fix(ai): generate uuidv7 item ids

packages/ai/src/schema/ids.ts

@@ -21,8 +21,21 @@ export type ProviderID = typeof ProviderID.Type
 export const ResponseID = Schema.String
 export type ResponseID = Schema.Schema.Type<typeof ResponseID>
 
+const uuidv7 = () => {
+  const bytes = crypto.getRandomValues(new Uint8Array(16))
+  const timestamp = BigInt(Date.now())
+  bytes.set(
+    Array.from({ length: 6 }, (_, index) => Number((timestamp >> BigInt((5 - index) * 8)) & 0xffn)),
+    0,
+  )
+  bytes[6] = 0x70 | ((bytes[6] ?? 0) & 0x0f)
+  bytes[8] = 0x80 | ((bytes[8] ?? 0) & 0x3f)
+  const hex = Array.from(bytes, (byte) => byte.toString(16).padStart(2, "0")).join("")
+  return `${hex.slice(0, 8)}-${hex.slice(8, 12)}-${hex.slice(12, 16)}-${hex.slice(16, 20)}-${hex.slice(20)}`
+}
+
 export const ResponseItemID = Object.assign(Schema.String, {
-  create: (prefix: string): ResponseItemID => `${prefix}_${crypto.randomUUID()}`,
+  create: (prefix: string): ResponseItemID => `${prefix}_${uuidv7()}`,
   isPrefixed: (value: string) => {
     const separator = value.indexOf("_")
     return separator > 0 && separator < value.length - 1

packages/ai/test/schema.test.ts

@@ -11,6 +11,7 @@ import {
   LanguageModel,
   ModelID,
   ProviderID,
+  ResponseItemID,
   Usage,
 } from "../src/schema"
 import { ProviderShared } from "../src/protocols/shared"
@@ -68,6 +69,12 @@ describe("llm schema", () => {
     expect(ContentPart.guards.text({ type: "text", text: "hi" })).toBe(true)
     expect(ContentPart.guards.media({ type: "text", text: "hi" })).toBe(false)
   })
+
+  test("creates prefixed UUIDv7 response item ids", () => {
+    const id = ResponseItemID.create("msg")
+    expect(id).toMatch(/^msg_[0-9a-f]{8}-[0-9a-f]{4}-7[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/)
+    expect(ResponseItemID.isPrefixed(id)).toBe(true)
+  })
 })
 
 describe("AI.Usage", () => {