From 643e275d77f62670da6f6558be9b7efe181527bc Mon Sep 17 00:00:00 2001
From: Hunter B <hmbown@gmail.com>
Date: Mon, 22 Jun 2026 21:04:41 -0700
Subject: [PATCH] Enable state store foreign key cascades

Turn on SQLite foreign key enforcement for every StateStore connection so delete_thread honors the schema's cascading child-row cleanup.

Add a regression test that persists messages, dynamic tools, checkpoints, and thread goals before deleting the parent thread.
---
 crates/state/src/lib.rs | 66 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/crates/state/src/lib.rs b/crates/state/src/lib.rs
index 34b7bfe45..bc7aad9b3 100644
--- a/crates/state/src/lib.rs
+++ b/crates/state/src/lib.rs
@@ -305,8 +305,11 @@ impl StateStore {
     }
 
     fn conn(&self) -> Result<Connection> {
-        Connection::open(&self.db_path)
-            .with_context(|| format!("failed to open state db {}", self.db_path.display()))
+        let conn = Connection::open(&self.db_path)
+            .with_context(|| format!("failed to open state db {}", self.db_path.display()))?;
+        conn.execute_batch("PRAGMA foreign_keys = ON;")
+            .context("failed to enable state db foreign keys")?;
+        Ok(conn)
     }
 
     fn init_schema(&self) -> Result<()> {
@@ -1818,6 +1821,13 @@ mod tests {
         }
     }
 
+    fn table_count(store: &StateStore, table: &str, thread_id: &str) -> i64 {
+        let conn = store.conn().expect("open test connection");
+        let query = format!("SELECT COUNT(*) FROM {table} WHERE thread_id = ?1");
+        conn.query_row(&query, params![thread_id], |row| row.get(0))
+            .expect("count rows")
+    }
+
     #[test]
     fn thread_goal_crud_round_trips_and_replaces() {
         let store = temp_state_store("thread-goal-crud");
@@ -1867,6 +1877,58 @@ mod tests {
         assert!(err.to_string().contains("thread missing-thread not found"));
     }
 
+    #[test]
+    fn delete_thread_cascades_child_rows() {
+        let store = temp_state_store("delete-thread-cascade");
+        store
+            .upsert_thread(&test_thread("thread-1"))
+            .expect("upsert thread");
+        store
+            .append_message("thread-1", "user", "hello", None)
+            .expect("append message");
+        store
+            .persist_dynamic_tools(
+                "thread-1",
+                &[DynamicToolRecord {
+                    position: 0,
+                    name: "lookup".to_string(),
+                    description: Some("Look something up".to_string()),
+                    input_schema: serde_json::json!({"type": "object"}),
+                }],
+            )
+            .expect("persist dynamic tools");
+        store
+            .save_checkpoint("thread-1", "checkpoint-1", &serde_json::json!({"ok": true}))
+            .expect("save checkpoint");
+        store
+            .upsert_thread_goal(&test_goal("thread-1", "finish the thread"))
+            .expect("upsert goal");
+
+        assert_eq!(table_count(&store, "messages", "thread-1"), 1);
+        assert_eq!(table_count(&store, "thread_dynamic_tools", "thread-1"), 1);
+        assert_eq!(table_count(&store, "checkpoints", "thread-1"), 1);
+        assert_eq!(table_count(&store, "thread_goals", "thread-1"), 1);
+
+        store.delete_thread("thread-1").expect("delete thread");
+
+        assert!(
+            store
+                .get_thread("thread-1")
+                .expect("read deleted thread")
+                .is_none()
+        );
+        assert_eq!(table_count(&store, "messages", "thread-1"), 0);
+        assert_eq!(table_count(&store, "thread_dynamic_tools", "thread-1"), 0);
+        assert_eq!(table_count(&store, "checkpoints", "thread-1"), 0);
+        assert_eq!(table_count(&store, "thread_goals", "thread-1"), 0);
+        assert!(
+            store
+                .get_thread_goal("thread-1")
+                .expect("read deleted goal")
+                .is_none()
+        );
+    }
+
     #[test]
     fn record_thread_goal_usage_accumulates_tokens_and_time() {
         let store = temp_state_store("thread-goal-usage");