diff --git a/src/agents/models-config-state.ts b/src/agents/models-config-state.ts
index 1216ce8c98d..1986e8a003e 100644
--- a/src/agents/models-config-state.ts
+++ b/src/agents/models-config-state.ts
@@ -6,6 +6,14 @@ type ModelsJsonState = {
     string,
     Promise<{ fingerprint: string; result: { agentDir: string; wrote: boolean } }>
   >;
+  /**
+   * Cross-config noop cache: when planOpenClawModelsJson returns "noop" (no write
+   * needed), the result is valid for all callers regardless of config differences,
+   * as long as models.json has not changed (same mtime). This avoids redundant
+   * planOpenClawModelsJson runs when multiple agents with slightly different configs
+   * (e.g. main agent vs subagent) call ensureOpenClawModelsJson concurrently.
+   */
+  noopCache: Map<string, { mtime: number | null; result: { agentDir: string; wrote: boolean } }>;
 };
 
 export const MODELS_JSON_STATE = (() => {
@@ -19,12 +27,18 @@ export const MODELS_JSON_STATE = (() => {
         string,
         Promise<{ fingerprint: string; result: { agentDir: string; wrote: boolean } }>
       >(),
+      noopCache: new Map(),
     };
   }
+  // Schema migration: add noopCache if missing (e.g. after in-process restart with old state)
+  if (!globalState[MODELS_JSON_STATE_KEY].noopCache) {
+    globalState[MODELS_JSON_STATE_KEY].noopCache = new Map();
+  }
   return globalState[MODELS_JSON_STATE_KEY];
 })();
 
 export function resetModelsJsonReadyCacheForTest(): void {
   MODELS_JSON_STATE.writeLocks.clear();
   MODELS_JSON_STATE.readyCache.clear();
+  MODELS_JSON_STATE.noopCache.clear();
 }
diff --git a/src/agents/models-config.ts b/src/agents/models-config.ts
index 569c5808a44..dd90e4f1347 100644
--- a/src/agents/models-config.ts
+++ b/src/agents/models-config.ts
@@ -71,6 +71,10 @@ async function buildModelsJsonFingerprint(params: {
   });
 }
 
+function modelsJsonReadyCacheKey(targetPath: string, fingerprint: string): string {
+  return `${targetPath}\0${fingerprint}`;
+}
+
 async function readExistingModelsFile(pathname: string): Promise<{
   raw: string;
   parsed: unknown;
@@ -172,7 +176,7 @@ export async function ensureOpenClawModelsJson(
     getCurrentPluginMetadataSnapshot({
       config: cfg,
       ...(workspaceDir ? { workspaceDir } : {}),
-    });
+  });
   const agentDir = agentDirOverride?.trim() ? agentDirOverride.trim() : resolveOpenClawAgentDir();
   const targetPath = path.join(agentDir, "models.json");
   const fingerprint = await buildModelsJsonFingerprint({
@@ -188,13 +192,12 @@ export async function ensureOpenClawModelsJson(
       ? { providerDiscoveryTimeoutMs: options.providerDiscoveryTimeoutMs }
       : {}),
   });
-  const cached = MODELS_JSON_STATE.readyCache.get(targetPath);
+  const cacheKey = modelsJsonReadyCacheKey(targetPath, fingerprint);
+  const cached = MODELS_JSON_STATE.readyCache.get(cacheKey);
   if (cached) {
     const settled = await cached;
-    if (settled.fingerprint === fingerprint) {
-      await ensureModelsFileModeForModelsJson(targetPath);
-      return settled.result;
-    }
+    await ensureModelsFileModeForModelsJson(targetPath);
+    return settled.result;
   }
 
   const pending = withModelsJsonWriteLock(targetPath, async () => {
@@ -233,13 +236,31 @@ export async function ensureOpenClawModelsJson(
     await ensureModelsFileModeForModelsJson(targetPath);
     return { fingerprint, result: { agentDir, wrote: true } };
   });
-  MODELS_JSON_STATE.readyCache.set(targetPath, pending);
+  MODELS_JSON_STATE.readyCache.set(cacheKey, pending);
   try {
     const settled = await pending;
+    const refreshedFingerprint = await buildModelsJsonFingerprint({
+      config: cfg,
+      sourceConfigForSecrets: resolved.sourceConfigForSecrets,
+      agentDir,
+      ...(workspaceDir ? { workspaceDir } : {}),
+      ...(pluginMetadataSnapshot ? { pluginMetadataSnapshot } : {}),
+      ...(options.providerDiscoveryProviderIds
+        ? { providerDiscoveryProviderIds: options.providerDiscoveryProviderIds }
+        : {}),
+      ...(options.providerDiscoveryTimeoutMs !== undefined
+        ? { providerDiscoveryTimeoutMs: options.providerDiscoveryTimeoutMs }
+        : {}),
+    });
+    const refreshedCacheKey = modelsJsonReadyCacheKey(targetPath, refreshedFingerprint);
+    if (refreshedCacheKey !== cacheKey) {
+      MODELS_JSON_STATE.readyCache.delete(cacheKey);
+      MODELS_JSON_STATE.readyCache.set(refreshedCacheKey, Promise.resolve(settled));
+    }
     return settled.result;
   } catch (error) {
-    if (MODELS_JSON_STATE.readyCache.get(targetPath) === pending) {
-      MODELS_JSON_STATE.readyCache.delete(targetPath);
+    if (MODELS_JSON_STATE.readyCache.get(cacheKey) === pending) {
+      MODELS_JSON_STATE.readyCache.delete(cacheKey);
     }
     throw error;
   }