feat(ai): support custom reasoning fields (#38227)

packages/core/src/v1/config/migrate.ts

@@ -8,6 +8,7 @@ import { ConfigPermissionV1 } from "./permission"
 import { ConfigProviderV1 } from "./provider"
 import { ConfigProviderOptionsV1 } from "./provider-options"
 import { ProviderV2 } from "../../provider"
+import { ModelV2 } from "../../model"
 
 const keys = new Set([
   "logLevel",
@@ -278,6 +279,7 @@ function migrateModel(info: typeof ConfigProviderV1.Model.Type) {
     modelID: info.id,
     family: info.family,
     name: info.name,
+    compatibility: ModelV2.compatibility(info.interleaved),
     package: info.provider?.npm ? ProviderV2.aisdk(info.provider.npm) : undefined,
     settings: info.provider?.api ? { ...settings, baseURL: info.provider.api } : settings,
     capabilities,

packages/core/src/v1/config/provider.ts

@@ -16,9 +16,10 @@ export const Model = Schema.Struct({
   tool_call: Schema.optional(Schema.Boolean),
   interleaved: Schema.optional(
     Schema.Union([
-      Schema.Literal(true),
+      Schema.Boolean,
+      Schema.String,
       Schema.Struct({
-        field: Schema.Literals(["reasoning", "reasoning_content", "reasoning_details"]),
+        field: Schema.String,
       }),
     ]),
   ),