Memory/QMD: treat plain-text no-results as empty

CHANGELOG.md

@@ -91,6 +91,7 @@ Docs: https://docs.openclaw.ai
 - Memory/QMD: run boot refresh in background by default, add configurable QMD maintenance timeouts, retry QMD after fallback failures, and scope QMD queries to OpenClaw-managed collections. (#9690, #9705, #10042) Thanks @vignesh07.
 - Memory/QMD: initialize QMD backend on gateway startup so background update timers restart after process reloads. (#10797) Thanks @vignesh07.
 - Config/Memory: auto-migrate legacy top-level `memorySearch` settings into `agents.defaults.memorySearch`. (#11278, #9143) Thanks @vignesh07.
+- Memory/QMD: treat plain-text `No results found` output from QMD as an empty result instead of throwing invalid JSON errors. (#9824)
 - Media understanding: recognize `.caf` audio attachments for transcription. (#10982) Thanks @succ985.
 - State dir: honor `OPENCLAW_STATE_DIR` for default device identity and canvas storage paths. (#4824) Thanks @kossoy.
 

src/memory/qmd-manager.test.ts

@@ -733,6 +733,112 @@ describe("QmdMemoryManager", () => {
     await manager.close();
   });
 
+
+  it("treats plain-text no-results stdout as an empty result set", async () => {
+    spawnMock.mockImplementation((_cmd: string, args: string[]) => {
+      if (args[0] === "query") {
+        const child = createMockChild({ autoClose: false });
+        setTimeout(() => {
+          child.stdout.emit("data", "No results found.");
+          child.closeWith(0);
+        }, 0);
+        return child;
+      }
+      return createMockChild();
+    });
+
+    const resolved = resolveMemoryBackendConfig({ cfg, agentId });
+    const manager = await QmdMemoryManager.create({ cfg, agentId, resolved });
+    expect(manager).toBeTruthy();
+    if (!manager) {
+      throw new Error("manager missing");
+    }
+
+    await expect(
+      manager.search("missing", { sessionKey: "agent:main:slack:dm:u123" }),
+    ).resolves.toEqual([]);
+    await manager.close();
+  });
+
+  it("treats plain-text no-results stdout without punctuation as empty", async () => {
+    spawnMock.mockImplementation((_cmd: string, args: string[]) => {
+      if (args[0] === "query") {
+        const child = createMockChild({ autoClose: false });
+        setTimeout(() => {
+          child.stdout.emit("data", "No results found\n\n");
+          child.closeWith(0);
+        }, 0);
+        return child;
+      }
+      return createMockChild();
+    });
+
+    const resolved = resolveMemoryBackendConfig({ cfg, agentId });
+    const manager = await QmdMemoryManager.create({ cfg, agentId, resolved });
+    expect(manager).toBeTruthy();
+    if (!manager) {
+      throw new Error("manager missing");
+    }
+
+    await expect(
+      manager.search("missing", { sessionKey: "agent:main:slack:dm:u123" }),
+    ).resolves.toEqual([]);
+    await manager.close();
+  });
+
+  it("treats plain-text no-results stderr as an empty result set", async () => {
+    spawnMock.mockImplementation((_cmd: string, args: string[]) => {
+      if (args[0] === "query") {
+        const child = createMockChild({ autoClose: false });
+        setTimeout(() => {
+          child.stderr.emit("data", "No results found.\n");
+          child.closeWith(0);
+        }, 0);
+        return child;
+      }
+      return createMockChild();
+    });
+
+    const resolved = resolveMemoryBackendConfig({ cfg, agentId });
+    const manager = await QmdMemoryManager.create({ cfg, agentId, resolved });
+    expect(manager).toBeTruthy();
+    if (!manager) {
+      throw new Error("manager missing");
+    }
+
+    await expect(
+      manager.search("missing", { sessionKey: "agent:main:slack:dm:u123" }),
+    ).resolves.toEqual([]);
+    await manager.close();
+  });
+
+  it("throws when stdout is empty without the no-results marker", async () => {
+    spawnMock.mockImplementation((_cmd: string, args: string[]) => {
+      if (args[0] === "query") {
+        const child = createMockChild({ autoClose: false });
+        setTimeout(() => {
+          child.stdout.emit("data", "   \n");
+          child.stderr.emit("data", "unexpected parser error");
+          child.closeWith(0);
+        }, 0);
+        return child;
+      }
+      return createMockChild();
+    });
+
+    const resolved = resolveMemoryBackendConfig({ cfg, agentId });
+    const manager = await QmdMemoryManager.create({ cfg, agentId, resolved });
+    expect(manager).toBeTruthy();
+    if (!manager) {
+      throw new Error("manager missing");
+    }
+
+    await expect(
+      manager.search("missing", { sessionKey: "agent:main:slack:dm:u123" }),
+    ).rejects.toThrow(/qmd query returned invalid JSON/);
+    await manager.close();
+  });
+
   describe("model cache symlink", () => {
     let defaultModelsDir: string;
     let customModelsDir: string;
@@ -815,6 +921,7 @@ describe("QmdMemoryManager", () => {
       await manager!.close();
     });
   });
+  });
 });
 
 async function waitForCondition(check: () => boolean, timeoutMs: number): Promise<void> {

src/memory/qmd-manager.ts

@@ -269,21 +269,16 @@ export class QmdMemoryManager implements MemorySearchManager {
     }
     const args = ["query", trimmed, "--json", "-n", String(limit), ...collectionFilterArgs];
     let stdout: string;
+    let stderr: string;
     try {
       const result = await this.runQmd(args, { timeoutMs: this.qmd.limits.timeoutMs });
       stdout = result.stdout;
+      stderr = result.stderr;
     } catch (err) {
       log.warn(`qmd query failed: ${String(err)}`);
       throw err instanceof Error ? err : new Error(String(err));
     }
-    let parsed: QmdQueryResult[] = [];
+    const parsed = this.parseQmdQueryJson(stdout, stderr);
-    try {
-      parsed = JSON.parse(stdout);
-    } catch (err) {
-      const message = err instanceof Error ? err.message : String(err);
-      log.warn(`qmd query returned invalid JSON: ${message}`);
-      throw new Error(`qmd query returned invalid JSON: ${message}`, { cause: err });
-    }
     const results: MemorySearchResult[] = [];
     for (const entry of parsed) {
       const doc = await this.resolveDocLocation(entry.docid);
@@ -981,6 +976,42 @@ export class QmdMemoryManager implements MemorySearchManager {
     ]);
   }
 
+  private parseQmdQueryJson(stdout: string, stderr: string): QmdQueryResult[] {
+    const trimmedStdout = stdout.trim();
+    const trimmedStderr = stderr.trim();
+    const stdoutIsMarker = Boolean(trimmedStdout) && this.isQmdNoResultsOutput(trimmedStdout);
+    const stderrIsMarker = Boolean(trimmedStderr) && this.isQmdNoResultsOutput(trimmedStderr);
+    if (stdoutIsMarker || (!trimmedStdout && stderrIsMarker)) {
+      return [];
+    }
+    if (!trimmedStdout) {
+      const context = trimmedStderr ? ` (stderr: ${this.summarizeQmdStderr(trimmedStderr)})` : "";
+      const message = `stdout empty${context}`;
+      log.warn(`qmd query returned invalid JSON: ${message}`);
+      throw new Error(`qmd query returned invalid JSON: ${message}`);
+    }
+    try {
+      const parsed = JSON.parse(trimmedStdout) as unknown;
+      if (!Array.isArray(parsed)) {
+        throw new Error("qmd query JSON response was not an array");
+      }
+      return parsed as QmdQueryResult[];
+    } catch (err) {
+      const message = err instanceof Error ? err.message : String(err);
+      log.warn(`qmd query returned invalid JSON: ${message}`);
+      throw new Error(`qmd query returned invalid JSON: ${message}`, { cause: err });
+    }
+  }
+
+  private isQmdNoResultsOutput(raw: string): boolean {
+    const normalized = raw.trim().toLowerCase().replace(/\s+/g, " ");
+    return normalized === "no results found" || normalized === "no results found.";
+  }
+
+  private summarizeQmdStderr(raw: string): string {
+    return raw.length <= 120 ? raw : `${raw.slice(0, 117)}...`;
+  }
+
   private buildCollectionFilterArgs(): string[] {
     const names = this.qmd.collections.map((collection) => collection.name).filter(Boolean);
     if (names.length === 0) {