feat(cli): treat opus 4.8 as adaptive thinking model like 4.7

.changeset/opus-4-8-adaptive-thinking.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/cli": patch
+---
+
+Fix Claude Opus 4.8 reasoning on Amazon Bedrock by treating it as an adaptive thinking model like Opus 4.7. This resolves the "thinking.type.enabled is not supported for this model" error and exposes the full low/medium/high/xhigh/max reasoning effort range.

packages/opencode/src/plugin/github-copilot/models.ts

@@ -125,7 +125,11 @@ function build(key: string, remote: Item, url: string, prev?: Model): Model {
         variants[effort] = {
           thinking: {
             type: "adaptive",
-            ...(model.api.id.includes("opus-4.7") ? { display: "summarized" } : {}),
+            // kilocode_change start - treat opus-4.8 like opus-4.7
+            ...(model.api.id.includes("opus-4.7") || model.api.id.includes("opus-4.8")
+              ? { display: "summarized" }
+              : {}),
+            // kilocode_change end
           },
           effort,
         }

packages/opencode/src/provider/transform.ts

@@ -542,9 +542,11 @@ function openaiReasoningEfforts(apiId: string, releaseDate: string): string[] |
 }
 
 function anthropicAdaptiveEfforts(apiId: string): string[] | null {
-  if (["opus-4-7", "opus-4.7"].some((v) => apiId.includes(v))) {
+  // kilocode_change start - treat opus-4.8 like opus-4.7
+  if (["opus-4-7", "opus-4.7", "opus-4-8", "opus-4.8"].some((v) => apiId.includes(v))) {
     return ["low", "medium", "high", "xhigh", "max"]
   }
+  // kilocode_change end
   if (["opus-4-6", "opus-4.6", "sonnet-4-6", "sonnet-4.6"].some((v) => apiId.includes(v))) {
     return ["low", "medium", "high", "max"]
   }
@@ -780,9 +782,11 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
       if (adaptiveEfforts) {
         let efforts = [...adaptiveEfforts]
         if (model.providerID === "github-copilot") {
-          if (model.api.id.includes("opus-4.7")) {
+          // kilocode_change start - treat opus-4.8 like opus-4.7
+          if (model.api.id.includes("opus-4.7") || model.api.id.includes("opus-4.8")) {
             efforts = ["medium"]
           }
+          // kilocode_change end
           // Efforts currently supported are: low, medium, high
           efforts = efforts.filter((v) => v !== "max" && v !== "xhigh")
         }
@@ -792,9 +796,11 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
             {
               thinking: {
                 type: "adaptive",
-                ...(model.api.id.includes("opus-4-7") || model.api.id.includes("opus-4.7")
+                // kilocode_change start - treat opus-4.8 like opus-4.7
+                ...(["opus-4-7", "opus-4.7", "opus-4-8", "opus-4.8"].some((v) => model.api.id.includes(v))
                   ? { display: "summarized" }
                   : {}),
+                // kilocode_change end
               },
               effort,
             },
@@ -827,9 +833,11 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
               reasoningConfig: {
                 type: "adaptive",
                 maxReasoningEffort: effort,
-                ...(model.api.id.includes("opus-4-7") || model.api.id.includes("opus-4.7")
+                // kilocode_change start - treat opus-4.8 like opus-4.7
+                ...(["opus-4-7", "opus-4.7", "opus-4-8", "opus-4.8"].some((v) => model.api.id.includes(v))
                   ? { display: "summarized" }
                   : {}),
+                // kilocode_change end
               },
             },
           ]),

packages/opencode/test/kilocode/transform-opus-4.7.test.ts

@@ -30,7 +30,7 @@ function mockModel(overrides: Partial<any> = {}): any {
   }
 }
 
-describe("ProviderTransform.variants - Claude Opus 4.7", () => {
+describe("ProviderTransform.variants - Claude Opus 4.7 / 4.8", () => {
   test("opus-4-7 returns adaptive thinking variants including xhigh (native anthropic)", () => {
     const model = mockModel({
       api: {
@@ -75,6 +75,50 @@ describe("ProviderTransform.variants - Claude Opus 4.7", () => {
     })
   })
 
+  test("opus-4-8 returns adaptive thinking variants including xhigh (native anthropic)", () => {
+    const model = mockModel({
+      api: {
+        id: "claude-opus-4-8",
+        url: "https://api.anthropic.com",
+        npm: "@ai-sdk/anthropic",
+      },
+    })
+    const result = ProviderTransform.variants(model)
+    expect(Object.keys(result)).toEqual(["low", "medium", "high", "xhigh", "max"])
+    expect(result.xhigh).toEqual({
+      thinking: { type: "adaptive", display: "summarized" },
+      effort: "xhigh",
+    })
+  })
+
+  test("opus-4.8 dot-form returns adaptive thinking variants via @ai-sdk/gateway", () => {
+    const model = mockModel({
+      id: "anthropic/claude-opus-4-8",
+      api: {
+        id: "anthropic/claude-opus-4.8",
+        url: "https://gateway.ai",
+        npm: "@ai-sdk/gateway",
+      },
+    })
+    const result = ProviderTransform.variants(model)
+    expect(Object.keys(result)).toEqual(["low", "medium", "high", "xhigh", "max"])
+  })
+
+  test("opus-4-8 on bedrock returns adaptive reasoningConfig with xhigh", () => {
+    const model = mockModel({
+      api: {
+        id: "anthropic.claude-opus-4-8",
+        url: "https://bedrock.amazonaws.com",
+        npm: "@ai-sdk/amazon-bedrock",
+      },
+    })
+    const result = ProviderTransform.variants(model)
+    expect(Object.keys(result)).toEqual(["low", "medium", "high", "xhigh", "max"])
+    expect(result.xhigh).toEqual({
+      reasoningConfig: { type: "adaptive", maxReasoningEffort: "xhigh", display: "summarized" },
+    })
+  })
+
   test("opus-4-6 keeps original adaptive efforts without xhigh", () => {
     const model = mockModel({
       api: {