_mode>"
                        .to_string(),
                },
                ContentItem::InputText {
                    text: "Preserved compacted developer context.".to_string(),
                },
            ],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        },
    ];
    let answer_event: codex_history::RetainedContextEvent = serde_json::from_value(serde_json::json!({
        "type": "verified_answer", "turn_id": "parent-answer-turn", "call_id": "parent-answer-call",
        "questions": [{"question": "Parent-local action?", "answer": "Parent only."}]
    })).expect("verified answer fixture");
    let delivery = codex_history::ResponseItemEnvelope {
        item: serde_json::from_value(serde_json::json!({
            "type": "function_call_output", "id": "parent-delivery",
            "name": "send_message_to_thread", "output": "Parent delivery"
        }))
        .unwrap(),
        metadata: Some(codex_history::CodexHarnessMetadata {
            user_input_order: Some(7),
            sender_user_messages: Some(Box::new(codex_history::SenderUserMessages {
                receiver_turn_id: "parent-turn".to_owned(),
                receiver_message_id: "parent-delivery".to_owned(),
                text: "Parent-only sender context".to_owned(),
            })),
            ..Default::default()
        }),
    };
    let mut retained_context = codex_history::RetainedContext::default();
    retained_context.record(&answer_event);
    retained_context.record_sender_user_messages(delivery.metadata.as_ref().unwrap());
    parent_thread
        .session
        .persist_rollout_items(&[
            RolloutItem::Compacted(CompactedItem {
                message: String::new(),
                replacement_history: Some(
                    replacement_history
                        .into_iter()
                        .map(Into::into)
                        .chain([delivery.clone()])
                        .collect(),
                ),
                retained_context: Some(retained_context),
                guardian_history: Some(codex_history::GuardianHistoryCheckpoint(vec![
                    user_message("Parent-local approval must not be inherited."),
                ])),
                mcp_resource_origins: None,
                window_number: None,
                first_window_id: None,
                previous_window_id: None,
                window_id: None,
                compaction_response_id: None,
                latest_token_usage_record: None,
            }),
            RolloutItem::RetainedContext(answer_event),
            RolloutItem::ResponseItem(delivery),
            RolloutItem::TurnContext(turn_context.to_turn_context_item()),
            rollout_response_item(spawn_agent_call(&parent_spawn_call_id)),
        ])
        .await;
    parent_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    parent_thread
        .session
        .flush_rollout()
        .await
        .expect("parent rollout should flush");

    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            child_config,
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                multi_agent_v2_usage_hints: Some(ResolvedMultiAgentV2UsageHints {
                    root: None,
                    subagent: Some(catalog_role("Catalog child subagent guidance.")),
                }),
                ..Default::default()
            },
        )
        .await
        .expect("forked spawn should sanitize compacted usage hints")
        .thread_id;

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let history = child_thread.session.clone_history().await;
    assert!(
        !history_contains_text(
            history.conversation_history_snapshot().review_items(),
            "Parent-local approval must not be inherited.",
        ),
        "a subagent must not inherit its parent review checkpoint",
    );
    assert_eq!(
        history_contains_text(history.raw_items(), "parent-private-release"),
        !thread_context_enabled,
        "only retained mode changes parent approval inheritance",
    );
    let mut inherited_context = codex_history::RetainedContext::default();
    if thread_context_enabled {
        inherited_context.reserve_order();
    } else {
        inherited_context.mark_user_messages_incomplete();
    }
    assert_eq!(history.retained_context(), &inherited_context);
    assert!(
        history_contains_text(history.raw_items(), "compacted parent summary"),
        "forked child history should retain compacted non-hint content"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Catalog parent root guidance."),
        "forked child history should strip the resolved parent hint from compacted replacement history"
    );
    assert!(
        history_contains_text(history.raw_items(), "Catalog child subagent guidance."),
        "full-history forked child should add the resolved child hint after compacted-history sanitization"
    );
    assert!(
        !history
            .raw_items()
            .any(|item| matches!(item, ResponseItem::AgentMessage { .. })),
        "forked child history should not inherit compacted parent agent messages"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Parent root guidance."),
        "forked child history should strip stale parent hints from compacted replacement history"
    );
    assert!(
        !history_contains_text(
            history.raw_items(),
            "Proactive multi-agent delegation is active."
        ),
        "forked child history should strip stale policy fragments from compound compacted messages"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Parent developer instructions."),
        "forked child history should replace parent instructions in compacted replacement history"
    );
    assert!(
        history_contains_text(
            history.raw_items(),
            "Compacted context before.\nChild developer instructions.\nCompacted context after."
        ),
        "forked child history should replace compacted parent instructions without removing surrounding context"
    );
    assert!(
        history_contains_text(
            history.raw_items(),
            "Preserved compacted developer context."
        ),
        "forked child history should preserve unrelated compacted developer fragments"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

/// Full-history forks must restore child instructions when compaction discarded
/// the only matching parent instruction fragment from effective history.
#[tokio::test]
async fn spawn_agent_full_fork_restores_instructions_after_compaction_discards_parent_fragment() {
    let harness = AgentControlHarness::new().await;
    let mut parent_config = harness.config.clone();
    let _ = parent_config.features.enable(Feature::MultiAgentV2);
    parent_config.developer_instructions = Some("Parent developer instructions.".to_string());
    let mut child_config = parent_config.clone();
    child_config.developer_instructions = Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.subagent_developer_instructions =
        Some("Child developer instructions.".to_string());

    let new_thread = harness
        .manager
        .start_thread(StartThreadOptions::new(parent_config))
        .await
        .expect("start parent thread");
    let parent_thread_id = new_thread.thread_id;
    let parent_thread = new_thread.thread;
    let turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-compacted-stale-instructions".to_string();
    let replacement_history = vec![
        ResponseItem::Message {
            id: None,
            role: "user".to_string(),
            content: vec![ContentItem::InputText {
                text: "compacted parent summary".to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        },
        ResponseItem::Message {
            id: None,
            role: "developer".to_string(),
            content: vec![ContentItem::InputText {
                text: "Preserved compacted developer context.".to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        },
    ];

    // Preserve the parent's live baseline while its durable checkpoint omits the
    // developer fragment that appeared in obsolete pre-compaction history.
    parent_thread
        .session
        .replace_history(
            replacement_history.clone(),
            Some(turn_context.to_turn_context_item()),
        )
        .await;
    parent_thread
        .session
        .persist_rollout_items(&[
            rollout_response_item(ResponseItem::Message {
                id: None,
                role: "developer".to_string(),
                content: vec![ContentItem::InputText {
                    text: "Parent developer instructions.".to_string(),
                }],
                phase: None,
                internal_chat_message_metadata_passthrough: None,
            }),
            RolloutItem::Compacted(CompactedItem {
                message: String::new(),
                replacement_history: Some(
                    replacement_history.into_iter().map(Into::into).collect(),
                ),
                retained_context: None,
                guardian_history: None,
                mcp_resource_origins: None,
                window_number: None,
                first_window_id: None,
                previous_window_id: None,
                window_id: None,
                compaction_response_id: None,
                latest_token_usage_record: None,
            }),
            RolloutItem::TurnContext(turn_context.to_turn_context_item()),
            rollout_response_item(spawn_agent_call(&parent_spawn_call_id)),
        ])
        .await;
    parent_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    parent_thread
        .session
        .flush_rollout()
        .await
        .expect("parent rollout should flush");

    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            child_config,
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                ..Default::default()
            },
        )
        .await
        .expect("forked spawn should preserve effective compacted instructions")
        .thread_id;
    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let history = child_thread.session.clone_history().await;
    assert!(
        history_contains_text(
            history.raw_items(),
            "Preserved compacted developer context."
        ),
        "full-history fork should preserve unrelated compacted developer fragments"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Parent developer instructions."),
        "full-history fork should not restore stale pre-compaction parent instructions"
    );
    assert!(
        history_contains_text(history.raw_items(), "Child developer instructions."),
        "full-history fork should append child instructions absent from effective compacted history"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

/// A legacy compaction clears the child's baseline, so its first turn must
/// rebuild configured developer instructions exactly once.
#[tokio::test]
async fn spawn_agent_full_fork_legacy_compaction_rebuilds_child_instructions_once() {
    let managed_policy = "Managed policy for every agent.";
    let current_managed_fragment = format!(
        "<managed_developer_instructions>\n{managed_policy}\n</managed_developer_instructions>"
    );
    let stale_managed_fragment =
        "<managed_developer_instructions>\nOld managed policy.\n</managed_developer_instructions>";
    for (case, parent_developer_instructions) in [
        ("without parent instructions", None),
        (
            "with parent instructions",
            Some("Parent developer instructions."),
        ),
    ] {
        let harness = AgentControlHarness::new().await;
        let mut parent_config = harness.config.clone();
        let _ = parent_config.features.enable(Feature::MultiAgentV2);
        parent_config.developer_instructions = parent_developer_instructions.map(str::to_string);
        let mut requirements = parent_config.config_layer_stack.requirements().clone();
        requirements.additional_developer_instructions = Some(codex_config::Sourced::new(
            managed_policy.to_string(),
            codex_config::RequirementSource::Unknown,
        ));
        let mut requirements_toml = parent_config.config_layer_stack.requirements_toml().clone();
        requirements_toml.additional_developer_instructions = Some(managed_policy.to_string());
        parent_config.config_layer_stack = codex_config::ConfigLayerStack::new(
            parent_config
                .config_layer_stack
                .all_layers_low_to_high()
                .cloned()
                .collect(),
            requirements,
            requirements_toml,
        )
        .expect("managed requirements stack");
        let mut child_config = parent_config.clone();
        child_config.developer_instructions = Some("Child developer instructions.".to_string());
        child_config.multi_agent_v2.subagent_developer_instructions =
            Some("Child developer instructions.".to_string());

        let new_thread = harness
            .manager
            .start_thread(StartThreadOptions::new(parent_config))
            .await
            .expect("start parent thread");
        let parent_thread_id = new_thread.thread_id;
        let parent_thread = new_thread.thread;
        let turn_context = parent_thread.session.new_default_turn().await;
        let parent_spawn_call_id = match parent_developer_instructions {
            Some(_) => "spawn-call-legacy-compact-with-parent",
            None => "spawn-call-legacy-compact-without-parent",
        };
        let parent_user_message = ResponseItem::Message {
            id: None,
            role: "user".to_string(),
            content: vec![ContentItem::InputText {
                text: "parent task before legacy compaction".to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        };

        // A live parent can reestablish its baseline after resuming a rollout
        // whose older compaction record cannot restore that baseline to a child.
        parent_thread
            .session
            .replace_history(
                vec![parent_user_message.clone()],
                Some(turn_context.to_turn_context_item()),
            )
            .await;
        let mut rollout_items = vec![
            rollout_response_item(parent_user_message),
            RolloutItem::Compacted(CompactedItem {
                message: "legacy compacted summary".to_string(),
                replacement_history: None,
                retained_context: None,
                guardian_history: None,
                mcp_resource_origins: None,
                window_number: None,
                first_window_id: None,
                previous_window_id: None,
                window_id: None,
                compaction_response_id: None,
                latest_token_usage_record: None,
            }),
        ];
        if let Some(instructions) = parent_developer_instructions {
            rollout_items.push(rollout_response_item(ResponseItem::Message {
                id: None,
                role: "developer".to_string(),
                content: vec![ContentItem::InputText {
                    text: instructions.to_string(),
                }],
                phase: None,
                internal_chat_message_metadata_passthrough: None,
            }));
        }
        rollout_items.push(rollout_response_item(ResponseItem::Message {
            id: None,
            role: "developer".to_string(),
            content: vec![ContentItem::InputText {
                text: stale_managed_fragment.to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        }));
        rollout_items.push(RolloutItem::TurnContext(
            turn_context.to_turn_context_item(),
        ));
        rollout_items.push(rollout_response_item(spawn_agent_call(
            parent_spawn_call_id,
        )));
        parent_thread
            .session
            .persist_rollout_items(&rollout_items)
            .await;
        parent_thread
            .session
            .ensure_rollout_materialized(PersistContext::Standard)
            .await;
        parent_thread
            .session
            .flush_rollout()
            .await
            .expect("parent rollout should flush");

        let child_thread_id = harness
            .control
            .spawn_agent_with_metadata(
                child_config,
                text_input("child task"),
                Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                    parent_thread_id,
                    depth: 1,
                    agent_path: None,
                    agent_nickname: None,
                    agent_role: None,
                })),
                SpawnAgentOptions {
                    fork_parent_spawn_call_id: Some(parent_spawn_call_id.to_string()),
                    fork_mode: Some(SpawnAgentForkMode::FullHistory),
                    ..Default::default()
                },
            )
            .await
            .expect("forked spawn should preserve legacy compacted history")
            .thread_id;
        let child_thread = harness
            .manager
            .get_thread(child_thread_id)
            .await
            .expect("child thread should be registered");
        while child_thread
            .session
            .reference_context_item()
            .await
            .is_none()
        {
            tokio::task::yield_now().await;
        }
        let history = child_thread.session.clone_history().await;
        let mut instruction_count = 0;
        let mut managed_instructions = Vec::new();
        for item in history.raw_items() {
            let ResponseItem::Message { role, content, .. } = item else {
                continue;
            };
            if role != "developer" {
                continue;
            }
            for content_item in content {
                if let ContentItem::InputText { text } = content_item {
                    instruction_count += usize::from(text == "Child developer instructions.");
                    if ManagedDeveloperInstructions::matches_text(text) {
                        managed_instructions.push(text.as_str());
                    }
                }
            }
        }
        assert_eq!(
            (instruction_count, managed_instructions),
            (1, vec![current_managed_fragment.as_str()]),
            "{case}: canonical context reconstruction must keep only the current child and managed developer instructions"
        );

        let _ = harness
            .control
            .shutdown_live_agent(child_thread_id)
            .await
            .expect("child shutdown should submit");
        let _ = parent_thread
            .submit(Op::Shutdown {})
            .await
            .expect("parent shutdown should submit");
    }
}

#[tokio::test]
async fn spawn_agent_fork_flushes_parent_rollout_before_loading_history() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;
    let turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-unflushed".to_string();
    parent_thread
        .session
        .record_conversation_items(
            turn_context.as_ref(),
            turn_context.model_info(),
            &[
                assistant_message("unflushed final answer", Some(MessagePhase::FinalAnswer)),
                spawn_agent_call(&parent_spawn_call_id),
            ],
        )
        .await;

    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            harness.config.clone(),
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id.clone()),
                fork_mode: Some(SpawnAgentForkMode::FullHistory),
                ..Default::default()
            },
        )
        .await
        .expect("forked spawn should flush parent rollout before loading history")
        .thread_id;

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let history = child_thread.session.clone_history().await;
    assert!(
        history_contains_text(history.raw_items(), "unflushed final answer"),
        "forked child history should include unflushed assistant final answers after flushing the parent rollout"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn spawn_agent_fork_last_n_turns_keeps_only_recent_turns() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    parent_thread
        .inject_response_items(vec![user_message("old parent context")])
        .await
        .expect("inject old parent context");
    let queued_communication = InterAgentCommunication::new(
        AgentPath::root(),
        AgentPath::try_from("/root/worker").expect("agent path"),
        Vec::new(),
        "queued message".to_string(),
        /*trigger_turn*/ false,
    );
    let queued_turn_context = parent_thread.session.new_default_turn().await;
    parent_thread
        .session
        .record_conversation_items(
            queued_turn_context.as_ref(),
            queued_turn_context.model_info(),
            &[queued_communication.to_response_input_item().into()],
        )
        .await;

    let triggered_communication = InterAgentCommunication::new(
        AgentPath::root(),
        AgentPath::try_from("/root/worker").expect("agent path"),
        Vec::new(),
        "triggered context".to_string(),
        /*trigger_turn*/ true,
    );
    let triggered_turn_context = parent_thread.session.new_default_turn().await;
    parent_thread
        .session
        .record_conversation_items(
            triggered_turn_context.as_ref(),
            triggered_turn_context.model_info(),
            &[triggered_communication.to_response_input_item().into()],
        )
        .await;
    parent_thread
        .inject_response_items(vec![user_message("current parent task")])
        .await
        .expect("inject current parent task");
    let spawn_turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-last-n".to_string();
    parent_thread
        .session
        .record_conversation_items(
            spawn_turn_context.as_ref(),
            spawn_turn_context.model_info(),
            &[spawn_agent_call(&parent_spawn_call_id)],
        )
        .await;
    parent_thread
        .session
        .persist_rollout_items(&[RolloutItem::TurnContext(
            spawn_turn_context.to_turn_context_item(),
        )])
        .await;
    parent_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    parent_thread
        .session
        .flush_rollout()
        .await
        .expect("parent rollout should flush");

    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            harness.config.clone(),
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id.clone()),
                fork_mode: Some(SpawnAgentForkMode::LastNTurns(2)),
                ..Default::default()
            },
        )
        .await
        .expect("forked spawn should keep only the last two turns")
        .thread_id;

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let history = child_thread.session.clone_history().await;

    assert!(
        !history_contains_text(history.raw_items(), "old parent context"),
        "forked child history should drop parent context outside the requested last-N turn window"
    );
    assert!(
        !history_contains_text(history.raw_items(), "queued message"),
        "forked child history should drop queued inter-agent messages outside the requested last-N turn window"
    );
    assert!(
        !history_contains_text(history.raw_items(), "triggered context"),
        "forked child history should filter assistant inter-agent messages even when they fall inside the requested last-N turn window"
    );
    assert!(
        history_contains_text(history.raw_items(), "current parent task"),
        "forked child history should keep the parent user message from the requested last-N turn window"
    );
    assert!(
        child_thread
            .session
            .reference_context_item()
            .await
            .is_none(),
        "last-N forked child should rebuild context after truncating the cached prefix"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn spawn_agent_fork_last_n_turns_drops_parent_startup_prefix_when_under_limit() {
    let harness = AgentControlHarness::new().await;
    let selected_capability_roots = vec![SelectedCapabilityRoot {
        id: "demo@1".to_string(),
        location: CapabilityRootLocation::Environment {
            environment_id: "build".to_string(),
            path: PathUri::parse("file:///plugins/demo").expect("plugin root URI"),
        },
    }];
    let mut thread_extension_init = ExtensionDataInit::new();
    thread_extension_init.insert(selected_capability_roots.clone());
    let parent = harness
        .manager
        .start_thread(StartThreadOptions {
            environments: Some(Vec::new()),
            thread_extension_init,
            ..StartThreadOptions::new(harness.config.clone())
        })
        .await
        .expect("start parent thread");
    let parent_thread_id = parent.thread_id;
    let parent_thread = parent.thread;
    let startup_turn_context = parent_thread.session.new_default_turn().await;
    parent_thread
        .session
        .record_conversation_items(
            startup_turn_context.as_ref(),
            startup_turn_context.model_info(),
            &[ResponseItem::Message {
                id: None,
                role: "developer".to_string(),
                content: vec![ContentItem::InputText {
                    text: "parent startup developer context".to_string(),
                }],
                phase: None,
                internal_chat_message_metadata_passthrough: None,
            }],
        )
        .await;
    parent_thread
        .inject_response_items(vec![user_message("current parent task")])
        .await
        .expect("inject current parent task");
    let spawn_turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-last-n-under-limit".to_string();
    parent_thread
        .session
        .record_conversation_items(
            spawn_turn_context.as_ref(),
            spawn_turn_context.model_info(),
            &[spawn_agent_call(&parent_spawn_call_id)],
        )
        .await;
    parent_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    parent_thread
        .session
        .flush_rollout()
        .await
        .expect("parent rollout should flush");

    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            harness.config.clone(),
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::LastNTurns(2)),
                ..Default::default()
            },
        )
        .await
        .expect("bounded forked spawn should drop startup prefix")
        .thread_id;

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let history = child_thread.session.clone_history().await;
    assert!(
        history_contains_text(history.raw_items(), "current parent task"),
        "bounded fork should retain the requested recent parent turn"
    );
    assert!(
        !history_contains_text(history.raw_items(), "parent startup developer context"),
        "bounded fork should drop parent startup context even when fewer turns exist than requested"
    );
    assert_eq!(
        &child_thread.session.services.selected_capability_roots,
        &selected_capability_roots
    );
    assert!(
        child_thread
            .session
            .reference_context_item()
            .await
            .is_none(),
        "bounded forked child should still rebuild context after truncating the cached prefix"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn spawn_agent_fork_last_n_turns_strips_parent_usage_hints() {
    let persistent_fragment =
        "<persistent_mode>\nParent persistent instructions.\n</persistent_mode>";
    let harness = AgentControlHarness::new().await;
    let mut parent_config = harness.config.clone();
    let _ = parent_config.features.enable(Feature::MultiAgentV2);
    parent_config.developer_instructions = Some("Parent developer instructions.".to_string());
    parent_config.multi_agent_v2.root_agent_usage_hint_text =
        Some("Parent root guidance.".to_string());
    let mut child_config = harness.config.clone();
    let _ = child_config.features.enable(Feature::MultiAgentV2);
    child_config.developer_instructions = Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.subagent_developer_instructions =
        Some("Child developer instructions.".to_string());
    child_config.multi_agent_v2.subagent_usage_hint_text =
        Some("Child subagent guidance.".to_string());
    let new_thread = harness
        .manager
        .start_thread(StartThreadOptions::new(parent_config))
        .await
        .expect("start parent thread");
    let parent_thread_id = new_thread.thread_id;
    let parent_thread = new_thread.thread;
    parent_thread
        .inject_response_items(vec![user_message("parent task")])
        .await
        .expect("inject parent task");
    let turn_context = parent_thread.session.new_default_turn().await;
    let parent_spawn_call_id = "spawn-call-last-n-usage-hints".to_string();
    parent_thread
        .session
        .record_conversation_items(
            turn_context.as_ref(),
            turn_context.model_info(),
            &[
                ResponseItem::Message {
                    id: None,
                    role: "developer".to_string(),
                    content: vec![ContentItem::InputText {
                        text: "Parent root guidance.".to_string(),
                    }],
                    phase: None,
                    internal_chat_message_metadata_passthrough: None,
                },
                ResponseItem::Message {
                    id: None,
                    role: "developer".to_string(),
                    content: vec![
                        ContentItem::InputText {
                            text: "Parent developer instructions.".to_string(),
                        },
                        ContentItem::InputText {
                            text: "Preserved bounded developer context.".to_string(),
                        },
                        ContentItem::InputText {
                            text: persistent_fragment.to_string(),
                        },
                    ],
                    phase: None,
                    internal_chat_message_metadata_passthrough: None,
                },
                spawn_agent_call(&parent_spawn_call_id),
            ],
        )
        .await;
    parent_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    parent_thread
        .session
        .flush_rollout()
        .await
        .expect("parent rollout should flush");

    let child_thread_id = harness
        .control
        .spawn_agent_with_metadata(
            child_config,
            text_input("child task"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some(parent_spawn_call_id),
                fork_mode: Some(SpawnAgentForkMode::LastNTurns(2)),
                ..Default::default()
            },
        )
        .await
        .expect("bounded forked spawn should sanitize parent usage hints")
        .thread_id;

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let history = child_thread.session.clone_history().await;
    assert!(
        history_contains_text(history.raw_items(), "parent task"),
        "bounded fork should retain the requested recent parent turn"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Parent root guidance."),
        "bounded fork should strip stale parent root hints before the child rebuilds startup context"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Parent developer instructions."),
        "bounded fork should remove parent instructions before the child rebuilds startup context"
    );
    assert!(
        !history_contains_text(history.raw_items(), "Child developer instructions."),
        "bounded fork should not inject child instructions before its canonical context rebuild"
    );
    assert!(
        !history_contains_text(history.raw_items(), persistent_fragment),
        "bounded fork should remove persistent instructions before rebuilding context for the child's effort"
    );
    assert!(
        history_contains_text(history.raw_items(), "Preserved bounded developer context."),
        "bounded fork should preserve unrelated developer fragments"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn spawn_agent_respects_legacy_max_threads_alias() {
    let max_threads = 1usize;
    let (_home, config) = test_config_with_cli_overrides(vec![(
        "agents.max_threads".to_string(),
        TomlValue::Integer(max_threads as i64),
    )])
    .await;
    let manager = ThreadManager::with_models_provider_and_home_for_tests(
        CodexAuth::from_api_key("dummy"),
        config.model_provider.clone(),
        config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
    );
    let control = manager.agent_control();

    let _ = manager
        .start_thread(StartThreadOptions::new(config.clone()))
        .await
        .expect("start thread");

    let first_agent_id = control
        .spawn_agent(
            config.clone(),
            text_input("hello"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed");

    let err = control
        .spawn_agent(
            config,
            text_input("hello again"),
            /*session_source*/ None,
        )
        .await
        .expect_err("spawn_agent should respect max threads");
    let CodexErrorDetails::AgentLimitReached {
        max_threads: seen_max_threads,
    } = err.details()
    else {
        panic!("expected AgentLimitReached");
    };
    assert_eq!(*seen_max_threads, max_threads);

    let _ = control
        .shutdown_live_agent(first_agent_id)
        .await
        .expect("shutdown agent");
}

#[tokio::test]
async fn spawn_agent_releases_slot_after_shutdown() {
    let max_threads = 1usize;
    let (_home, config) = test_config_with_cli_overrides(vec![(
        "agents.max_concurrent_threads_per_session".to_string(),
        TomlValue::Integer(max_threads as i64),
    )])
    .await;
    let manager = ThreadManager::with_models_provider_and_home_for_tests(
        CodexAuth::from_api_key("dummy"),
        config.model_provider.clone(),
        config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
    );
    let control = manager.agent_control();

    let first_agent_id = control
        .spawn_agent(
            config.clone(),
            text_input("hello"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed");
    let _ = control
        .shutdown_live_agent(first_agent_id)
        .await
        .expect("shutdown agent");

    let second_agent_id = control
        .spawn_agent(
            config.clone(),
            text_input("hello again"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed after shutdown");
    let _ = control
        .shutdown_live_agent(second_agent_id)
        .await
        .expect("shutdown agent");
}

#[tokio::test]
async fn spawn_agent_limit_shared_across_clones() {
    let max_threads = 1usize;
    let (_home, config) = test_config_with_cli_overrides(vec![(
        "agents.max_concurrent_threads_per_session".to_string(),
        TomlValue::Integer(max_threads as i64),
    )])
    .await;
    let manager = ThreadManager::with_models_provider_and_home_for_tests(
        CodexAuth::from_api_key("dummy"),
        config.model_provider.clone(),
        config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
    );
    let control = manager.agent_control();
    let cloned = control.clone();

    let first_agent_id = cloned
        .spawn_agent(
            config.clone(),
            text_input("hello"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed");

    let err = control
        .spawn_agent(
            config,
            text_input("hello again"),
            /*session_source*/ None,
        )
        .await
        .expect_err("spawn_agent should respect shared guard");
    let CodexErrorDetails::AgentLimitReached { max_threads } = err.details() else {
        panic!("expected AgentLimitReached");
    };
    assert_eq!(*max_threads, 1);

    let _ = control
        .shutdown_live_agent(first_agent_id)
        .await
        .expect("shutdown agent");
}

#[tokio::test]
async fn resume_agent_respects_max_threads_limit() {
    let max_threads = 1usize;
    let (_home, config) = test_config_with_cli_overrides(vec![(
        "agents.max_concurrent_threads_per_session".to_string(),
        TomlValue::Integer(max_threads as i64),
    )])
    .await;
    let manager = ThreadManager::with_models_provider_and_home_for_tests(
        CodexAuth::from_api_key("dummy"),
        config.model_provider.clone(),
        config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
    );
    let control = manager.agent_control();

    let resumable_id = control
        .spawn_agent(
            config.clone(),
            text_input("hello"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed");
    let _ = control
        .shutdown_live_agent(resumable_id)
        .await
        .expect("shutdown resumable thread");

    let active_id = control
        .spawn_agent(
            config.clone(),
            text_input("occupy"),
            /*session_source*/ None,
        )
        .await
        .expect("spawn_agent should succeed for active slot");

    let err = control
        .resume_agent_from_rollout(config, resumable_id, SessionSource::Exec)
        .await
        .expect_err("resume should respect max threads");
    let CodexErrorDetails::AgentLimitReached {
        max_threads: seen_max_threads,
    } = err.details()
    else {
        panic!("expected AgentLimitReached");
    };
    assert_eq!(*seen_max_threads, max_threads);

    let _ = control
        .shutdown_live_agent(active_id)
        .await
        .expect("shutdown active thread");
}

#[tokio::test]
async fn resume_agent_releases_slot_after_resume_failure() {
    let max_threads = 1usize;
    let (_home, config) = test_config_with_cli_overrides(vec![(
        "agents.max_concurrent_threads_per_session".to_string(),
        TomlValue::Integer(max_threads as i64),
    )])
    .await;
    let manager = ThreadManager::with_models_provider_and_home_for_tests(
        CodexAuth::from_api_key("dummy"),
        config.model_provider.clone(),
        config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
    );
    let control = manager.agent_control();

    let _ = control
        .resume_agent_from_rollout(config.clone(), ThreadId::new(), SessionSource::Exec)
        .await
        .expect_err("resume should fail for missing rollout path");

    let resumed_id = control
        .spawn_agent(config, text_input("hello"), /*session_source*/ None)
        .await
        .expect("spawn should succeed after failed resume");
    let _ = control
        .shutdown_live_agent(resumed_id)
        .await
        .expect("shutdown resumed thread");
}

#[tokio::test]
async fn spawn_child_completion_notifies_parent_history() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let _ = child_thread
        .submit(Op::Shutdown {})
        .await
        .expect("child shutdown should submit");

    assert_eq!(wait_for_subagent_notification(&parent_thread).await, true);
}

#[tokio::test]
async fn multi_agent_v2_completion_ignores_dead_direct_parent() {
    let harness = AgentControlHarness::new().await;
    let mut config = harness.config.clone();
    let _ = config.features.enable(Feature::MultiAgentV2);
    let root = harness
        .manager
        .start_thread(StartThreadOptions::new(config.clone()))
        .await
        .expect("root thread should start");
    let root_thread_id = root.thread_id;
    let root_thread = root.thread;
    let worker_path = AgentPath::root().join("worker_a").expect("worker path");
    let worker_thread_id = harness
        .control
        .spawn_agent(
            config.clone(),
            text_input("hello worker"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: root_thread_id,
                depth: 1,
                agent_path: Some(worker_path.clone()),
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("worker spawn should succeed");
    let tester_path = worker_path.join("tester").expect("tester path");
    let tester_thread_id = harness
        .control
        .spawn_agent(
            config,
            text_input("hello tester"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: worker_thread_id,
                depth: 2,
                agent_path: Some(tester_path.clone()),
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("tester spawn should succeed");
    harness
        .control
        .shutdown_live_agent(worker_thread_id)
        .await
        .expect("worker shutdown should succeed");

    let tester_thread = harness
        .manager
        .get_thread(tester_thread_id)
        .await
        .expect("tester thread should exist");
    let tester_turn = tester_thread.session.new_default_turn().await;
    tester_thread
        .session
        .send_event(
            tester_turn.as_ref(),
            EventMsg::TurnComplete(TurnCompleteEvent {
                turn_id: tester_turn.sub_id.clone(),
                started_at: None,
                last_agent_message: Some("done".to_string()),
                error: None,
                completed_at: None,
                duration_ms: None,
                time_to_first_token_ms: None,
            }),
        )
        .await;

    sleep(Duration::from_millis(100)).await;

    assert!(
        !harness
            .manager
            .captured_ops()
            .into_iter()
            .any(|(thread_id, op)| {
                thread_id == worker_thread_id
                    && matches!(
                        op,
                        Op::InterAgentCommunication { communication, .. }
                            if communication.author == tester_path
                                && communication.recipient == worker_path
                                && communication.content == "done"
                    )
            })
    );

    let root_history = root_thread.session.clone_history().await;
    assert!(!history_contains_assistant_inter_agent_communication(
        root_history.raw_items(),
        &InterAgentCommunication::new(
            tester_path,
            AgentPath::root(),
            Vec::new(),
            "done".to_string(),
            /*trigger_turn*/ true,
        )
    ));
    assert!(!has_subagent_notification(root_history.raw_items()));
}

#[tokio::test]
async fn multi_agent_v2_completion_queues_message_for_direct_parent() {
    let harness = AgentControlHarness::new().await;
    let (_root_thread_id, root_thread) = harness.start_thread().await;
    let (worker_thread_id, _worker_thread) = harness.start_thread().await;
    let mut tester_config = harness.config.clone();
    let _ = tester_config.features.enable(Feature::MultiAgentV2);
    let tester_thread_id = harness
        .manager
        .start_thread(StartThreadOptions::new(tester_config.clone()))
        .await
        .expect("tester thread should start")
        .thread_id;
    let tester_thread = harness
        .manager
        .get_thread(tester_thread_id)
        .await
        .expect("tester thread should exist");
    let worker_path = AgentPath::root().join("worker_a").expect("worker path");
    let tester_path = worker_path.join("tester").expect("tester path");
    harness.control.maybe_start_completion_watcher(
        tester_thread_id,
        Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
            parent_thread_id: worker_thread_id,
            depth: 2,
            agent_path: Some(tester_path.clone()),
            agent_nickname: None,
            agent_role: Some("explorer".to_string()),
        })),
        tester_path.to_string(),
        Some(tester_path.clone()),
    );
    let tester_turn = tester_thread.session.new_default_turn().await;
    tester_thread
        .session
        .send_event(
            tester_turn.as_ref(),
            EventMsg::TurnComplete(TurnCompleteEvent {
                turn_id: tester_turn.sub_id.clone(),
                started_at: None,
                last_agent_message: Some("done".to_string()),
                error: None,
                completed_at: None,
                duration_ms: None,
                time_to_first_token_ms: None,
            }),
        )
        .await;

    let expected_message = crate::session_prefix::format_inter_agent_completion_message(
        worker_path.clone(),
        tester_path.clone(),
        &AgentStatus::Completed(Some("done".to_string())),
    )
    .expect("completed status should render");
    let expected = (
        worker_thread_id,
        Op::InterAgentCommunication {
            communication: InterAgentCommunication::new(
                tester_path.clone(),
                worker_path.clone(),
                Vec::new(),
                expected_message.clone(),
                /*trigger_turn*/ false,
            ),
            start_options: Default::default(),
        },
    );

    timeout(Duration::from_secs(5), async {
        loop {
            let captured = harness
                .manager
                .captured_ops()
                .into_iter()
                .find(|entry| captured_op_matches(entry, &expected));
            if captured.is_some() {
                break;
            }
            sleep(Duration::from_millis(10)).await;
        }
    })
    .await
    .expect("completion watcher should queue a direct-parent message");

    let root_history = root_thread.session.clone_history().await;
    assert!(!history_contains_assistant_inter_agent_communication(
        root_history.raw_items(),
        &InterAgentCommunication::new(
            tester_path,
            AgentPath::root(),
            Vec::new(),
            expected_message,
            /*trigger_turn*/ false,
        )
    ));
}

#[tokio::test]
async fn completion_watcher_notifies_parent_when_child_is_missing() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;
    let child_thread_id = ThreadId::new();

    harness.control.maybe_start_completion_watcher(
        child_thread_id,
        Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
            parent_thread_id,
            depth: 1,
            agent_path: None,
            agent_nickname: None,
            agent_role: Some("explorer".to_string()),
        })),
        child_thread_id.to_string(),
        /*child_agent_path*/ None,
    );

    assert_eq!(wait_for_subagent_notification(&parent_thread).await, true);

    let history = parent_thread.session.clone_history().await;
    assert_eq!(
        history_contains_text(
            history.raw_items(),
            &format!("\"agent_path\":\"{child_thread_id}\"")
        ),
        true
    );
    assert_eq!(
        history_contains_text(history.raw_items(), "\"status\":\"not_found\""),
        true
    );
}

#[tokio::test]
async fn spawn_thread_subagent_gets_random_nickname_in_session_source() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let snapshot = child_thread.config_snapshot().await;

    let SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
        parent_thread_id: seen_parent_thread_id,
        depth,
        agent_nickname,
        agent_role,
        ..
    }) = snapshot.session_source
    else {
        panic!("expected thread-spawn sub-agent source");
    };
    assert_eq!(seen_parent_thread_id, parent_thread_id);
    assert_eq!(depth, 1);
    assert!(agent_nickname.is_some());
    assert_eq!(agent_role, Some("explorer".to_string()));
}

#[tokio::test]
async fn spawn_thread_subagents_persist_parent_originator_across_new_and_truncated_fork() {
    let harness = AgentControlHarness::new().await;
    let parent = harness
        .manager
        .start_thread(StartThreadOptions {
            metrics_service_name: Some("codex_work_desktop".to_string()),
            environments: Some(Vec::new()),
            ..StartThreadOptions::new(harness.config.clone())
        })
        .await
        .expect("parent thread should start");
    let parent_originator = persisted_originator(&parent.thread).await;
    assert_eq!(parent_originator, "codex_work_desktop");

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: parent.thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let child_originator = persisted_originator(&child_thread).await;
    assert_eq!(child_originator, parent_originator);

    let child = harness
        .control
        .spawn_agent_with_metadata(
            harness.config.clone(),
            text_input("hello forked child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: parent.thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
            SpawnAgentOptions {
                fork_parent_spawn_call_id: Some("spawn-call-last-n".to_string()),
                fork_mode: Some(SpawnAgentForkMode::LastNTurns(1)),
                ..Default::default()
            },
        )
        .await
        .expect("forked child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child.thread_id)
        .await
        .expect("child thread should be registered");
    let child_originator = persisted_originator(&child_thread).await;
    assert_eq!(child_originator, parent_originator);
}

#[tokio::test]
async fn spawn_thread_subagent_uses_role_specific_nickname_candidates() {
    let mut harness = AgentControlHarness::new().await;
    harness.config.agent_roles.insert(
        "researcher".to_string(),
        AgentRoleConfig {
            description: Some("Research role".to_string()),
            config_file: None,
            nickname_candidates: Some(vec!["Atlas".to_string()]),
        },
    );
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("researcher".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should be registered");
    let snapshot = child_thread.config_snapshot().await;

    let SessionSource::SubAgent(SubAgentSource::ThreadSpawn { agent_nickname, .. }) =
        snapshot.session_source
    else {
        panic!("expected thread-spawn sub-agent source");
    };
    assert_eq!(agent_nickname, Some("Atlas".to_string()));
}

#[tokio::test]
async fn resume_thread_subagent_restores_stored_metadata() {
    let (home, config) = test_config().await;
    let thread_store = Arc::new(InMemoryThreadStore::default());
    let auth_manager = AuthManager::from_auth_for_testing(CodexAuth::from_api_key("dummy"));
    let manager = ThreadManager::new(
        &config,
        auth_manager.clone(),
        crate::thread_manager::build_models_manager(&config, auth_manager),
        crate::CodexAppsToolsCache::default(),
        SessionSource::Exec,
        Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
        empty_extension_registry(),
        Arc::new(crate::test_support::EmptyUserInstructionsProvider),
        /*analytics_events_client*/ None,
        crate::thread_manager::passthrough_image_store(),
        thread_store.clone(),
        /*agent_graph_store*/ None,
        uuid::Uuid::new_v4().to_string(),
        /*attestation_provider*/ None,
        /*external_time_provider*/ None,
    );
    let control = manager.agent_control();
    let harness = AgentControlHarness {
        _home: home,
        config,
        state_db: None,
        manager,
        control,
    };
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;
    let agent_path = AgentPath::from_string("/root/explorer".to_string())
        .expect("test agent path should be valid");

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: Some(agent_path.clone()),
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    child_thread
        .session
        .ensure_rollout_materialized(PersistContext::Standard)
        .await;
    child_thread
        .session
        .flush_rollout()
        .await
        .expect("flush child rollout");
    let mut status_rx = harness
        .control
        .subscribe_status(child_thread_id)
        .await
        .expect("status subscription should succeed");
    if matches!(status_rx.borrow().clone(), AgentStatus::PendingInit) {
        timeout(Duration::from_secs(5), async {
            loop {
                status_rx
                    .changed()
                    .await
                    .expect("child status should advance past pending init");
                if !matches!(status_rx.borrow().clone(), AgentStatus::PendingInit) {
                    break;
                }
            }
        })
        .await
        .expect("child should initialize before shutdown");
    }
    let original_snapshot = child_thread.config_snapshot().await;
    let original_nickname = original_snapshot
        .session_source
        .get_nickname()
        .expect("spawned sub-agent should have a nickname");
    timeout(Duration::from_secs(5), async {
        loop {
            if let Ok(stored_thread) = thread_store
                .read_thread(ReadThreadParams {
                    thread_id: child_thread_id,
                    include_archived: true,
                    include_history: false,
                })
                .await
                && stored_thread.agent_nickname.is_some()
                && stored_thread.agent_role.as_deref() == Some("explorer")
                && stored_thread.agent_path.as_deref() == Some(agent_path.as_str())
            {
                break;
            }
            sleep(Duration::from_millis(10)).await;
        }
    })
    .await
    .expect("child thread metadata should be persisted to sqlite before shutdown");

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should submit");

    let resumed_thread_id = harness
        .control
        .resume_agent_from_rollout(
            harness.config.clone(),
            child_thread_id,
            SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            }),
        )
        .await
        .expect("resume should succeed");
    assert_eq!(resumed_thread_id, child_thread_id);

    let resumed_snapshot = harness
        .manager
        .get_thread(resumed_thread_id)
        .await
        .expect("resumed child thread should exist")
        .config_snapshot()
        .await;
    let SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
        parent_thread_id: resumed_parent_thread_id,
        depth: resumed_depth,
        agent_path: resumed_agent_path,
        agent_nickname: resumed_nickname,
        agent_role: resumed_role,
        ..
    }) = resumed_snapshot.session_source
    else {
        panic!("expected thread-spawn sub-agent source");
    };
    assert_eq!(resumed_parent_thread_id, parent_thread_id);
    assert_eq!(resumed_depth, 1);
    assert_eq!(resumed_agent_path, Some(agent_path));
    assert_eq!(resumed_nickname, Some(original_nickname));
    assert_eq!(resumed_role, Some("explorer".to_string()));

    let _ = harness
        .control
        .shutdown_live_agent(resumed_thread_id)
        .await
        .expect("resumed child shutdown should submit");
}

#[tokio::test]
async fn resume_agent_from_rollout_reads_archived_rollout_path() {
    let harness = AgentControlHarness::new().await;
    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello"),
            /*session_source*/ None,
        )
        .await
        .expect("child spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    persist_thread_for_tree_resume(&child_thread, "persist before archiving").await;
    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should succeed");
    let store = LocalThreadStore::new(
        LocalThreadStoreConfig::from_config(&harness.config),
        harness.state_db.clone(),
    );
    store
        .archive_thread(ArchiveThreadParams {
            thread_id: child_thread_id,
        })
        .await
        .expect("child thread should archive");

    let resumed_thread_id = harness
        .control
        .resume_agent_from_rollout(harness.config.clone(), child_thread_id, SessionSource::Exec)
        .await
        .expect("resume should find archived rollout");
    assert_eq!(resumed_thread_id, child_thread_id);

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("resumed child shutdown should succeed");
}

#[tokio::test]
async fn resume_agent_from_paginated_rollout_loads_model_context() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_paginated_thread().await;
    let child_thread_id = harness
        .spawn_anonymous_child(
            parent_thread_id,
            SpawnAgentOptions {
                parent_thread_id: Some(parent_thread_id),
                ..Default::default()
            },
        )
        .await;
    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    assert_eq!(
        child_thread.config_snapshot().await.history_mode,
        ThreadHistoryMode::Paginated
    );
    persist_thread_for_tree_resume(&child_thread, "persist before resume").await;
    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("child shutdown should succeed");

    let resumed_thread_id = harness
        .control
        .resume_agent_from_rollout(harness.config.clone(), child_thread_id, SessionSource::Exec)
        .await
        .expect("resume should load paginated model context");
    assert_eq!(resumed_thread_id, child_thread_id);
    let resumed_thread = harness
        .manager
        .get_thread(resumed_thread_id)
        .await
        .expect("resumed child thread should exist");
    assert!(
        history_contains_text(
            resumed_thread.session.clone_history().await.raw_items(),
            "persist before resume",
        ),
        "resumed child should keep its persisted model context"
    );

    let _ = harness
        .control
        .shutdown_live_agent(child_thread_id)
        .await
        .expect("resumed child shutdown should succeed");
    let _ = parent_thread
        .submit(Op::Shutdown {})
        .await
        .expect("parent shutdown should submit");
}

#[tokio::test]
async fn list_agent_subtree_thread_ids_includes_anonymous_and_closed_descendants() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;
    let worker_path = AgentPath::root().join("worker").expect("worker path");
    let reviewer_path = AgentPath::root().join("reviewer").expect("reviewer path");

    let worker_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello worker"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: Some(worker_path.clone()),
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("worker spawn should succeed");
    let worker_child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello worker child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: worker_thread_id,
                depth: 2,
                agent_path: Some(
                    worker_path
                        .join("child")
                        .expect("worker child path should be valid"),
                ),
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("worker child spawn should succeed");
    let no_path_child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello anonymous child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: worker_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("no-path child spawn should succeed");
    let no_path_grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello anonymous grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: no_path_child_thread_id,
                depth: 3,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("no-path grandchild spawn should succeed");
    let _reviewer_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello reviewer"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: Some(reviewer_path),
                agent_nickname: None,
                agent_role: Some("reviewer".to_string()),
            })),
        )
        .await
        .expect("reviewer spawn should succeed");

    let _ = harness
        .control
        .shutdown_live_agent(no_path_grandchild_thread_id)
        .await
        .expect("no-path grandchild shutdown should succeed");

    let mut worker_subtree_thread_ids = harness
        .manager
        .list_agent_subtree_thread_ids(worker_thread_id)
        .await
        .expect("worker subtree thread ids should load");
    worker_subtree_thread_ids.sort_by_key(ToString::to_string);
    let mut expected_worker_subtree_thread_ids = vec![
        worker_thread_id,
        worker_child_thread_id,
        no_path_child_thread_id,
        no_path_grandchild_thread_id,
    ];
    expected_worker_subtree_thread_ids.sort_by_key(ToString::to_string);
    assert_eq!(
        worker_subtree_thread_ids,
        expected_worker_subtree_thread_ids
    );

    let mut no_path_child_subtree_thread_ids = harness
        .manager
        .list_agent_subtree_thread_ids(no_path_child_thread_id)
        .await
        .expect("no-path subtree thread ids should load");
    no_path_child_subtree_thread_ids.sort_by_key(ToString::to_string);
    let mut expected_no_path_child_subtree_thread_ids =
        vec![no_path_child_thread_id, no_path_grandchild_thread_id];
    expected_no_path_child_subtree_thread_ids.sort_by_key(ToString::to_string);
    assert_eq!(
        no_path_child_subtree_thread_ids,
        expected_no_path_child_subtree_thread_ids
    );
}

#[tokio::test]
async fn list_agent_subtree_thread_ids_finds_live_descendants_of_unloaded_root() {
    let (_home, config) = test_config().await;
    let manager = ThreadManager::with_models_provider_home_and_state_for_tests(
        CodexAuth::from_api_key("dummy"),
        config.model_provider.clone(),
        config.codex_home.to_path_buf(),
        std::sync::Arc::new(codex_exec_server::EnvironmentManager::default_for_tests()),
        /*state_db*/ None,
    );
    let control = manager.agent_control();
    let parent_thread_id = manager
        .start_thread(StartThreadOptions::new(config.clone()))
        .await
        .expect("parent should start")
        .thread_id;

    let child_thread_id = control
        .spawn_agent(
            config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = control
        .spawn_agent(
            config,
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    manager.remove_thread(&parent_thread_id).await;

    let mut subtree_thread_ids = manager
        .list_agent_subtree_thread_ids(parent_thread_id)
        .await
        .expect("live subtree should load");
    subtree_thread_ids.sort_by_key(ToString::to_string);
    let mut expected_subtree_thread_ids =
        vec![parent_thread_id, child_thread_id, grandchild_thread_id];
    expected_subtree_thread_ids.sort_by_key(ToString::to_string);

    assert_eq!(subtree_thread_ids, expected_subtree_thread_ids);
}

#[tokio::test]
async fn shutdown_agent_tree_closes_live_descendants() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let _ = harness
        .control
        .shutdown_agent_tree(parent_thread_id)
        .await
        .expect("tree shutdown should succeed");

    assert_eq!(
        harness.control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );

    let shutdown_ids = harness
        .manager
        .captured_ops()
        .into_iter()
        .filter_map(|(thread_id, op)| matches!(op, Op::Shutdown).then_some(thread_id))
        .collect::<Vec<_>>();
    let mut expected_shutdown_ids = vec![parent_thread_id, child_thread_id, grandchild_thread_id];
    expected_shutdown_ids.sort_by_key(std::string::ToString::to_string);
    let mut shutdown_ids = shutdown_ids;
    shutdown_ids.sort_by_key(std::string::ToString::to_string);
    assert_eq!(shutdown_ids, expected_shutdown_ids);
}

#[tokio::test]
async fn shutdown_agent_tree_closes_descendants_when_started_at_child() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, _parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let _ = harness
        .control
        .close_agent(child_thread_id)
        .await
        .expect("child close should succeed");

    let _ = harness
        .control
        .shutdown_agent_tree(parent_thread_id)
        .await
        .expect("tree shutdown should succeed");

    assert_eq!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );

    let shutdown_ids = harness
        .manager
        .captured_ops()
        .into_iter()
        .filter_map(|(thread_id, op)| matches!(op, Op::Shutdown).then_some(thread_id))
        .collect::<Vec<_>>();
    let mut expected_shutdown_ids = vec![parent_thread_id, child_thread_id, grandchild_thread_id];
    expected_shutdown_ids.sort_by_key(std::string::ToString::to_string);
    let mut shutdown_ids = shutdown_ids;
    shutdown_ids.sort_by_key(std::string::ToString::to_string);
    assert_eq!(shutdown_ids, expected_shutdown_ids);
}

#[tokio::test]
async fn resume_agent_from_rollout_does_not_reopen_closed_descendants() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&parent_thread, "parent persisted").await;
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let _ = harness
        .control
        .close_agent(child_thread_id)
        .await
        .expect("child close should succeed");
    let _ = harness
        .control
        .shutdown_live_agent(parent_thread_id)
        .await
        .expect("parent shutdown should succeed");

    let resumed_parent_thread_id = harness
        .control
        .resume_agent_from_rollout(
            harness.config.clone(),
            parent_thread_id,
            SessionSource::Exec,
        )
        .await
        .expect("single-thread resume should succeed");
    assert_eq!(resumed_parent_thread_id, parent_thread_id);
    assert_ne!(
        harness.control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );

    let _ = harness
        .control
        .shutdown_agent_tree(parent_thread_id)
        .await
        .expect("tree shutdown after resume should succeed");
}

#[tokio::test]
async fn resume_closed_child_reopens_open_descendants() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&parent_thread, "parent persisted").await;
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let _ = harness
        .control
        .close_agent(child_thread_id)
        .await
        .expect("child close should succeed");

    let resumed_child_thread_id = harness
        .control
        .resume_agent_from_rollout(
            harness.config.clone(),
            child_thread_id,
            SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: None,
            }),
        )
        .await
        .expect("child resume should succeed");
    assert_eq!(resumed_child_thread_id, child_thread_id);
    assert_ne!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_ne!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );

    let _ = harness
        .control
        .close_agent(child_thread_id)
        .await
        .expect("child close after resume should succeed");
    let _ = harness
        .control
        .shutdown_live_agent(parent_thread_id)
        .await
        .expect("parent shutdown should succeed");
}

#[tokio::test]
async fn resume_agent_from_rollout_reopens_open_descendants_after_manager_shutdown() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&parent_thread, "parent persisted").await;
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let report = harness
        .manager
        .shutdown_all_threads_bounded(Duration::from_secs(5))
        .await;
    assert_eq!(report.submit_failed, Vec::<ThreadId>::new());
    assert_eq!(report.timed_out, Vec::<ThreadId>::new());

    let resumed_parent_thread_id = harness
        .control
        .resume_agent_from_rollout(
            harness.config.clone(),
            parent_thread_id,
            SessionSource::Exec,
        )
        .await
        .expect("tree resume should succeed");
    assert_eq!(resumed_parent_thread_id, parent_thread_id);
    assert_ne!(
        harness.control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );
    assert_ne!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_ne!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );

    let _ = harness
        .control
        .shutdown_agent_tree(parent_thread_id)
        .await
        .expect("tree shutdown after subtree resume should succeed");
}

#[tokio::test]
async fn resume_agent_from_rollout_uses_edge_data_when_descendant_metadata_source_is_stale() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&parent_thread, "parent persisted").await;
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let state_db = grandchild_thread
        .state_db()
        .expect("sqlite state db should be available");
    let mut stale_metadata = state_db
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild metadata query should succeed")
        .expect("grandchild metadata should exist");
    stale_metadata.source =
        serde_json::to_string(&SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
            parent_thread_id: ThreadId::new(),
            depth: 99,
            agent_path: None,
            agent_nickname: None,
            agent_role: Some("worker".to_string()),
        }))
        .expect("stale session source should serialize");
    state_db
        .upsert_thread(&stale_metadata)
        .await
        .expect("stale grandchild metadata should persist");

    let report = harness
        .manager
        .shutdown_all_threads_bounded(Duration::from_secs(5))
        .await;
    assert_eq!(report.submit_failed, Vec::<ThreadId>::new());
    assert_eq!(report.timed_out, Vec::<ThreadId>::new());

    let resumed_parent_thread_id = harness
        .control
        .resume_agent_from_rollout(
            harness.config.clone(),
            parent_thread_id,
            SessionSource::Exec,
        )
        .await
        .expect("tree resume should succeed");
    assert_eq!(resumed_parent_thread_id, parent_thread_id);
    assert_ne!(
        harness.control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );
    assert_ne!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_ne!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );

    let resumed_grandchild_snapshot = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("resumed grandchild thread should exist")
        .config_snapshot()
        .await;
    let SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
        parent_thread_id: resumed_parent_thread_id,
        depth: resumed_depth,
        ..
    }) = resumed_grandchild_snapshot.session_source
    else {
        panic!("expected thread-spawn sub-agent source");
    };
    assert_eq!(resumed_parent_thread_id, child_thread_id);
    assert_eq!(resumed_depth, 2);

    let _ = harness
        .control
        .shutdown_agent_tree(parent_thread_id)
        .await
        .expect("tree shutdown after subtree resume should succeed");
}

#[tokio::test]
async fn resume_agent_from_rollout_skips_descendants_when_parent_resume_fails() {
    let harness = AgentControlHarness::new().await;
    let (parent_thread_id, parent_thread) = harness.start_thread().await;

    let child_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello child"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id,
                depth: 1,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("explorer".to_string()),
            })),
        )
        .await
        .expect("child spawn should succeed");
    let grandchild_thread_id = harness
        .control
        .spawn_agent(
            harness.config.clone(),
            text_input("hello grandchild"),
            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
                parent_thread_id: child_thread_id,
                depth: 2,
                agent_path: None,
                agent_nickname: None,
                agent_role: Some("worker".to_string()),
            })),
        )
        .await
        .expect("grandchild spawn should succeed");

    let child_thread = harness
        .manager
        .get_thread(child_thread_id)
        .await
        .expect("child thread should exist");
    let grandchild_thread = harness
        .manager
        .get_thread(grandchild_thread_id)
        .await
        .expect("grandchild thread should exist");
    persist_thread_for_tree_resume(&parent_thread, "parent persisted").await;
    persist_thread_for_tree_resume(&child_thread, "child persisted").await;
    persist_thread_for_tree_resume(&grandchild_thread, "grandchild persisted").await;
    wait_for_live_thread_spawn_children(&harness.control, parent_thread_id, &[child_thread_id])
        .await;
    wait_for_live_thread_spawn_children(&harness.control, child_thread_id, &[grandchild_thread_id])
        .await;

    let child_rollout_path = child_thread
        .rollout_path()
        .expect("child thread should have rollout path");
    let report = harness
        .manager
        .shutdown_all_threads_bounded(Duration::from_secs(5))
        .await;
    assert_eq!(report.submit_failed, Vec::<ThreadId>::new());
    assert_eq!(report.timed_out, Vec::<ThreadId>::new());
    tokio::fs::remove_file(&child_rollout_path)
        .await
        .expect("child rollout path should be removable");

    let resumed_parent_thread_id = harness
        .control
        .resume_agent_from_rollout(
            harness.config.clone(),
            parent_thread_id,
            SessionSource::Exec,
        )
        .await
        .expect("root resume should succeed");
    assert_eq!(resumed_parent_thread_id, parent_thread_id);
    assert_ne!(
        harness.control.get_status(parent_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(child_thread_id).await,
        AgentStatus::NotFound
    );
    assert_eq!(
        harness.control.get_status(grandchild_thread_id).await,
        AgentStatus::NotFound
    );

    let _ = harness
        .control
        .shutdown_agent_tree(parent_thread_id)
        .await
        .expect("tree shutdown after partial subtree resume should succeed");
}