diff --git a/extensions/opencode-go/api.ts b/extensions/opencode-go/api.ts
index ff5bf4c42c1..c61f4cfcfa4 100644
--- a/extensions/opencode-go/api.ts
+++ b/extensions/opencode-go/api.ts
@@ -1,3 +1,7 @@
+import {
+  applyAgentDefaultModelPrimary,
+  resolveAgentModelPrimaryValue,
+} from "openclaw/plugin-sdk/provider-onboard";
 import { OPENCODE_GO_DEFAULT_MODEL_REF } from "./onboard.js";
 
 export {
@@ -6,47 +10,18 @@ export {
   OPENCODE_GO_DEFAULT_MODEL_REF,
 } from "./onboard.js";
 
-function resolveCurrentPrimaryModel(model: unknown): string | undefined {
-  if (typeof model === "string") {
-    return model.trim() || undefined;
-  }
-  if (
-    model &&
-    typeof model === "object" &&
-    typeof (model as { primary?: unknown }).primary === "string"
-  ) {
-    return ((model as { primary: string }).primary || "").trim() || undefined;
-  }
-  return undefined;
-}
-
 export function applyOpencodeGoModelDefault(
   cfg: import("openclaw/plugin-sdk/provider-onboard").OpenClawConfig,
 ): {
   next: import("openclaw/plugin-sdk/provider-onboard").OpenClawConfig;
   changed: boolean;
 } {
-  const current = resolveCurrentPrimaryModel(cfg.agents?.defaults?.model);
+  const current = resolveAgentModelPrimaryValue(cfg.agents?.defaults?.model);
   if (current === OPENCODE_GO_DEFAULT_MODEL_REF) {
     return { next: cfg, changed: false };
   }
   return {
-    next: {
-      ...cfg,
-      agents: {
-        ...cfg.agents,
-        defaults: {
-          ...cfg.agents?.defaults,
-          model:
-            cfg.agents?.defaults?.model && typeof cfg.agents.defaults.model === "object"
-              ? {
-                  ...cfg.agents.defaults.model,
-                  primary: OPENCODE_GO_DEFAULT_MODEL_REF,
-                }
-              : { primary: OPENCODE_GO_DEFAULT_MODEL_REF },
-        },
-      },
-    },
+    next: applyAgentDefaultModelPrimary(cfg, OPENCODE_GO_DEFAULT_MODEL_REF),
     changed: true,
   };
 }
diff --git a/extensions/opencode/api.ts b/extensions/opencode/api.ts
index cff5be61fc7..a67ab37f9b3 100644
--- a/extensions/opencode/api.ts
+++ b/extensions/opencode/api.ts
@@ -1,3 +1,7 @@
+import {
+  applyAgentDefaultModelPrimary,
+  resolveAgentModelPrimaryValue,
+} from "openclaw/plugin-sdk/provider-onboard";
 import { OPENCODE_ZEN_DEFAULT_MODEL_REF } from "./onboard.js";
 export {
   applyOpencodeZenConfig,
@@ -12,27 +16,13 @@ const LEGACY_OPENCODE_ZEN_DEFAULT_MODELS = new Set([
 
 export const OPENCODE_ZEN_DEFAULT_MODEL = OPENCODE_ZEN_DEFAULT_MODEL_REF;
 
-function resolveCurrentPrimaryModel(model: unknown): string | undefined {
-  if (typeof model === "string") {
-    return model.trim() || undefined;
-  }
-  if (
-    model &&
-    typeof model === "object" &&
-    typeof (model as { primary?: unknown }).primary === "string"
-  ) {
-    return ((model as { primary: string }).primary || "").trim() || undefined;
-  }
-  return undefined;
-}
-
 export function applyOpencodeZenModelDefault(
   cfg: import("openclaw/plugin-sdk/provider-onboard").OpenClawConfig,
 ): {
   next: import("openclaw/plugin-sdk/provider-onboard").OpenClawConfig;
   changed: boolean;
 } {
-  const current = resolveCurrentPrimaryModel(cfg.agents?.defaults?.model);
+  const current = resolveAgentModelPrimaryValue(cfg.agents?.defaults?.model);
   const normalizedCurrent =
     current && LEGACY_OPENCODE_ZEN_DEFAULT_MODELS.has(current)
       ? OPENCODE_ZEN_DEFAULT_MODEL
@@ -41,22 +31,7 @@ export function applyOpencodeZenModelDefault(
     return { next: cfg, changed: false };
   }
   return {
-    next: {
-      ...cfg,
-      agents: {
-        ...cfg.agents,
-        defaults: {
-          ...cfg.agents?.defaults,
-          model:
-            cfg.agents?.defaults?.model && typeof cfg.agents.defaults.model === "object"
-              ? {
-                  ...cfg.agents.defaults.model,
-                  primary: OPENCODE_ZEN_DEFAULT_MODEL,
-                }
-              : { primary: OPENCODE_ZEN_DEFAULT_MODEL },
-        },
-      },
-    },
+    next: applyAgentDefaultModelPrimary(cfg, OPENCODE_ZEN_DEFAULT_MODEL),
     changed: true,
   };
 }