Stop re-exporting skill APIs from codex-core (#37984)

## What changed

- Import skill metadata and mention helpers directly from `codex-skills`.
- Import host skill loading types directly from `codex-skills-extension`.
- Make the remaining `codex-core` skills module private and remove its skill API re-exports, including the `HostSkillsService` re-export from `codex-core-api`.

GitOrigin-RevId: 26bf8fffd980df9c4d0c308d7e983ceab9a5df82

codex-rs/app-server/src/request_processors/catalog_processor.rs

@@ -16,7 +16,7 @@ pub(crate) struct CatalogRequestProcessor {
 const SKILLS_LIST_CWD_CONCURRENCY: usize = 5;
 
 fn skills_to_info(
-    skills: &[codex_core::skills::SkillMetadata],
+    skills: &[codex_skills::SkillMetadata],
     disabled_paths: &HashSet<AbsolutePathBuf>,
 ) -> Vec<codex_app_server_protocol::SkillMetadata> {
     skills
@@ -89,7 +89,7 @@ fn hooks_to_info(hooks: &[codex_hooks::HookListEntry]) -> Vec<HookMetadata> {
 }
 
 fn errors_to_info(
-    errors: &[codex_core::skills::SkillError],
+    errors: &[codex_skills::SkillError],
 ) -> Vec<codex_app_server_protocol::SkillErrorInfo> {
     errors
         .iter()
@@ -555,7 +555,7 @@ impl CatalogRequestProcessor {
                             );
                         }
                     };
-                    let skills_input = codex_core::skills::HostSkillsLoadInput::new(
+                    let skills_input = codex_skills_extension::HostSkillsLoadInput::new(
                         cwd_abs.clone(),
                         effective_skill_roots,
                         config_layer_stack,

codex-rs/app-server/src/request_processors/plugins.rs

@@ -59,7 +59,7 @@ pub(crate) struct PluginRequestProcessor {
 }
 
 fn plugin_skills_to_info(
-    skills: &[codex_core::skills::SkillMetadata],
+    skills: &[codex_skills::SkillMetadata],
     disabled_skill_paths: &HashSet<AbsolutePathBuf>,
 ) -> Vec<SkillSummary> {
     skills

codex-rs/app-server/src/skills_watcher.rs

@@ -7,8 +7,6 @@ use codex_app_server_protocol::ServerNotification;
 use codex_app_server_protocol::SkillsChangedNotification;
 use codex_core::ThreadManager;
 use codex_core::config::Config;
-use codex_core::skills::HostSkillsLoadInput;
-use codex_core::skills::HostSkillsService;
 use codex_file_watcher::FileWatcher;
 use codex_file_watcher::FileWatcherSubscriber;
 use codex_file_watcher::Receiver;
@@ -17,6 +15,8 @@ use codex_file_watcher::WatchPath;
 use codex_file_watcher::WatchRegistration;
 use codex_protocol::protocol::TurnEnvironmentSelection;
 use codex_skills::system_cache_root_dir;
+use codex_skills_extension::HostSkillsLoadInput;
+use codex_skills_extension::HostSkillsService;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use tokio_util::sync::CancellationToken;
 use tokio_util::sync::DropGuard;

codex-rs/core-api/src/lib.rs

@@ -50,7 +50,6 @@ pub use codex_core::config::find_codex_home;
 pub use codex_core::init_state_db;
 pub use codex_core::local_agent_graph_store_from_state_db;
 pub use codex_core::resolve_installation_id;
-pub use codex_core::skills::HostSkillsService;
 pub use codex_core::thread_store_from_config;
 pub use codex_exec_server::EnvironmentManager;
 pub use codex_exec_server::EnvironmentRegistryConnectRequest;

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

@@ -1,11 +1,11 @@
 use super::*;
-use crate::HostSkillsService;
 use crate::config::ConfigBuilder;
 use crate::plugins::plugins_manager_for_config;
 use crate::skills_load_input_from_config;
 use codex_protocol::config_types::ServiceTier;
 use codex_protocol::models::BaseInstructionsProvenance;
 use codex_protocol::openai_models::ReasoningEffort;
+use codex_skills_extension::HostSkillsService;
 use codex_utils_absolute_path::test_support::PathExt;
 use pretty_assertions::assert_eq;
 use std::fs;

codex-rs/core/src/lib.rs

@@ -81,7 +81,6 @@ pub(crate) mod prompt_debug;
 pub use prompt_debug::build_prompt_input;
 pub(crate) mod mentions {
     pub(crate) use crate::plugins::build_connector_slug_counts;
-    pub(crate) use crate::plugins::build_skill_name_counts;
     pub(crate) use crate::plugins::collect_explicit_app_ids;
     pub(crate) use crate::plugins::collect_explicit_plugin_mentions;
     pub(crate) use crate::plugins::collect_tool_mentions_from_messages;
@@ -90,11 +89,7 @@ mod sandbox_tags;
 pub mod sandboxing;
 mod session_prefix;
 mod session_startup_prewarm;
-pub mod skills;
+mod skills;
-pub(crate) use skills::HostSkillsService;
-pub(crate) use skills::SkillMetadata;
-pub(crate) use skills::build_skill_name_counts;
-pub(crate) use skills::collect_explicit_skill_mentions;
 pub(crate) use skills::maybe_emit_implicit_skill_invocation;
 pub(crate) use skills::skills_load_input_from_config;
 mod stream_events_utils;

codex-rs/core/src/mcp_skill_dependencies.rs

@@ -17,7 +17,6 @@ use codex_rmcp_client::perform_oauth_login;
 use tokio_util::sync::CancellationToken;
 use tracing::warn;
 
-use crate::SkillMetadata;
 use crate::config::edit::ConfigEditsBuilder;
 use crate::session::session::Session;
 use crate::session::turn_context::TurnContext;
@@ -28,6 +27,7 @@ use codex_mcp::mcp_permission_prompt_is_auto_approved;
 use codex_mcp::oauth_login_support;
 use codex_mcp::resolve_oauth_scopes;
 use codex_mcp::should_retry_without_scopes;
+use codex_skills::SkillMetadata;
 use codex_skills::SkillToolDependency;
 
 const SKILL_MCP_DEPENDENCY_PROMPT_ID: &str = "skill_mcp_dependency_install";

codex-rs/core/src/plugins/mentions.rs

@@ -102,8 +102,6 @@ pub(crate) fn collect_explicit_plugin_mentions(
         .collect()
 }
 
-pub(crate) use crate::build_skill_name_counts;
-
 pub(crate) fn build_connector_slug_counts(
     connectors: &[connectors::AppInfo],
 ) -> HashMap<String, usize> {

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

@@ -20,7 +20,6 @@ pub(crate) use injection::build_plugin_injections;
 pub(crate) use render::render_explicit_plugin_instructions;
 
 pub(crate) use mentions::build_connector_slug_counts;
-pub(crate) use mentions::build_skill_name_counts;
 pub(crate) use mentions::collect_explicit_app_ids;
 pub(crate) use mentions::collect_explicit_plugin_mentions;
 pub(crate) use mentions::collect_tool_mentions_from_messages;

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

@@ -303,7 +303,6 @@ pub(crate) struct PreviousTurnSettings {
     pub(crate) realtime_active: Option<bool>,
 }
 
-use crate::HostSkillsService;
 use crate::exec_policy::ExecPolicyUpdateError;
 use crate::guardian::GuardianReviewOptions;
 use crate::guardian::GuardianReviewSessionManager;
@@ -384,6 +383,7 @@ use codex_protocol::protocol::TokenUsageInfo;
 use codex_protocol::protocol::TurnModerationMetadataEvent;
 use codex_protocol::protocol::WarningEvent;
 use codex_protocol::user_input::UserInput;
+use codex_skills_extension::HostSkillsService;
 use codex_tools::UnifiedExecShellMode;
 use codex_utils_absolute_path::AbsolutePathBuf;
 #[cfg(test)]

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

@@ -7,7 +7,6 @@ use crate::environment_selection::ThreadEnvironments;
 use crate::environment_selection::TurnEnvironmentSnapshot;
 use crate::session::turn_context::TurnEnvironmentConfig;
 use crate::shell_snapshot::ShellSnapshot;
-use crate::skills::SkillError;
 use crate::state::ActiveTurn;
 use codex_extension_api::ExtensionDataInit;
 use codex_http_client::ClientRouteClass;
@@ -26,6 +25,7 @@ use codex_protocol::protocol::MultiAgentVersion;
 use codex_protocol::protocol::ThreadHistoryMode;
 use codex_protocol::protocol::ThreadSource;
 use codex_protocol::protocol::TurnEnvironmentSelections;
+use codex_skills::SkillError;
 use std::sync::OnceLock;
 use tokio::sync::Semaphore;
 

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

@@ -6,7 +6,6 @@ use std::sync::atomic::Ordering;
 use crate::client::ModelClientSession;
 use crate::client_common::Prompt;
 use crate::client_common::ResponseEvent;
-use crate::collect_explicit_skill_mentions;
 use crate::compact::InitialContextInjection;
 use crate::compact::run_inline_auto_compact_task;
 use crate::compact_remote::run_inline_remote_auto_compact_task;
@@ -25,7 +24,6 @@ use crate::hook_runtime::run_pending_session_start_hooks;
 use crate::hook_runtime::run_turn_stop_hooks;
 use crate::mcp_skill_dependencies::maybe_prompt_and_install_mcp_dependencies;
 use crate::mentions::build_connector_slug_counts;
-use crate::mentions::build_skill_name_counts;
 use crate::mentions::collect_explicit_app_ids;
 use crate::mentions::collect_explicit_plugin_mentions;
 use crate::mentions::collect_tool_mentions_from_messages;
@@ -109,6 +107,8 @@ use codex_protocol::protocol::WarningEvent;
 use codex_protocol::user_input::UserInput;
 use codex_skills::ToolMentionKind;
 use codex_skills::app_id_from_path;
+use codex_skills::build_skill_name_counts;
+use codex_skills::collect_explicit_skill_mentions;
 use codex_skills::tool_kind_for_path;
 use codex_skills_extension::HostSkillPrompts;
 use codex_skills_extension::InjectedHostSkillPrompts;

codex-rs/core/src/skills.rs

@@ -9,21 +9,14 @@ use codex_extension_api::SkillInvocationInput;
 use codex_extension_api::SkillInvocationKind;
 use codex_otel::sanitize_metric_tag_value;
 use codex_protocol::protocol::SkillScope;
+use codex_skills::SkillMetadata;
+use codex_skills::detect_implicit_skill_invocation_for_command;
+use codex_skills_extension::HostSkillsLoadInput;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_plugins::PluginSkillRoot;
 use std::collections::HashSet;
 use tokio::sync::Mutex;
 
-pub use codex_skills::SkillError;
-pub use codex_skills::SkillMetadata;
-pub use codex_skills::SkillPolicy;
-pub use codex_skills::build_skill_name_counts;
-pub use codex_skills::collect_explicit_skill_mentions;
-pub use codex_skills::detect_implicit_skill_invocation_for_command;
-pub use codex_skills_extension::HostSkillsLoadInput;
-pub use codex_skills_extension::HostSkillsService;
-pub use codex_skills_extension::SkillLoadOutcome;
-
 #[derive(Debug, Default)]
 struct ImplicitSkillInvocations(Mutex<HashSet<String>>);
 

codex-rs/core/src/state/service.rs

@@ -1,7 +1,6 @@
 use std::path::PathBuf;
 use std::sync::Arc;
 
-use crate::HostSkillsService;
 use crate::agent::AgentControl;
 use crate::agents_md_manager::AgentsMdManager;
 use crate::attestation::AttestationProvider;
@@ -38,6 +37,7 @@ use codex_protocol::capabilities::SelectedCapabilityRoot;
 use codex_protocol::mcp::ClientMcpExtensions;
 use codex_rollout::state_db::StateDbHandle;
 use codex_rollout_trace::ThreadTraceContext;
+use codex_skills_extension::HostSkillsService;
 use codex_thread_store::LiveThread;
 use codex_thread_store::ThreadStore;
 use tokio::runtime::Handle;

codex-rs/core/src/thread_manager.rs

@@ -1,5 +1,4 @@
 use crate::CodexAppsToolsCache;
-use crate::HostSkillsService;
 use crate::agent::AgentControl;
 use crate::attestation::AttestationProvider;
 use crate::codex_thread::CodexThread;
@@ -68,6 +67,7 @@ use codex_protocol::protocol::TurnAbortedEvent;
 use codex_protocol::protocol::TurnEnvironmentSelection;
 use codex_protocol::protocol::W3cTraceContext;
 use codex_rollout::state_db::StateDbHandle;
+use codex_skills_extension::HostSkillsService;
 use codex_thread_store::InMemoryThreadStore;
 use codex_thread_store::LoadThreadHistoryParams;
 use codex_thread_store::LocalThreadStore;