diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index cc1514f48a8..ddd66510da5 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -333,6 +333,8 @@ export namespace ProviderTransform {
     if (!model.capabilities.reasoning) return {}
 
     const id = model.id.toLowerCase()
+    const isAnthropicAdaptive = ["opus-4-6", "opus-4.6", "sonnet-4-6", "sonnet-4.6"].some((v) => model.api.id.includes(v))
+    const adaptiveEfforts = ["low", "medium", "high", "max"]
     if (
       id.includes("deepseek") ||
       id.includes("minimax") ||
@@ -366,6 +368,19 @@ export namespace ProviderTransform {
 
       case "@ai-sdk/gateway":
         if (model.id.includes("anthropic")) {
+          if (isAnthropicAdaptive) {
+            return Object.fromEntries(
+              adaptiveEfforts.map((effort) => [
+                effort,
+                {
+                  thinking: {
+                    type: "adaptive",
+                  },
+                  effort,
+                },
+              ]),
+            )
+          }
           return {
             high: {
               thinking: {
@@ -502,10 +517,9 @@ export namespace ProviderTransform {
       case "@ai-sdk/google-vertex/anthropic":
         // https://v5.ai-sdk.dev/providers/ai-sdk-providers/google-vertex#anthropic-provider
 
-        if (model.api.id.includes("opus-4-6") || model.api.id.includes("opus-4.6")) {
-          const efforts = ["low", "medium", "high", "max"]
+        if (isAnthropicAdaptive) {
           return Object.fromEntries(
-            efforts.map((effort) => [
+            adaptiveEfforts.map((effort) => [
               effort,
               {
                 thinking: {
@@ -534,10 +548,9 @@ export namespace ProviderTransform {
 
       case "@ai-sdk/amazon-bedrock":
         // https://v5.ai-sdk.dev/providers/ai-sdk-providers/amazon-bedrock
-        if (model.api.id.includes("opus-4-6") || model.api.id.includes("opus-4.6")) {
-          const efforts = ["low", "medium", "high", "max"]
+        if (isAnthropicAdaptive) {
           return Object.fromEntries(
-            efforts.map((effort) => [
+            adaptiveEfforts.map((effort) => [
               effort,
               {
                 reasoningConfig: {
diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index 57131d76a98..189bdfd32b4 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -1705,6 +1705,66 @@ describe("ProviderTransform.variants", () => {
   })
 
   describe("@ai-sdk/gateway", () => {
+    test("anthropic sonnet 4.6 models return adaptive thinking options", () => {
+      const model = createMockModel({
+        id: "anthropic/claude-sonnet-4-6",
+        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.medium).toEqual({
+        thinking: {
+          type: "adaptive",
+        },
+        effort: "medium",
+      })
+    })
+
+    test("anthropic sonnet 4.6 dot-format models return adaptive thinking options", () => {
+      const model = createMockModel({
+        id: "anthropic/claude-sonnet-4-6",
+        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.medium).toEqual({
+        thinking: {
+          type: "adaptive",
+        },
+        effort: "medium",
+      })
+    })
+
+    test("anthropic opus 4.6 dot-format models return adaptive thinking options", () => {
+      const model = createMockModel({
+        id: "anthropic/claude-opus-4-6",
+        providerID: "gateway",
+        api: {
+          id: "anthropic/claude-opus-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("anthropic models return anthropic thinking options", () => {
       const model = createMockModel({
         id: "anthropic/claude-sonnet-4",
@@ -2064,6 +2124,26 @@ describe("ProviderTransform.variants", () => {
   })
 
   describe("@ai-sdk/anthropic", () => {
+    test("sonnet 4.6 returns adaptive thinking options", () => {
+      const model = createMockModel({
+        id: "anthropic/claude-sonnet-4-6",
+        providerID: "anthropic",
+        api: {
+          id: "claude-sonnet-4-6",
+          url: "https://api.anthropic.com",
+          npm: "@ai-sdk/anthropic",
+        },
+      })
+      const result = ProviderTransform.variants(model)
+      expect(Object.keys(result)).toEqual(["low", "medium", "high", "max"])
+      expect(result.high).toEqual({
+        thinking: {
+          type: "adaptive",
+        },
+        effort: "high",
+      })
+    })
+
     test("returns high and max with thinking config", () => {
       const model = createMockModel({
         id: "anthropic/claude-4",
@@ -2092,6 +2172,26 @@ describe("ProviderTransform.variants", () => {
   })
 
   describe("@ai-sdk/amazon-bedrock", () => {
+    test("anthropic sonnet 4.6 returns adaptive reasoning options", () => {
+      const model = createMockModel({
+        id: "bedrock/anthropic-claude-sonnet-4-6",
+        providerID: "bedrock",
+        api: {
+          id: "anthropic.claude-sonnet-4-6",
+          url: "https://bedrock.amazonaws.com",
+          npm: "@ai-sdk/amazon-bedrock",
+        },
+      })
+      const result = ProviderTransform.variants(model)
+      expect(Object.keys(result)).toEqual(["low", "medium", "high", "max"])
+      expect(result.max).toEqual({
+        reasoningConfig: {
+          type: "adaptive",
+          maxReasoningEffort: "max",
+        },
+      })
+    })
+
     test("returns WIDELY_SUPPORTED_EFFORTS with reasoningConfig", () => {
       const model = createMockModel({
         id: "bedrock/llama-4",