feat(harness): support per-subagent compaction config

agentscope-harness/src/main/java/io/agentscope/harness/agent/HarnessAgentBuilderSupport.java

@@ -399,6 +399,8 @@ static SubagentFactory buildDeclaredFactory(
                 capturedLocalFilesystemSpec = b.localFilesystemSpec;
         final List<AgentSkillRepository> capturedSkillRepos = List.copyOf(b.skillRepositories);
         final Path capturedProjectGlobalSkillsDir = b.projectGlobalSkillsDir;
+        final CompactionConfig capturedCompactionConfig = b.compactionConfig;
+        final boolean capturedDisableCompaction = b.disableCompaction;
         // See buildGeneralPurposeFactory: propagate the parent's (distributed) state store so the
         // subagent's conversation survives cross-node re-materialization. Null in local defaults.
         final io.agentscope.core.state.AgentStateStore capturedStateStore = b.stateStoreOverride;
@@ -470,6 +472,15 @@ static SubagentFactory buildDeclaredFactory(
             if (capturedModelExec != null) sub.modelExecutionConfig(capturedModelExec);
             if (capturedToolExec != null) sub.toolExecutionConfig(capturedToolExec);
 
+            CompactionConfig declaredCompactionConfig = decl.getCompactionConfig();
+            if (declaredCompactionConfig != null) {
+                sub.compaction(declaredCompactionConfig);
+            } else if (capturedDisableCompaction) {
+                sub.disableCompaction();
+            } else if (capturedCompactionConfig != null) {
+                sub.compaction(capturedCompactionConfig);
+            }
+
             if (capturedDisableFilesystemTools) sub.disableFilesystemTools();
             if (capturedDisableShellTool) sub.disableShellTool();
             if (capturedDisableMemoryTools) sub.disableMemoryTools();

agentscope-harness/src/main/java/io/agentscope/harness/agent/subagent/SubagentDeclaration.java

@@ -15,6 +15,7 @@
  */
 package io.agentscope.harness.agent.subagent;
 
+import io.agentscope.harness.agent.memory.compaction.CompactionConfig;
 import java.nio.file.Path;
 import java.util.List;
 import java.util.Map;
@@ -95,6 +96,7 @@ public enum Mode {
     private final Boolean exposeToUser;
     private final List<String> tools;
     private final List<String> skills;
+    private final CompactionConfig compactionConfig;
 
     /** Base URL of the remote task server (e.g. {@code http://host:8080}). */
     private final String url;
@@ -119,6 +121,7 @@ private SubagentDeclaration(Builder b) {
         this.exposeToUser = b.exposeToUser;
         this.tools = b.tools != null ? List.copyOf(b.tools) : List.of();
         this.skills = b.skills != null ? List.copyOf(b.skills) : List.of();
+        this.compactionConfig = b.compactionConfig;
         this.url = b.url;
         this.headers = b.headers != null && !b.headers.isEmpty() ? Map.copyOf(b.headers) : null;
     }
@@ -280,6 +283,16 @@ public List<String> getSkills() {
         return skills;
     }
 
+    /**
+     * Optional compaction configuration for this subagent.
+     *
+     * <p>When {@code null}, the subagent inherits the parent agent's compaction configuration and
+     * enabled/disabled state.
+     */
+    public CompactionConfig getCompactionConfig() {
+        return compactionConfig;
+    }
+
     /** Returns {@code true} when this declaration targets a remote task HTTP server. */
     public boolean isRemote() {
         return url != null && !url.isBlank();
@@ -328,6 +341,7 @@ public static final class Builder {
         private Boolean exposeToUser;
         private List<String> tools;
         private List<String> skills;
+        private CompactionConfig compactionConfig;
         private String url;
         private Map<String, String> headers;
 
@@ -501,6 +515,18 @@ public Builder skills(List<String> skills) {
             return this;
         }
 
+        /**
+         * Sets a compaction configuration for this subagent.
+         *
+         * <p>An explicit declaration-level configuration takes precedence over the parent agent's
+         * compaction configuration and can enable compaction for this subagent even when the parent
+         * disables it.
+         */
+        public Builder compaction(CompactionConfig compactionConfig) {
+            this.compactionConfig = compactionConfig;
+            return this;
+        }
+
         /**
          * Remote task server base URL. Mutually exclusive with {@link #workspace(Path)} and a
          * non-blank {@link #inlineAgentsBody(String)}.

agentscope-harness/src/test/java/io/agentscope/harness/agent/HarnessAgentTest.java

@@ -943,6 +943,74 @@ void declaredSubagent_inheritsExecutionConfigsFromParent() throws Exception {
                 "declared subagent must inherit parent modelExecutionConfig");
     }
 
+    @Test
+    void declaredSubagent_explicitCompactionOverridesDisabledParent() throws Exception {
+        Files.createDirectories(workspace);
+        CompactionConfig subagentCompaction = CompactionConfig.builder().triggerMessages(5).build();
+        SubagentDeclaration decl =
+                SubagentDeclaration.builder()
+                        .name("compact-worker")
+                        .description("worker with independent compaction")
+                        .inlineAgentsBody("You are a worker subagent.")
+                        .compaction(subagentCompaction)
+                        .build();
+
+        List<SubagentEntry> entries =
+                HarnessAgent.builder()
+                        .model(stubModel("ok"))
+                        .workspace(workspace)
+                        .disableCompaction()
+                        .subagent(decl)
+                        .buildSubagentEntries(workspace);
+
+        HarnessAgent child =
+                (HarnessAgent)
+                        entries.stream()
+                                .filter(e -> "compact-worker".equals(e.name()))
+                                .findFirst()
+                                .orElseThrow()
+                                .factory()
+                                .create(RuntimeContext.empty());
+
+        assertSame(subagentCompaction, decl.getCompactionConfig());
+        assertNotNull(
+                child.getCompactionHook(),
+                "declaration-level compaction must override the disabled parent");
+    }
+
+    @Test
+    void declaredSubagent_withoutCompactionOverrideInheritsDisabledParent() throws Exception {
+        Files.createDirectories(workspace);
+        SubagentDeclaration decl =
+                SubagentDeclaration.builder()
+                        .name("non-compacting-worker")
+                        .description("worker inheriting disabled compaction")
+                        .inlineAgentsBody("You are a worker subagent.")
+                        .build();
+
+        List<SubagentEntry> entries =
+                HarnessAgent.builder()
+                        .model(stubModel("ok"))
+                        .workspace(workspace)
+                        .disableCompaction()
+                        .subagent(decl)
+                        .buildSubagentEntries(workspace);
+
+        HarnessAgent child =
+                (HarnessAgent)
+                        entries.stream()
+                                .filter(e -> "non-compacting-worker".equals(e.name()))
+                                .findFirst()
+                                .orElseThrow()
+                                .factory()
+                                .create(RuntimeContext.empty());
+
+        assertNull(decl.getCompactionConfig());
+        assertNull(
+                child.getCompactionHook(),
+                "subagent without an override must inherit disabled compaction");
+    }
+
     // =========================================================================
     // general-purpose mirroring
     // =========================================================================