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

packages/schema/src/model.ts

@@ -41,6 +41,17 @@ export interface Ref extends Schema.Schema.Type<typeof Ref> {}
 export const Family = Schema.String.pipe(Schema.brand("Model.Family"))
 export type Family = typeof Family.Type
 
+export type ReasoningField = "reasoning" | "reasoning_content" | "reasoning_text" | (string & {})
+export const ReasoningField: Schema.Codec<ReasoningField> = Schema.Union([
+  Schema.Literals(["reasoning", "reasoning_content", "reasoning_text"]),
+  Schema.String,
+]).annotate({ identifier: "Model.ReasoningField" })
+
+export interface Compatibility extends Schema.Schema.Type<typeof Compatibility> {}
+export const Compatibility = Schema.Struct({
+  reasoningField: ReasoningField.pipe(optional),
+}).annotate({ identifier: "Model.Compatibility" })
+
 export interface Capabilities extends Schema.Schema.Type<typeof Capabilities> {}
 export const Capabilities = Schema.Struct({
   tools: Schema.Boolean,
@@ -75,6 +86,7 @@ export const Info = Schema.Struct({
   providerID: Provider.ID,
   family: Family.pipe(optional),
   name: Schema.String,
+  compatibility: Compatibility.pipe(optional),
   package: Provider.Package.pipe(optional),
   ...Provider.Overlays,
   capabilities: Capabilities,

packages/schema/test/model.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import { Schema } from "effect"
 import { Model } from "../src/model.js"
 
 describe("Model.Ref", () => {
@@ -20,3 +21,12 @@ describe("Model.Ref", () => {
     expect(() => Model.Ref.parse("openai/gpt-5#high#extra")).toThrow()
   })
 })
+
+describe("Model.ReasoningField", () => {
+  test("accepts suggested and custom fields", () => {
+    const decode = Schema.decodeUnknownSync(Model.ReasoningField)
+
+    for (const field of ["reasoning", "reasoning_content", "reasoning_text", "vendor_reasoning"])
+      expect(decode(field)).toBe(field)
+  })
+})