diff --git a/CHANGELOG.md b/CHANGELOG.md
index 89d5367de0c..f7d1b248bcb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -118,6 +118,7 @@ Docs: https://docs.openclaw.ai
 - Memory/Remote HTTP: centralize remote memory HTTP calls behind a shared guarded helper (`withRemoteHttpResponse`) so embeddings and batch flows use one request/release path.
 - Memory/Embeddings: apply configured remote-base host pinning (`allowedHostnames`) across OpenAI/Voyage/Gemini embedding requests to keep private/self-hosted endpoints working without cross-host drift. (#18198) Thanks @ianpcook.
 - Memory/Batch: route OpenAI/Voyage/Gemini batch upload/create/status/download requests through the same guarded HTTP path for consistent SSRF policy enforcement.
+- Memory/Index: detect memory source-set changes (for example enabling `sessions` after an existing memory-only index) and trigger a full reindex so existing session transcripts are indexed without requiring `--force`. (#17576) Thanks @TarsAI-Agent.
 - Memory/QMD: on Windows, resolve bare `qmd`/`mcporter` command names to npm shim executables (`.cmd`) before spawning, so qmd boot updates and mcporter-backed searches no longer fail with `spawn ... ENOENT` on default npm installs. (#23899) Thanks @arcbuilder-ai.
 - Memory/QMD: parse plain-text `qmd collection list --json` output when older qmd builds ignore JSON mode, and retry memory searches once after re-ensuring managed collections when qmd returns `Collection not found ...`. (#23613) Thanks @leozhucn.
 - Signal/RPC: guard malformed Signal RPC JSON responses with a clear status-scoped error and add regression coverage for invalid JSON responses. (#22995) Thanks @adhitShet.
diff --git a/src/memory/index.test.ts b/src/memory/index.test.ts
index 421fd7d4ddd..9174805105d 100644
--- a/src/memory/index.test.ts
+++ b/src/memory/index.test.ts
@@ -93,6 +93,8 @@ describe("memory index", () => {
   function createCfg(params: {
     storePath: string;
     extraPaths?: string[];
+    sources?: Array<"memory" | "sessions">;
+    sessionMemory?: boolean;
     model?: string;
     vectorEnabled?: boolean;
     cacheEnabled?: boolean;
@@ -115,6 +117,8 @@ describe("memory index", () => {
             },
             cache: params.cacheEnabled ? { enabled: true } : undefined,
             extraPaths: params.extraPaths,
+            sources: params.sources,
+            experimental: { sessionMemory: params.sessionMemory ?? false },
           },
         },
         list: [{ id: "main", default: true }],
@@ -195,6 +199,85 @@ describe("memory index", () => {
     await statusOnly.manager.close?.();
   });
 
+  it("reindexes sessions when source config adds sessions to an existing index", async () => {
+    const indexSourceChangePath = path.join(
+      workspaceDir,
+      `index-source-change-${Date.now()}.sqlite`,
+    );
+    const stateDir = path.join(fixtureRoot, `state-source-change-${Date.now()}`);
+    const sessionDir = path.join(stateDir, "agents", "main", "sessions");
+    await fs.mkdir(sessionDir, { recursive: true });
+    await fs.writeFile(
+      path.join(sessionDir, "session-source-change.jsonl"),
+      [
+        JSON.stringify({
+          type: "message",
+          message: {
+            role: "user",
+            content: [{ type: "text", text: "session change test user line" }],
+          },
+        }),
+        JSON.stringify({
+          type: "message",
+          message: {
+            role: "assistant",
+            content: [{ type: "text", text: "session change test assistant line" }],
+          },
+        }),
+      ].join("\n") + "\n",
+    );
+
+    const previousStateDir = process.env.OPENCLAW_STATE_DIR;
+    process.env.OPENCLAW_STATE_DIR = stateDir;
+
+    const firstCfg = createCfg({
+      storePath: indexSourceChangePath,
+      sources: ["memory"],
+      sessionMemory: false,
+    });
+    const secondCfg = createCfg({
+      storePath: indexSourceChangePath,
+      sources: ["memory", "sessions"],
+      sessionMemory: true,
+    });
+
+    try {
+      const first = await getMemorySearchManager({ cfg: firstCfg, agentId: "main" });
+      expect(first.manager).not.toBeNull();
+      if (!first.manager) {
+        throw new Error("manager missing");
+      }
+      await first.manager.sync?.({ reason: "test" });
+      const firstStatus = first.manager.status();
+      expect(
+        firstStatus.sourceCounts?.find((entry) => entry.source === "sessions")?.files ?? 0,
+      ).toBe(0);
+      await first.manager.close?.();
+
+      const second = await getMemorySearchManager({ cfg: secondCfg, agentId: "main" });
+      expect(second.manager).not.toBeNull();
+      if (!second.manager) {
+        throw new Error("manager missing");
+      }
+      await second.manager.sync?.({ reason: "test" });
+      const secondStatus = second.manager.status();
+      expect(secondStatus.sourceCounts?.find((entry) => entry.source === "sessions")?.files).toBe(
+        1,
+      );
+      expect(
+        secondStatus.sourceCounts?.find((entry) => entry.source === "sessions")?.chunks ?? 0,
+      ).toBeGreaterThan(0);
+      await second.manager.close?.();
+    } finally {
+      if (previousStateDir === undefined) {
+        delete process.env.OPENCLAW_STATE_DIR;
+      } else {
+        process.env.OPENCLAW_STATE_DIR = previousStateDir;
+      }
+      await fs.rm(stateDir, { recursive: true, force: true });
+    }
+  });
+
   it("reindexes when the embedding model changes", async () => {
     const indexModelPath = path.join(workspaceDir, `index-model-change-${Date.now()}.sqlite`);
     const base = createCfg({ storePath: indexModelPath });
diff --git a/src/memory/manager-sync-ops.ts b/src/memory/manager-sync-ops.ts
index 61b479b3d29..03035fb9fcb 100644
--- a/src/memory/manager-sync-ops.ts
+++ b/src/memory/manager-sync-ops.ts
@@ -45,6 +45,7 @@ type MemoryIndexMeta = {
   model: string;
   provider: string;
   providerKey?: string;
+  sources?: MemorySource[];
   chunkTokens: number;
   chunkOverlap: number;
   vectorDims?: number;
@@ -851,12 +852,14 @@ export abstract class MemoryManagerSyncOps {
     }
     const vectorReady = await this.ensureVectorReady();
     const meta = this.readMeta();
+    const configuredSources = this.resolveConfiguredSourcesForMeta();
     const needsFullReindex =
       params?.force ||
       !meta ||
       (this.provider && meta.model !== this.provider.model) ||
       (this.provider && meta.provider !== this.provider.id) ||
       meta.providerKey !== this.providerKey ||
+      this.metaSourcesDiffer(meta, configuredSources) ||
       meta.chunkTokens !== this.settings.chunking.tokens ||
       meta.chunkOverlap !== this.settings.chunking.overlap ||
       (vectorReady && !meta?.vectorDims);
@@ -1056,6 +1059,7 @@ export abstract class MemoryManagerSyncOps {
         model: this.provider?.model ?? "fts-only",
         provider: this.provider?.id ?? "none",
         providerKey: this.providerKey!,
+        sources: this.resolveConfiguredSourcesForMeta(),
         chunkTokens: this.settings.chunking.tokens,
         chunkOverlap: this.settings.chunking.overlap,
       };
@@ -1126,6 +1130,7 @@ export abstract class MemoryManagerSyncOps {
       model: this.provider?.model ?? "fts-only",
       provider: this.provider?.id ?? "none",
       providerKey: this.providerKey!,
+      sources: this.resolveConfiguredSourcesForMeta(),
       chunkTokens: this.settings.chunking.tokens,
       chunkOverlap: this.settings.chunking.overlap,
     };
@@ -1172,4 +1177,34 @@ export abstract class MemoryManagerSyncOps {
       )
       .run(META_KEY, value);
   }
+
+  private resolveConfiguredSourcesForMeta(): MemorySource[] {
+    const normalized = Array.from(this.sources)
+      .filter((source): source is MemorySource => source === "memory" || source === "sessions")
+      .toSorted();
+    return normalized.length > 0 ? normalized : ["memory"];
+  }
+
+  private normalizeMetaSources(meta: MemoryIndexMeta): MemorySource[] {
+    if (!Array.isArray(meta.sources)) {
+      // Backward compatibility for older indexes that did not persist sources.
+      return ["memory"];
+    }
+    const normalized = Array.from(
+      new Set(
+        meta.sources.filter(
+          (source): source is MemorySource => source === "memory" || source === "sessions",
+        ),
+      ),
+    ).toSorted();
+    return normalized.length > 0 ? normalized : ["memory"];
+  }
+
+  private metaSourcesDiffer(meta: MemoryIndexMeta, configuredSources: MemorySource[]): boolean {
+    const metaSources = this.normalizeMetaSources(meta);
+    if (metaSources.length !== configuredSources.length) {
+      return true;
+    }
+    return metaSources.some((source, index) => source !== configuredSources[index]);
+  }
 }