fix(provider): generalize Claude adaptive thinking (#38757)

packages/opencode/src/provider/transform.ts

@@ -635,24 +635,23 @@ function openaiCompatibleReasoningEfforts(id: string) {
   return gpt5CodexReasoningEfforts(apiId) ?? versionedGpt5ReasoningEfforts(apiId) ?? OPENAI_EFFORTS
 }
 
-function anthropicOpus47OrLater(apiId: string) {
-  // Matches "opus-4.7" (Anthropic/Bedrock/Vertex) and "claude-4.7-opus" (SAP AI Core inverted).
-  // 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)
-  if (!version) return false
-  const major = Number(version[1] ?? version[3])
-  const minor = Number(version[2] ?? version[4])
+function anthropicUsesModernAdaptiveThinking(apiId: string) {
+  if (!apiId.toLowerCase().includes("claude-")) return false
+  // Covers family-first IDs such as claude-opus-4.7 and version-first IDs such as claude-4.7-opus.
+  // Limit minors to two digits so release dates in IDs such as claude-opus-4-20250514 are not versions.
+  const version = /claude-(?:[a-z]+-)?(\d+)(?:[.-](\d{1,2}))?(?:[.@-]|$)/i.exec(apiId)
+  if (!version) return true
+  const major = Number(version[1])
+  const minor = Number(version[2] ?? 0)
   return major > 4 || (major === 4 && minor >= 7)
 }
 
-function anthropicSonnet5OrLater(apiId: string) {
-  const version = /sonnet-(\d+)(?:[.@-]|$)|claude-(\d+)-sonnet(?:[.@-]|$)/i.exec(apiId)
-  if (!version) return false
-  return Number(version[1] ?? version[2]) >= 5
+function anthropicOpus45(apiId: string) {
+  return ["opus-4-5", "opus-4.5"].some((value) => apiId.includes(value))
 }
 
 function anthropicAdaptiveEfforts(apiId: string): string[] | null {
-  if (anthropicOpus47OrLater(apiId) || anthropicSonnet5OrLater(apiId) || apiId.includes("fable-5")) {
+  if (anthropicUsesModernAdaptiveThinking(apiId)) {
     return ["low", "medium", "high", "xhigh", "max"]
   }
   if (
@@ -666,7 +665,7 @@ function anthropicAdaptiveEfforts(apiId: string): string[] | null {
 }
 
 function anthropicOmitsThinking(apiId: string) {
-  return anthropicOpus47OrLater(apiId) || anthropicSonnet5OrLater(apiId) || apiId.includes("fable-5")
+  return anthropicUsesModernAdaptiveThinking(apiId)
 }
 
 function googleThinkingLevelEfforts(apiId: string) {
@@ -990,8 +989,10 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
         )
       }
 
-      if (["opus-4-5", "opus-4.5"].some((v) => model.api.id.includes(v))) {
-        return Object.fromEntries(WIDELY_SUPPORTED_EFFORTS.map((effort) => [effort, { effort }]))
+      if (anthropicOpus45(model.api.id)) {
+        return Object.fromEntries(
+          WIDELY_SUPPORTED_EFFORTS.map((effort) => [effort, anthropicOpus45Effort(model, effort)]),
+        )
       }
 
       return {
@@ -1103,7 +1104,7 @@ export function variants(model: Provider.Model): Record<string, Record<string, a
       if (id.includes("anthropic")) {
         if (adaptiveEfforts) {
           // Bedrock adaptive splits `effort` out into `output_config` (vs Anthropic
-          // native which inlines it). Opus 4.7+ flipped `display` default to "omitted".
+          // native which inlines it). Claude 4.7+ defaults `display` to "omitted".
           return wrapInSapModelParams(
             Object.fromEntries(
               adaptiveEfforts.map((effort) => [
@@ -1711,6 +1712,14 @@ function reasoningEffort(model: Provider.Model, effort: string) {
             ...(anthropicOmitsThinking(model.api.id) ? { display: "summarized" } : {}),
           },
         }
+      if (anthropicOpus45(model.api.id))
+        return {
+          reasoningConfig: {
+            type: "enabled",
+            budgetTokens: Math.min(16_000, Math.floor(model.limit.output / 2 - 1)),
+            maxReasoningEffort: effort,
+          },
+        }
       if (model.api.id.includes("anthropic")) return
       return { reasoningConfig: { type: "enabled", maxReasoningEffort: effort } }
     case "@ai-sdk/gateway":
@@ -1751,7 +1760,7 @@ function reasoningEffort(model: Provider.Model, effort: string) {
 }
 
 function anthropicEffort(model: Provider.Model, effort: string) {
-  if (["opus-4-5", "opus-4.5"].some((value) => model.api.id.includes(value))) return { effort }
+  if (anthropicOpus45(model.api.id)) return anthropicOpus45Effort(model, effort)
   // Kimi defaults to omitting adaptive thinking text unless summarized display is requested.
   if (isKimiFamily(model)) return { thinking: { type: "adaptive", display: "summarized" }, effort }
   if (!anthropicAdaptiveEfforts(model.api.id)) return
@@ -1764,6 +1773,16 @@ function anthropicEffort(model: Provider.Model, effort: string) {
   }
 }
 
+function anthropicOpus45Effort(model: Provider.Model, effort: string) {
+  return {
+    thinking: {
+      type: "enabled",
+      budgetTokens: Math.min(16_000, Math.floor(model.limit.output / 2 - 1)),
+    },
+    effort,
+  }
+}
+
 function reasoningBudget(model: Provider.Model, budget: number) {
   switch (model.api.npm) {
     case "@openrouter/ai-sdk-provider":

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

@@ -3213,6 +3213,7 @@ describe("ProviderTransform.reasoningVariants", () => {
       { thinking: { type: "adaptive", display: "summarized" }, effort: "high" },
       "claude-opus-4-7",
     ],
+    ["@ai-sdk/anthropic", { thinking: { type: "adaptive", display: "summarized" }, effort: "high" }, "claude-opus-5"],
     ["@ai-sdk/google", { thinkingConfig: { includeThoughts: true, thinkingLevel: "high" } }],
     ["@ai-sdk/google-vertex", { thinkingConfig: { includeThoughts: true, thinkingLevel: "high" } }],
     [
@@ -3264,13 +3265,18 @@ describe("ProviderTransform.reasoningVariants", () => {
     )
   })
 
-  test("uses bare effort for Claude Opus 4.5", () => {
+  test("combines effort with extended thinking for Claude Opus 4.5", () => {
     expect(
       ProviderTransform.reasoningVariants(
         model([{ type: "effort", values: ["high"] }]),
         target("@ai-sdk/anthropic", "claude-opus-4-5"),
       ),
-    ).toEqual({ high: { effort: "high" } })
+    ).toEqual({
+      high: {
+        thinking: { type: "enabled", budgetTokens: 16_000 },
+        effort: "high",
+      },
+    })
   })
 
   test("uses explicit effort metadata for Anthropic-compatible models", () => {
@@ -3319,6 +3325,38 @@ describe("ProviderTransform.reasoningVariants", () => {
     })
   })
 
+  test("uses adaptive reasoning config for Claude Opus 5 on Bedrock", () => {
+    const result = ProviderTransform.reasoningVariants(
+      model([{ type: "effort", values: ["low", "medium", "high", "xhigh", "max"] }]),
+      target("@ai-sdk/amazon-bedrock", "us.anthropic.claude-opus-5"),
+    )
+    expect(Object.keys(result ?? {})).toEqual(["low", "medium", "high", "xhigh", "max"])
+    expect(result?.high).toEqual({
+      reasoningConfig: {
+        type: "adaptive",
+        maxReasoningEffort: "high",
+        display: "summarized",
+      },
+    })
+  })
+
+  test("combines effort with extended thinking for Claude Opus 4.5 on Bedrock", () => {
+    expect(
+      ProviderTransform.reasoningVariants(
+        model([{ type: "effort", values: ["high"] }]),
+        target("@ai-sdk/amazon-bedrock", "us.anthropic.claude-opus-4-5-20251101-v1:0"),
+      ),
+    ).toEqual({
+      high: {
+        reasoningConfig: {
+          type: "enabled",
+          budgetTokens: 16_000,
+          maxReasoningEffort: "high",
+        },
+      },
+    })
+  })
+
   test("does not replace unsupported Anthropic Bedrock effort options with token budgets", () => {
     expect(
       ProviderTransform.reasoningVariants(
@@ -4617,11 +4655,17 @@ describe("ProviderTransform.variants", () => {
 
   describe("@ai-sdk/anthropic", () => {
     for (const testCase of [
+      {
+        name: "opus 4 dated",
+        apiIds: ["claude-opus-4-20250514"],
+        efforts: ["high", "max"],
+        expectedHigh: { thinking: { type: "enabled", budgetTokens: 16000 } },
+      },
       {
         name: "opus 4.5",
         apiIds: ["claude-opus-4-5-20251101", "claude-opus-4.5-20251101"],
         efforts: ["low", "medium", "high"],
-        expectedHigh: { effort: "high" },
+        expectedHigh: { thinking: { type: "enabled", budgetTokens: 16000 }, effort: "high" },
       },
       {
         name: "sonnet 4.6",
@@ -4653,6 +4697,18 @@ 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: "unversioned future model",
+        apiIds: ["claude-future"],
+        efforts: ["low", "medium", "high", "xhigh", "max"],
+        expectedHigh: { thinking: { type: "adaptive", display: "summarized" }, effort: "high" },
+      },
       {
         name: "fable 5",
         apiIds: ["claude-fable-5"],
@@ -4772,6 +4828,28 @@ 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 +4945,28 @@ 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 +5155,12 @@ 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`, () => {