fix(provider): support OpenAI pro reasoning mode (#36694)

packages/opencode/src/provider/provider.ts

@@ -1267,14 +1267,7 @@ export function fromModelsDevProvider(provider: ModelsDev.Provider): Info {
         id: ModelV2.ID.make(id),
         name: `${model.name} ${mode[0].toUpperCase()}${mode.slice(1)}`,
         cost: opts.cost ? mergeDeep(base.cost, cost(opts.cost)) : base.cost,
-        options: opts.provider?.body
-          ? Object.fromEntries(
-              Object.entries(opts.provider.body).map(([k, v]) => [
-                k.replace(/_([a-z])/g, (_, c) => c.toUpperCase()),
-                v,
-              ]),
-            )
-          : base.options,
+        options: modeOptions(base, opts.provider?.body),
         headers: opts.provider?.headers ?? base.headers,
       }
     }
@@ -1289,6 +1282,17 @@ export function fromModelsDevProvider(provider: ModelsDev.Provider): Info {
   }
 }
 
+function modeOptions(model: Model, body: Record<string, unknown> | undefined) {
+  if (!body) return model.options
+  const options = Object.fromEntries(
+    Object.entries(body).map(([key, value]) => [key.replace(/_([a-z])/g, (_, char) => char.toUpperCase()), value]),
+  )
+  const reasoning = body.reasoning
+  if (model.api.npm !== "@ai-sdk/openai" || !isRecord(reasoning) || typeof reasoning.mode !== "string") return options
+  const { reasoning: _, ...rest } = options
+  return { ...rest, reasoningMode: reasoning.mode }
+}
+
 function modelSuggestions(provider: Info | undefined, modelID: ModelV2.ID, enableExperimentalModels: boolean) {
   const available = provider
     ? Object.keys(provider.models).filter((id) => {