fix(provider): enable opus 5 adaptive thinking

packages/opencode/src/provider/transform.ts

@@ -637,8 +637,9 @@ function openaiCompatibleReasoningEfforts(id: string) {
 
 function anthropicOpus47OrLater(apiId: string) {
   // Matches "opus-4.7" (Anthropic/Bedrock/Vertex) and "claude-4.7-opus" (SAP AI Core inverted).
+  // The minor is optional: Anthropic dropped it at opus 5, so bare "claude-opus-5" must match too.
   // Greedy \d+ correctly extends to multi-digit majors (e.g. "claude-10.0-opus") for forward compatibility.
-  const version = /opus-(\d+)[.-](\d+)(?:[.@-]|$)|claude-(\d+)[.-](\d+)-opus(?:[.@-]|$)/i.exec(apiId)
+  const version = /opus-(\d+)(?:[.-](\d+))?(?:[.@-]|$)|claude-(\d+)(?:[.-](\d+))?-opus(?:[.@-]|$)/i.exec(apiId)
   if (!version) return false
   const major = Number(version[1] ?? version[3])
   const minor = Number(version[2] ?? version[4])

packages/opencode/test/provider/transform.test.ts

@@ -4653,6 +4653,12 @@ describe("ProviderTransform.variants", () => {
         efforts: ["low", "medium", "high", "xhigh", "max"],
         expectedHigh: { thinking: { type: "adaptive", display: "summarized" }, effort: "high" },
       },
+      {
+        name: "opus 5",
+        apiIds: ["claude-opus-5", "claude-opus-5-20260724"],
+        efforts: ["low", "medium", "high", "xhigh", "max"],
+        expectedHigh: { thinking: { type: "adaptive", display: "summarized" }, effort: "high" },
+      },
       {
         name: "fable 5",
         apiIds: ["claude-fable-5"],
@@ -4772,6 +4778,28 @@ describe("ProviderTransform.variants", () => {
         effort: "high",
       })
     })
+
+    test("opus 5 uses adaptive reasoning for Vertex model IDs", () => {
+      const result = ProviderTransform.variants(
+        createMockModel({
+          id: "google-vertex-anthropic/claude-opus-5@default",
+          providerID: "google-vertex-anthropic",
+          api: {
+            id: "claude-opus-5@default",
+            url: "https://us-central1-aiplatform.googleapis.com",
+            npm: "@ai-sdk/google-vertex/anthropic",
+          },
+        }),
+      )
+      expect(Object.keys(result)).toEqual(["low", "medium", "high", "xhigh", "max"])
+      expect(result.high).toEqual({
+        thinking: {
+          type: "adaptive",
+          display: "summarized",
+        },
+        effort: "high",
+      })
+    })
   })
 
   describe("@ai-sdk/amazon-bedrock", () => {
@@ -4867,6 +4895,28 @@ describe("ProviderTransform.variants", () => {
       })
     })
 
+    test("anthropic opus 5 returns adaptive reasoning options with xhigh", () => {
+      const result = ProviderTransform.variants(
+        createMockModel({
+          id: "bedrock/anthropic-claude-opus-5",
+          providerID: "bedrock",
+          api: {
+            id: "us.anthropic.claude-opus-5-v1:0",
+            url: "https://bedrock.amazonaws.com",
+            npm: "@ai-sdk/amazon-bedrock",
+          },
+        }),
+      )
+      expect(Object.keys(result)).toEqual(["low", "medium", "high", "xhigh", "max"])
+      expect(result.high).toEqual({
+        reasoningConfig: {
+          type: "adaptive",
+          maxReasoningEffort: "high",
+          display: "summarized",
+        },
+      })
+    })
+
     test("returns WIDELY_SUPPORTED_EFFORTS with reasoningConfig", () => {
       const model = createMockModel({
         id: "bedrock/llama-4",
@@ -5055,6 +5105,12 @@ describe("ProviderTransform.variants", () => {
         efforts: ["low", "medium", "high", "xhigh", "max"],
         thinking: { type: "adaptive", display: "summarized" },
       },
+      {
+        name: "opus 5",
+        apiIds: ["anthropic--claude-opus-5", "anthropic--claude-5-opus"],
+        efforts: ["low", "medium", "high", "xhigh", "max"],
+        thinking: { type: "adaptive", display: "summarized" },
+      },
     ]) {
       for (const apiId of testCase.apiIds) {
         test(`${testCase.name} ${apiId} returns adaptive thinking variants under modelParams`, () => {