Move external agent config out of core (#18850)

## Summary
- Move external agent config migration logic and tests from `codex-core`
into `app-server/src/config`.
- Keep the migration service crate-private to app-server and update the
API adapter imports.
- Remove stale core re-exports and expose only the needed marketplace
source helper.

## Testing
- `cargo test -p codex-app-server config::external_agent_config`
- `just fmt`
- `just fix -p codex-app-server`
- `just fix -p codex-core`
- `git diff --check`

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

@@ -1,18 +1,18 @@
-use crate::config::Config;
-use crate::config::ConfigBuilder;
-use crate::plugins::MarketplaceAddRequest;
-use crate::plugins::PluginId;
-use crate::plugins::PluginInstallRequest;
-use crate::plugins::PluginsManager;
-use crate::plugins::add_marketplace;
-use crate::plugins::configured_plugins_from_stack;
-use crate::plugins::find_marketplace_manifest_path;
-use crate::plugins::is_local_marketplace_source;
-use crate::plugins::parse_marketplace_source;
+use codex_config::types::PluginConfig;
+use codex_core::config::Config;
+use codex_core::config::ConfigBuilder;
+use codex_core::plugins::MarketplaceAddRequest;
+use codex_core::plugins::PluginId;
+use codex_core::plugins::PluginInstallRequest;
+use codex_core::plugins::PluginsManager;
+use codex_core::plugins::add_marketplace;
+use codex_core::plugins::is_local_marketplace_source;
 use codex_core_plugins::marketplace::MarketplacePluginInstallPolicy;
+use codex_core_plugins::marketplace::find_marketplace_manifest_path;
 use codex_protocol::protocol::Product;
 use serde_json::Value as JsonValue;
 use std::collections::BTreeMap;
+use std::collections::HashMap;
 use std::collections::HashSet;
 use std::ffi::OsString;
 use std::fs;
@@ -29,13 +29,13 @@ const EXTERNAL_OFFICIAL_MARKETPLACE_NAME: &str = "claude-plugins-official";
 const EXTERNAL_OFFICIAL_MARKETPLACE_SOURCE: &str = "anthropics/claude-plugins-official";
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct ExternalAgentConfigDetectOptions {
+pub(crate) struct ExternalAgentConfigDetectOptions {
     pub include_home: bool,
     pub cwds: Option<Vec<PathBuf>>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum ExternalAgentConfigMigrationItemType {
+pub(crate) enum ExternalAgentConfigMigrationItemType {
     Config,
     Skills,
     AgentsMd,
@@ -44,24 +44,24 @@ pub enum ExternalAgentConfigMigrationItemType {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct PluginsMigration {
+pub(crate) struct PluginsMigration {
     pub marketplace_name: String,
     pub plugin_names: Vec<String>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct MigrationDetails {
+pub(crate) struct MigrationDetails {
     pub plugins: Vec<PluginsMigration>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct PendingPluginImport {
+pub(crate) struct PendingPluginImport {
     pub cwd: Option<PathBuf>,
     pub details: MigrationDetails,
 }
 
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
-pub struct PluginImportOutcome {
+pub(crate) struct PluginImportOutcome {
     pub succeeded_marketplaces: Vec<String>,
     pub succeeded_plugin_ids: Vec<String>,
     pub failed_marketplaces: Vec<String>,
@@ -69,7 +69,7 @@ pub struct PluginImportOutcome {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct ExternalAgentConfigMigrationItem {
+pub(crate) struct ExternalAgentConfigMigrationItem {
     pub item_type: ExternalAgentConfigMigrationItemType,
     pub description: String,
     pub cwd: Option<PathBuf>,
@@ -77,13 +77,13 @@ pub struct ExternalAgentConfigMigrationItem {
 }
 
 #[derive(Clone)]
-pub struct ExternalAgentConfigService {
+pub(crate) struct ExternalAgentConfigService {
     codex_home: PathBuf,
     external_agent_home: PathBuf,
 }
 
 impl ExternalAgentConfigService {
-    pub fn new(codex_home: PathBuf) -> Self {
+    pub(crate) fn new(codex_home: PathBuf) -> Self {
         let external_agent_home = default_external_agent_home();
         Self {
             codex_home,
@@ -99,7 +99,7 @@ impl ExternalAgentConfigService {
         }
     }
 
-    pub async fn detect(
+    pub(crate) async fn detect(
         &self,
         params: ExternalAgentConfigDetectOptions,
     ) -> io::Result<Vec<ExternalAgentConfigMigrationItem>> {
@@ -119,7 +119,7 @@ impl ExternalAgentConfigService {
         Ok(items)
     }
 
-    pub async fn import(
+    pub(crate) async fn import(
         &self,
         migration_items: Vec<ExternalAgentConfigMigrationItem>,
     ) -> io::Result<Vec<PendingPluginImport>> {
@@ -297,10 +297,21 @@ impl ExternalAgentConfigService {
                 .await
             {
                 Ok(config) => {
-                    let configured_plugin_ids =
-                        configured_plugins_from_stack(&config.config_layer_stack)
-                            .into_keys()
-                            .collect::<HashSet<_>>();
+                    let configured_plugin_ids = config
+                        .config_layer_stack
+                        .get_user_layer()
+                        .and_then(|user_layer| user_layer.config.get("plugins"))
+                        .and_then(|plugins| {
+                            match plugins.clone().try_into::<HashMap<String, PluginConfig>>() {
+                                Ok(plugins) => Some(plugins),
+                                Err(err) => {
+                                    tracing::warn!("invalid plugins config: {err}");
+                                    None
+                                }
+                            }
+                        })
+                        .map(|plugins| plugins.into_keys().collect::<HashSet<_>>())
+                        .unwrap_or_default();
                     let configured_marketplace_plugins = configured_marketplace_plugins(
                         &config,
                         &PluginsManager::new(self.codex_home.clone()),
@@ -410,7 +421,7 @@ impl ExternalAgentConfigService {
         Ok((local_details, remote_details))
     }
 
-    pub async fn import_plugins(
+    pub(crate) async fn import_plugins(
         &self,
         cwd: Option<&Path>,
         details: Option<MigrationDetails>,
@@ -638,7 +649,7 @@ fn extract_plugin_migration_details(
     let loadable_marketplaces = collect_marketplace_import_sources(settings, source_root)
         .into_iter()
         .filter_map(|(marketplace_name, source)| {
-            parse_marketplace_source(&source.source, source.ref_name)
+            is_local_marketplace_source(&source.source, source.ref_name)
                 .ok()
                 .map(|_| marketplace_name)
         })

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

@@ -0,0 +1 @@
+pub(crate) mod external_agent_config;

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

@@ -1,3 +1,8 @@
+use crate::config::external_agent_config::ExternalAgentConfigDetectOptions;
+use crate::config::external_agent_config::ExternalAgentConfigMigrationItem as CoreMigrationItem;
+use crate::config::external_agent_config::ExternalAgentConfigMigrationItemType as CoreMigrationItemType;
+use crate::config::external_agent_config::ExternalAgentConfigService;
+use crate::config::external_agent_config::PendingPluginImport;
 use crate::error_code::INTERNAL_ERROR_CODE;
 use codex_app_server_protocol::ExternalAgentConfigDetectParams;
 use codex_app_server_protocol::ExternalAgentConfigDetectResponse;
@@ -7,11 +12,6 @@ use codex_app_server_protocol::ExternalAgentConfigMigrationItemType;
 use codex_app_server_protocol::JSONRPCErrorError;
 use codex_app_server_protocol::MigrationDetails;
 use codex_app_server_protocol::PluginsMigration;
-use codex_core::external_agent_config::ExternalAgentConfigDetectOptions;
-use codex_core::external_agent_config::ExternalAgentConfigMigrationItem as CoreMigrationItem;
-use codex_core::external_agent_config::ExternalAgentConfigMigrationItemType as CoreMigrationItemType;
-use codex_core::external_agent_config::ExternalAgentConfigService;
-use codex_core::external_agent_config::PendingPluginImport;
 use std::io;
 use std::path::PathBuf;
 
@@ -108,12 +108,12 @@ impl ExternalAgentConfigApi {
                         description: migration_item.description,
                         cwd: migration_item.cwd,
                         details: migration_item.details.map(|details| {
-                            codex_core::external_agent_config::MigrationDetails {
+                            crate::config::external_agent_config::MigrationDetails {
                                 plugins: details
                                     .plugins
                                     .into_iter()
                                     .map(|plugin| {
-                                        codex_core::external_agent_config::PluginsMigration {
+                                        crate::config::external_agent_config::PluginsMigration {
                                             marketplace_name: plugin.marketplace_name,
                                             plugin_names: plugin.plugin_names,
                                         }

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

@@ -70,6 +70,7 @@ mod app_server_tracing;
 mod bespoke_event_handling;
 mod codex_message_processor;
 mod command_exec;
+mod config;
 mod config_api;
 mod dynamic_tools;
 mod error_code;

codex-rs/core/src/lib.rs

@@ -32,7 +32,6 @@ mod context_manager;
 pub mod exec;
 pub mod exec_env;
 mod exec_policy;
-pub mod external_agent_config;
 pub mod file_watcher;
 mod flags;
 #[cfg(test)]

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

@@ -56,7 +56,7 @@ pub async fn add_marketplace(
         .map_err(|err| MarketplaceAddError::Internal(format!("failed to add marketplace: {err}")))?
 }
 
-pub(crate) fn is_local_marketplace_source(
+pub fn is_local_marketplace_source(
     source: &str,
     explicit_ref: Option<String>,
 ) -> Result<bool, MarketplaceAddError> {

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

@@ -25,7 +25,6 @@ pub use codex_plugin::validate_plugin_segment;
 pub type LoadedPlugin = codex_plugin::LoadedPlugin<McpServerConfig>;
 pub type PluginLoadOutcome = codex_plugin::PluginLoadOutcome<McpServerConfig>;
 
-pub(crate) use codex_core_plugins::marketplace::find_marketplace_manifest_path;
 pub(crate) use discoverable::list_tool_suggest_discoverable_plugins;
 pub(crate) use injection::build_plugin_injections;
 pub use installed_marketplaces::INSTALLED_MARKETPLACES_DIR;
@@ -46,13 +45,11 @@ pub use manager::PluginRemoteSyncError;
 pub use manager::PluginUninstallError;
 pub use manager::PluginsManager;
 pub use manager::RemotePluginSyncResult;
-pub(crate) use manager::configured_plugins_from_stack;
 pub use marketplace_add::MarketplaceAddError;
 pub use marketplace_add::MarketplaceAddOutcome;
 pub use marketplace_add::MarketplaceAddRequest;
 pub use marketplace_add::add_marketplace;
-pub(crate) use marketplace_add::is_local_marketplace_source;
-pub(crate) use marketplace_add::parse_marketplace_source;
+pub use marketplace_add::is_local_marketplace_source;
 pub use marketplace_remove::MarketplaceRemoveError;
 pub use marketplace_remove::MarketplaceRemoveOutcome;
 pub use marketplace_remove::MarketplaceRemoveRequest;