diff --git a/src/commands/models/set.ts b/src/commands/models/set.ts
index d0506acbdf6..163fdc204c5 100644
--- a/src/commands/models/set.ts
+++ b/src/commands/models/set.ts
@@ -1,12 +1,46 @@
 import type { RuntimeEnv } from "../../runtime.js";
+import { loadModelCatalog } from "../../agents/model-catalog.js";
+import { modelKey } from "../../agents/model-selection.js";
+import { readConfigFileSnapshot } from "../../config/config.js";
 import { logConfigUpdated } from "../../config/logging.js";
-import { applyDefaultModelPrimaryUpdate, updateConfig } from "./shared.js";
+import { applyDefaultModelPrimaryUpdate, resolveModelTarget, updateConfig } from "./shared.js";
 
 export async function modelsSetCommand(modelRaw: string, runtime: RuntimeEnv) {
-  const updated = await updateConfig((cfg) => {
-    return applyDefaultModelPrimaryUpdate({ cfg, modelRaw, field: "model" });
+  // 1. Read config and resolve the model reference
+  const snapshot = await readConfigFileSnapshot();
+  if (!snapshot.valid) {
+    const issues = snapshot.issues.map((i) => `- ${i.path}: ${i.message}`).join("\n");
+    throw new Error(`Invalid config at ${snapshot.path}\n${issues}`);
+  }
+  const cfg = snapshot.config;
+  const resolved = resolveModelTarget({ raw: modelRaw, cfg });
+  const key = `${resolved.provider}/${resolved.model}`;
+
+  // 2. Validate against catalog (skip when catalog is empty — initial setup)
+  const catalog = await loadModelCatalog({ config: cfg });
+  if (catalog.length > 0) {
+    const catalogKeys = new Set(catalog.map((e) => modelKey(e.provider, e.id)));
+    if (!catalogKeys.has(key)) {
+      throw new Error(
+        `Unknown model: ${key}\nModel not found in catalog. Run "openclaw models list" to see available models.`,
+      );
+    }
+  }
+
+  // 3. Track whether this is a new entry
+  const isNewEntry = !cfg.agents?.defaults?.models?.[key];
+
+  // 4. Update config (using upstream's helper for the actual mutation)
+  const updated = await updateConfig((c) => {
+    return applyDefaultModelPrimaryUpdate({ cfg: c, modelRaw, field: "model" });
   });
 
+  // 5. Warn and log
+  if (isNewEntry) {
+    runtime.log(
+      `Warning: "${key}" had no entry in models config. Added with empty config (no provider routing).`,
+    );
+  }
   logConfigUpdated(runtime);
   runtime.log(`Default model: ${updated.agents?.defaults?.model?.primary ?? modelRaw}`);
 }