diff --git a/mateclaw-server/src/main/java/vip/mate/wiki/tool/WikiTool.java b/mateclaw-server/src/main/java/vip/mate/wiki/tool/WikiTool.java
index 2e28a671..cd225274 100644
--- a/mateclaw-server/src/main/java/vip/mate/wiki/tool/WikiTool.java
+++ b/mateclaw-server/src/main/java/vip/mate/wiki/tool/WikiTool.java
@@ -275,6 +275,7 @@ public class WikiTool {
             @ToolParam(description = "Search query") String query,
             @ToolParam(description = "Mode: keyword|semantic|hybrid (default: hybrid)", required = false) String mode,
             @ToolParam(description = "Max results (default 5, max 20)", required = false) Integer topK,
+            @ToolParam(description = "Knowledge layer filter: fact | experience | all (default all). 'fact' = factual pages (and unlayered pages); 'experience' = synthesis/analysis pages.", required = false) String layer,
             @ToolParam(description = "Target knowledge base name (from wiki_list_kbs). Omit to use the agent's primary KB; switch to `kbId` when two KBs share the name.", required = false) String kbName,
             @ToolParam(description = "Numeric KB id from wiki_list_kbs. Use when `kbName` returns an ambiguous-name error.", required = false) Long kbId) {
 
@@ -289,15 +290,17 @@ public class WikiTool {
         int k = (topK != null && topK > 0) ? Math.min(topK, 20) : 5;
         List<PageSearchResult> results = hybridRetriever.search(kbId, query, mode, k);
 
-        // Drop hits whose page type this agent may not read, so search cannot
-        // surface pages a direct read would refuse.
+        // Drop hits this agent may not read (by page type) or that fall outside
+        // the requested knowledge layer. Both need the page, so fetch it once.
         WikiPageTypePermissionService.Access access = pageTypeAccess(agentId, kbId);
-        if (access != null) {
+        boolean layerFilter = layer != null && !layer.isBlank() && !"all".equalsIgnoreCase(layer.trim());
+        if (access != null || layerFilter) {
             final Long resolvedKbId = kbId;
+            final String layerWanted = layer;
             results = results.stream()
                     .filter(r -> {
                         WikiPageEntity p = pageService.getBySlug(resolvedKbId, r.slug());
-                        return canRead(access, p);
+                        return canRead(access, p) && matchesLayer(p == null ? null : p.getKnowledgeLayer(), layerWanted);
                     })
                     .toList();
         }
@@ -1069,6 +1072,20 @@ public class WikiTool {
         return access == null || access.canRead(pageType);
     }
 
+    /**
+     * Whether a page's knowledge layer matches a retrieval filter. A null/blank
+     * or {@code all} filter matches everything; an unlayered page counts as
+     * {@code fact} (the RFC default), so {@code layer=fact} includes legacy
+     * pages while {@code layer=experience} returns only experience pages.
+     */
+    static boolean matchesLayer(String pageLayer, String filter) {
+        if (filter == null || filter.isBlank() || "all".equalsIgnoreCase(filter.trim())) {
+            return true;
+        }
+        String effective = (pageLayer == null || pageLayer.isBlank()) ? "fact" : pageLayer.trim().toLowerCase();
+        return effective.equals(filter.trim().toLowerCase());
+    }
+
     /**
      * Gate a write/mutate operation by pageType permission. Returns an error
      * JSON string to short-circuit the tool when the write is not permitted, or
diff --git a/mateclaw-server/src/test/java/vip/mate/wiki/tool/WikiToolLayerFilterTest.java b/mateclaw-server/src/test/java/vip/mate/wiki/tool/WikiToolLayerFilterTest.java
new file mode 100644
index 00000000..8aa7a9ba
--- /dev/null
+++ b/mateclaw-server/src/test/java/vip/mate/wiki/tool/WikiToolLayerFilterTest.java
@@ -0,0 +1,41 @@
+package vip.mate.wiki.tool;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Unit tests for the retrieval knowledge-layer filter ({@link WikiTool#matchesLayer}).
+ */
+class WikiToolLayerFilterTest {
+
+    @Test
+    void noFilterOrAll_matchesEverything() {
+        assertTrue(WikiTool.matchesLayer("experience", null));
+        assertTrue(WikiTool.matchesLayer("experience", ""));
+        assertTrue(WikiTool.matchesLayer("experience", "all"));
+        assertTrue(WikiTool.matchesLayer(null, "all"));
+    }
+
+    @Test
+    void factFilter_includesUnlayeredPages() {
+        assertTrue(WikiTool.matchesLayer(null, "fact"));     // legacy / unlayered counts as fact
+        assertTrue(WikiTool.matchesLayer("", "fact"));
+        assertTrue(WikiTool.matchesLayer("fact", "fact"));
+        assertFalse(WikiTool.matchesLayer("experience", "fact"));
+    }
+
+    @Test
+    void experienceFilter_excludesFactAndUnlayered() {
+        assertTrue(WikiTool.matchesLayer("experience", "experience"));
+        assertFalse(WikiTool.matchesLayer("fact", "experience"));
+        assertFalse(WikiTool.matchesLayer(null, "experience"));
+    }
+
+    @Test
+    void caseInsensitive() {
+        assertTrue(WikiTool.matchesLayer("Experience", "EXPERIENCE"));
+        assertTrue(WikiTool.matchesLayer("FACT", "fact"));
+    }
+}