diff --git a/src/config/sessions/per-session-store.ts b/src/config/sessions/per-session-store.ts
new file mode 100644
index 000000000..48ba3c0b2
--- /dev/null
+++ b/src/config/sessions/per-session-store.ts
@@ -0,0 +1,137 @@
+/**
+ * Per-session metadata storage to eliminate lock contention.
+ *
+ * Instead of storing all session metadata in a single sessions.json file
+ * (which requires a global lock), each session gets its own .meta.json file.
+ * This allows parallel updates without blocking.
+ */
+
+import fs from "node:fs/promises";
+import path from "node:path";
+import JSON5 from "json5";
+import type { SessionEntry } from "./types.js";
+import { resolveSessionTranscriptsDirForAgent } from "./paths.js";
+
+const META_SUFFIX = ".meta.json";
+
+/**
+ * Get the path to a session's metadata file.
+ */
+export function getSessionMetaPath(sessionId: string, agentId?: string): string {
+  const sessionsDir = resolveSessionTranscriptsDirForAgent(agentId);
+  return path.join(sessionsDir, `${sessionId}${META_SUFFIX}`);
+}
+
+/**
+ * Load session metadata from per-session file.
+ * Returns undefined if the file doesn't exist.
+ */
+export async function loadSessionMeta(
+  sessionId: string,
+  agentId?: string,
+): Promise<SessionEntry | undefined> {
+  const metaPath = getSessionMetaPath(sessionId, agentId);
+  try {
+    const content = await fs.readFile(metaPath, "utf-8");
+    const entry = JSON5.parse(content) as SessionEntry;
+    return entry;
+  } catch (err) {
+    const code = (err as { code?: string }).code;
+    if (code === "ENOENT") return undefined;
+    throw err;
+  }
+}
+
+/**
+ * Save session metadata to per-session file.
+ * Uses atomic write (write to temp, then rename) to prevent corruption.
+ */
+export async function saveSessionMeta(
+  sessionId: string,
+  entry: SessionEntry,
+  agentId?: string,
+): Promise<void> {
+  const metaPath = getSessionMetaPath(sessionId, agentId);
+  const dir = path.dirname(metaPath);
+  await fs.mkdir(dir, { recursive: true });
+
+  // Atomic write: write to temp file, then rename
+  const tempPath = `${metaPath}.tmp.${process.pid}.${Date.now()}`;
+  const content = JSON.stringify(entry, null, 2);
+
+  try {
+    await fs.writeFile(tempPath, content, "utf-8");
+    await fs.rename(tempPath, metaPath);
+  } catch (err) {
+    // Clean up temp file on error
+    await fs.unlink(tempPath).catch(() => {});
+    throw err;
+  }
+}
+
+/**
+ * Update session metadata atomically.
+ * Reads current state, applies patch, and writes back.
+ * No lock needed since we use atomic writes and per-session files.
+ */
+export async function updateSessionMeta(
+  sessionId: string,
+  patch: Partial<SessionEntry>,
+  agentId?: string,
+): Promise<SessionEntry> {
+  const existing = await loadSessionMeta(sessionId, agentId);
+  const updatedAt = Date.now();
+  const merged: SessionEntry = {
+    ...existing,
+    ...patch,
+    sessionId,
+    updatedAt,
+  };
+  await saveSessionMeta(sessionId, merged, agentId);
+  return merged;
+}
+
+/**
+ * Delete session metadata file.
+ */
+export async function deleteSessionMeta(sessionId: string, agentId?: string): Promise<void> {
+  const metaPath = getSessionMetaPath(sessionId, agentId);
+  await fs.unlink(metaPath).catch((err) => {
+    if ((err as { code?: string }).code !== "ENOENT") throw err;
+  });
+}
+
+/**
+ * List all session metadata files in the sessions directory.
+ * Returns an array of session IDs.
+ */
+export async function listSessionMetas(agentId?: string): Promise<string[]> {
+  const sessionsDir = resolveSessionTranscriptsDirForAgent(agentId);
+  try {
+    const files = await fs.readdir(sessionsDir);
+    return files.filter((f) => f.endsWith(META_SUFFIX)).map((f) => f.slice(0, -META_SUFFIX.length));
+  } catch (err) {
+    if ((err as { code?: string }).code === "ENOENT") return [];
+    throw err;
+  }
+}
+
+/**
+ * Load all session metadata from per-session files.
+ * This is used for backwards compatibility and for building the session index.
+ */
+export async function loadAllSessionMetas(agentId?: string): Promise<Record<string, SessionEntry>> {
+  const sessionIds = await listSessionMetas(agentId);
+  const entries: Record<string, SessionEntry> = {};
+
+  await Promise.all(
+    sessionIds.map(async (sessionId) => {
+      const entry = await loadSessionMeta(sessionId, agentId);
+      if (entry) {
+        entries[sessionId] = entry;
+      }
+    }),
+  );
+
+  return entries;
+}
diff --git a/src/config/sessions/store.ts b/src/config/sessions/store.ts
index 0f36e0ebb..0feb72691 100644
--- a/src/config/sessions/store.ts
+++ b/src/config/sessions/store.ts
@@ -342,17 +342,102 @@ export async function updateSessionStoreEntry(params: {
   update: (entry: SessionEntry) => Promise<Partial<SessionEntry> | null>;
 }): Promise<SessionEntry | null> {
   const { storePath, sessionKey, update } = params;
-  return await withSessionStoreLock(storePath, async () => {
-    const store = loadSessionStore(storePath);
-    const existing = store[sessionKey];
-    if (!existing) return null;
-    const patch = await update(existing);
-    if (!patch) return existing;
-    const next = mergeSessionEntry(existing, patch);
-    store[sessionKey] = next;
-    await saveSessionStoreUnlocked(storePath, store);
-    return next;
-  });
+
+  // Fast path: read the store without locking to get the session entry
+  // The store is cached and TTL-validated, so this is cheap
+  const store = loadSessionStore(storePath);
+  const existing = store[sessionKey];
+  if (!existing) return null;
+
+  // Get the sessionId for per-session file access
+  const sessionId = existing.sessionId;
+  if (!sessionId) {
+    // Fallback to locked update for legacy entries without sessionId
+    return await withSessionStoreLock(storePath, async () => {
+      const freshStore = loadSessionStore(storePath, { skipCache: true });
+      const freshExisting = freshStore[sessionKey];
+      if (!freshExisting) return null;
+      const patch = await update(freshExisting);
+      if (!patch) return freshExisting;
+      const next = mergeSessionEntry(freshExisting, patch);
+      freshStore[sessionKey] = next;
+      await saveSessionStoreUnlocked(storePath, freshStore);
+      return next;
+    });
+  }
+
+  // Compute the patch
+  const patch = await update(existing);
+  if (!patch) return existing;
+
+  // Merge and create the updated entry
+  const next = mergeSessionEntry(existing, patch);
+
+  // Write to per-session meta file (no global lock needed)
+  const { updateSessionMeta } = await import("./per-session-store.js");
+  const agentId = extractAgentIdFromStorePath(storePath);
+  await updateSessionMeta(sessionId, next, agentId);
+
+  // Update the in-memory cache so subsequent reads see the update
+  store[sessionKey] = next;
+  invalidateSessionStoreCache(storePath);
+
+  // Async background sync to sessions.json (debounced, best-effort)
+  debouncedSyncToSessionsJson(storePath, sessionKey, next);
+
+  return next;
+}
+
+// Helper to extract agentId from store path
+function extractAgentIdFromStorePath(storePath: string): string | undefined {
+  // storePath is like: ~/.openclaw/agents/{agentId}/sessions/sessions.json
+  const match = storePath.match(/agents\/([^/]+)\/sessions/);
+  return match?.[1];
+}
+
+// Debounced sync to sessions.json to keep it in sync (background, best-effort)
+const pendingSyncs = new Map<string, { sessionKey: string; entry: SessionEntry }>();
+let syncTimer: NodeJS.Timeout | null = null;
+
+function debouncedSyncToSessionsJson(
+  storePath: string,
+  sessionKey: string,
+  entry: SessionEntry,
+): void {
+  const key = `${storePath}::${sessionKey}`;
+  pendingSyncs.set(key, { sessionKey, entry });
+
+  if (syncTimer) return; // Already scheduled
+
+  syncTimer = setTimeout(async () => {
+    syncTimer = null;
+    const toSync = new Map(pendingSyncs);
+    pendingSyncs.clear();
+
+    // Group by storePath
+    const byStore = new Map<string, Array<{ sessionKey: string; entry: SessionEntry }>>();
+    for (const [key, value] of toSync) {
+      const [sp] = key.split("::");
+      const list = byStore.get(sp) ?? [];
+      list.push(value);
+      byStore.set(sp, list);
+    }
+
+    // Batch update each store
+    for (const [sp, entries] of byStore) {
+      try {
+        await withSessionStoreLock(sp, async () => {
+          const store = loadSessionStore(sp, { skipCache: true });
+          for (const { sessionKey: sk, entry: e } of entries) {
+            store[sk] = e;
+          }
+          await saveSessionStoreUnlocked(sp, store);
+        });
+      } catch {
+        // Best-effort sync, ignore errors
+      }
+    }
+  }, 5000); // 5 second debounce
 }
 
 export async function recordSessionMetaFromInbound(params: {