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":