Fix /compact triggering empty-response retries and rejected tool errors after the compact tool finishes

ericdallo · ericdallo · commit 4ce3ed6dbf5b · 2026-03-25T13:19:19.000-03:00
diff --git a/AGENTS.md b/AGENTS.md
@@ -3,7 +3,7 @@ ECA Agent Guide (AGENTS.md)
 - Build (requires Clojure CLI + Babashka):
   - All-in-one debug CLI (JVM, nREPL): `bb debug-cli`
   - Production CLI (JVM): `bb prod-cli`  |  Production JAR: `bb prod-jar`
-  - Native image (GraalVM, `GRAALVM_HOME` set): `bb native-cli`
+  - In production we use a native image (GraalVM, `GRAALVM_HOME` set): `bb native-cli`
 - Test (Kaocha via `:test` alias):
   - Run all unit tests: `bb test`  (same as `clojure -M:test`)
   - Run a single unit test namespace: `clojure -M:test --focus eca.main-test`
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Fix `/compact` triggering empty-response retries and rejected tool errors after the compact tool finishes.
+
 ## 0.116.6
 
 - Bump plumcp to 0.2.0-beta5.
diff --git a/integration-test/integration/chat/commands_test.clj b/integration-test/integration/chat/commands_test.clj
@@ -5,6 +5,7 @@
    [integration.eca :as eca]
    [integration.fixture :as fixture]
    [integration.helper :refer [match-content] :as h]
+   [llm-mock.mocks :as llm.mocks]
    [matcher-combinators.matchers :as m]
    [matcher-combinators.test :refer [match?]]))
 
@@ -100,3 +101,93 @@
             :commands (m/embeds
                        [{:name "mcpServerSample:my-prompt" :arguments [{:name "some-arg-1"}]}])}
            resp)))))
+
+(deftest compact-command
+  (eca/start-process!)
+
+  (eca/request! (fixture/initialize-request))
+  (eca/notify! (fixture/initialized-notification))
+
+  (let [chat-id* (atom nil)]
+    (testing "Setup: send an initial message to create chat history"
+      (llm.mocks/set-case! :simple-text-0)
+      (let [resp (eca/request! (fixture/chat-prompt-request
+                                {:model "anthropic/claude-sonnet-4-6"
+                                 :message "Tell me a joke!"}))
+            chat-id (reset! chat-id* (:chatId resp))]
+        (match-content chat-id "user" {:type "text" :text "Tell me a joke!\n"})
+        (match-content chat-id "system" {:type "metadata" :title "Some Cool Title"})
+        (match-content chat-id "system" {:type "progress" :state "running" :text "Waiting model"})
+        (match-content chat-id "system" {:type "progress" :state "running" :text "Generating"})
+        (match-content chat-id "assistant" {:type "text" :text "Knock"})
+        (match-content chat-id "assistant" {:type "text" :text " knock!"})
+        (match-content chat-id "system" {:type "usage"})
+        (match-content chat-id "system" {:type "progress" :state "finished"})))
+
+    (testing "Compact calls the tool and finishes cleanly without a second LLM request"
+      (llm.mocks/set-case! :compact-0)
+      (let [resp (eca/request! (fixture/chat-prompt-request
+                                {:chat-id @chat-id*
+                                 :model "anthropic/claude-sonnet-4-6"
+                                 :message "/compact"}))
+            chat-id (:chatId resp)]
+
+        (is (match? {:chatId (m/pred string?)
+                     :model "anthropic/claude-sonnet-4-6"
+                     :status "prompting"}
+                    resp))
+
+        ;; User message
+        (match-content chat-id "user" {:type "text" :text "/compact\n"})
+        ;; Progress
+        (match-content chat-id "system" {:type "progress" :state "running" :text "Waiting model"})
+        (match-content chat-id "system" {:type "progress" :state "running" :text "Generating"})
+        ;; Tool call preparation (streaming)
+        (match-content chat-id "assistant" {:type "toolCallPrepare"
+                                            :origin "native"
+                                            :id "compact-1"
+                                            :name "compact_chat"
+                                            :argumentsText ""
+                                            :summary "Compacting..."})
+        (match-content chat-id "assistant" {:type "toolCallPrepare"
+                                            :origin "native"
+                                            :id "compact-1"
+                                            :name "compact_chat"
+                                            :argumentsText "{\"summary\":\"Test summary of the conversation\"}"
+                                            :summary "Compacting..."})
+        ;; Usage from LLM response
+        (match-content chat-id "system" {:type "usage"})
+        ;; Tool execution
+        (match-content chat-id "assistant" {:type "toolCallRun"
+                                            :origin "native"
+                                            :id "compact-1"
+                                            :name "compact_chat"
+                                            :arguments {:summary "Test summary of the conversation"}
+                                            :manualApproval false
+                                            :summary "Compacting..."})
+        (match-content chat-id "assistant" {:type "toolCallRunning"
+                                            :origin "native"
+                                            :id "compact-1"
+                                            :name "compact_chat"
+                                            :summary "Compacting..."})
+        (match-content chat-id "system" {:type "progress" :state "running" :text "Calling tool"})
+        (match-content chat-id "assistant" {:type "toolCalled"
+                                            :origin "native"
+                                            :id "compact-1"
+                                            :name "compact_chat"
+                                            :error false
+                                            :totalTimeMs (m/pred number?)
+                                            :outputs [{:type "text" :text "Compacted successfully!"}]})
+        ;; Chat finishes, then compact side-effect sends summary messages
+        (match-content chat-id "system" {:type "progress" :state "finished"})
+        (match-content chat-id "system" {:type "text" :text "Compacted chat"})
+        (match-content chat-id "system" {:type "usage"})
+
+        ;; Key assertion: only one LLM request was made (no tool_result continuation).
+        ;; Before the fix, the continue-fn would trigger a second LLM call whose
+        ;; request body would overwrite this one and contain tool_result messages.
+        (is (not-any? (fn [{:keys [content]}]
+                        (and (sequential? content)
+                             (some #(= "tool_result" (:type %)) content)))
+                      (:messages (llm.mocks/get-req-body :compact-0)))
+            "Only one LLM request should be made - no tool_result continuation")))))
diff --git a/integration-test/llm_mock/anthropic.clj b/integration-test/llm_mock/anthropic.clj
@@ -257,6 +257,27 @@
         (sse-send! ch "message_stop" {:type "message_stop"})
         (hk/close ch)))))
 
+(defn ^:private compact-0 [ch]
+  ;; LLM calls eca__compact_chat with a summary — no text or reasoning
+  (sse-send! ch "content_block_start"
+             {:type "content_block_start"
+              :index 0
+              :content_block {:type "tool_use"
+                              :id "compact-1"
+                              :name "eca__compact_chat"}})
+  (sse-send! ch "content_block_delta"
+             {:type "content_block_delta"
+              :index 0
+              :delta {:type "input_json_delta"
+                      :partial_json "{\"summary\":\"Test summary of the conversation\"}"}})
+  (sse-send! ch "message_delta"
+             {:type "message_delta"
+              :delta {:stop_reason "tool_use"}
+              :usage {:input_tokens 100
+                      :output_tokens 50}})
+  (sse-send! ch "message_stop" {:type "message_stop"})
+  (hk/close ch))
+
 (defn ^:private chat-title-text-0 [ch]
   (hk/send! ch
             (json/generate-string
@@ -286,4 +307,5 @@
                        :reasoning-0 (reasoning-0 ch)
                        :reasoning-1 (reasoning-1 ch)
                        :tool-calling-0 (tool-calling-0 ch body)
-                       :mcp-tool-call-0 (mcp-tool-call-0 ch body)))))})))
+                       :mcp-tool-call-0 (mcp-tool-call-0 ch body)
+                       :compact-0 (compact-0 ch)))))})))
diff --git a/src/eca/features/chat.clj b/src/eca/features/chat.clj
@@ -608,10 +608,14 @@
                 :on-tools-called (tc/on-tools-called!
                                   (assoc chat-ctx :continue-fn
                                          (fn [tc-all-tools tc-user-messages]
-                                           (if (lifecycle/auto-compact? chat-id agent full-model config @db*)
-                                             (trigger-auto-compact! chat-ctx tc-all-tools tc-user-messages)
-                                             {:tools tc-all-tools
-                                              :new-messages (get-in @db* [:chats chat-id :messages])})))
+                                           (if (get-in @db* [:chats chat-id :compact-done?])
+                                             (do (swap! db* update-in [:chats chat-id] dissoc :compact-done?)
+                                                 (lifecycle/finish-chat-prompt! :idle chat-ctx)
+                                                 nil)
+                                             (if (lifecycle/auto-compact? chat-id agent full-model config @db*)
+                                               (trigger-auto-compact! chat-ctx tc-all-tools tc-user-messages)
+                                               {:tools tc-all-tools
+                                                :new-messages (get-in @db* [:chats chat-id :messages])}))))
                                   received-msgs* add-to-history! user-messages)
                 :on-reason (fn [{:keys [status id text external-id delta-reasoning? redacted? data]}]
                              (lifecycle/assert-chat-not-stopped! chat-ctx)
diff --git a/src/eca/features/tools/chat.clj b/src/eca/features/tools/chat.clj
@@ -12,6 +12,9 @@
     ;; Save summary to replace chat history later
     (swap! db* assoc-in [:chats chat-id :last-summary] summary)
 
+    ;; Signal that compact is done so the LLM loop stops
+    (swap! db* assoc-in [:chats chat-id :compact-done?] true)
+
     (tools.util/single-text-content "Compacted successfully!")))
 
 (def definitions
diff --git a/test/eca/features/tools/chat_test.clj b/test/eca/features/tools/chat_test.clj
@@ -28,7 +28,9 @@
             (is (= false (:compacting? chat-state))
                 "Should set compacting? to false")
             (is (= test-summary (:last-summary chat-state))
-                "Should save the summary as last-summary"))))))
+                "Should save the summary as last-summary")
+            (is (= true (:compact-done? chat-state))
+                "Should set compact-done? to true"))))))
 
   (testing "Handles empty summary"
     (let [db* (h/db*)
@@ -45,7 +47,8 @@
         
         (let [chat-state (get-in @db* [:chats chat-id])]
           (is (= false (:compacting? chat-state)))
-          (is (= empty-summary (:last-summary chat-state))))))))
+          (is (= empty-summary (:last-summary chat-state)))
+          (is (= true (:compact-done? chat-state))))))))
 
 (deftest compact-chat-enabled-test
   (testing "Tool is enabled when chat is compacting"
