diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index 20c73d0216..7a6f192164 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -759,7 +759,7 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
     }
 
     case "@ai-sdk/gateway":
-      if (model.id.includes("anthropic")) {
+      if (model.api.id.includes("anthropic")) {
         if (adaptiveEfforts) {
           return Object.fromEntries(
             adaptiveEfforts.map((effort) => [
@@ -792,8 +792,8 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
           },
         }
       }
-      if (model.id.includes("google")) {
-        if (id.includes("2.5")) {
+      if (model.api.id.includes("google")) {
+        if (model.api.id.includes("2.5")) {
           return {
             high: {
               thinkingConfig: {
@@ -804,7 +804,7 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
             max: {
               thinkingConfig: {
                 includeThoughts: true,
-                thinkingBudget: googleThinkingBudgetMax(id),
+                thinkingBudget: googleThinkingBudgetMax(model.api.id.toLowerCase()),
               },
             },
           }
diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index e69dab70f6..3ef2ca3bd0 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -3372,6 +3372,42 @@ describe("ProviderTransform.variants", () => {
   })
 
   describe("@ai-sdk/gateway", () => {
+    test("configured anthropic aliases route by the API ID", () => {
+      const model = createMockModel({
+        id: "my-claude",
+        providerID: "gateway",
+        api: {
+          id: "anthropic/claude-sonnet-4-6",
+          url: "https://gateway.ai",
+          npm: "@ai-sdk/gateway",
+        },
+      })
+      const result = ProviderTransform.variants(model)
+      expect(Object.keys(result)).toEqual(["low", "medium", "high", "max"])
+      expect(result.high).toEqual({
+        thinking: {
+          type: "adaptive",
+        },
+        effort: "high",
+      })
+    })
+
+    test("configured google aliases route by the API ID", () => {
+      const model = createMockModel({
+        id: "my-gemini",
+        providerID: "gateway",
+        api: {
+          id: "google/gemini-2.5-pro",
+          url: "https://gateway.ai",
+          npm: "@ai-sdk/gateway",
+        },
+      })
+      expect(ProviderTransform.variants(model)).toEqual({
+        high: { thinkingConfig: { includeThoughts: true, thinkingBudget: 16_000 } },
+        max: { thinkingConfig: { includeThoughts: true, thinkingBudget: 32_768 } },
+      })
+    })
+
     test("anthropic sonnet 4.6 models return adaptive thinking options", () => {
       const model = createMockModel({
         id: "anthropic/claude-sonnet-4-6",