diff --git a/src/agents/pi-embedded-runner/run.ts b/src/agents/pi-embedded-runner/run.ts
index 870453f38..6b34ae97c 100644
--- a/src/agents/pi-embedded-runner/run.ts
+++ b/src/agents/pi-embedded-runner/run.ts
@@ -92,8 +92,22 @@ export async function runEmbeddedPiAgent(
       const resolvedWorkspace = resolveUserPath(params.workspaceDir);
       const prevCwd = process.cwd();
 
-      const provider = (params.provider ?? DEFAULT_PROVIDER).trim() || DEFAULT_PROVIDER;
-      const modelId = (params.model ?? DEFAULT_MODEL).trim() || DEFAULT_MODEL;
+      // Check config for defaults first
+      let targetProvider = params.provider;
+      let targetModel = params.model;
+
+      if (!targetProvider && !targetModel && params.config?.agents?.defaults?.model?.primary) {
+        // Resolve primary model from config (e.g. "google-gemini-cli/gemini-3-pro-preview")
+        const primary = params.config.agents.defaults.model.primary;
+        const parts = primary.split("/");
+        if (parts.length === 2) {
+          targetProvider = parts[0];
+          targetModel = parts[1];
+        }
+      }
+
+      const provider = (targetProvider ?? DEFAULT_PROVIDER).trim() || DEFAULT_PROVIDER;
+      const modelId = (targetModel ?? DEFAULT_MODEL).trim() || DEFAULT_MODEL;
       const agentDir = params.agentDir ?? resolveMoltbotAgentDir();
       const fallbackConfigured =
         (params.config?.agents?.defaults?.model?.fallbacks?.length ?? 0) > 0;