fix(cli): support adaptive thinking for opus 5

Co-authored-by: kiloconnect[bot] <240665456+kiloconnect[bot]@users.noreply.github.com>

.changeset/adaptive-opus-five.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/cli": patch
+---
+
+Support adaptive thinking levels for Claude Opus 5.

packages/opencode/src/provider/transform.ts

@@ -616,10 +616,10 @@ function anthropicOpus47OrLater(apiId: string) {
   return major > 4 || (major === 4 && minor >= 7)
 }
 
-// kilocode_change start - fable and sonnet-5 models are adaptive thinking models like opus-4.7/4.8
+// kilocode_change start - Claude 5 models are adaptive thinking models like opus-4.7/4.8
 function anthropicClaude5(apiId: string) {
   const id = apiId.toLowerCase()
-  return id.includes("fable") || /sonnet[.-]5/.test(id)
+  return id.includes("fable") || /(?:opus|sonnet)[.-]5/.test(id)
 }
 // kilocode_change end
 
@@ -640,7 +640,7 @@ function anthropicAdaptiveEfforts(apiId: string): string[] | null {
 }
 
 function anthropicOmitsThinking(apiId: string) {
-  return anthropicOpus47OrLater(apiId) || anthropicClaude5(apiId) // kilocode_change - include Kilo's fable/sonnet-5 aliases
+  return anthropicOpus47OrLater(apiId) || anthropicClaude5(apiId) // kilocode_change - include Kilo's Claude 5 aliases
 }
 
 function googleThinkingLevelEfforts(apiId: string) {

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

@@ -207,6 +207,50 @@ describe("ProviderTransform.variants - Claude Opus 4.7 / 4.8", () => {
     })
   })
 
+  test("opus-5 returns adaptive thinking variants including xhigh (native anthropic)", () => {
+    const model = mockModel({
+      api: {
+        id: "claude-opus-5",
+        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-5 returns adaptive thinking variants via @ai-sdk/gateway", () => {
+    const model = mockModel({
+      id: "anthropic/claude-opus-5",
+      api: {
+        id: "anthropic/claude-opus-5",
+        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-5 on bedrock returns adaptive reasoningConfig with xhigh", () => {
+    const model = mockModel({
+      api: {
+        id: "anthropic.claude-opus-5",
+        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("sonnet-4.6 keeps original adaptive efforts without xhigh", () => {
     const model = mockModel({
       api: {