Base chat retention cleanup on updated-at instead of created-at

Author: ericdallo

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Skip redundant MCP `tool/serverUpdated` notification after prompts/resources listing when the server has none.
+- Chat retention (`chatRetentionDays`) now considers when the chat was last updated instead of when it was created, keeping old but still active chats.
 
 ## 0.154.0
 

docs/config.json

@@ -58,8 +58,8 @@
     },
     "chatRetentionDays": {
       "type": "integer",
-      "description": "Number of days to keep old chats and tool call output cache before cleanup. Set to 0 to disable cleanup entirely.",
-      "markdownDescription": "Number of days to keep old chats and tool call output cache before cleanup. Set to `0` to disable cleanup entirely.",
+      "description": "Number of days to keep chats (since last update) and tool call output cache before cleanup. Set to 0 to disable cleanup entirely.",
+      "markdownDescription": "Number of days to keep chats (since last update) and tool call output cache before cleanup. Set to `0` to disable cleanup entirely.",
       "default": 14
     },
     "agent": {

src/eca/db.clj

@@ -801,7 +801,8 @@
       false)))
 
 (defn cleanup-old-chats!
-  "Deletes chats older than retention-days: removes them from memory and their
+  "Deletes chats not updated for retention-days (falling back to `:created-at`
+   when `:updated-at` is missing): removes them from memory and their
    per-chat cache files, then refreshes the chats index once. When
    retention-days is non-positive, cleanup is disabled."
   [db* metrics retention-days]
@@ -813,16 +814,16 @@
              (fn [chats]
                (into {}
                      (filter (fn [[id chat]]
-                               (let [created-at (:created-at chat)]
-                                 (if (and created-at (< created-at cutoff))
+                               (let [recency (or (:updated-at chat) (:created-at chat))]
+                                 (if (and recency (< recency cutoff))
                                    (do (swap! removed-ids* conj id) false)
                                    true))))
                      chats)))
       (when-let [removed-ids (not-empty @removed-ids*)]
         ;; Tombstone the ids so the index merge-on-write does not resurrect
         ;; them from an index file shared with another live server.
         (swap! db* update :deleted-chat-ids (fnil into #{}) removed-ids)
-        (logger/info logger-tag (str "Cleaned up " (count removed-ids) " chat(s) older than " retention-days " days"))
+        (logger/info logger-tag (str "Cleaned up " (count removed-ids) " chat(s) not updated for " retention-days " days"))
         (let [db @db*
               workspaces (db-workspaces db)]
           (doseq [chat-id removed-ids]

test/eca/db_test.clj

@@ -458,24 +458,38 @@
                                  "recent-chat" {:id "recent-chat"
                                                 :created-at two-days-ago
                                                 :messages [{:role "user" :content "hello"}]}
+                                 "old-but-active" {:id "old-but-active"
+                                                   :created-at fifteen-days-ago
+                                                   :updated-at two-days-ago
+                                                   :messages [{:role "user" :content "hi again"}]}
+                                 "stale-updated" {:id "stale-updated"
+                                                  :created-at fifteen-days-ago
+                                                  :updated-at fifteen-days-ago
+                                                  :messages [{:role "user" :content "bye"}]}
                                  "no-timestamp" {:id "no-timestamp"
                                                  :messages [{:role "user" :content "hey"}]}}})]
-          (doseq [id ["old-chat" "recent-chat" "no-timestamp"]]
+          (doseq [id ["old-chat" "recent-chat" "old-but-active" "stale-updated" "no-timestamp"]]
             (db/save-chat! @db* id nil))
-          (testing "deletes old chats (memory + file), keeps recent and chats without created-at"
+          (testing "deletes stale chats (memory + file), keeps recently updated and chats without timestamps"
             (db/cleanup-old-chats! db* nil 14)
             (is (nil? (get-in @db* [:chats "old-chat"]))
                 "Chat older than 14 days should be removed")
             (is (some? (get-in @db* [:chats "recent-chat"]))
                 "Chat newer than 14 days should be kept")
+            (is (some? (get-in @db* [:chats "old-but-active"]))
+                "Chat created long ago but updated recently should be kept")
+            (is (nil? (get-in @db* [:chats "stale-updated"]))
+                "Chat not updated for more than 14 days should be removed")
             (is (some? (get-in @db* [:chats "no-timestamp"]))
                 "Chat without created-at should be kept")
-            (is (= #{"old-chat"} (:deleted-chat-ids @db*))
+            (is (= #{"old-chat" "stale-updated"} (:deleted-chat-ids @db*))
                 "Removed chat ids are tombstoned so index merges cannot resurrect them")
             (is (not (fs/exists? (chat-cache-file workspaces "old-chat")))
                 "old chat's cache file is deleted")
+            (is (not (fs/exists? (chat-cache-file workspaces "stale-updated")))
+                "stale chat's cache file is deleted")
             (is (fs/exists? (chat-cache-file workspaces "recent-chat")))
-            (is (= #{"recent-chat" "no-timestamp"} (set (keys (read-index workspaces)))))))
+            (is (= #{"recent-chat" "old-but-active" "no-timestamp"} (set (keys (read-index workspaces)))))))
         (finally (fs/delete-tree tmpdir))))))
 
 (deftest cleanup-old-chats-no-op-test