chore: initial commit

src/api/types.ts

@@ -0,0 +1,35 @@
+export interface ApiEnvelope<T> {
+  code: string
+  message: string
+  data: T
+  requestId: string | null
+  traceId: string | null
+  timestamp: string
+}
+
+export type ApiFieldErrors = Record<string, string>
+
+export class ApiError extends Error {
+  constructor(
+    message: string,
+    readonly code = 'NETWORK_ERROR',
+    readonly status?: number,
+    readonly fieldErrors?: ApiFieldErrors,
+    readonly traceId?: string | null,
+  ) {
+    super(message)
+    this.name = 'ApiError'
+  }
+}
+
+export function isApiEnvelope(value: unknown): value is ApiEnvelope<unknown> {
+  if (!value || typeof value !== 'object') return false
+  const record = value as Record<string, unknown>
+  return typeof record.code === 'string' && typeof record.message === 'string' && 'data' in record
+}
+
+export function asFieldErrors(value: unknown): ApiFieldErrors | undefined {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) return undefined
+  const entries = Object.entries(value).filter((entry): entry is [string, string] => typeof entry[1] === 'string')
+  return entries.length > 0 ? Object.fromEntries(entries) : undefined
+}