Make external session detection limits configurable (#34449)

## What changed

- Add `maxSessionAgeDays` and `maxSessions` to the external-agent config detection request.
- Apply the requested limits when discovering sessions from supported migration sources.
- Preserve the existing defaults of a 30-day maximum age and 50 sessions when either option is omitted.

GitOrigin-RevId: 46376e94b64f1f61d8776e34d82cdd2cdeb36ca0

codex-rs/app-server-protocol/schema/json/ClientRequest.json

@@ -876,6 +876,24 @@
           "description": "If true, include detection under the user's home directory.",
           "type": "boolean"
         },
+        "maxSessionAgeDays": {
+          "description": "Maximum age in days for detected sessions. Missing values use the default limit.",
+          "format": "uint32",
+          "minimum": 0.0,
+          "type": [
+            "integer",
+            "null"
+          ]
+        },
+        "maxSessions": {
+          "description": "Maximum number of sessions to detect. Missing values use the default limit.",
+          "format": "uint32",
+          "minimum": 0.0,
+          "type": [
+            "integer",
+            "null"
+          ]
+        },
         "migrationSource": {
           "description": "Optional migration-source selector. Missing or unrecognized values use the default source.",
           "type": [

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -9577,6 +9577,24 @@
             "description": "If true, include detection under the user's home directory.",
             "type": "boolean"
           },
+          "maxSessionAgeDays": {
+            "description": "Maximum age in days for detected sessions. Missing values use the default limit.",
+            "format": "uint32",
+            "minimum": 0.0,
+            "type": [
+              "integer",
+              "null"
+            ]
+          },
+          "maxSessions": {
+            "description": "Maximum number of sessions to detect. Missing values use the default limit.",
+            "format": "uint32",
+            "minimum": 0.0,
+            "type": [
+              "integer",
+              "null"
+            ]
+          },
           "migrationSource": {
             "description": "Optional migration-source selector. Missing or unrecognized values use the default source.",
             "type": [

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json

@@ -5755,6 +5755,24 @@
           "description": "If true, include detection under the user's home directory.",
           "type": "boolean"
         },
+        "maxSessionAgeDays": {
+          "description": "Maximum age in days for detected sessions. Missing values use the default limit.",
+          "format": "uint32",
+          "minimum": 0.0,
+          "type": [
+            "integer",
+            "null"
+          ]
+        },
+        "maxSessions": {
+          "description": "Maximum number of sessions to detect. Missing values use the default limit.",
+          "format": "uint32",
+          "minimum": 0.0,
+          "type": [
+            "integer",
+            "null"
+          ]
+        },
         "migrationSource": {
           "description": "Optional migration-source selector. Missing or unrecognized values use the default source.",
           "type": [

codex-rs/app-server-protocol/schema/json/v2/ExternalAgentConfigDetectParams.json

@@ -15,6 +15,24 @@
       "description": "If true, include detection under the user's home directory.",
       "type": "boolean"
     },
+    "maxSessionAgeDays": {
+      "description": "Maximum age in days for detected sessions. Missing values use the default limit.",
+      "format": "uint32",
+      "minimum": 0.0,
+      "type": [
+        "integer",
+        "null"
+      ]
+    },
+    "maxSessions": {
+      "description": "Maximum number of sessions to detect. Missing values use the default limit.",
+      "format": "uint32",
+      "minimum": 0.0,
+      "type": [
+        "integer",
+        "null"
+      ]
+    },
     "migrationSource": {
       "description": "Optional migration-source selector. Missing or unrecognized values use the default source.",
       "type": [

codex-rs/app-server-protocol/schema/typescript/v2/ExternalAgentConfigDetectParams.ts

@@ -11,6 +11,14 @@ includeHome?: boolean,
  * Zero or more working directories to include for repo-scoped detection.
  */
 cwds?: Array<string> | null,
+/**
+ * Maximum age in days for detected sessions. Missing values use the default limit.
+ */
+maxSessionAgeDays?: number | null,
+/**
+ * Maximum number of sessions to detect. Missing values use the default limit.
+ */
+maxSessions?: number | null,
 /**
  * Deprecated field retained for compatibility. This field is ignored; use `migrationSource`
  * to select the migration source.

codex-rs/app-server-protocol/src/protocol/v2/config.rs

@@ -699,6 +699,12 @@ pub struct ExternalAgentConfigDetectParams {
     /// Zero or more working directories to include for repo-scoped detection.
     #[ts(optional = nullable)]
     pub cwds: Option<Vec<PathBuf>>,
+    /// Maximum age in days for detected sessions. Missing values use the default limit.
+    #[ts(optional = nullable)]
+    pub max_session_age_days: Option<u32>,
+    /// Maximum number of sessions to detect. Missing values use the default limit.
+    #[ts(optional = nullable)]
+    pub max_sessions: Option<u32>,
     /// Deprecated field retained for compatibility. This field is ignored; use `migrationSource`
     /// to select the migration source.
     #[ts(optional = nullable)]

codex-rs/app-server/src/external_agent_migration/processor.rs

@@ -1,4 +1,5 @@
 use std::sync::Arc;
+use std::time::Duration;
 
 use crate::config_manager::ConfigManager;
 use crate::error_code::internal_error;
@@ -30,6 +31,7 @@ use codex_external_agent_migration::ExternalAgentConfigImportItemResult as CoreI
 use codex_external_agent_migration::ExternalAgentConfigImportOutcome as CoreImportOutcome;
 use codex_external_agent_migration::ExternalAgentConfigMigrationItemType as CoreMigrationItemType;
 use codex_external_agent_migration::ExternalAgentConfigService;
+use codex_external_agent_migration::ExternalAgentSessionImportLimits;
 use codex_external_agent_migration::PluginImportOutcome;
 use codex_external_agent_migration::record_import_error;
 use codex_external_agent_migration::sessions::ExternalAgentSessionMigration as CoreSessionMigration;
@@ -119,6 +121,18 @@ impl ExternalAgentConfigRequestProcessor {
         let migration_service = self
             .migration_service
             .with_migration_source(params.migration_source.as_deref());
+        let default_session_import_limits = ExternalAgentSessionImportLimits::default();
+        let migration_service =
+            migration_service.with_session_import_limits(ExternalAgentSessionImportLimits {
+                max_age: params
+                    .max_session_age_days
+                    .map(|days| Duration::from_secs(u64::from(days) * 24 * 60 * 60))
+                    .unwrap_or(default_session_import_limits.max_age),
+                max_sessions: params
+                    .max_sessions
+                    .map(|max_sessions| max_sessions as usize)
+                    .unwrap_or(default_session_import_limits.max_sessions),
+            });
         let options = ExternalAgentConfigDetectOptions {
             include_home: params.include_home,
             include_memory: self.external_agent_memory_import_enabled().await,

codex-rs/external-agent-migration/src/detect/mod.rs

@@ -378,9 +378,11 @@ impl ExternalAgentConfigService {
         }
 
         if scope.is_home() {
-            let sessions = self
+            let sessions = self.source.recent_sessions(
-                .source
+                &self.external_agent_home,
-                .recent_sessions(&self.external_agent_home, &self.codex_home)?;
+                &self.codex_home,
+                self.session_import_limits,
+            )?;
             if !sessions.is_empty() {
                 items.push(ExternalAgentConfigMigrationItem {
                     item_type: ExternalAgentConfigMigrationItemType::Sessions,

codex-rs/external-agent-migration/src/detect/sessions/cla.rs

@@ -1,7 +1,6 @@
-#[cfg(test)]
-use super::common::SESSION_IMPORT_MAX_COUNT;
 use super::common::SessionFileCandidate;
 use super::common::detect_recent_sessions;
+use crate::model::ExternalAgentSessionImportLimits;
 use crate::sessions::ExternalAgentSessionMigration;
 use std::fs;
 use std::io;
@@ -10,6 +9,18 @@ use std::path::Path;
 pub fn detect_recent_cla_sessions(
     external_agent_home: &Path,
     codex_home: &Path,
+) -> io::Result<Vec<ExternalAgentSessionMigration>> {
+    detect_recent_cla_sessions_with_limits(
+        external_agent_home,
+        codex_home,
+        ExternalAgentSessionImportLimits::default(),
+    )
+}
+
+pub(crate) fn detect_recent_cla_sessions_with_limits(
+    external_agent_home: &Path,
+    codex_home: &Path,
+    limits: ExternalAgentSessionImportLimits,
 ) -> io::Result<Vec<ExternalAgentSessionMigration>> {
     let projects_root = external_agent_home.join("projects");
     if !projects_root.is_dir() {
@@ -42,7 +53,9 @@ pub fn detect_recent_cla_sessions(
             });
         }
     }
-    detect_recent_sessions(codex_home, candidates, /*require_existing_cwd*/ true)
+    detect_recent_sessions(
+        codex_home, candidates, /*require_existing_cwd*/ true, limits,
+    )
 }
 
 #[cfg(test)]
@@ -233,7 +246,8 @@ mod tests {
         let timestamp = chrono::Utc::now().to_rfc3339_opts(chrono::SecondsFormat::Secs, true);
         let modified_at = SystemTime::now();
         let mut expected = Vec::new();
-        for index in 0..=SESSION_IMPORT_MAX_COUNT {
+        let default_limits = ExternalAgentSessionImportLimits::default();
+        for index in 0..=default_limits.max_sessions {
             let file_name = format!("{index:02}-session.jsonl");
             let title = format!("session {index}");
             let path = write_session(
@@ -275,7 +289,7 @@ mod tests {
         }
 
         let changed_at = SystemTime::now()
-            + Duration::from_secs(/*secs*/ SESSION_IMPORT_MAX_COUNT as u64 + 1);
+            + Duration::from_secs(/*secs*/ default_limits.max_sessions as u64 + 1);
         for (index, session) in all_sessions.iter().enumerate() {
             let title = session.title.as_deref().expect("session title");
             std::fs::write(

codex-rs/external-agent-migration/src/detect/sessions/common.rs

@@ -1,3 +1,4 @@
+use crate::model::ExternalAgentSessionImportLimits;
 use crate::sessions::ExternalAgentSessionMigration;
 use crate::sessions::ledger::load_import_ledger;
 use crate::sessions::ledger::save_import_ledger;
@@ -9,10 +10,6 @@ use std::fs;
 use std::io;
 use std::path::Path;
 use std::path::PathBuf;
-use std::time::Duration;
-
-pub(super) const SESSION_IMPORT_MAX_COUNT: usize = 50;
-const SESSION_IMPORT_MAX_AGE: Duration = Duration::from_secs(30 * 24 * 60 * 60);
 
 pub(super) struct SessionFileCandidate {
     pub path: PathBuf,
@@ -23,11 +20,12 @@ pub(super) fn detect_recent_sessions(
     codex_home: &Path,
     candidates: impl IntoIterator<Item = SessionFileCandidate>,
     require_existing_cwd: bool,
+    limits: ExternalAgentSessionImportLimits,
 ) -> io::Result<Vec<ExternalAgentSessionMigration>> {
     let now = now_unix_seconds();
     let mut ledger = load_import_ledger(codex_home)?;
     let source_states = ledger.source_states();
-    let mut recent = BinaryHeap::with_capacity(SESSION_IMPORT_MAX_COUNT + 1);
+    let mut recent = BinaryHeap::new();
 
     for candidate in candidates {
         let Ok(metadata) = fs::metadata(&candidate.path) else {
@@ -39,9 +37,7 @@ pub(super) fn detect_recent_sessions(
         let Ok(modified_at) = modified_at.duration_since(std::time::UNIX_EPOCH) else {
             continue;
         };
-        if (modified_at.as_secs() as i64)
+        if (modified_at.as_secs() as i64) < now.saturating_sub(limits.max_age.as_secs() as i64) {
-            < now.saturating_sub(SESSION_IMPORT_MAX_AGE.as_secs() as i64)
-        {
             continue;
         }
         let Ok(modified_at_nanos) = i64::try_from(modified_at.as_nanos()) else {
@@ -62,7 +58,7 @@ pub(super) fn detect_recent_sessions(
             candidate.path,
             candidate.fallback_cwd,
         ));
-        if recent.len() > SESSION_IMPORT_MAX_COUNT {
+        if recent.len() > limits.max_sessions {
             recent.pop();
         }
     }

codex-rs/external-agent-migration/src/detect/sessions/cur.rs

@@ -1,7 +1,6 @@
-#[cfg(test)]
-use super::common::SESSION_IMPORT_MAX_COUNT;
 use super::common::SessionFileCandidate;
 use super::common::detect_recent_sessions;
+use crate::model::ExternalAgentSessionImportLimits;
 use crate::sessions::ExternalAgentSessionMigration;
 use std::fs;
 use std::io;
@@ -11,6 +10,18 @@ use std::path::PathBuf;
 pub fn detect_recent_cur_sessions(
     external_agent_home: &Path,
     codex_home: &Path,
+) -> io::Result<Vec<ExternalAgentSessionMigration>> {
+    detect_recent_cur_sessions_with_limits(
+        external_agent_home,
+        codex_home,
+        ExternalAgentSessionImportLimits::default(),
+    )
+}
+
+pub(crate) fn detect_recent_cur_sessions_with_limits(
+    external_agent_home: &Path,
+    codex_home: &Path,
+    limits: ExternalAgentSessionImportLimits,
 ) -> io::Result<Vec<ExternalAgentSessionMigration>> {
     let projects_root = external_agent_home.join("projects");
     if !projects_root.is_dir() {
@@ -34,7 +45,9 @@ pub fn detect_recent_cur_sessions(
             });
         }
     }
-    detect_recent_sessions(codex_home, candidates, /*require_existing_cwd*/ false)
+    detect_recent_sessions(
+        codex_home, candidates, /*require_existing_cwd*/ false, limits,
+    )
 }
 
 fn cur_transcript_files(transcripts_root: &Path) -> Vec<PathBuf> {

codex-rs/external-agent-migration/src/detect/sessions/cur_tests.rs

@@ -171,7 +171,8 @@ fn detects_cur_sessions_in_batches_and_redetects_modified_imports() {
     let encoded_project = encode_project_path(&project_root);
     let modified_at = SystemTime::now();
     let mut expected = Vec::new();
-    for index in 0..=SESSION_IMPORT_MAX_COUNT {
+    let default_limits = ExternalAgentSessionImportLimits::default();
+    for index in 0..=default_limits.max_sessions {
         let session_id = format!("session-{index:02}");
         let title = format!("request {index}");
         let path = write_transcript(&external_agent_home, &encoded_project, &session_id, &title);

codex-rs/external-agent-migration/src/detect/sessions/mod.rs

@@ -4,6 +4,8 @@ mod connectors_cla;
 mod cur;
 
 pub use cla::detect_recent_cla_sessions;
+pub(crate) use cla::detect_recent_cla_sessions_with_limits;
 pub use connectors_cla::ImportedSessionConnectorAttribution;
 pub use connectors_cla::detect_imported_cla_session_connectors;
 pub use cur::detect_recent_cur_sessions;
+pub(crate) use cur::detect_recent_cur_sessions_with_limits;

codex-rs/external-agent-migration/src/lib.rs

@@ -64,6 +64,7 @@ pub use service::ExternalAgentConfigImportSuccess;
 pub use service::ExternalAgentConfigMigrationItem;
 pub use service::ExternalAgentConfigMigrationItemType;
 pub use service::ExternalAgentConfigService;
+pub use service::ExternalAgentSessionImportLimits;
 pub use service::MigrationDetails;
 pub use service::NamedMigration;
 pub use service::PendingPluginImport;

codex-rs/external-agent-migration/src/migration_source.rs

@@ -2,8 +2,9 @@ use crate::ClaSource;
 use crate::CurSource;
 use crate::RewriteProfile;
 use crate::detect::plugins;
-use crate::detect::sessions::detect_recent_cla_sessions;
+use crate::detect::sessions::detect_recent_cla_sessions_with_limits;
-use crate::detect::sessions::detect_recent_cur_sessions;
+use crate::detect::sessions::detect_recent_cur_sessions_with_limits;
+use crate::model::ExternalAgentSessionImportLimits;
 use crate::sessions::ExternalAgentSessionMigration;
 use crate::sessions::SessionMetadataMode;
 use serde_json::Value as JsonValue;
@@ -122,10 +123,15 @@ impl ExternalAgentSource {
         self,
         external_agent_home: &Path,
         codex_home: &Path,
+        limits: ExternalAgentSessionImportLimits,
     ) -> io::Result<Vec<ExternalAgentSessionMigration>> {
         match self {
-            Self::Cla => detect_recent_cla_sessions(external_agent_home, codex_home),
+            Self::Cla => {
-            Self::Cur => detect_recent_cur_sessions(external_agent_home, codex_home),
+                detect_recent_cla_sessions_with_limits(external_agent_home, codex_home, limits)
+            }
+            Self::Cur => {
+                detect_recent_cur_sessions_with_limits(external_agent_home, codex_home, limits)
+            }
         }
     }
 

codex-rs/external-agent-migration/src/model.rs

@@ -1,5 +1,27 @@
 use crate::sessions::ExternalAgentSessionMigration;
 use std::path::PathBuf;
+use std::time::Duration;
+
+const DEFAULT_SESSION_IMPORT_MAX_AGE: Duration = Duration::from_secs(30 * 24 * 60 * 60);
+const DEFAULT_SESSION_IMPORT_MAX_COUNT: usize = 50;
+
+/// Bounds session discovery for an external-agent import.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ExternalAgentSessionImportLimits {
+    /// Oldest source-session modification age that remains eligible.
+    pub max_age: Duration,
+    /// Maximum number of eligible sessions returned by detection.
+    pub max_sessions: usize,
+}
+
+impl Default for ExternalAgentSessionImportLimits {
+    fn default() -> Self {
+        Self {
+            max_age: DEFAULT_SESSION_IMPORT_MAX_AGE,
+            max_sessions: DEFAULT_SESSION_IMPORT_MAX_COUNT,
+        }
+    }
+}
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ExternalAgentConfigDetectOptions {

codex-rs/external-agent-migration/src/service.rs

@@ -13,6 +13,7 @@ pub use crate::model::ExternalAgentConfigImportRawError;
 pub use crate::model::ExternalAgentConfigImportSuccess;
 pub use crate::model::ExternalAgentConfigMigrationItem;
 pub use crate::model::ExternalAgentConfigMigrationItemType;
+pub use crate::model::ExternalAgentSessionImportLimits;
 pub use crate::model::MigrationDetails;
 pub use crate::model::NamedMigration;
 pub use crate::model::PendingPluginImport;
@@ -64,6 +65,7 @@ pub struct ExternalAgentConfigService {
     pub(crate) external_agent_home: PathBuf,
     pub(crate) analytics_events_client: Option<AnalyticsEventsClient>,
     pub(crate) source: ExternalAgentSource,
+    pub(crate) session_import_limits: ExternalAgentSessionImportLimits,
     state_db: Option<StateDbHandle>,
 }
 
@@ -82,6 +84,7 @@ impl ExternalAgentConfigService {
             external_agent_home,
             analytics_events_client: Some(analytics_events_client),
             source,
+            session_import_limits: ExternalAgentSessionImportLimits::default(),
             state_db,
         }
     }
@@ -96,10 +99,17 @@ impl ExternalAgentConfigService {
             external_agent_home,
             analytics_events_client: self.analytics_events_client.clone(),
             source,
+            session_import_limits: self.session_import_limits,
             state_db: self.state_db.clone(),
         }
     }
 
+    pub fn with_session_import_limits(&self, limits: ExternalAgentSessionImportLimits) -> Self {
+        let mut service = self.clone();
+        service.session_import_limits = limits;
+        service
+    }
+
     pub fn session_metadata_mode(&self) -> SessionMetadataMode {
         self.source.session_metadata_mode()
     }
@@ -122,6 +132,7 @@ impl ExternalAgentConfigService {
             external_agent_home,
             analytics_events_client: None,
             source,
+            session_import_limits: ExternalAgentSessionImportLimits::default(),
             state_db: None,
         }
     }

codex-rs/tui/src/external_agent_config_migration_flow.rs

@@ -274,6 +274,8 @@ pub(crate) async fn handle_external_agent_config_migration_prompt(
             .external_agent_config_detect(ExternalAgentConfigDetectParams {
                 include_home: true,
                 cwds: Some(vec![cwd.clone()]),
+                max_session_age_days: None,
+                max_sessions: None,
                 source: None,
                 migration_source: Some(source.migration_source().to_string()),
             })